Toxins

12 pages, 593 KiB

Open AccessEditor’s ChoiceReview

Botulinum Toxin—A High-Dosage Effect on Functional Outcome and Spasticity-Related Pain in Subjects with Stroke

by Domenico Intiso, Antonello Marco Centra, Michele Gravina, Angelo Chiaramonte, Michelangelo Bartolo and Filomena Di Rienzo

Toxins 2023, 15(8), 509; https://doi.org/10.3390/toxins15080509 - 18 Aug 2023

Cited by 3 | Viewed by 1699

Abstract

Stroke patients can develop spasticity and spasticity-related pain (SRP). These disorders are frequent and can contribute to functional limitations and disabling conditions. Many reports have suggested that higher doses than initially recommended of BTX-A can be used effectively and safely, especially in the [...] Read more.

Stroke patients can develop spasticity and spasticity-related pain (SRP). These disorders are frequent and can contribute to functional limitations and disabling conditions. Many reports have suggested that higher doses than initially recommended of BTX-A can be used effectively and safely, especially in the case of severe spasticity; however, whether the treatment produces any benefit on the functional outcome and SRP is unclear. Studies published between January 1989 and December 2022 were retrieved from MEDLINE/PubMed, Embase, and Cochrane Central Register. Only obabotulinumtoxinA (obaBTX-A), onabotulinumtoxinA, (onaBTX-A), and incobotulinumtoxinA (incoBTX-A) were considered. The term “high dosage” indicates ≥600 U. Nine studies met the inclusion criteria. Globally, 460 subjects were treated with BTX-A high dose, and 301 suffered from stroke. Studies had variable method designs, sample sizes, and aims. Only five (55.5%) reported data about the functional outcome after BTX-A injection. Functional measures were also variable, and the improvement was observed predominantly in the disability assessment scale (DAS). SRP pain was quantified by visual analog scale (VAS) and only three studies reported the BTX-A effect. There is no scientific evidence that this therapeutic strategy unequivocally improves the functionality of the limbs. Although no clear-cut evidence emerges, certain patients with spasticity might obtain goal-oriented improvement from high-dose BTX-A. Likewise, data are insufficient to recommend high BTX dosage in SRP. Full article

(This article belongs to the Special Issue Botulinum Neurotoxin: Shared/Common Mechanisms in the Treatment of Pain, Spasticity and Movement Disorders)

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17 pages, 7408 KiB

Open AccessEditor’s ChoiceArticle

A Multi-Layer-Controlled Strategy for Cloning and Expression of Toxin Genes in Escherichia coli

by Jessie Vandierendonck, Yana Girardin, Pieter De Bruyn, Henri De Greve and Remy Loris

Toxins 2023, 15(8), 508; https://doi.org/10.3390/toxins15080508 - 18 Aug 2023

Cited by 3 | Viewed by 2645

Abstract

Molecular cloning and controlled expression remain challenging when the target gene encodes a protein that is toxic to the host. We developed a set of multi-layer control systems to enable cloning of genes encoding proteins known to be highly toxic in Escherichia coli [...] Read more.

Molecular cloning and controlled expression remain challenging when the target gene encodes a protein that is toxic to the host. We developed a set of multi-layer control systems to enable cloning of genes encoding proteins known to be highly toxic in Escherichia coli and other bacteria. The different multi-layer control systems combine a promoter–operator system on a transcriptional level with a riboswitch for translational control. Additionally, replicational control is ensured by using a strain that reduces the plasmid copy number. The use of weaker promoters (such as P_BAD or PfdeA) in combination with the effective theophylline riboswitch is essential for cloning genes that encode notoriously toxic proteins that directly target translation and transcription. Controlled overexpression is possible, allowing the system to be used for evaluating in vivo effects of the toxin. Systems with a stronger promoter can be used for successful overexpression and purification of the desired protein but are limited to toxins that are more moderate and do not interfere with their own production. Full article

(This article belongs to the Section Bacterial Toxins)

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14 pages, 1933 KiB

Open AccessEditor’s ChoiceReview

Modulation of Autophagy and Cell Death by Bacterial Outer-Membrane Vesicles

by Camille Pin, Laure David and Eric Oswald

Toxins 2023, 15(8), 502; https://doi.org/10.3390/toxins15080502 - 14 Aug 2023

Cited by 3 | Viewed by 2639

Abstract

Bacteria, akin to eukaryotic cells, possess the ability to release extracellular vesicles, lipidic nanostructures that serve diverse functions in host–pathogen interactions during infections. In particular, Gram-negative bacteria produce specific vesicles with a single lipidic layer called OMVs (Outer Membrane Vesicles). These vesicles exhibit [...] Read more.

Bacteria, akin to eukaryotic cells, possess the ability to release extracellular vesicles, lipidic nanostructures that serve diverse functions in host–pathogen interactions during infections. In particular, Gram-negative bacteria produce specific vesicles with a single lipidic layer called OMVs (Outer Membrane Vesicles). These vesicles exhibit remarkable capabilities, such as disseminating throughout the entire organism, transporting toxins, and being internalized by eukaryotic cells. Notably, the cytosolic detection of lipopolysaccharides (LPSs) present at their surface initiates an immune response characterized by non-canonical inflammasome activation, resulting in pyroptotic cell death and the release of pro-inflammatory cytokines. However, the influence of these vesicles extends beyond their well-established roles, as they also profoundly impact host cell viability by directly interfering with essential cellular machinery. This comprehensive review highlights the disruptive effects of these vesicles, particularly on autophagy and associated cell death, and explores their implications for pathogen virulence during infections, as well as their potential in shaping novel therapeutic approaches. Full article

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16 pages, 2621 KiB

Open AccessEditor’s ChoiceArticle

A Metalloproteinase Cocktail from the Venom of Protobothrops flavoviridis Cleaves Amyloid Beta Peptides at the α-Cleavage Site

by Eugene Futai, Hajime Kawasaki, Shinichi Sato, Khadija Daoudi, Masafumi Hidaka, Taisuke Tomita and Tomohisa Ogawa

Toxins 2023, 15(8), 500; https://doi.org/10.3390/toxins15080500 - 12 Aug 2023

Cited by 2 | Viewed by 2974

Abstract

A disintegrin and metalloproteinase (ADAM) family proteins are a major class of membrane-anchored multidomain proteinases that are responsible for the shedding of cell surface protein ectodomains, including amyloid precursor protein (APP). Human ADAM 9, 10, and 17 proteolyze APPs and produce non-amyloid-genic p3 [...] Read more.

A disintegrin and metalloproteinase (ADAM) family proteins are a major class of membrane-anchored multidomain proteinases that are responsible for the shedding of cell surface protein ectodomains, including amyloid precursor protein (APP). Human ADAM 9, 10, and 17 proteolyze APPs and produce non-amyloid-genic p3 peptides, instead of neurotoxic amyloid-β peptides (Aβs; Aβ40 and Aβ42), which form fibrils and accumulate in the brain of patients with Alzheimer’s disease (AD). The ADAM family is closely related to snake venom metalloproteinases (SVMPs), which are derived from ancestral ADAMs but act as soluble proteinases. To test the therapeutic potential of SVMPs, we purified SVMPs from Protobothrops flavoviridis venom using metal ion affinity and pooled into a cocktail. Thus, 9 out of 11 SVMPs in the P. flavoviridis genome were identified in the cocktail. SVMPs inhibited Aβ secretion when added to human cell culture medium without affecting APP proteolysis. SVMPs degraded synthetic Aβ40 and Aβ42 peptides at the same cleavage site (α-site of APP) as ADAM9, 10, and 17. SVMPs did not degrade Aβ fibrils but interfered with their formation, assessed using thioflavin-T. Thus, SVMPs have therapeutic potential for AD as an Aβ-degrading protease, and the finding adds to the discovery of bioactive peptides from venoms as novel therapeutics. Full article

(This article belongs to the Special Issue Potential Therapeutic Applications of Animal Venoms and Toxins)

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42 pages, 1270 KiB

Open AccessEditor’s ChoiceReview

T-2 and HT-2 Toxins: Toxicity, Occurrence and Analysis: A Review

by Julie Meneely, Brett Greer, Oluwatobi Kolawole and Christopher Elliott

Toxins 2023, 15(8), 481; https://doi.org/10.3390/toxins15080481 - 29 Jul 2023

Cited by 22 | Viewed by 3646

Abstract

One of the major classes of mycotoxins posing serious hazards to humans and animals and potentially causing severe economic impact to the cereal industry are the trichothecenes, produced by many fungal genera. As such, indicative limits for the sum of T-2 and HT-2 [...] Read more.

One of the major classes of mycotoxins posing serious hazards to humans and animals and potentially causing severe economic impact to the cereal industry are the trichothecenes, produced by many fungal genera. As such, indicative limits for the sum of T-2 and HT-2 were introduced in the European Union in 2013 and discussions are ongoing as to the establishment of maximum levels. This review provides a concise assessment of the existing understanding concerning the toxicological effects of T-2 and HT-2 in humans and animals, their biosynthetic pathways, occurrence, impact of climate change on their production and an evaluation of the analytical methods applied to their detection. This study highlights that the ecology of F. sporotrichioides and F. langsethiae as well as the influence of interacting environmental factors on their growth and activation of biosynthetic genes are still not fully understood. Predictive models of Fusarium growth and subsequent mycotoxin production would be beneficial in predicting the risk of contamination and thus aid early mitigation. With the likelihood of regulatory maximum limits being introduced, increased surveillance using rapid, on-site tests in addition to confirmatory methods will be required. allowing the industry to be proactive rather than reactive. Full article

(This article belongs to the Section Mycotoxins)

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41 pages, 1727 KiB

Open AccessEditor’s ChoiceReview

Mycotoxins in Cereal-Based Products and Their Impacts on the Health of Humans, Livestock Animals and Pets

by Jianmei Yu and Ivana Ramos Pedroso

Toxins 2023, 15(8), 480; https://doi.org/10.3390/toxins15080480 - 28 Jul 2023

Cited by 27 | Viewed by 6524

Abstract

Cereal grains are the most important food staples for human beings and livestock animals. They can be processed into various types of food and feed products such as bread, pasta, breakfast cereals, cake, snacks, beer, complete feed, and pet foods. However, cereal grains [...] Read more.

Cereal grains are the most important food staples for human beings and livestock animals. They can be processed into various types of food and feed products such as bread, pasta, breakfast cereals, cake, snacks, beer, complete feed, and pet foods. However, cereal grains are vulnerable to the contamination of soil microorganisms, particularly molds. The toxigenic fungi/molds not only cause quality deterioration and grain loss, but also produce toxic secondary metabolites, mycotoxins, which can cause acute toxicity, death, and chronic diseases such as cancer, immunity suppression, growth impairment, and neural tube defects in humans, livestock animals and pets. To protect human beings and animals from these health risks, many countries have established/adopted regulations to limit exposure to mycotoxins. The purpose of this review is to update the evidence regarding the occurrence and co-occurrence of mycotoxins in cereal grains and cereal-derived food and feed products and their health impacts on human beings, livestock animals and pets. The effort for safe food and feed supplies including prevention technologies, detoxification technologies/methods and up-to-date regulation limits of frequently detected mycotoxins in cereal grains for food and feed in major cereal-producing countries are also provided. Some important areas worthy of further investigation are proposed. Full article

(This article belongs to the Special Issue Recent Advances of Detection, Health Intervention Treatment and Drug Development of Mycotoxins in Food and Feed)

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40 pages, 4411 KiB

Open AccessEditor’s ChoiceReview

Ciguatera Fish Poisoning in the Caribbean Sea and Atlantic Ocean: Reconciling the Multiplicity of Ciguatoxins and Analytical Chemistry Approach for Public Health Safety

by Ivannah Pottier, Richard J. Lewis and Jean-Paul Vernoux

Toxins 2023, 15(7), 453; https://doi.org/10.3390/toxins15070453 - 10 Jul 2023

Cited by 7 | Viewed by 3346

Abstract

Ciguatera is a major circumtropical poisoning caused by the consumption of marine fish and invertebrates contaminated with ciguatoxins (CTXs): neurotoxins produced by endemic and benthic dinoflagellates which are biotransformed in the fish food-web. We provide a history of ciguatera research conducted over the [...] Read more.

