Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
7.3
4.3
Journals
Antibiotics
Sections
Synthetic and Natural Products-Based Antimicrobial and Antiparasitic Agents
share announcement

Synthetic and Natural Products-Based Antimicrobial and Antiparasitic Agents

A topical collection in Antibiotics (ISSN 2079-6382). This collection belongs to the section "Novel Antimicrobial Agents".

Viewed by 20660

Editor

Prof. Dr. Antonio Eduardo Miller Crotti

E-Mail Website
Collection Editor
Department of Chemistry, Faculty of Philosophy, Sciences, and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
Interests: natural products; organic synthesis; biological and pharmacological activities; mass spectrometry; structural elucidation; reaction mechanisms
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Microbial and parasites are responsible for a wide diversity of diseases in humans and animals. The need for novel antimicrobials and antiparasitic agents has emerged as the current drugs have become less efficient due to resistance development. The potential of synthetic, semi-synthetic, and natural products as alternative antimicrobial (antibacterial, antifungal, and antiviral) and antiparasitic (especially antileishmanial, anti-trypanosomal, antischistosomal, and anti-toxoplasma, but not limited to them) agents will be addressed in this Special Issue. This issue will cover the discovery and design of new synthetic and semi-synthetic compounds, as well as their mechanisms of action, and structure–activity relationship (SAR) studies. Studies on bioactive microbial and plant-derived natural products and/or their semi-synthetic derivatives, as well as essential oils and their constituents, are also welcome. Authors are invited to contribute their submissions as reviews, research papers, or communications.

Prof. Dr. Antonio Eduardo Miller Crotti
Collection Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Antibiotics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • antibacterial
  • antifungal
  • antiviral
  • Candida
  • Chagas's disease
  • essential oils
  • Helicobacter
  • Leishmania
  • Schistosoma
  • Staphylococcus
  • Streptococcus
  • Toxoplasma
  • Trypanosoma

Published Papers (16 papers)

Download All Papers

2025

Jump to: 2024

21 pages, 5481 KiB  
Article
Mechanism Insight of Cell Death Signaling by Thymol Derivatives on Trypanosomatidae Protozoan Parasites
by Amani Omrani, Meriam Ben Youssef, Ines Sifaoui, Eduardo Hernández-Álvarez, Carlos J. Bethencourt-Estrella, Isabel L. Bazzocchi, Hichem Sebai, Jacob Lorenzo-Morales, Ignacio A. Jiménez and José E. Piñero
Antibiotics 2025, 14(4), 383; https://doi.org/10.3390/antibiotics14040383 - 5 Apr 2025
Viewed by 236
Abstract
Leishmaniasis and Chagas disease are parasitic diseases considered to be among the most important neglected diseases, with implications for both developed and developing countries. Currently, there are no effective therapeutic treatments for these diseases due to challenges in drug administration, high toxicity, high [...] Read more.
Leishmaniasis and Chagas disease are parasitic diseases considered to be among the most important neglected diseases, with implications for both developed and developing countries. Currently, there are no effective therapeutic treatments for these diseases due to challenges in drug administration, high toxicity, high costs, and drug resistance. In this study, a series of eleven thymol derivatives were designed, synthesized, and evaluated for their in vitro kinetoplastid activity against Leishmania amazonensis and Trypanosoma cruzi, as well as their cytotoxicity against a murine macrophage cell line. The most active compounds, thymol anysoate (9) and thymol picolinate (10), displayed the highest kinetoplastid activity with IC50 values of 22.87 and 25.16 µM against L. amazonensis and T. cruzi, respectively. Notably, both compounds demonstrated an excellent selectivity index against the mammal cell line. Structure–activity relationship studies revealed that the ester group plays a crucial role in activity. The most promising derivatives, 9 and 10, activate autophagy and apoptosis-like processes in the treated cells. Atomic force microscopy observations showed that derivative 9 induces the formation of cytoplasmic vacuoles, indicating an autophagic process, and drug-likeness analysis revealed that it meets all the pharmacokinetic criteria. Overall, these results highlight derivative 9 as a potential lead compound for the development of new drugs for the treatment of Trypanosomatidae infections and warrants further studies to elucidate the cell death cascade involved. Full article
►▼ Show Figures