Ciguatera is a major circumtropical poisoning caused by the consumption of marine fish and invertebrates contaminated with ciguatoxins (CTXs): neurotoxins produced by endemic and benthic dinoflagellates which are biotransformed in the fish food-web. We provide a history of ciguatera research conducted over the past 70 years on ciguatoxins from the Pacific Ocean (P-CTXs) and Caribbean Sea (C-CTXs) and describe their main chemical, biochemical, and toxicological properties. Currently, there is no official method for the extraction and quantification of ciguatoxins, regardless their origin, mainly due to limited CTX-certified reference materials. In this review, the extraction and purification procedures of C-CTXs are investigated, considering specific objectives such as isolating reference materials, analysing fish toxin profiles, or ensuring food safety control. Certain in vitro assays may provide sufficient sensitivity to detect C-CTXs at sub-ppb levels in fish, but they do not allow for individual identification of CTXs. Recent advances in analysis using liquid chromatography coupled with low- or high-resolution mass spectrometry provide new opportunities to identify known C-CTXs, to gain structural insights into new analogues, and to quantify C-CTXs. Together, these methods reveal that ciguatera arises from a multiplicity of CTXs, although one major form (C-CTX-1) seems to dominate. However, questions arise regarding the abundance and instability of certain C-CTXs, which are further complicated by the wide array of CTX-producing dinoflagellates and fish vectors. Further research is needed to assess the toxic potential of the new C-CTX and their role in ciguatera fish poisoning. With the identification of C-CTXs in the coastal USA and Eastern Atlantic Ocean, the investigation of ciguatera fish poisoning is now a truly global effort. Full article

(This article belongs to the Special Issue Analytical Chemistry Techniques in Toxin Detection)

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17 pages, 2440 KiB

Open AccessEditor’s ChoiceArticle

Characterization of Particle-Size-Based Homogeneity and Mycotoxin Distribution Using Laser Diffraction Particle Size Analysis

by Kai Zhang, Ivy Tran and Steven Tan

Toxins 2023, 15(7), 450; https://doi.org/10.3390/toxins15070450 - 6 Jul 2023

Cited by 2 | Viewed by 2775

Abstract

Sample homogeneity dictates whether analyzing a test portion of an entire sample can provide representative information about incurred mycotoxins. In this study, we evaluated particle-size-distribution-based homogeneity of laboratory mycotoxin samples using laser diffraction particle size analysis and International Organization for Standardization (ISO) Guide [...] Read more.

Sample homogeneity dictates whether analyzing a test portion of an entire sample can provide representative information about incurred mycotoxins. In this study, we evaluated particle-size-distribution-based homogeneity of laboratory mycotoxin samples using laser diffraction particle size analysis and International Organization for Standardization (ISO) Guide 35: 2017. Incurred whole corn, compound feed, peanut butter, and wheat flour (500 g each) were comminuted using wet, cryogenic, or dry milling. We used a sample dividing (riffling) device to obtain representative subsamples (25 g each) and developed a laser diffraction particle size analysis procedure by optimizing key parameters such as the refractive index, absorption, and stirring rate. The homogeneity of the particle size distribution within laboratory subsamples was characterized using the optimized laser diffraction procedure. An assessment of homogeneity was also performed for individual mycotoxins in each incurred matrix sample following the procedure described in ISO Guide 35. The concentrations of the incurred mycotoxins were determined using liquid chromatography–mass spectrometry (LC-MS). Within- and between-subsample variances of incurred aflatoxin B1 in peanut butter; deoxynivalenol in corn, compound feed, and wheat flour; and fumonisins in compound feed corroborated that when the particle size measurements were less than 850 µm, mycotoxins concentrations were consistent across independent test portions, which was confirmed using an analysis of variance (F-test). This study highlights the benefits of laser diffraction particle size analysis and suggests its use as a test procedure to evaluate homogeneity in new sample commodities. Full article

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17 pages, 13784 KiB

Open AccessEditor’s ChoiceReview

Biological Activities and Ecological Significance of Fire Ant Venom Alkaloids

by Guangxin Xu and Li Chen

Toxins 2023, 15(7), 439; https://doi.org/10.3390/toxins15070439 - 3 Jul 2023

Cited by 3 | Viewed by 3444

Abstract

Venoms produced by arthropods act as chemical weapons to paralyze prey or deter competitors. The utilization of venom is an essential feature in the biology and ecology of venomous arthropods. Solenopsis fire ants (Hymenoptera: Formicidae) are medically important venomous ants. They have acquired [...] Read more.

Venoms produced by arthropods act as chemical weapons to paralyze prey or deter competitors. The utilization of venom is an essential feature in the biology and ecology of venomous arthropods. Solenopsis fire ants (Hymenoptera: Formicidae) are medically important venomous ants. They have acquired different patterns of venom use to maximize their competitive advantages rendered by the venom when facing different challenges. The major components of fire ant venom are piperidine alkaloids, which have strong insecticidal and antibiotic activities. The alkaloids protect fire ants from pathogens over the course of their lives and can be used to defend them from predators and competitors. They are also utilized by some of the fire ants’ natural enemies, such as phorid flies to locate host ants. Collectively, these ants’ diverse alkaloid compositions and functions have ecological significance for their survival, successful invasion, and rapid range expansion. The venom alkaloids with powerful biological activities may have played an important role in shaping the assembly of communities in both native and introduced ranges. Full article

(This article belongs to the Special Issue Ant Venom)

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23 pages, 11155 KiB

Open AccessEditor’s ChoiceArticle

Cyanotoxins Increase Cytotoxicity and Promote Nonalcoholic Fatty Liver Disease Progression by Enhancing Cell Steatosis

by Suryakant Niture, Sashi Gadi, Qi Qi, Leslimar Rios-Colon, Sabin Khatiwada, Vandana, Reshan A. Fernando, Keith E. Levine and Deepak Kumar

Toxins 2023, 15(7), 411; https://doi.org/10.3390/toxins15070411 - 25 Jun 2023

Cited by 6 | Viewed by 2392

Abstract

Freshwater prokaryotic cyanobacteria within harmful algal blooms produce cyanotoxins which are considered major pollutants in the aquatic system. Direct exposure to cyanotoxins through inhalation, skin contact, or ingestion of contaminated drinking water can target the liver and may cause hepatotoxicity. In the current [...] Read more.

Freshwater prokaryotic cyanobacteria within harmful algal blooms produce cyanotoxins which are considered major pollutants in the aquatic system. Direct exposure to cyanotoxins through inhalation, skin contact, or ingestion of contaminated drinking water can target the liver and may cause hepatotoxicity. In the current study, we investigated the effect of low concentrations of cyanotoxins on cytotoxicity, inflammation, modulation of unfolded protein response (UPR), steatosis, and fibrosis signaling in human hepatocytes and liver cell models. Exposure to low concentrations of microcystin-LR (MC-LR), microcystin-RR (MC-RR), nodularin (NOD), and cylindrospermopsin (CYN) in human bipotent progenitor cell line HepaRG and hepatocellular carcinoma (HCC) cell lines HepG2 and SK-Hep1 resulted in increased cell toxicity. MC-LR, NOD, and CYN differentially regulated inflammatory signaling, activated UPR signaling and lipogenic gene expression, and induced cellular steatosis and fibrotic signaling in HCC cells. MC-LR, NOD, and CYN also regulated AKT/mTOR signaling and inhibited autophagy. Chronic exposure to MC-LR, NOD, and CYN upregulated the expression of lipogenic and fibrosis biomarkers. Moreover, RNA sequencing (RNA seq) data suggested that exposure of human hepatocytes, HepaRG, and HCC HepG2 cells to MC-LR and CYN modulated expression levels of several genes that regulate non-alcoholic fatty liver disease (NAFLD). Our data suggest that low concentrations of cyanotoxins can cause hepatotoxicity and cell steatosis and promote NAFLD progression. Full article

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31 pages, 7206 KiB

Open AccessEditor’s ChoiceArticle

Diversity of Mycotoxins and Other Secondary Metabolites Recovered from Blood Oranges Infected by Colletotrichum, Alternaria, and Penicillium Species

by Ermes Ivan Rovetto, Carlos Luz, Federico La Spada, Giuseppe Meca, Mario Riolo and Santa Olga Cacciola

Toxins 2023, 15(7), 407; https://doi.org/10.3390/toxins15070407 - 21 Jun 2023

Cited by 11 | Viewed by 2548

Abstract

This study identified secondary metabolites produced by Alternaria alternata, Colletotrichum gloeosporioides, and Penicillium digitatum in fruits of two blood orange cultivars before harvest. Analysis was performed by UHPLC–Q-TOF-MS. Three types of fruits were selected, asymptomatic, symptomatic showing necrotic lesions caused by [...] Read more.

This study identified secondary metabolites produced by Alternaria alternata, Colletotrichum gloeosporioides, and Penicillium digitatum in fruits of two blood orange cultivars before harvest. Analysis was performed by UHPLC–Q-TOF-MS. Three types of fruits were selected, asymptomatic, symptomatic showing necrotic lesions caused by hail, and mummified. Extracts from peel and juice were analyzed separately. Penicillium digitatum was the prevalent species recovered from mummified and hail-injured fruits. Among 47 secondary metabolites identified, 16, 18, and 13 were of A. alternata, C. gloeosporioides, and P. digitatum, respectively. Consistently with isolations, indicating the presence of these fungi also in asymptomatic fruits, the metabolic profiles of the peel of hail-injured and asymptomatic fruits did not differ substantially. Major differences were found in the profiles of juice from hail-injured and mummified fruits, such as a significant higher presence of 5,4-dihydroxy-3,7,8-trimethoxy-6C-methylflavone and Atrovenetin, particularly in the juice of mummified fruits of the Tarocco Lempso cultivar. Moreover, the mycotoxins patulin and Rubratoxin B were detected exclusively in mummified fruits. Patulin was detected in both the juice and peel, with a higher relative abundance in the juice, while Rubratoxin B was detected only in the juice. These findings provide basic information for evaluating and preventing the risk of contamination by mycotoxins in the citrus fresh fruit supply chain and juice industry. Full article

(This article belongs to the Section Mycotoxins)

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23 pages, 3384 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Snake Antivenoms—Toward Better Understanding of the Administration Route

by Erika Gamulin, Sanja Mateljak Lukačević, Beata Halassy and Tihana Kurtović

Toxins 2023, 15(6), 398; https://doi.org/10.3390/toxins15060398 - 15 Jun 2023

Cited by 2 | Viewed by 3069

Abstract

Envenomations induced by animal bites and stings constitute a significant public health burden. Even though a standardized protocol does not exist, parenterally administered polyclonal antivenoms remain the mainstay in snakebite therapy. There is a prevailing opinion that their application by the i.m. route [...] Read more.

Envenomations induced by animal bites and stings constitute a significant public health burden. Even though a standardized protocol does not exist, parenterally administered polyclonal antivenoms remain the mainstay in snakebite therapy. There is a prevailing opinion that their application by the i.m. route has poor efficacy and that i.v. administration should preferentially be chosen in order to achieve better accomplishment of the antivenom therapeutic activity. Recently, it has been demonstrated that neutralization not only in the systemic circulation but also in the lymphatic system might be of great importance for the clinical outcome since it represents another relevant body compartment through which the absorption of the venom components occurs. In this review, the present-day and summarized knowledge of the laboratory and clinical findings on the i.v. and i.m. routes of antivenom administration is provided, with a special emphasis on the contribution of the lymphatic system to the process of venom elimination. Until now, antivenom-mediated neutralization has not yet been discussed in the context of the synergistic action of both blood and lymph. A current viewpoint might help to improve the comprehension of the venom/antivenom pharmacokinetics and the optimal approach for drug application. There is a great need for additional dependable, practical, well-designed studies, as well as more practice-related experience reports. As a result, opportunities for resolving long-standing disputes over choosing one therapeutic principle over another might be created, improving the safety and effectiveness of snakebite management. Full article

(This article belongs to the Special Issue Passive Immunotherapy and Its Applications in Envenomation and Infectious Diseases: In Tribute to Gaston Ramon (1886–1963))

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16 pages, 624 KiB

Open AccessEditor’s ChoiceReview

Improving the Efficacy of Botulinum Toxin for Cervical Dystonia: A Scoping Review

by Roberto Erro, Marina Picillo, Maria Teresa Pellecchia and Paolo Barone

Toxins 2023, 15(6), 391; https://doi.org/10.3390/toxins15060391 - 9 Jun 2023

Cited by 8 | Viewed by 4207

Abstract

Cervical dstonia (CD) is a chronic disorder with a significant detrimental impact on quality of life, requiring long-term treatment. Intramuscular injections of botulinum neurotoxin (BoNT) every 12 to 16 weeks have become the first-line option for CD. Despite the remarkable efficacy of BoNT [...] Read more.

Cervical dstonia (CD) is a chronic disorder with a significant detrimental impact on quality of life, requiring long-term treatment. Intramuscular injections of botulinum neurotoxin (BoNT) every 12 to 16 weeks have become the first-line option for CD. Despite the remarkable efficacy of BoNT as a treatment for CD, a significantly high proportion of patients report poor outcomes and discontinue the treatment. The reasons that drive sub-optimal response or treatment failure in a proportion of patients include but are not limited to inappropriate muscle targets and/or BoNT dosing, improper method of injections, subjective feeling of inefficacy, and the formation of neutralizing antibodies against the neurotoxin. The current review aims to complement published research focusing on the identification of the factors that might explain the failure of BoNT treatment in CD, highlighting possible solutions to improve its outcomes. Thus, the use of the new phenomenological classification of cervical dystonia known as COL-CAP might improve the identification of the muscle targets, but more sensitive information might come from the use of kinematic or scintigraphic techniques and the use of electromyographic or ultrasound guidance might ensure the accuracy of the injections. Suggestions are made for the development of a patient-centered model for the management of cervical dystonia and to emphasize that unmet needs in the field are to increase awareness about the non-motor spectrum of CD, which might influence the perception of the efficacy from BoNT injections, and the development of dedicated rehabilitation programs for CD that might enhance its effectiveness. Full article

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23 pages, 5583 KiB

Open AccessEditor’s ChoiceArticle

The Clostridium botulinum C2 Toxin Subunit C2IIa Delivers Enzymes with Positively Charged N-Termini into the Cytosol of Target Cells

by Sebastian Heber, Joscha Borho, Nicole Stadler, Fanny Wondany, Irina König, Jens Michaelis, Panagiotis Papatheodorou, Holger Barth and Maximilian Fellermann

Toxins 2023, 15(6), 390; https://doi.org/10.3390/toxins15060390 - 9 Jun 2023

Cited by 4 | Viewed by 2286

Abstract

The binary Clostridium (C.) botulinum C2 toxin consists of two non-linked proteins. The proteolytically activated binding/transport subunit C2IIa forms barrel-shaped homoheptamers, which bind to cell surface receptors, mediate endocytosis, and translocate the enzyme subunit C2I into the cytosol of target cells. [...] Read more.

The binary Clostridium (C.) botulinum C2 toxin consists of two non-linked proteins. The proteolytically activated binding/transport subunit C2IIa forms barrel-shaped homoheptamers, which bind to cell surface receptors, mediate endocytosis, and translocate the enzyme subunit C2I into the cytosol of target cells. Here, we investigate whether C2IIa can be harnessed as a transporter for proteins/enzymes fused to polycationic tags, as earlier demonstrated for the related anthrax toxin transport subunit PA₆₃. To test C2IIa-mediated transport in cultured cells, reporter enzymes are generated by fusing different polycationic tags to the N- or C-terminus of other bacterial toxins’ catalytic A subunits. C2IIa as well as PA₆₃ deliver N-terminally polyhistidine-tagged proteins more efficiently compared to C-terminally tagged ones. However, in contrast to PA₆₃, C2IIa does not efficiently deliver polylysine-tagged proteins into the cytosol of target cells. Moreover, untagged enzymes with a native cationic N-terminus are efficiently transported by both C2IIa and PA₆₃. In conclusion, the C2IIa-transporter serves as a transport system for enzymes that harbor positively charged amino acids at their N-terminus. The charge distribution at the N-terminus of cargo proteins and their ability to unfold in the endosome and subsequently refold in the cytosol determine transport feasibility and efficiency. Full article

(This article belongs to the Special Issue Intracellular Transport of Toxins: Insights into Mechanisms of Cytotoxicity and Applications in Cell Biology and Medicine)

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15 pages, 7662 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Domperidone Protects Cells from Intoxication with Clostridioides difficile Toxins by Inhibiting Hsp70-Assisted Membrane Translocation

by Maria Braune-Yan, Jinfang Jia, Mary Wahba, Johannes Schmid, Panagiotis Papatheodorou, Holger Barth and Katharina Ernst

Toxins 2023, 15(6), 384; https://doi.org/10.3390/toxins15060384 - 7 Jun 2023

Cited by 2 | Viewed by 2056

Abstract

Clostridioides difficile infections cause severe symptoms ranging from diarrhea to pseudomembranous colitis due to the secretion of AB-toxins, TcdA and TcdB. Both toxins are taken up into cells through receptor-mediated endocytosis, autoproteolytic processing and translocation of their enzyme domains from acidified endosomes into [...] Read more.

Clostridioides difficile infections cause severe symptoms ranging from diarrhea to pseudomembranous colitis due to the secretion of AB-toxins, TcdA and TcdB. Both toxins are taken up into cells through receptor-mediated endocytosis, autoproteolytic processing and translocation of their enzyme domains from acidified endosomes into the cytosol. The enzyme domains glucosylate small GTPases such as Rac1, thereby inhibiting processes such as actin cytoskeleton regulation. Here, we demonstrate that specific pharmacological inhibition of Hsp70 activity protected cells from TcdB intoxication. In particular, the established inhibitor VER-155008 and the antiemetic drug domperidone, which was found to be an Hsp70 inhibitor, reduced the number of cells with TcdB-induced intoxication morphology in HeLa, Vero and intestinal CaCo-2 cells. These drugs also decreased the intracellular glucosylation of Rac1 by TcdB. Domperidone did not inhibit TcdB binding to cells or enzymatic activity but did prevent membrane translocation of TcdB’s glucosyltransferase domain into the cytosol. Domperidone also protected cells from intoxication with TcdA as well as CDT toxin produced by hypervirulent strains of Clostridioides difficile. Our results reveal Hsp70 requirement as a new aspect of the cellular uptake mechanism of TcdB and identified Hsp70 as a novel drug target for potential therapeutic strategies required to combat severe Clostridioides difficile infections. Full article

(This article belongs to the Special Issue Toxin-Host Interaction of Clostridium Toxins)

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22 pages, 2662 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

One Size Fits All—Venomics of the Iberian Adder (Vipera seoanei, Lataste 1878) Reveals Low Levels of Venom Variation across Its Distributional Range

by Ignazio Avella, Maik Damm, Inês Freitas, Wolfgang Wüster, Nahla Lucchini, Óscar Zuazo, Roderich D. Süssmuth and Fernando Martínez-Freiría

Toxins 2023, 15(6), 371; https://doi.org/10.3390/toxins15060371 - 1 Jun 2023

Cited by 7 | Viewed by 3134

Abstract

European vipers (genus Vipera) are medically important snakes displaying considerable venom variation, occurring at different levels in this group. The presence of intraspecific venom variation, however, remains understudied in several Vipera species. Vipera seoanei is a venomous snake endemic to the northern [...] Read more.

European vipers (genus Vipera) are medically important snakes displaying considerable venom variation, occurring at different levels in this group. The presence of intraspecific venom variation, however, remains understudied in several Vipera species. Vipera seoanei is a venomous snake endemic to the northern Iberian Peninsula and south-western France, presenting notable phenotypic variation and inhabiting several diverse habitats across its range. We analysed the venoms of 49 adult specimens of V. seoanei from 20 localities across the species’ Iberian distribution. We used a pool of all individual venoms to generate a V. seoanei venom reference proteome, produced SDS-PAGE profiles of all venom samples, and visualised patterns of variation using NMDS. By applying linear regression, we then assessed presence and nature of venom variation between localities, and investigated the effect of 14 predictors (biological, eco-geographic, genetic) on its occurrence. The venom comprised at least 12 different toxin families, of which five (i.e., PLA₂, svSP, DI, snaclec, svMP) accounted for about 75% of the whole proteome. The comparative analyses of the SDS-PAGE venom profiles showed them to be remarkably similar across the sampled localities, suggesting low geographic variability. The regression analyses suggested significant effects of biological and habitat predictors on the little variation we detected across the analysed V. seoanei venoms. Other factors were also significantly associated with the presence/absence of individual bands in the SDS-PAGE profiles. The low levels of venom variability we detected within V. seoanei might be the result of a recent population expansion, or of processes other than directional positive selection. Full article

(This article belongs to the Section Animal Venoms)

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15 pages, 1860 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Next-Generation Sequencing for Venomics: Application of Multi-Enzymatic Limited Digestion for Inventorying the Snake Venom Arsenal

by Fernanda Gobbi Amorim, Damien Redureau, Thomas Crasset, Lou Freuville, Dominique Baiwir, Gabriel Mazzucchelli, Stefanie K. Menzies, Nicholas R. Casewell and Loïc Quinton

Toxins 2023, 15(6), 357; https://doi.org/10.3390/toxins15060357 - 25 May 2023

Cited by 4 | Viewed by 2663

Abstract

To improve the characterization of snake venom protein profiles, we report the application of a new generation of proteomic methodology to deeply characterize complex protein mixtures. The new approach, combining a synergic multi-enzymatic and a time-limited digestion (MELD), is a versatile and straightforward [...] Read more.

To improve the characterization of snake venom protein profiles, we report the application of a new generation of proteomic methodology to deeply characterize complex protein mixtures. The new approach, combining a synergic multi-enzymatic and a time-limited digestion (MELD), is a versatile and straightforward protocol previously developed by our group. The higher number of overlapping peptides generated during MELD increases the quality of downstream peptide sequencing and of protein identification. In this context, this work aims at applying the MELD strategy to a venomics purpose for the first time, and especially for the characterization of snake venoms. We used four venoms as the test models for this proof of concept: two Elapidae (Dendroaspis polylepis and Naja naja) and two Viperidae (Bitis arietans and Echis ocellatus). Each venom was reduced and alkylated before being submitted to two different protocols: the classical bottom-up proteomics strategy including a digestion step with trypsin only, or MELD, which combines the activities of trypsin, Glu-C and chymotrypsin with a limited digestion approach. The resulting samples were then injected on an M-Class chromatographic system, and hyphenated to a Q-Exactive Mass Spectrometer. Toxins and protein identification were performed by Peaks Studio X+. The results show that MELD considerably improves the number of sequenced (de novo) peptides and identified peptides from protein databases, leading to the unambiguous identification of a greater number of toxins and proteins. For each venom, MELD was successful, not only in terms of the identification of the major toxins (increasing of sequence coverage), but also concerning the less abundant cellular components (identification of new groups of proteins). In light of these results, MELD represents a credible methodology to be applied as the next generation of proteomics approaches dedicated to venomic analysis. It may open new perspectives for the sequencing and inventorying of the venom arsenal and should expand global knowledge about venom composition. Full article

(This article belongs to the Special Issue Omics Approaches to Study Toxins)

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28 pages, 3823 KiB

Open AccessEditor’s ChoiceReview

Mycochemicals against Cancer Stem Cells

by Massimo Tacchini, Gianni Sacchetti, Alessandra Guerrini and Guglielmo Paganetto

Toxins 2023, 15(6), 360; https://doi.org/10.3390/toxins15060360 - 25 May 2023

Cited by 6 | Viewed by 2538

Abstract

Since ancient times, mushrooms have been considered valuable allies of human well-being both from a dietary and medicinal point of view. Their essential role in several traditional medicines is explained today by the discovery of the plethora of biomolecules that have shown proven [...] Read more.

Since ancient times, mushrooms have been considered valuable allies of human well-being both from a dietary and medicinal point of view. Their essential role in several traditional medicines is explained today by the discovery of the plethora of biomolecules that have shown proven efficacy for treating various diseases, including cancer. Numerous studies have already been conducted to explore the antitumoural properties of mushroom extracts against cancer. Still, very few have reported the anticancer properties of mushroom polysaccharides and mycochemicals against the specific population of cancer stem cells (CSCs). In this context, β-glucans are relevant in modulating immunological surveillance against this subpopulation of cancer cells within tumours. Small molecules, less studied despite their spread and assortment, could exhibit the same importance. In this review, we discuss several pieces of evidence of the association between β-glucans and small mycochemicals in modulating biological mechanisms which are proven to be involved with CSCs development. Experimental evidence and an in silico approach are evaluated with the hope of contributing to future strategies aimed at the direct study of the action of these mycochemicals on this subpopulation of cancer cells. Full article

(This article belongs to the Special Issue Advances in Research for the Potential Use of Plant Toxins)

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34 pages, 3313 KiB

Open AccessEditor’s ChoiceArticle

MicotoXilico: An Interactive Database to Predict Mutagenicity, Genotoxicity, and Carcinogenicity of Mycotoxins

by Josefa Tolosa, Eva Serrano Candelas, José Luis Vallés Pardo, Addel Goya, Salvador Moncho, Rafael Gozalbes and Martina Palomino Schätzlein

Toxins 2023, 15(6), 355; https://doi.org/10.3390/toxins15060355 - 24 May 2023

Cited by 5 | Viewed by 2773

Abstract

Mycotoxins are secondary metabolites produced by certain filamentous fungi. They are common contaminants found in a wide variety of food matrices, thus representing a threat to public health, as they can be carcinogenic, mutagenic, or teratogenic, among other toxic effects. Several hundreds of [...] Read more.

Mycotoxins are secondary metabolites produced by certain filamentous fungi. They are common contaminants found in a wide variety of food matrices, thus representing a threat to public health, as they can be carcinogenic, mutagenic, or teratogenic, among other toxic effects. Several hundreds of mycotoxins have been reported, but only a few of them are regulated, due to the lack of data regarding their toxicity and mechanisms of action. Thus, a more comprehensive evaluation of the toxicity of mycotoxins found in foodstuffs is required. In silico toxicology approaches, such as Quantitative Structure–Activity Relationship (QSAR) models, can be used to rapidly assess chemical hazards by predicting different toxicological endpoints. In this work, for the first time, a comprehensive database containing 4360 mycotoxins classified in 170 categories was constructed. Then, specific robust QSAR models for the prediction of mutagenicity, genotoxicity, and carcinogenicity were generated, showing good accuracy, precision, sensitivity, and specificity. It must be highlighted that the developed QSAR models are compliant with the OECD regulatory criteria, and they can be used for regulatory purposes. Finally, all data were integrated into a web server that allows the exploration of the mycotoxin database and toxicity prediction. In conclusion, the developed tool is a valuable resource for scientists, industry, and regulatory agencies to screen the mutagenicity, genotoxicity, and carcinogenicity of non-regulated mycotoxins. Full article

(This article belongs to the Special Issue Mycotoxins and Fungal Toxins: Current Status and Future Perspectives)

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13 pages, 2421 KiB

Open AccessEditor’s ChoiceArticle

Bioactives Overproduction through Operational Strategies in the Ichthyotoxic Microalga Heterosigma akashiwo Culture

by Adrián Macías-de la Rosa, Miguel Ángel González-Cardoso, María del Carmen Cerón-García, Lorenzo López-Rosales, Juan José Gallardo-Rodríguez, Sergio Seoane, Asterio Sánchez-Mirón and Francisco García-Camacho

Toxins 2023, 15(5), 349; https://doi.org/10.3390/toxins15050349 - 20 May 2023

Cited by 3 | Viewed by 1970

Abstract

The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a [...] Read more.