Graphical abstract

19 pages, 9320 KiB  
Review
Harnessing the Power of Antimicrobial Peptides: From Mechanisms to Delivery Optimization for Topical Infections
by Songhita Mukhopadhyay, Souha H. Youssef, Yunmei Song, Usha Y. Nayak and Sanjay Garg
Antibiotics 2025, 14(4), 379; https://doi.org/10.3390/antibiotics14040379 - 4 Apr 2025
Viewed by 334
Abstract
Antimicrobial peptides (AMPs) have emerged as promising agents for treating topical infections due to their enhanced biocompatibility and resistance to systemic degradation. AMPs possess host immunomodulatory effects and disintegrate bacterial cell membranes, a mechanism less prone to microbial resistance compared to conventional antibiotics, [...] Read more.
Antimicrobial peptides (AMPs) have emerged as promising agents for treating topical infections due to their enhanced biocompatibility and resistance to systemic degradation. AMPs possess host immunomodulatory effects and disintegrate bacterial cell membranes, a mechanism less prone to microbial resistance compared to conventional antibiotics, making AMPs potential candidates for antimicrobial delivery. The review discusses the challenges posed by antimicrobial resistance (AMR) and explores the mechanisms by which bacteria develop resistance to AMPs. The authors provide a detailed analysis of the mechanisms of action of AMPs, their limitations, and strategies to improve their efficacy. Conventional AMP delivery systems, including polymeric, synthetic, and lipid-based nanoparticles and cubosomes, face challenges of microbial resistance mechanisms via efflux pump systems, bacterial cell membrane modifications, and protease enzyme release. This review explores strategies to optimize these delivery systems. Furthermore, market statistics and the growing interest in peptide antibiotics have been explored in this review. The authors provide future research directions, such as exploring gene-targeting approaches to combat emerging bacterial resistance against AMPs, and emphasize considering the conformational stability of peptides, the skin microbiome’s nature at the infection site, and proteolytic stability for developing efficient AMP delivery systems for topical infections. Full article
►▼ Show Figures

Graphical abstract

19 pages, 1642 KiB  
Article
Antiparasitic and Antifungal Activities of Cetyl-Maritima, a New N-Cetyl-Modified Maritima Derivative
by Ibrahim S. Al Nasr, Jingyi Ma, Tariq A. Khan, Waleed S. Koko, Imen Ben Abdelmalek, Rainer Schobert, Wendy van de Sande and Bernhard Biersack
Antibiotics 2025, 14(3), 321; https://doi.org/10.3390/antibiotics14030321 - 19 Mar 2025
Viewed by 406
Abstract
Background/Objectives: New drugs are urgently needed for the treatment of neglected tropical diseases including leishmaniasis and eumycetoma, as well as globally occurring parasitic diseases such as toxoplasmosis. Fragrances, both natural and synthetic, were shown to be a rich source for the development of [...] Read more.
Background/Objectives: New drugs are urgently needed for the treatment of neglected tropical diseases including leishmaniasis and eumycetoma, as well as globally occurring parasitic diseases such as toxoplasmosis. Fragrances, both natural and synthetic, were shown to be a rich source for the development of new anti-infectives and warrant deeper investigations. Exemplarily, we synthetically optimized the fragrance 4-(4,8-dimethyl-3,7-nonadienyl)-pyridine, a.k.a. Maritima, a pyridine derivative with marine odor. Methods: A new cationic N-cetyl-modified derivative of Maritima (dubbed Cetyl-Maritima), obtained by alkylation of Maritima, was tested for its activity against Madurella mycetomatis (M. mycetomatis) fungi, as well as against Toxoplasma gondii (T. gondii) and Leishmania major (L. major) protozoal parasites. Results: Cetyl-Maritima was found to be more strongly antifungal than the parent Maritima and a known antibiotic cetylpyridinium salt. Cetyl-Maritima also showed a similar activity against T. gondii parasites and, most notably, exhibited sub-micromolar activity against L. major amastigotes. Conclusions: The considerable antileishmanial activity of Cetyl-Maritima might lead to the development of a new potent and cost-effective drug candidate for the therapy of leishmaniasis and other infectious diseases caused by kinetoplastid parasites. Full article
►▼ Show Figures