The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s⁻¹·m⁻²). Continuous mode at the dilution rate of 0.2·day⁻¹ and 700 µE·s⁻¹·m⁻² provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L⁻¹·day⁻¹), and maximum fucoxanthin productivity (0.16 mg·L⁻¹·day⁻¹). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L⁻¹) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained. Full article

(This article belongs to the Section Marine and Freshwater Toxins)

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20 pages, 1502 KiB

Open AccessEditor’s ChoiceSystematic Review

Safety of Onabotulinumtoxin A in Chronic Migraine: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

by Maria Tiziana Corasaniti, Giacinto Bagetta, Pierluigi Nicotera, Assunta Tarsitano, Paolo Tonin, Giorgio Sandrini, Gary W. Lawrence and Damiana Scuteri

Toxins 2023, 15(5), 332; https://doi.org/10.3390/toxins15050332 - 12 May 2023

Cited by 7 | Viewed by 2898

Abstract

Some 14% of global prevalence, based on high-income country populations, suffers from migraine. Chronic migraine is very disabling, being characterized by at least 15 headache days per month of which at least 8 days present the features of migraine. Onabotulinumtoxin A, targeting the [...] Read more.

Some 14% of global prevalence, based on high-income country populations, suffers from migraine. Chronic migraine is very disabling, being characterized by at least 15 headache days per month of which at least 8 days present the features of migraine. Onabotulinumtoxin A, targeting the machinery for exocytosis of neurotransmitters and neuropeptides, has been approved for use in chronic migraine since 2010. This systematic review and meta-analysis appraises the safety of onabotulinumtoxin A treatment for chronic migraine and the occurrence of treatment-related adverse events (TRAEs) in randomized, clinical studies in comparison with placebo or other comparators and preventative treatments according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieved 888 total records. Nine studies are included and seven were eligible for meta-analysis. The present study demonstrates that toxin produces more TRAEs than placebo, but less than oral topiramate, supporting the safety of onabotulinumtoxin A, and highlights the heterogeneity of the studies present in the literature (I² = 96%; p < 0.00001). This points to the need for further, adequately powered, randomized clinical trials assessing the safety of onabotulinumtoxin A in combination with the newest treatment options. Full article

(This article belongs to the Special Issue Botulinum Neurotoxin: Shared/Common Mechanisms in the Treatment of Pain, Spasticity and Movement Disorders)

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16 pages, 2106 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

A Three-Monoclonal Antibody Combination Potently Neutralizes BoNT/G Toxin in Mice

by Yongfeng Fan, Jianlong Lou, Christina C. Tam, Weihua Wen, Fraser Conrad, Priscila Leal da Silva Alves, Luisa W. Cheng, Consuelo Garcia-Rodriguez, Shauna Farr-Jones and James D. Marks

Toxins 2023, 15(5), 316; https://doi.org/10.3390/toxins15050316 - 30 Apr 2023

Cited by 5 | Viewed by 2139

Abstract

Equine-derived antitoxin (BAT^®) is the only treatment for botulism from botulinum neurotoxin serotype G (BoNT/G). BAT^® is a foreign protein with potentially severe adverse effects and is not renewable. To develop a safe, more potent, and renewable antitoxin, humanized monoclonal [...] Read more.

Equine-derived antitoxin (BAT^®) is the only treatment for botulism from botulinum neurotoxin serotype G (BoNT/G). BAT^® is a foreign protein with potentially severe adverse effects and is not renewable. To develop a safe, more potent, and renewable antitoxin, humanized monoclonal antibodies (mAbs) were generated. Yeast displayed single chain Fv (scFv) libraries were prepared from mice immunized with BoNT/G and BoNT/G domains and screened with BoNT/G using fluorescence-activated cell sorting (FACS). Fourteen scFv-binding BoNT/G were isolated with K_D values ranging from 3.86 nM to 103 nM (median K_D 20.9 nM). Five mAb-binding non-overlapping epitopes were humanized and affinity matured to create antibodies hu6G6.2, hu6G7.2, hu6G9.1, hu6G10, and hu6G11.2, with IgG K_D values ranging from 51 pM to 8 pM. Three IgG combinations completely protected mice challenged with 10,000 LD₅₀s of BoNT/G at a total mAb dose of 6.25 μg per mouse. The mAb combinations have the potential for use in the diagnosis and treatment of botulism due to serotype G and, along with antibody combinations to BoNT/A, B, C, D, E, and F, provide the basis for a fully recombinant heptavalent botulinum antitoxin to replace the legacy equine product. Full article

(This article belongs to the Special Issue Human Antibody Engineering for Prevention and Treatment of Botulism)

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10 pages, 1805 KiB

Open AccessEditor’s ChoiceArticle

The Co-Occurrence of T-2 Toxin, Deoxynivalenol, and Fumonisin B1 Activated the Glutathione Redox System in the EU-Limiting Doses in Laying Hens

by Szabina Kulcsár, Benjámin Kövesi, Krisztián Balogh, Erika Zándoki, Zsolt Ancsin, Márta Erdélyi and Miklós Mézes

Toxins 2023, 15(5), 305; https://doi.org/10.3390/toxins15050305 - 23 Apr 2023

Cited by 10 | Viewed by 1987

Abstract

Different mycotoxins in feed lead to combined exposure, increasing adverse effects on animal health. Trichothecene mycotoxins have been associated with inducing oxidative stress, which is neutralized by the glutathione system within the antioxidant defense, depending on the dose and duration of exposure. T-2 [...] Read more.

Different mycotoxins in feed lead to combined exposure, increasing adverse effects on animal health. Trichothecene mycotoxins have been associated with inducing oxidative stress, which is neutralized by the glutathione system within the antioxidant defense, depending on the dose and duration of exposure. T-2 toxin, deoxynivalenol (DON), and fumonisin B1 (FB1) are commonly found in feed commodities simultaneously. In the present study, the intracellular biochemical and gene expression changes were investigated in the case of multi-mycotoxin exposure, focusing on certain elements of the glutathione redox system. In a short-term feeding trial, an in vivo study was performed with low (EU-proposed) doses: T-2/HT-2 toxin: 0.25 mg; DON/2-AcDON/15-AcDON.: 5 mg; FB1: 20 mg/kg feed, and high doses (twice the low dose) in laying hens. The multi-mycotoxin exposure affected the glutathione system; GSH concentration and GPx activity was higher in the liver in the low-dose group on day 1 compared to the control. Furthermore, the gene expression of antioxidant enzymes increased significantly on day 1 in both exposure levels compared to the control. The results suggest that when EU-limiting doses are applied, individual mycotoxins may have a synergistic effect in the induction of oxidative stress. Full article

(This article belongs to the Section Mycotoxins)

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15 pages, 3169 KiB

Open AccessEditor’s ChoiceArticle

Immunomodulatory Effects of Cylindrospermopsin in Human T Cells and Monocytes

by Antonio Casas-Rodríguez, Óscar Cebadero-Dominguez, María Puerto, Ana María Cameán and Angeles Jos

Toxins 2023, 15(4), 301; https://doi.org/10.3390/toxins15040301 - 20 Apr 2023

Cited by 3 | Viewed by 1964

Abstract

Cylindrospermopsin (CYN) is a cyanotoxin with an increasing occurrence, and therefore it is important to elucidate its toxicity profile. CYN has been classified as a cytotoxin, although the scientific literature has already revealed that it affects a wide range of organs and systems. [...] Read more.

Cylindrospermopsin (CYN) is a cyanotoxin with an increasing occurrence, and therefore it is important to elucidate its toxicity profile. CYN has been classified as a cytotoxin, although the scientific literature has already revealed that it affects a wide range of organs and systems. However, research on its potential immunotoxicity is still limited. Thus, this study aimed to evaluate the impact of CYN on two human cell lines representative of the immune system: THP-1 (monocytes) and Jurkat (lymphocytes). CYN reduced cell viability, leading to mean effective concentrations (EC50 24 h) of 6.00 ± 1.04 µM and 5.20 ± 1.20 µM for THP-1 and Jurkat cells, respectively, and induced cell death mainly by apoptosis in both experimental models. Moreover, CYN decreased the differentiation of monocytes to macrophages after 48 h of exposure. In addition, an up-regulation of the mRNA expression of different cytokines, such as interleukin (IL) 2, IL-8, tumor necrosis factor-alpha (TNF-α) and interferon-gamma (INF-γ), was also observed mainly after 24 h exposure in both cell lines. However, only an increase in TNF-α in THP-1 supernatants was observed by ELISA. Overall, these results suggest the immunomodulatory activity of CYN in vitro. Therefore, further research is required to evaluate the impact of CYN on the human immune system. Full article

(This article belongs to the Special Issue Toxicology Research on Cyanotoxins)

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22 pages, 3174 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Application of an Extracellular Matrix-Mimicking Fluorescent Polymer for the Detection of Proteolytic Venom Toxins

by Eric Wachtel, Matyas A. Bittenbinder, Bas van de Velde, Julien Slagboom, Axel de Monts de Savasse, Luis L. Alonso, Nicholas R. Casewell, Freek J. Vonk and Jeroen Kool

Toxins 2023, 15(4), 294; https://doi.org/10.3390/toxins15040294 - 18 Apr 2023

Cited by 1 | Viewed by 2204

Abstract

The cytotoxicity caused by snake venoms is a serious medical problem that greatly contributes to the morbidity observed in snakebite patients. The cytotoxic components found in snake venoms belong to a variety of toxin classes and may cause cytotoxic effects by targeting a [...] Read more.

The cytotoxicity caused by snake venoms is a serious medical problem that greatly contributes to the morbidity observed in snakebite patients. The cytotoxic components found in snake venoms belong to a variety of toxin classes and may cause cytotoxic effects by targeting a range of molecular structures, including cellular membranes, the extracellular matrix (ECM) and the cytoskeleton. Here, we present a high-throughput assay (384-well plate) that monitors ECM degradation by snake venom toxins via the application of fluorescent versions of model ECM substrates, specifically gelatin and collagen type I. Both crude venoms and fractionated toxins of a selection of medically relevant viperid and elapid species, separated via size-exclusion chromatography, were studied using the self-quenching, fluorescently labelled ECM–polymer substrates. The viperid venoms showed significantly higher proteolytic degradation when compared to elapid venoms, although the venoms with higher snake venom metalloproteinase content did not necessarily exhibit stronger substrate degradation than those with a lower one. Gelatin was generally more readily cleaved than collagen type I. In the viperid venoms, which were subjected to fractionation by SEC, two (B. jararaca and C. rhodostoma, respectively) or three (E. ocellatus) active proteases were identified. Therefore, the assay allows the study of proteolytic activity towards the ECM in vitro for crude and fractionated venoms. Full article

(This article belongs to the Special Issue Animal Venoms: Proteomics, Biochemical Activities and Application)

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12 pages, 1938 KiB

Open AccessEditor’s ChoiceArticle

Quantitative and Qualitative Pain Evaluation in Response to OnabotulinumtoxinA for Chronic Migraine: An Observational Real-Life Study

by Claudia Altamura, Nicoletta Brunelli, Giovanna Viticchi, Sergio Salvemini, Gianluca Cecchi, Marilena Marcosano, Luisa Fofi, Mauro Silvestrini and Fabrizio Vernieri

Toxins 2023, 15(4), 284; https://doi.org/10.3390/toxins15040284 - 15 Apr 2023

Cited by 6 | Viewed by 1855

Abstract

(1) Background: Randomized controlled trials and real-life studies demonstrated the efficacy of OnabotulinumtoxinA (OBT-A) for CM prevention. However, no studies specifically addressed its effect on pain’s quantitative intensity and qualitative characteristics. (2) Methods: This is an ambispective study: a post-hoc retrospective analysis of [...] Read more.

(1) Background: Randomized controlled trials and real-life studies demonstrated the efficacy of OnabotulinumtoxinA (OBT-A) for CM prevention. However, no studies specifically addressed its effect on pain’s quantitative intensity and qualitative characteristics. (2) Methods: This is an ambispective study: a post-hoc retrospective analysis of real-life prospectively collected data from two Italian headache centers on CM patients treated with OBT-A over one year (i.e., Cy1-4). The primary endpoint was the changes in pain intensity (Numeric Rating Scale, NRS; the Present Pain Intensity (PPI) scale, the 6-point Behavioral Rating Scale (BRS-6)) and quality scale (the short-form McGill Pain Questionnaire (SF-MPQ)) scores. We also assessed the relationship between changes in intensity and quality of pain and disability scale (MIDAS; HIT-6) scores, monthly headache days (MHDs), and monthly acute medication intake (MAMI) (3) Results: We retrieved 152 cases (51.5 years SD 11.3, 80.3% females). From baseline to Cy-4, MHDs, MAMI, NRS, PPI, and BRS-6 scores decreased (consistently p < 0.001). Only the throbbing (p = 0.004), splitting (p = 0.018), and sickening (p = 0.017) qualities of pain collected in the SF-MPQ were reduced. Score variations in MIDAS related to those in PPI scales (p = 0.035), in the BRS-6 (p = 0.001), and in the NRS (p = 0.003). Similarly, HIT-6 score changes related to PPI score modifications (p = 0.027), in BRS-6 (p = 0.001) and NRS (p = 0.006). Conversely, MAMI variation was not associated with qualitative or quantitative pain score modifications except BRS-6 (p = 0.018). (4) Conclusions: Our study shows that OBT-A alleviates migraine by reducing its impact on multiple aspects, such as frequency, disability, and pain intensity. The beneficial effect on pain intensity seems specific to pain characteristics related to C-fiber transmission and is associated with a reduction in migraine-related disability. Full article

(This article belongs to the Special Issue Botulinum Toxin and Migraine: Goals and Perspectives)

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12 pages, 329 KiB

Open AccessEditor’s ChoiceArticle

Proton-Pump Inhibitors and Serum Concentrations of Uremic Toxins in Patients with Chronic Kidney Disease

by Carolla El Chamieh, Islam Amine Larabi, Solène M. Laville, Christian Jacquelinet, Christian Combe, Denis Fouque, Maurice Laville, Luc Frimat, Roberto Pecoits-Filho, Céline Lange, Bénédicte Stengel, Natalia Alencar De Pinho, Jean-Claude Alvarez, Ziad A. Massy and Sophie Liabeuf

Toxins 2023, 15(4), 276; https://doi.org/10.3390/toxins15040276 - 7 Apr 2023

Cited by 2 | Viewed by 2671

Abstract

Use of proton-pump inhibitors (PPIs) is common in patients with chronic kidney disease (CKD). PPIs and many uremic toxins (UTs) are eliminated by the kidney’s tubular organic anion transporter system. In a cross-sectional study, we sought to evaluate the association between PPI prescription [...] Read more.

Use of proton-pump inhibitors (PPIs) is common in patients with chronic kidney disease (CKD). PPIs and many uremic toxins (UTs) are eliminated by the kidney’s tubular organic anion transporter system. In a cross-sectional study, we sought to evaluate the association between PPI prescription and serum concentrations of various UTs. We studied a randomly selected sub-group of participants in the CKD-REIN cohort (adult patients with a confirmed diagnosis of CKD and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²) with available frozen samples collected at baseline. PPI prescription was recorded at baseline. Serum concentrations of 10 UTs were measured using a validated liquid chromatography tandem mass spectrometry technique. Multiple linear regression was performed, with the log UT concentration as the dependent variable. Of the 680 included patients (median age: 68 years; median eGFR: 32 mL/min/1.73 m²), 31% had PPI prescriptions at baseline. Patients using PPIs had higher levels of certain UTs in comparison to other patients, including total and free indoxyl sulfate (IS), total and free p-cresylsulfate, total and free p-cresylglucuronide (PCG), phenylacetylglutamine (PAG), free kynurenine, and free hippuric acid. After adjustment for baseline co-morbidities, number of co-prescribed drugs, and laboratory data, including eGFR, associations between PPI prescription and elevated serum concentrations of free and total IS, free and total PCG, and PAG remained significant. Our results indicate that PPI prescription is independently associated with serum UT retention. These findings are interesting to better understand the factors that may modulate serum UT concentration in CKD patients, however, they will need to be confirmed by longitudinal studies. Full article

(This article belongs to the Section Uremic Toxins)

18 pages, 433 KiB

Open AccessEditor’s ChoiceReview

Impact of Enniatin and Deoxynivalenol Co-Occurrence on Plant, Microbial, Insect, Animal and Human Systems: Current Knowledge and Future Perspectives

by Irene Valenti, Francesco Tini, Milos Sevarika, Alessandro Agazzi, Giovanni Beccari, Ilaria Bellezza, Luisa Ederli, Silvia Grottelli, Matias Pasquali, Roberto Romani, Marco Saracchi and Lorenzo Covarelli

Toxins 2023, 15(4), 271; https://doi.org/10.3390/toxins15040271 - 6 Apr 2023

Cited by 5 | Viewed by 4084

Abstract

Fusarium mycotoxins commonly contaminate agricultural products resulting in a serious threat to both animal and human health. The co-occurrence of different mycotoxins in the same cereal field is very common, so the risks as well as the functional and ecological effects of mycotoxins [...] Read more.

Fusarium mycotoxins commonly contaminate agricultural products resulting in a serious threat to both animal and human health. The co-occurrence of different mycotoxins in the same cereal field is very common, so the risks as well as the functional and ecological effects of mycotoxins cannot always be predicted by focusing only on the effect of the single contaminants. Enniatins (ENNs) are among the most frequently detected emerging mycotoxins, while deoxynivalenol (DON) is probably the most common contaminant of cereal grains worldwide. The purpose of this review is to provide an overview of the simultaneous exposure to these mycotoxins, with emphasis on the combined effects in multiple organisms. Our literature analysis shows that just a few studies on ENN–DON toxicity are available, suggesting the complexity of mycotoxin interactions, which include synergistic, antagonistic, and additive effects. Both ENNs and DON modulate drug efflux transporters, therefore this specific ability deserves to be explored to better understand their complex biological role. Additionally, future studies should investigate the interaction mechanisms of mycotoxin co-occurrence on different model organisms, using concentrations closer to real exposures. Full article

(This article belongs to the Special Issue Mycotoxin Spectrum in Food and Feed)

17 pages, 2908 KiB

Open AccessEditor’s ChoiceArticle

Proteomics of Vespa velutina nigrithorax Venom Sac Queens and Workers: A Quantitative SWATH-MS Analysis

by Manuela Alonso-Sampedro, Xesús Feás, Susana Belén Bravo, María Pilar Chantada-Vázquez and Carmen Vidal

Toxins 2023, 15(4), 266; https://doi.org/10.3390/toxins15040266 - 3 Apr 2023

Cited by 4 | Viewed by 3953

Abstract

Health risks caused by stings from Vespa velutina nigrithorax (VV), also known as the yellow-legged Asian hornet, have become a public concern, but little is known about its venom composition. This study presents the proteome profile of the VV’s venom sac (VS) based on [...] Read more.

Health risks caused by stings from Vespa velutina nigrithorax (VV), also known as the yellow-legged Asian hornet, have become a public concern, but little is known about its venom composition. This study presents the proteome profile of the VV’s venom sac (VS) based on Sequential Window Acquisition of all Theoretical Mass Spectra (SWATH-MS). The study also performed proteomic quantitative analysis and examined the biological pathways and molecular functions of the proteins in the VS of VV gynes (i.e., future queens [SQ]) and workers [SW]. The total protein content per VS was significantly higher in the SW than in the SQ (274 ± 54 µg/sac vs. 175 ± 22 µg/sac; p = 0.02). We quantified a total of 228 proteins in the VS, belonging to 7 different classes: Insecta (n = 191); Amphibia and Reptilia (n = 20); Bacilli, γ-Proteobacteria and Pisoniviricetes (n = 12); and Arachnida (n = 5). Among the 228 identified proteins, 66 showed significant differential expression between SQ and SW. The potential allergens hyaluronidase A, venom antigen 5 and phospholipase A1 were significantly downregulated in the SQ venom. Full article

(This article belongs to the Special Issue Advances in Venom Immunology and Allergy)

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13 pages, 11408 KiB

Open AccessEditor’s ChoiceArticle

In Vitro High-Throughput Genotoxicity Testing Using γH2AX Biomarker, Microscopy and Reproducible Automatic Image Analysis in ImageJ—A Pilot Study with Valinomycin

by Bára Křížkovská, Martin Schätz, Jan Lipov, Jitka Viktorová and Eva Jablonská

Toxins 2023, 15(4), 263; https://doi.org/10.3390/toxins15040263 - 1 Apr 2023

Cited by 1 | Viewed by 1781

Abstract

(1) Background: The detection of DNA double-strand breaks in vitro using the phosphorylated histone biomarker (γH2AX) is an increasingly popular method of measuring in vitro genotoxicity, as it is sensitive, specific and suitable for high-throughput analysis. The γH2AX response is either detected by [...] Read more.

(1) Background: The detection of DNA double-strand breaks in vitro using the phosphorylated histone biomarker (γH2AX) is an increasingly popular method of measuring in vitro genotoxicity, as it is sensitive, specific and suitable for high-throughput analysis. The γH2AX response is either detected by flow cytometry or microscopy, the latter being more accessible. However, authors sparsely publish details, data, and workflows from overall fluorescence intensity quantification, which hinders the reproducibility. (2) Methods: We used valinomycin as a model genotoxin, two cell lines (HeLa and CHO-K1) and a commercial kit for γH2AX immunofluorescence detection. Bioimage analysis was performed using the open-source software ImageJ. Mean fluorescent values were measured using segmented nuclei from the DAPI channel and the results were expressed as the area-scaled relative fold change in γH2AX fluorescence over the control. Cytotoxicity is expressed as the relative area of the nuclei. We present the workflows, data, and scripts on GitHub. (3) Results: The outputs obtained by an introduced method are in accordance with expected results, i.e., valinomycin was genotoxic and cytotoxic to both cell lines used after 24 h of incubation. (4) Conclusions: The overall fluorescence intensity of γH2AX obtained from bioimage analysis appears to be a promising alternative to flow cytometry. Workflow, data, and script sharing are crucial for further improvement of the bioimage analysis methods. Full article

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20 pages, 1295 KiB

Open AccessEditor’s ChoiceArticle

Model of the Origin of a Ciguatoxic Grouper (Plectropomus leopardus)

by Michael J. Holmes and Richard J. Lewis

Toxins 2023, 15(3), 230; https://doi.org/10.3390/toxins15030230 - 21 Mar 2023

Cited by 5 | Viewed by 2028

Abstract

Published data were used to model the transfer of ciguatoxins (CTX) across three trophic levels of a marine food chain on the Great Barrier Reef (GBR), Australia, to produce a mildly toxic common coral trout (Plectropomus leopardus), one of the most [...] Read more.

Published data were used to model the transfer of ciguatoxins (CTX) across three trophic levels of a marine food chain on the Great Barrier Reef (GBR), Australia, to produce a mildly toxic common coral trout (Plectropomus leopardus), one of the most targeted food fishes on the GBR. Our model generated a 1.6 kg grouper with a flesh concentration of 0.1 µg/kg of Pacific-ciguatoxin-1 (P-CTX-1 = CTX1B) from 1.1 to 4.3 µg of P-CTX-1 equivalents (eq.) entering the food chain from 0.7 to 2.7 million benthic dinoflagellates (Gambierdiscus sp.) producing 1.6 pg/cell of the P-CTX-1 precursor, P-CTX-4B (CTX4B). We simulated the food chain transfer of ciguatoxins via surgeonfishes by modelling Ctenochaetus striatus feeding on turf algae. A C. striatus feeding on ≥1000 Gambierdiscus/cm² of turf algae accumulates sufficient toxin in <2 days that when preyed on, produces a 1.6 kg common coral trout with a flesh concentration of 0.1 µg/kg P-CTX-1. Our model shows that even transient blooms of highly ciguatoxic Gambierdiscus can generate ciguateric fishes. In contrast, sparse cell densities of ≤10 Gambierdiscus/cm² are unlikely to pose a significant risk, at least in areas where the P-CTX-1 family of ciguatoxins predominate. The ciguatera risk from intermediate Gambierdiscus densities (~100 cells/cm²) is more difficult to assess, as it requires feeding times for surgeonfish (~4–14 days) that overlap with turnover rates of turf algae that are grazed by herbivorous fishes, at least in regions such as the GBR, where stocks of herbivorous fishes are not impacted by fishing. We use our model to explore how the duration of ciguatoxic Gambierdiscus blooms, the type of ciguatoxins they produce, and fish feeding behaviours can produce differences in relative toxicities between trophic levels. Our simple model indicates thresholds for the design of risk and mitigation strategies for ciguatera and the variables that can be manipulated to explore alternate scenarios for the accumulation and transfer of P-CTX-1 analogues through marine food chains and, potentially, for other ciguatoxins in other regions, as more data become available. Full article

(This article belongs to the Special Issue Ciguatoxins 2022–2023)

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11 pages, 1604 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Artificial Substrates Coupled with qPCR (AS-qPCR) Assay for the Detection of the Toxic Benthopelagic Dinoflagellate Vulcanodinium rugosum

by Aurélien Bouquet, Christine Felix, Estelle Masseret, Coralie Reymond, Eric Abadie, Mohamed Laabir and Jean Luc Rolland

Toxins 2023, 15(3), 217; https://doi.org/10.3390/toxins15030217 - 11 Mar 2023

Cited by 2 | Viewed by 1836

Abstract

Vulcanodinium rugosum is an emerging benthopelagic neuro-toxic dinoflagellate species responsible for seasonal Pinnatoxins and Portimines contaminations of shellfish and marine animals. This species is challenging to detect in the environment, as it is present in low abundance and difficult to be identified using [...] Read more.