Figure 1

13 pages, 1986 KiB  
Article
Antibacterial Effects of Synthetic Plantaricins Against Staphylococcus aureus
by Seung-Eun Oh, Sojeong Heo, Gawon Lee, Jina Kim, Mi-Sun Kwak and Do-Won Jeong
Antibiotics 2025, 14(3), 311; https://doi.org/10.3390/antibiotics14030311 - 17 Mar 2025
Viewed by 352
Abstract
Background/Objectives: Plantaricins without a signal sequence were synthesized based on bacteriocins, plantaricins A, E, F, J, and K, of Lactiplantibacillus plantarum KM2. The antibacterial activities of four combinations of synthetic plantaricins—spPlnA, E&F, E&J, and J&K—were identified against Staphylococcus aureus ATCC 12692. And in [...] Read more.
Background/Objectives: Plantaricins without a signal sequence were synthesized based on bacteriocins, plantaricins A, E, F, J, and K, of Lactiplantibacillus plantarum KM2. The antibacterial activities of four combinations of synthetic plantaricins—spPlnA, E&F, E&J, and J&K—were identified against Staphylococcus aureus ATCC 12692. And in this experiment, we aimed to identify the antimicrobial mechanism of the synthesized plantaricin sample against S. aureus. Methods/Results: The minimal inhibitory concentrations for each combination were 1.4 μg/mL, 1.8 μg/mL, 1.6 μg/mL, and 1.6 μg/mL, respectively. Raman spectra changed after treating S. aureus ATCC 12692 with synthetic plantaricins. Furthermore, transmission electron microscopy results revealed that the four synthetic plantaricin combinations could induce the cell lysis of S. aureus ATCC 12692. Finally, the four synthetic plantaricin combinations maintained their antibacterial effect at temperatures below 40 °C, and at pH levels of pH = (4–7). Except for spPlnJ&K, they are stable against the action of α–amylase and lysozyme. Overall, these results indicate that, excepting spPlnJ&K, the three synthetic plantaricin combinations exhibit similar antibacterial activity. Conclusions: Through this study, we confirmed that synthetic plantaricin exhibited antimicrobial activity against S. aureus, demonstrating its potential as a direct antimicrobial agent. However, since the antimicrobial activity decreased due to protease, it was confirmed that its use is limited in environments where protease is present. Full article
►▼ Show Figures