Vulcanodinium rugosum is an emerging benthopelagic neuro-toxic dinoflagellate species responsible for seasonal Pinnatoxins and Portimines contaminations of shellfish and marine animals. This species is challenging to detect in the environment, as it is present in low abundance and difficult to be identified using light microscopy. In this work, we developed a method using artificial substrates coupled with qPCR (AS-qPCR) to detect V. rugosum in a marine environment. This sensitive, specific and easy-to-standardize alternative to current techniques does not require specialized expertise in taxonomy. After determining the limits and specificity of the qPCR, we searched for the presence of V. rugosum in four French Mediterranean lagoons using artificial substrates collected every two weeks for one year. The AS-qPCR method revealed its occurrences in summer 2021 in every studied lagoon and detected cells in more samples than light microscopy. As V. rugosum development induces shellfish contamination even at low microalga densities, the AS-qPCR method is accurate and relevant for monitoring V. rugosum in a marine environment. Full article

(This article belongs to the Special Issue Advances in Marine Toxins: Characterization, Analysis and Surveillance)

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13 pages, 1822 KiB

Open AccessEditor’s ChoiceArticle

Dispersive Magnetic Solid-Phase Extraction as a Novelty Sample Treatment for the Determination of the Main Aflatoxins in Paprika

by María García-Nicolás, Natalia Arroyo-Manzanares and Pilar Viñas

Toxins 2023, 15(2), 160; https://doi.org/10.3390/toxins15020160 - 15 Feb 2023

Cited by 7 | Viewed by 2544

Abstract

Dispersive magnetic solid-phase extraction (DMSPE) technique is proposed as a new sensitive and effective sample treatment method for the determination of aflatoxins in paprika samples. DMSPE was followed by ultrahigh-performance liquid chromatography and high-resolution mass spectrometry detection (UHPLC-HRMS) using a non-targeted acquisition mode [...] Read more.

Dispersive magnetic solid-phase extraction (DMSPE) technique is proposed as a new sensitive and effective sample treatment method for the determination of aflatoxins in paprika samples. DMSPE was followed by ultrahigh-performance liquid chromatography and high-resolution mass spectrometry detection (UHPLC-HRMS) using a non-targeted acquisition mode for the detection of main aflatoxins (aflatoxin G1, G2, B1 and B2) and derivatives. DMSPE was based on the use of magnetic nanocomposite coated with polypyrrole (PPy) polymer and the main experimental parameters influencing the extraction efficiency in adsorption and desorption steps have been studied and optimized. Analyses were performed using 250 µL magnetic PPy nanocomposite into the sample solution, adsorbing the analytes in 30 min and desorbing them with ethyl acetate (2 mL) in 15 min. The method has been validated, obtaining quantification limits between 3.5 and 4.7 µg kg⁻¹ and recoveries between 89.5–97.7%. The high recovery rate, wide detection range and the use for the first time of the reusable Fe₃O₄@PPy nanomaterial in suspension for solid food matrices, guarantee the usefulness of the method developed for adequate control of aflatoxins levels in paprika. The proposed methodology was applied for the analysis of 31 samples (conventional and organic) revealing the absence of aflatoxins in the samples. Full article

(This article belongs to the Collection Aflatoxins)

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26 pages, 3854 KiB

Open AccessEditor’s ChoiceArticle

Mixtures of Mycotoxins, Phytoestrogens, and Other Secondary Metabolites in Whole-Plant Corn Silages and Total Mixed Rations of Dairy Farms in Central and Northern Mexico

by Felipe Penagos-Tabares, Michael Sulyok, Juan-Ignacio Artavia, Samanta-Irais Flores-Quiroz, César Garzón-Pérez, Ezequías Castillo-Lopez, Luis Zavala, Juan-David Orozco, Johannes Faas, Rudolf Krska and Qendrim Zebeli

Toxins 2023, 15(2), 153; https://doi.org/10.3390/toxins15020153 - 13 Feb 2023

Cited by 7 | Viewed by 2701

Abstract

Mycotoxins and endocrine disruptors such as phytoestrogens can affect cattle health, reproduction, and productivity. Most studies of mycotoxins in dairy feeds in Mexico and worldwide have been focused on a few (regulated) mycotoxins. In contrast, less known fungal toxins, phytoestrogens, and other metabolites [...] Read more.

Mycotoxins and endocrine disruptors such as phytoestrogens can affect cattle health, reproduction, and productivity. Most studies of mycotoxins in dairy feeds in Mexico and worldwide have been focused on a few (regulated) mycotoxins. In contrast, less known fungal toxins, phytoestrogens, and other metabolites have been neglected and underestimated. This study analyzed a broad spectrum (>800) of mycotoxins, phytoestrogens, and fungal, plant, and unspecific secondary metabolites in whole-plant corn silages (WPCSs) and total mixed rations (TMRs) collected from 19 Mexican dairy farms. A validated multi-metabolite liquid chromatography/electrospray ionization–tandem mass spectrometric (LC/ESI–MS/MS) method was used. Our results revealed 125 of >800 tested (potentially toxic) secondary metabolites. WPCSs/TMRs in Mexico presented ubiquitous contamination with mycotoxins, phytoestrogens, and other metabolites. The average number of mycotoxins per TMR was 24, ranging from 9 to 31. Fusarium-derived secondary metabolites showed the highest frequencies, concentrations, and diversity among the detected fungal compounds. The most frequently detected mycotoxins in TMRs were zearalenone (ZEN) (100%), fumonisin B1 (FB1) (84%), and deoxynivalenol (84%). Aflatoxin B1 (AFB1) and ochratoxin A (OTA), previously reported in Mexico, were not detected. All TMR samples tested positive for phytoestrogens. Among the investigated dietary ingredients, corn stover, sorghum silage, and concentrate proportions were the most correlated with levels of total mycotoxins, fumonisins (Fs), and ergot alkaloids, respectively. Full article

(This article belongs to the Special Issue Detection, Control and Contamination of Mycotoxins (Volume II))

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15 pages, 636 KiB

Open AccessEditor’s ChoiceArticle

Advantages of Multiplexing Ability of the Orbitrap Mass Analyzer in the Multi-Mycotoxin Analysis

by Dávid Rakk, József Kukolya, Biljana D. Škrbić, Csaba Vágvölgyi, Mónika Varga and András Szekeres

Toxins 2023, 15(2), 134; https://doi.org/10.3390/toxins15020134 - 7 Feb 2023

Cited by 5 | Viewed by 2058

Abstract

In routine measurements, the length of the analysis time and nfumber of samples analysed during a time unit are crucial parameters, which are especially important for the food analysis, particularly in the case of mycotoxin determinations. High-resolution equipment, including time-of-flight or Orbitrap analyzators, [...] Read more.

In routine measurements, the length of the analysis time and nfumber of samples analysed during a time unit are crucial parameters, which are especially important for the food analysis, particularly in the case of mycotoxin determinations. High-resolution equipment, including time-of-flight or Orbitrap analyzators, can provide stable instrumental background for high-throughput analyses. In this report, a short, 1 min MS-based multi-mycotoxin method was developed with the application of a short column as a reduced chromatographic separation, taking advantages of the multiplexing and high-resolution capability of the QExactive Orbitrap MS possessing sub-1 ppm mass accuracy. The performance of the method was evaluated regarding selectivity, LOD, LOQ, linearity, matrix effect, and recovery, and compared to a UHPLC-MS/MS method. The final multiplexing method was able to quantify 11 mycotoxins in defined ranges (aflatoxins (corn, 2.8–600 μg/kg; wheat, 1.5–350 μg/kg), deoxynivalenol (corn, 640–9600 μg/kg; wheat, 128–3500 μg/kg), fumonisins (corn, 20–1500 μg/kg; wheat, 30–3500 μg/kg), HT-2 (corn, 64–5200 μg/kg; wheat, 61–3500 μg/kg), T-2 (corn, 10–800 μg/kg; wheat, 4–250 μg/kg), ochratoxin (corn, 4.7–600 μg/kg; wheat, 1–1000 μg/kg), zearalenone (corn, 64–4800 μg/kg; wheat, 4–500 μg/kg)) within one minute in corn and wheat matrices at the MRL levels stated by the European Union. Full article

(This article belongs to the Special Issue Rapid Detection of Mycotoxin Contamination 2.0)

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20 pages, 4386 KiB

Open AccessEditor’s ChoiceArticle

Effect of Plasma-Activated Water Bubbles on Fusarium graminearum, Deoxynivalenol, and Germination of Naturally Infected Barley during Steeping

by Ehsan Feizollahi, Urmila Basu, Rudolph Fredua-Agyeman, Brasathe Jeganathan, Lusine Tonoyan, Stephen E. Strelkov, Thava Vasanthan, Arno G. Siraki and M. S. Roopesh

Toxins 2023, 15(2), 124; https://doi.org/10.3390/toxins15020124 - 3 Feb 2023

Cited by 8 | Viewed by 3404

Abstract

Contamination of barley by deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, causes considerable financial loss to the grain and malting industries. In this study, two atmospheric cold plasma (ACP) reactors were used to produce plasma-activated water (PAW) bubbles. The potential of [...] Read more.

Contamination of barley by deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, causes considerable financial loss to the grain and malting industries. In this study, two atmospheric cold plasma (ACP) reactors were used to produce plasma-activated water (PAW) bubbles. The potential of PAW bubbles for the steeping of naturally infected barley (NIB) during the malting process was investigated. The PAW bubbles produced by treating water for 30 min using a bubble spark discharge (BSD) at low temperature resulted in the greatest concentration of oxygen-nitrogen reactive species (RONS). This treatment resulted in 57.3% DON degradation compared with 36.9% in the control sample; however, the same treatment reduced germination significantly (p < 0.05). Direct BSD ACP treatment for 20 min at low temperature and indirect treatment for 30 min increased the percentage of germinated rootlets of the seedlings compared with the control. Considering both the DON reduction and germination improvement of barley seeds, continuous jet ACP treatment for 30 min performed better than the other treatments used in this study. At higher temperature of PAW bubbles, the concentration of RONS was significantly (p < 0.05) reduced. Based on quantitative polymerase chain reaction (qPCR) analysis and fungal culture tests, the PAW bubble treatment did not significantly reduce infection of NIB. Nonetheless, this study provides useful information for the malting industry for PAW treatment optimization and its use in barley steeping for DON reduction and germination improvement. Full article

(This article belongs to the Section Mycotoxins)

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23 pages, 1462 KiB

Open AccessEditor’s ChoiceReview

Food-Derived Uremic Toxins in Chronic Kidney Disease

by Mara Lauriola, Ricard Farré, Pieter Evenepoel, Saskia Adriana Overbeek and Björn Meijers

Toxins 2023, 15(2), 116; https://doi.org/10.3390/toxins15020116 - 1 Feb 2023

Cited by 13 | Viewed by 5025

Abstract

Patients with chronic kidney disease (CKD) have a higher cardiovascular risk compared to the average population, and this is partially due to the plasma accumulation of solutes known as uremic toxins. The binding of some solutes to plasma proteins complicates their removal via [...] Read more.

Patients with chronic kidney disease (CKD) have a higher cardiovascular risk compared to the average population, and this is partially due to the plasma accumulation of solutes known as uremic toxins. The binding of some solutes to plasma proteins complicates their removal via conventional therapies, e.g., hemodialysis. Protein-bound uremic toxins originate either from endogenous production, diet, microbial metabolism, or the environment. Although the impact of diet on uremic toxicity in CKD is difficult to quantify, nutrient intake plays an important role. Indeed, most uremic toxins are gut-derived compounds. They include Maillard reaction products, hippurates, indoles, phenols, and polyamines, among others. In this review, we summarize the findings concerning foods and dietary components as sources of uremic toxins or their precursors. We then discuss their endogenous metabolism via human enzyme reactions or gut microbial fermentation. Lastly, we present potential dietary strategies found to be efficacious or promising in lowering uremic toxins plasma levels. Aligned with current nutritional guidelines for CKD, a low-protein diet with increased fiber consumption and limited processed foods seems to be an effective treatment against uremic toxins accumulation. Full article

(This article belongs to the Special Issue Kidney Disease-Gut Dysbiosis: What Is the Role of Uremic Toxins?)

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17 pages, 2702 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Brown Spider Venom Phospholipase-D Activity upon Different Lipid Substrates

by Daniele Chaves-Moreira, Luiza Helena Gremski, Fábio Rogério de Moraes, Larissa Vuitika, Ana Carolina Martins Wille, Jorge Enrique Hernández González, Olga Meiri Chaim, Andrea Senff-Ribeiro, Raghuvir Krishnaswamy Arni and Silvio Sanches Veiga

Toxins 2023, 15(2), 109; https://doi.org/10.3390/toxins15020109 - 27 Jan 2023

Cited by 7 | Viewed by 2296

Abstract

Brown spider envenomation results in dermonecrosis, characterized by an intense inflammatory reaction. The principal toxins of brown spider venoms are phospholipase-D isoforms, which interact with different cellular membrane components, degrade phospholipids, and generate bioactive mediators leading to harmful effects. The Loxosceles intermedia phospholipase [...] Read more.

Brown spider envenomation results in dermonecrosis, characterized by an intense inflammatory reaction. The principal toxins of brown spider venoms are phospholipase-D isoforms, which interact with different cellular membrane components, degrade phospholipids, and generate bioactive mediators leading to harmful effects. The Loxosceles intermedia phospholipase D, LiRecDT1, possesses a loop that modulates the accessibility to the active site and plays a crucial role in substrate. In vitro and in silico analyses were performed to determine aspects of this enzyme’s substrate preference. Sphingomyelin d18:1/6:0 was the preferred substrate of LiRecDT1 compared to other Sphingomyelins. Lysophosphatidylcholine 16:0/0:0 was preferred among other lysophosphatidylcholines, but much less than Sphingomyelin d18:1/6:0. In contrast, phosphatidylcholine d18:1/16:0 was not cleaved. Thus, the number of carbon atoms in the substrate plays a vital role in determining the optimal activity of this phospholipase-D. The presence of an amide group at C2 plays a key role in recognition and activity. In silico analyses indicated that a subsite containing the aromatic residues Y228 and W230 appears essential for choline recognition by cation-π interactions. These findings may help to explain why different cells, with different phospholipid fatty acid compositions exhibit distinct susceptibilities to brown spider venoms. Full article

(This article belongs to the Special Issue Animal Venom: Challenges and Perspectives in Drug Discovery)

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13 pages, 431 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Incremental Doses of Aflatoxin B₁ on In Vitro Ruminal Nutrient Digestibility and Fermentation Profile of a Lactating Dairy Cow Diet in a Dual-Flow Continuous Culture System

by Felipe Xavier Amaro, Yun Jiang, Kathy Arriola, Matheus R. Pupo, Bruna C. Agustinho, Sarah L. Bennett, James R. Vinyard, Lais Tomaz, Richard R. Lobo, Andres Pech-Cervantes, Jose A. Arce-Cordero, Antonio P. Faciola, Adegbola Tolulope Adesogan and Diwakar Vyas

Toxins 2023, 15(2), 90; https://doi.org/10.3390/toxins15020090 - 18 Jan 2023

Cited by 2 | Viewed by 2267

Abstract

Aflatoxin B₁ (AFB₁) is a mycotoxin known to impair human and animal health. It is also believed to have a deleterious effect on ruminal nutrient digestibility under in vitro batch culture systems. The objective of this study was to evaluate [...] Read more.

Aflatoxin B₁ (AFB₁) is a mycotoxin known to impair human and animal health. It is also believed to have a deleterious effect on ruminal nutrient digestibility under in vitro batch culture systems. The objective of this study was to evaluate the effects of increasing the dose of AFB₁ on ruminal dry matter and nutrient digestibility, fermentation profile, and N flows using a dual-flow continuous culture system fed a diet formulated for lactating dairy cows. Eight fermenter vessels were used in a replicated 4 × 4 Latin square design with 10 d periods (7 d adaptation and 3 d sample collection). Treatments were randomly applied to fermenters on diet DM basis: (1) 0 μg of AFB₁/kg of DM (Control); (2) 50 μg of AFB₁/kg of DM (AF50); (3) 100 μg of AFB₁/kg of DM (AF100); and (4) 150 μg of AFB₁/kg of DM (AF150). Treatments did not affect nutrient digestibility, fermentation, and N flows. Aflatoxin B₁ concentration in ruminal fluid increased with dose but decreased to undetectable levels after 4 h post-dosing. In conclusion, adding incremental doses of AFB₁ did not affect ruminal fermentation, digestibility of nutrients, and N flows in a dual-flow continuous culture system fed diets formulated for lactating dairy cows. Full article

(This article belongs to the Collection Aflatoxins)

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23 pages, 2709 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Bivalve Shellfish Safety in Portugal: Variability of Faecal Levels, Metal Contaminants and Marine Biotoxins during the Last Decade (2011–2020)

by Ana Catarina Braga, Susana Margarida Rodrigues, Helena Maria Lourenço, Pedro Reis Costa and Sónia Pedro

Toxins 2023, 15(2), 91; https://doi.org/10.3390/toxins15020091 - 18 Jan 2023

Cited by 7 | Viewed by 2796

Abstract

Bivalves are a high-value product whose production has markedly increased, reaching 9863 tonnes in Portugal in 2021. Bivalves’ habitats—lagoons, estuaries and coastal waters—are exposed to biological and anthropogenic contaminants, which can bioaccumulate in these organisms and pose a significant public health risk. The [...] Read more.

Bivalves are a high-value product whose production has markedly increased, reaching 9863 tonnes in Portugal in 2021. Bivalves’ habitats—lagoons, estuaries and coastal waters—are exposed to biological and anthropogenic contaminants, which can bioaccumulate in these organisms and pose a significant public health risk. The need to obtain a safe product for human consumption led to the implementation of standardised hygiene regulations for harvesting and marketing bivalve molluscs, resulting in routine monitoring of bivalve production areas for microbial quality, metal contaminants, and marine biotoxins. While excessive levels of biotoxins and metal contamination lead to temporary harvesting bans, high faecal contamination leads to area reclassification and impose post-harvest treatments. In this study, the seasonal and temporal variability of these parameters were analysed using historical data generated by the monitoring programme during the last decade. Moreover, the impact of the monitoring program on bivalve harvesting from 2011 to 2020 was assessed. This program presented a considerable improvement over time, with an increase in the sampling effort and the overall program representativeness. Finally, contamination risk, revising control measures, and defining recommendations for risk mitigation measures are given in the light of ten years’ monitoring. Full article

(This article belongs to the Special Issue Bioactive Toxins in Marine Organism: Detection and Harmful Impacts)

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16 pages, 1050 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Effects of Botulinum Toxin Type A on the Nociceptive and Lemniscal Somatosensory Systems in Chronic Migraine: An Electrophysiological Study

by Gabriele Sebastianelli, Francesco Casillo, Antonio Di Renzo, Chiara Abagnale, Ettore Cioffi, Vincenzo Parisi, Cherubino Di Lorenzo, Mariano Serrao, Francesco Pierelli, Jean Schoenen and Gianluca Coppola

Toxins 2023, 15(1), 76; https://doi.org/10.3390/toxins15010076 - 14 Jan 2023

Cited by 7 | Viewed by 3835

Abstract

(1) Background: OnabotulinumtoxinA (BoNT-A) is a commonly used prophylactic treatment for chronic migraine (CM). Although randomized placebo studies have shown its clinical efficacy, the mechanisms by which it exerts its therapeutic effect are still incompletely understood and debated. (2) Methods: We studied in [...] Read more.

(1) Background: OnabotulinumtoxinA (BoNT-A) is a commonly used prophylactic treatment for chronic migraine (CM). Although randomized placebo studies have shown its clinical efficacy, the mechanisms by which it exerts its therapeutic effect are still incompletely understood and debated. (2) Methods: We studied in 15 CM patients the cephalic and extracephalic nociceptive and lemniscal sensory systems using electrophysiological techniques before and 1 and 3 months after one session of pericranial BoNT-A injections according to the PREEMPT protocol. We recorded the nociceptive blink reflex (nBR), the trigemino-cervical reflex (nTCR), the pain-related cortical evoked potential (PREP), and the upper limb somatosensory evoked potential (SSEP). (3) Results: Three months after a single session of prophylactic therapy with BoNT-A in CM patients, we found (a) an increase in the homolateral and contralateral nBR AUC, (b) an enhancement of the contralateral nBR AUC habituation slope and the nTCR habituation slope, (c) a decrease in PREP N-P 1st and 2nd amplitude block, and (d) no effect on SSEPs. (4) Conclusions: Our study provides electrophysiological evidence for the ability of a single session of BoNT-A injections to exert a neuromodulatory effect at the level of trigeminal system through a reduction in input from meningeal and other trigeminovascular nociceptors. Moreover, by reducing activity in cortical pain processing areas, BoNT-A restores normal functioning of the descending pain modulation systems. Full article

(This article belongs to the Special Issue Botulinum Toxin and Migraine: Goals and Perspectives)

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18 pages, 6580 KiB

Open AccessEditor’s ChoiceArticle

Highly Evolvable: Investigating Interspecific and Intraspecific Venom Variation in Taipans (Oxyuranus spp.) and Brown Snakes (Pseudonaja spp.)

by Jory van Thiel, Luis L. Alonso, Julien Slagboom, Nathan Dunstan, Roel M. Wouters, Cassandra M. Modahl, Freek J. Vonk, Timothy N. W. Jackson and Jeroen Kool

Toxins 2023, 15(1), 74; https://doi.org/10.3390/toxins15010074 - 13 Jan 2023

Cited by 11 | Viewed by 3396

Abstract

Snake venoms are complex mixtures of toxins that differ on interspecific (between species) and intraspecific (within species) levels. Whether venom variation within a group of closely related species is explained by the presence, absence and/or relative abundances of venom toxins remains largely unknown. [...] Read more.

Snake venoms are complex mixtures of toxins that differ on interspecific (between species) and intraspecific (within species) levels. Whether venom variation within a group of closely related species is explained by the presence, absence and/or relative abundances of venom toxins remains largely unknown. Taipans (Oxyuranus spp.) and brown snakes (Pseudonaja spp.) represent medically relevant species of snakes across the Australasian region and provide an excellent model clade for studying interspecific and intraspecific venom variation. Using liquid chromatography with ultraviolet and mass spectrometry detection, we analyzed a total of 31 venoms covering all species of this monophyletic clade, including widespread localities. Our results reveal major interspecific and intraspecific venom variation in Oxyuranus and Pseudonaja species, partially corresponding with their geographical regions and phylogenetic relationships. This extensive venom variability is generated by a combination of the absence/presence and differential abundance of venom toxins. Our study highlights that venom systems can be highly dynamical on the interspecific and intraspecific levels and underscores that the rapid toxin evolvability potentially causes major impacts on neglected tropical snakebites. Full article

(This article belongs to the Section Animal Venoms)

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17 pages, 2837 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Montane Rattlesnakes in México: Venoms of Crotalus tancitarensis and Related Species within the Crotalus intermedius Group

by Emily R. Grabowsky, Anthony J. Saviola, Javier Alvarado-Díaz, Adrian Quijada Mascareñas, Kirk C. Hansen, John R. Yates III and Stephen P. Mackessy

Toxins 2023, 15(1), 72; https://doi.org/10.3390/toxins15010072 - 13 Jan 2023

Cited by 2 | Viewed by 2832

Abstract

The Crotalus intermedius group is a clade of rattlesnakes consisting of several species adapted to a high elevation habitat, primarily in México. Crotalus tancitarensis was previously classified as C. intermedius, until individuals occurring on Cerro Tancítaro in Michoacán, México, were reevaluated and [...] Read more.

The Crotalus intermedius group is a clade of rattlesnakes consisting of several species adapted to a high elevation habitat, primarily in México. Crotalus tancitarensis was previously classified as C. intermedius, until individuals occurring on Cerro Tancítaro in Michoacán, México, were reevaluated and classified as a new species (C. tancitarensis) based on scale pattern and geographic location. This study aimed to characterize the venom of C. tancitarensis and compare the venom profile to those of other species within the Crotalus intermedius group using gel electrophoresis, biochemical assays, reverse-phase high performance liquid chromatography, mass spectrometry, and lethal toxicity (LD₅₀) assays. Results show that the venom profiles of species within the Crotalus intermedius group are similar, but with distinct differences in phospholipase A₂ (PLA₂), metalloproteinase PI (SVMP PI), and kallikrein-like serine proteinase (SVSP) activity and relative abundance. Proteomic analysis indicated that the highland forms produce venoms with 50–60 protein isoforms and a composition typical of type I rattlesnake venoms (abundant SVMPs, lack of presynaptic PLA₂-based neurotoxins), as well as a diversity of typical Crotalus venom components such as serine proteinases, PLA₂s, C-type lectins, and less abundant toxins (LAAOs, CRiSPs, etc.). The overall venom profile of C. tancitarensis appears most similar to C. transversus, which is consistent with a previous mitochondrial DNA analysis of the Crotalus intermedius group. These rattlesnakes of the Mexican highlands represent a radiation of high elevation specialists, and in spite of divergence of species in these Sky Island habitats, venom composition of species analyzed here has remained relatively conserved. The majority of protein family isoforms are conserved in all members of the clade, and as seen in other more broadly distributed rattlesnake species, differences in their venoms are largely due to relative concentrations of specific components. Full article

(This article belongs to the Section Animal Venoms)

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14 pages, 29465 KiB

Open AccessEditor’s ChoiceArticle

Solanum nigrum Fruit Extract Modulates Immune System Activity of Mealworm Beetle, Tenebrio molitor L.

by Arkadiusz Urbański, Natalia Konopińska, Natalia Bylewska, Radosław Gmyrek, Marta Spochacz-Santoro, Sabino Aurelio Bufo and Zbigniew Adamski

Toxins 2023, 15(1), 68; https://doi.org/10.3390/toxins15010068 - 12 Jan 2023

Cited by 3 | Viewed by 2488

Abstract

Here, we report the first evidence concerning the modulation of insect immune system activity after applying Solanum nigrum fruit extract (EXT). We focused on two main issues: (1) is EXT cytotoxic for Tenebrio molitor haemocytes? and (2) how EXT affects the basic immune [...] Read more.

Here, we report the first evidence concerning the modulation of insect immune system activity after applying Solanum nigrum fruit extract (EXT). We focused on two main issues: (1) is EXT cytotoxic for Tenebrio molitor haemocytes? and (2) how EXT affects the basic immune mechanisms of T. molitor. The results indicate cytotoxic action of 0.01 and 0.1% EXT on beetle haemocytes. Both the injection of EXT and incubating haemocytes with the EXT solution on microscopic slides significantly increased the number of apoptotic cells. However, 24 h after injection of 0.1% EXT cytotoxic effect of the tested extract probably was masked by the increased number of circulating haemocytes. Application of 0.01 and 0.1% EXT led to impairment of the activity of basic immune mechanisms such as phenoloxidase activity and the lysozyme-like antimicrobial activity of T. molitor haemolymph. Moreover, the EXT elicited significant changes in the expression level of selected immune genes. However, some of the immunomodulatory effects of EXT were different in beetles with and without an activated immune system. The obtained results are an essential step toward a complete understanding of the EXT mode of action on the T. molitor physiology and its potential usage in pest control. Full article

(This article belongs to the Special Issue Toxic Secondary Plant Metabolites: Toxicology, Medicine, Pharmacology, Ecotoxicology and Crop Protection)

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16 pages, 1613 KiB

Open AccessEditor’s ChoiceArticle

Sustainable Strategies to Counteract Mycotoxins Contamination and Cowpea Weevil in Chickpea Seeds during Post-Harvest

by Claudia Pisuttu, Samuele Risoli, Lorenzo Moncini, Cristina Nali, Elisa Pellegrini and Sabrina Sarrocco

Toxins 2023, 15(1), 61; https://doi.org/10.3390/toxins15010061 - 11 Jan 2023

Cited by 11 | Viewed by 3496

Abstract

Mycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of [...] Read more.