Figure 1

28 pages, 2752 KiB  
Article
Insight into the Phenolic Composition of Cabernet Sauvignon Grapevine Berries During Fermentation—Towards the Application of Winery By-Products for Antibacterial Purposes
by Okba Hatem, Anita Seres-Steinbach, György Schneider, Éva Szabó and László Kőrösi
Antibiotics 2025, 14(3), 236; https://doi.org/10.3390/antibiotics14030236 - 25 Feb 2025
Viewed by 546
Abstract
Background: Wine production generates significant amounts of grape marc, which can serve as a potential source of bioactive compounds, including polyphenols. Objectives: In this study, we aimed to investigate the polyphenol content of skin and seeds separated from grape marc, and test their [...] Read more.
Background: Wine production generates significant amounts of grape marc, which can serve as a potential source of bioactive compounds, including polyphenols. Objectives: In this study, we aimed to investigate the polyphenol content of skin and seeds separated from grape marc, and test their extracts against two significant bacteria, Listeria monocytogenes (LM) and Staphylococcus aureus (SA). Methods: A comprehensive analysis of the phenolic composition in the skin, seeds, and juice/wine derived from Cabernet Sauvignon grape berries was conducted over an 18-day fermentation period. High-performance liquid chromatography was performed to identify and quantify the main flavan-3-ols, flavonols, anthocyanins, and stilbenes. In addition, the total phenolic content (TPC) was determined by the Folin–Ciocalteu method. Results: The TPC of both seeds and skins significantly decreased over time. In parallel, the TPC in the wine gradually increased, indicating a release of phenolic compounds into the wine. We found that the TPC in seeds was consistently higher than in the skin at all examined time points. The main flavonoids in seeds were flavan-3-ols (catechin and epicatechin), while anthocyanins (delphinidin-, cyanidin-, petunidin-, peonidin-, and malvidin-3-O-glucoside) were the predominant ones in skins. Crude seed and skin extracts enriched in phenolics were prepared, of which only the crude seed extract was proven effective against LM and SA. Following the time-kill assay, our findings revealed that the minimal bactericidal concentration of the crude seed extract against LM was 5.02 mg/mL after 12 h incubation, demonstrating the eradication of the living bacterial cell number by ~6 log. A 24 h exposure time was required for complete inactivation of SA, but a lower concentration was sufficient (2.54 mg/mL). Conclusions: Grape waste remains a valuable source of polyphenols, with grape seeds, in particular, exhibiting significant antimicrobial activity against certain foodborne pathogens. Full article
►▼ Show Figures

Figure 1

2024

Jump to: 2025

14 pages, 3162 KiB  
Article
Goondicones A–H: Spiro-Isoindolinone Heartworm Anthelmintics from an Australian Pasture-Soil-Derived Streptomyces sp.
by Jianying Han, David F. Bruhn, Cynthia T. Childs, Yovany Moreno, Angela A. Salim, Taizong Wu and Robert J. Capon
Antibiotics 2024, 13(12), 1222; https://doi.org/10.3390/antibiotics13121222 - 17 Dec 2024
Viewed by 1067
Abstract
Background/Objectives: There is an urgent need for new and improved anthelmintics that are not constrained by existing resistance pathways and that can safeguard the health and welfare of animals. Methods: An integrated platform of chemical, bioassay, and cultivation profiling applied to a library [...] Read more.
Background/Objectives: There is an urgent need for new and improved anthelmintics that are not constrained by existing resistance pathways and that can safeguard the health and welfare of animals. Methods: An integrated platform of chemical, bioassay, and cultivation profiling applied to a library of microbes isolated from Australian livestock pasture soil was used to detect and guide the production, isolation, characterization, identification, and evaluation of new natural products with anthelmintic properties. Results: A global natural products social (GNPS) molecular network analysis of 110 Australian pasture-soil-derived microbial extracts prioritized for antiparasitic activity identified unique molecular families in the extract of Streptomyces sp. S4S-00185A06, a strain selectively active against Dirofilaria immitis microfilariae. UPLC-DAD analysis identified metabolites with unique UV-vis chromophores and unprecedented molecular formulas. A chemical investigation of Streptomyces sp. S4S-00185A06 yielded goondicones A–H (1–8) as new examples of a rare class of spiro-isoindolinones, with structures assigned on the basis of detailed spectroscopic analysis, ECD calculations, and biosynthetic considerations. Conclusions: While goondicones 1–8 exhibit little to no in vitro inhibitory activity against Gram-positive, Gram-negative, and/or fungal pathogens, human carcinoma cells, or the livestock gastrointestinal parasite Haemonchus contortus L1–L3 larvae, 5 and 6 (and, to a lesser extent, 1) inhibit the motility of heartworm Dirofilaria immitis microfilaria (IC50 10–11 μM). A structure activity relationship analysis based on the co-metabolites 1–8 suggests that (i) an 8-OH is preferable to 8–oxo moiety, (ii) 20-NMe and 3-OH moieties are essential, and (iii) C-9 epimerization exerts no discernible impact on in vitro potency. Full article
►▼ Show Figures

Graphical abstract

16 pages, 2343 KiB  
Article
Antiparasitic Activities of Acyl Hydrazones from Cinnamaldehydes and Structurally Related Fragrances
by Ibrahim S. Al Nasr, Waleed S. Koko, Tariq A. Khan, Rainer Schobert and Bernhard Biersack
Antibiotics 2024, 13(12), 1114; https://doi.org/10.3390/antibiotics13121114 - 22 Nov 2024
Cited by 1 | Viewed by 966
Abstract
Background: New drugs for the treatment of protozoal parasite infections such as toxoplasmosis and leishmaniasis are required. Cinnamaldehyde and its derivatives appear to be promising antiparasitic drug candidates. Methods: Acyl hydrazones of cinnamaldehyde, 4-dimethylaminocinnamaldehyde, and of the synthetic fragrances silvialTM and florhydral [...] Read more.
Background: New drugs for the treatment of protozoal parasite infections such as toxoplasmosis and leishmaniasis are required. Cinnamaldehyde and its derivatives appear to be promising antiparasitic drug candidates. Methods: Acyl hydrazones of cinnamaldehyde, 4-dimethylaminocinnamaldehyde, and of the synthetic fragrances silvialTM and florhydralTM were prepared and tested for activity against Toxoplasma gondii (T. gondii) and Leishmania major (L. major) parasites. Results: Three cinnamaldehyde acyl hydrazones (3-hydroxy-2-naphthoyl 2a and the salicyloyls 2c and 2d) showed good activity against T. gondii, and two compounds derived from cinnamaldehyde and florhydralTM (3-hydroxy-2-naphthoyls 2a and 4a) exhibited moderate activity against L. major promastigotes. Conclusions: In particular, the identified antitoxoplasmal activities are promising and might lead to the development of new potent and cost-effective drug candidates for the therapy of toxoplasmosis. Full article
►▼ Show Figures

Figure 1

13 pages, 2230 KiB  
Article
Goondapyrones A–J: Polyketide α and γ Pyrone Anthelmintics from an Australian Soil-Derived Streptomyces sp.
by Shengbin Jin, David F. Bruhn, Cynthia T. Childs, Erica Burkman, Yovany Moreno, Angela A. Salim, Zeinab G. Khalil and Robert J. Capon
Antibiotics 2024, 13(10), 989; https://doi.org/10.3390/antibiotics13100989 - 18 Oct 2024
Cited by 1 | Viewed by 1302
Abstract
An investigation of ×19 soil samples collected under the auspices of the Australian citizen science initiative, Soils for Science, returned ×559 chemically dereplicated microbial isolates, of which ×54 exhibited noteworthy anthelmintic activity against either the heartworm Dirofilaria immitis microfilaria and/or the gastrointestinal parasite [...] Read more.
An investigation of ×19 soil samples collected under the auspices of the Australian citizen science initiative, Soils for Science, returned ×559 chemically dereplicated microbial isolates, of which ×54 exhibited noteworthy anthelmintic activity against either the heartworm Dirofilaria immitis microfilaria and/or the gastrointestinal parasite Haemonchus contortus L1–L3 larvae. Chemical (GNPS and UPLC-DAD) and cultivation (MATRIX) profiling prompted a detailed chemical investigation of Streptomyces sp. S4S-00196A10, which yielded new anthelmintic polyketide goondapyrones A–J (1–10), together with the known actinopyrones A (11) and C (12). Structures for 1–12 were assigned on the basis of detailed spectroscopic and chemical analysis, with preliminary structure activity relationship analysis revealing selected γ-pyrones >50-fold and >13-fold more potent than isomeric α-pyrones against D. immitis mf motility (e.g., EC50 0.05 μM for 1; EC50 2.7 μM for 5) and H. contortus L1–L3 larvae development (e.g., EC50 0.58 μM for 1; EC50 8.2 μM for 5), respectively. Full article
►▼ Show Figures