Mycotoxins contamination and pest infestation of foods and feeds represent a pivotal threat for food safety and security worldwide, with crucial implications for human and animal health. Controlled atmosphere could be a sustainable strategy to reduce mycotoxins content and counteract the vitality of deleterious organisms in foodstuff. Ozone treatment (O₃, 500 ppb for 30, 60 or 90 min) and high nitrogen concentration (N₂, 99% for 21 consecutive days) were tested in the post-harvest management of four batches of Cicer arietinum grains to control the presence of mycotoxigenic fungi and their secondary metabolites, as well as pest (i.e., Callosobruchus maculatus) infestation. At the end of the treatment, O₃ significantly decreased the incidence of Penicillium spp. (by an average of −50%, independently to the time of exposure) and reduced the patulin and aflatoxins content after 30 min (−85 and −100%, respectively). High N₂ concentrations remarkably reduced mycotoxins contamination (by an average of −94%) and induced pest mortality (at 100% after 5 days of exposure). These results confirm the promising potential of O₃ and N₂ in post-harvest conservation strategies, leading to further investigations to evaluate the effects on the qualitative characteristics of grains. Full article

(This article belongs to the Special Issue Novel Strategies for Biodegradation and Detoxification of Mycotoxins)

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15 pages, 1634 KiB

Open AccessEditor’s ChoiceArticle

In Vitro Efficacy of Antivenom and Varespladib in Neutralising Chinese Russell’s Viper (Daboia siamensis) Venom Toxicity

by Mimi Lay, Qing Liang, Geoffrey K. Isbister and Wayne C. Hodgson

Toxins 2023, 15(1), 62; https://doi.org/10.3390/toxins15010062 - 11 Jan 2023

Cited by 9 | Viewed by 2616

Abstract

The venom of the Russell’s viper (Daboia siamensis) contains neurotoxic and myotoxic phospholipase A₂ toxins which can cause irreversible damage to motor nerve terminals. Due to the time delay between envenoming and antivenom administration, antivenoms may have limited efficacy against [...] Read more.

The venom of the Russell’s viper (Daboia siamensis) contains neurotoxic and myotoxic phospholipase A₂ toxins which can cause irreversible damage to motor nerve terminals. Due to the time delay between envenoming and antivenom administration, antivenoms may have limited efficacy against some of these venom components. Hence, there is a need for adjunct treatments to circumvent these limitations. In this study, we examined the efficacy of Chinese D. siamensis antivenom alone, and in combination with a PLA₂ inhibitor, Varespladib, in reversing the in vitro neuromuscular blockade in the chick biventer cervicis nerve-muscle preparation. Pre-synaptic neurotoxicity and myotoxicity were not reversed by the addition of Chinese D. siamensis antivenom 30 or 60 min after venom (10 µg/mL). The prior addition of Varespladib prevented the neurotoxic and myotoxic activity of venom (10 µg/mL) and was also able to prevent further reductions in neuromuscular block and muscle twitches when added 60 min after venom. The addition of the combination of Varespladib and antivenom 60 min after venom failed to produce further improvements than Varespladib alone. This demonstrates that the window of time in which antivenom remains effective is relatively short compared to Varespladib and small-molecule inhibitors may be effective in abrogating some activities of Chinese D. siamensis venom. Full article

(This article belongs to the Special Issue Advanced Research on Animal Venoms in China)

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34 pages, 4265 KiB

Open AccessEditor’s ChoiceArticle

A Feasibility Study into the Production of a Mussel Matrix Reference Material for the Cyanobacterial Toxins Microcystins and Nodularins

by Andrew D. Turner, Daniel G. Beach, Amanda Foss, Ingunn A. Samdal, Kjersti L. E. Løvberg, Julia Waack, Christine Edwards, Linda A. Lawton, Karl J. Dean, Benjamin H. Maskrey and Adam M. Lewis

Toxins 2023, 15(1), 27; https://doi.org/10.3390/toxins15010027 - 30 Dec 2022

Cited by 5 | Viewed by 2438

Abstract

Microcystins and nodularins, produced naturally by certain species of cyanobacteria, have been found to accumulate in aquatic foodstuffs such as fish and shellfish, resulting in a risk to the health of the seafood consumer. Monitoring of toxins in such organisms for risk management [...] Read more.

Microcystins and nodularins, produced naturally by certain species of cyanobacteria, have been found to accumulate in aquatic foodstuffs such as fish and shellfish, resulting in a risk to the health of the seafood consumer. Monitoring of toxins in such organisms for risk management purposes requires the availability of certified matrix reference materials to aid method development, validation and routine quality assurance. This study consequently targeted the preparation of a mussel tissue reference material incurred with a range of microcystin analogues and nodularins. Nine targeted analogues were incorporated into the material as confirmed through liquid chromatography with tandem mass spectrometry (LC-MS/MS), with an additional 15 analogues detected using LC coupled to non-targeted high resolution mass spectrometry (LC-HRMS). Toxins in the reference material and additional source tissues were quantified using LC-MS/MS, two different enzyme-linked immunosorbent assay (ELISA) methods and with an oxidative-cleavage method quantifying 3-methoxy-2-methyl-4-phenylbutyric acid (MMPB). Correlations between the concentrations quantified using the different methods were variable, likely relating to differences in assay cross-reactivities and differences in the abilities of each method to detect bound toxins. A consensus concentration of total soluble toxins determined from the four independent test methods was 2425 ± 575 µg/kg wet weight. A mean 43 ± 9% of bound toxins were present in addition to the freely extractable soluble form (57 ± 9%). The reference material produced was homogenous and stable when stored in the freezer for six months without any post-production stabilization applied. Consequently, a cyanotoxin shellfish reference material has been produced which demonstrates the feasibility of developing certified seafood matrix reference materials for a large range of cyanotoxins and could provide a valuable future resource for cyanotoxin risk monitoring, management and mitigation. Full article

(This article belongs to the Special Issue Cyanotoxins in the Food Chain)

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11 pages, 544 KiB

Open AccessEditor’s ChoiceArticle

Occurrence and Dietary Exposure Assessment to Enniatin B through Consumption of Cereal-Based Products in Spain and the Catalonia Region

by Jose A. Gallardo, Sonia Marín, Antonio J. Ramos, German Cano-Sancho and Vicente Sanchis

Toxins 2023, 15(1), 24; https://doi.org/10.3390/toxins15010024 - 29 Dec 2022

Cited by 8 | Viewed by 2272

Abstract

Enniatin B (ENNB) is a mycotoxin produced by moulds from the Fusarium genera and its toxic effects are still not fully elucidated, hence a safe reference exposure value has not been established yet. ENNB is the most prevalent emerging mycotoxin and is widely [...] Read more.

Enniatin B (ENNB) is a mycotoxin produced by moulds from the Fusarium genera and its toxic effects are still not fully elucidated, hence a safe reference exposure value has not been established yet. ENNB is the most prevalent emerging mycotoxin and is widely found in cereal-based products, nevertheless, there are no comprehensive exposure assessment studies. For that reason, the aim of this study was to characterise the occurrence of ENNB and estimate the exposure of the Spanish and Catalan populations. A total of 347 cereal-based products were collected in 2019 and were analysed using liquid chromatography-tandem mass spectrometry. Consumption data were obtained from the national food consumption surveys (ENALIA) and a regional survey conducted in Catalonia. The global exposure was estimated using deterministic and probabilistic methods. The results showed a high occurrence of close to 100% in all foodstuffs, with a range from 6 to 269 µg/kg, and a strong correlation with the levels of deoxynivalenol. Children aged one–nine years were the most exposed, showing mean estimates in the range 308–324 ng/kg bw/day and 95th percentiles 697–781 ng/kg bw/day. This study stresses the need for further toxicological data to establish reference doses and conclude formal risk assessment, accounting for the co-occurrence with deoxynivalenol. Full article

(This article belongs to the Special Issue Mycotoxin Exposure: Assessment, Corresponding Adverse Health Outcomes and Control Plans)

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18 pages, 2789 KiB

Open AccessEditor’s ChoiceArticle

A Novel Trichothecene Toxin Phenotype Associated with Horizontal Gene Transfer and a Change in Gene Function in Fusarium

by Robert H. Proctor, Guixia Hao, Hye-Seon Kim, Briana K. Whitaker, Imane Laraba, Martha M. Vaughan and Susan P. McCormick

Toxins 2023, 15(1), 12; https://doi.org/10.3390/toxins15010012 - 24 Dec 2022

Cited by 5 | Viewed by 2157

Abstract

Fusarium trichothecenes are among the mycotoxins of most concern to food and feed safety. Production of these mycotoxins and presence of the trichothecene biosynthetic gene (TRI) cluster have been confirmed in only two multispecies lineages of Fusarium: the Fusarium incarnatum [...] Read more.

Fusarium trichothecenes are among the mycotoxins of most concern to food and feed safety. Production of these mycotoxins and presence of the trichothecene biosynthetic gene (TRI) cluster have been confirmed in only two multispecies lineages of Fusarium: the Fusarium incarnatum-equiseti (Incarnatum) and F. sambucinum (Sambucinum) species complexes. Here, we identified and characterized a TRI cluster in a species that has not been formally described and is represented by Fusarium sp. NRRL 66739. This fungus is reported to be a member of a third Fusarium lineage: the F. buharicum species complex. Cultures of NRRL 66739 accumulated only two trichothecenes, 7-hydroxyisotrichodermin and 7-hydroxyisotrichodermol. Although these are not novel trichothecenes, the production profile of NRRL 66739 is novel, because in previous reports 7-hydroxyisotrichodermin and 7-hydroxyisotrichodermol were components of mixtures of 6–8 trichothecenes produced by several Fusarium species in Sambucinum. Heterologous expression analysis indicated that the TRI13 gene in NRRL 66739 confers trichothecene 7-hydroxylation. This contrasts the trichothecene 4-hydroxylation function of TRI13 in other Fusarium species. Phylogenetic analyses suggest that NRRL 66739 acquired the TRI cluster via horizontal gene transfer from a close relative of Incarnatum and Sambucinum. These findings provide insights into evolutionary processes that have shaped the distribution of trichothecene production among Fusarium species and the structural diversity of the toxins. Full article

(This article belongs to the Special Issue Fusarium Mycotoxins: Chemistry, Genetics and Biology)

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18 pages, 2788 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Commercial Antivenoms Exert Broad Paraspecific Immunological Binding and In Vitro Inhibition of Medically Important Bothrops Pit Viper Venoms

by Jaffer Alsolaiss, Nessrin Alomran, Laura Hawkins and Nicholas R. Casewell

Toxins 2023, 15(1), 1; https://doi.org/10.3390/toxins15010001 - 20 Dec 2022

Cited by 8 | Viewed by 1998

Abstract

Snakebite envenoming is a life threatening neglected tropical disease that represents a considerable public health concern in the tropics. Viperid snakes of the genus Bothrops are among those of greatest medical importance in Latin America, and they frequently cause severe systemic haemotoxicity and [...] Read more.

Snakebite envenoming is a life threatening neglected tropical disease that represents a considerable public health concern in the tropics. Viperid snakes of the genus Bothrops are among those of greatest medical importance in Latin America, and they frequently cause severe systemic haemotoxicity and local tissue destructive effects in human victims. Although snakebite antivenoms can be effective therapeutics, their efficacy is undermined by venom toxin variation among snake species. In this study we investigated the extent of paraspecific venom cross-reactivity exhibited by three distinct anti-Bothrops antivenoms (Soro antibotrópico-crotálico, BothroFav and PoliVal-ICP) against seven different Bothrops pit viper venoms from across Latin America. We applied a range of in vitro assays to assess the immunological binding and recognition of venom toxins by the antivenoms and their inhibitory activities against specific venom functionalities. Our findings demonstrated that, despite some variations, the monovalent antivenom BothroFav and the polyvalent antivenoms Soro antibotrópico-crotálico and PoliVap-ICP exhibited extensive immunological recognition of the distinct toxins found in the different Bothrops venoms, with Soro antibotrópico-crotálico generally outperformed by the other two products. In vitro functional assays revealed outcomes largely consistent with the immunological binding data, with PoliVap-ICP and BothroFav exhibiting the greatest inhibitory potencies against procoagulant and fibrinogen-depleting venom activities, though Soro antibotrópico-crotálico exhibited potent inhibition of venom metalloproteinase activities. Overall, our findings demonstrate broad levels of antivenom paraspecificity, with in vitro immunological binding and functional inhibition often highly comparable between venoms used to manufacture the antivenoms and those from related species, even in the case of the monovalent antivenom BothroFav. Our findings suggest that the current clinical utility of these antivenoms could possibly be expanded to other parts of Latin America that currently suffer from a lack of specific snakebite therapies. Full article

(This article belongs to the Section Animal Venoms)

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