Graphical abstract

15 pages, 298 KiB  
Article
Combinatory Use of hLF(1-11), a Synthetic Peptide Derived from Human Lactoferrin, and Fluconazole/Amphotericin B against Malassezia furfur Reveals a Synergistic/Additive Antifungal Effect
by Carlo P. J. M. Brouwer, Bart Theelen, Youp van der Linden, Nick Sarink, Mahfuzur Rahman, Saleh Alwasel, Claudia Cafarchia, Mick M. Welling and Teun Boekhout
Antibiotics 2024, 13(8), 790; https://doi.org/10.3390/antibiotics13080790 - 22 Aug 2024
Cited by 2 | Viewed by 1417
Abstract
Objective: The increasing resistance of Malassezia yeasts against commonly used antifungal drugs dictates the need for novel antifungal compounds. Human lactoferrin-based peptides show a broad spectrum of antimicrobial activities. Various assays were performed to find the optimal growth conditions of the yeasts and [...] Read more.
Objective: The increasing resistance of Malassezia yeasts against commonly used antifungal drugs dictates the need for novel antifungal compounds. Human lactoferrin-based peptides show a broad spectrum of antimicrobial activities. Various assays were performed to find the optimal growth conditions of the yeasts and to assess cell viability, using media with low lipid content to avoid peptide binding to medium components. Methods: In the current study, we tested the antimicrobial susceptibility of 30 strains of M. furfur that cover the known IGS1 genotypic variation. Results: hLF(1-11) inhibited the growth of all species tested, resulting in minimum inhibitory concentrations (MIC) values ranging from 12.5 to 100 μg/mL. In the combinatory tests, the majority of fractional inhibitory concentration indexes (FIC) for the tested strains of M. furfur were up to 1.0, showing that there is a synergistic or additive effect on the efficacy of the antifungal drugs when used in combination with hLF(1-11). Conclusion: Results showed that hLF(1-11) could be combined with fluconazole or amphotericin for the antimicrobial treatment of resistant strains, enhancing the potency of these antifungal drugs, resulting in an improved outcome for the patient. Full article
21 pages, 7367 KiB  
Article
In Vitro and In Silico Studies of the Antimicrobial Activity of Prenylated Phenylpropanoids of Green Propolis and Their Derivatives against Oral Bacteria
by Tatiana M. Vieira, Julia G. Barco, Sara L. de Souza, Anna L. O. Santos, Ismail Daoud, Seyfeddine Rahali, Noureddine Amdouni, Jairo K. Bastos, Carlos H. G. Martins, Ridha Ben Said and Antônio E. M. Crotti
Antibiotics 2024, 13(8), 787; https://doi.org/10.3390/antibiotics13080787 - 22 Aug 2024
Cited by 2 | Viewed by 1713
Abstract
Artepillin C, drupanin, and plicatin B are prenylated phenylpropanoids that naturally occur in Brazilian green propolis. In this study, these compounds and eleven of their derivatives were synthesized and evaluated for their in vitro antimicrobial activity against a representative panel of oral bacteria [...] Read more.
Artepillin C, drupanin, and plicatin B are prenylated phenylpropanoids that naturally occur in Brazilian green propolis. In this study, these compounds and eleven of their derivatives were synthesized and evaluated for their in vitro antimicrobial activity against a representative panel of oral bacteria in terms of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Plicatin B (2) and its hydrogenated derivative 8 (2′,3′,7,8-tetrahydro-plicatin B) were the most active compounds. Plicatin B (2) displayed strong activity against all the bacteria tested, with an MIC of 31.2 μg/mL against Streptococcus mutans, S. sanguinis, and S. mitis. On the other hand, compound 8 displayed strong activity against S. mutans, S. salivarius, S. sobrinus, Lactobacillus paracasei (MIC = 62.5 μg/mL), and S. mitis (MIC = 31.2 μg/mL), as well as moderate activity against Enterococcus faecalis and S. sanguinis (MIC = 125 μg/mL). Compounds 2 and 8 displayed bactericidal effects (MBC: MIC ≤ 4) against all the tested bacteria. In silico studies showed that the complexes formed by compounds 2 and 8 with the S. mitis, S. sanguinis, and S. mutans targets (3LE0, 4N82, and 3AIC, respectively) had energy score values similar to those of the native S. mitis, S. sanguinis, and S. mutans ligands due to the formation of strong hydrogen bonds. Moreover, all the estimated physicochemical parameters satisfied the drug-likeness criteria without violating the Lipinski, Veber, and Egan rules, so these compounds are not expected to cause problems with oral bioavailability and pharmacokinetics. Compounds 2 and 8 also had suitable ADMET parameters, as the online server pkCSM calculates. These results make compounds 2 and 8 good candidates as antibacterial agents against oral bacteria. Full article
►▼ Show Figures

Figure 1

13 pages, 1796 KiB  
Article
Synergistic Interactions between Selected β-Lactam Antibiotics and Cinnamic Acid and Its Chosen Derivatives
by Tomasz Zawiła, Denis Swolana, Marta Zawiła and Robert D. Wojtyczka
Antibiotics 2024, 13(8), 710; https://doi.org/10.3390/antibiotics13080710 - 29 Jul 2024
Cited by 2 | Viewed by 1152
Abstract
Staphylococcus epidermidis, a component of human microbiota, may also cause life-threatening opportunistic infections. These are becoming increasingly common infections associated with the implantation of various implants. Due to the exhaustion of antibiotic resources, new substances with antimicrobial activity are being sought. The present [...] Read more.
Staphylococcus epidermidis, a component of human microbiota, may also cause life-threatening opportunistic infections. These are becoming increasingly common infections associated with the implantation of various implants. Due to the exhaustion of antibiotic resources, new substances with antimicrobial activity are being sought. The present study examined the antibacterial effect of cinnamic acid and its derivatives and their combinations with β-lactam antibiotics on the growth of Staphylococcus epidermidis strains isolated from vascular infections. The data obtained during the research indicated that cinnamic acid and its derivatives, sinapic acid, ferulic acid, and p-coumaric acid, have weak antibacterial activity (MIC values at the level of 2048 and 4096 mg/L). The combination of cinnamic acid and its derivatives with β-lactam antibiotics increases the effectiveness of their action and may demonstrate various pharmacological effects depending on the established cutoff. Full article
►▼ Show Figures

Figure 1

25 pages, 2344 KiB  
Review
Vitis vinifera L. Leaf Extract, a Microbiota Green Ally against Infectious and Inflammatory Skin and Scalp Diseases: An In-Depth Update
by Marta Armari, Elisa Zavattaro, Cesar Francisco Trejo, Alice Galeazzi, Alessia Grossetti, Federica Veronese, Paola Savoia and Barbara Azzimonti
Antibiotics 2024, 13(8), 697; https://doi.org/10.3390/antibiotics13080697 - 26 Jul 2024
Cited by 4 | Viewed by 2549
Abstract
The skin microbiota, with its millions of bacteria, fungi, and viruses, plays a key role in balancing the health of the skin and scalp. Its continuous exposure to potentially harmful stressors can lead to abnormalities such as local dysbiosis, altered barrier function, pathobiont [...] Read more.
The skin microbiota, with its millions of bacteria, fungi, and viruses, plays a key role in balancing the health of the skin and scalp. Its continuous exposure to potentially harmful stressors can lead to abnormalities such as local dysbiosis, altered barrier function, pathobiont overabundance, and infections often sustained by multidrug-resistant bacteria. These factors contribute to skin impairment, deregulation of immune response, and chronic inflammation, with local and systemic consequences. In this scenario, according to the needs of the bio-circular-green economy model, novel harmless strategies, both for regulating the diverse epidermal infectious and inflammatory processes and for preserving or restoring the host skin eubiosis and barrier selectivity, are requested. Vitis vinifera L. leaves and their derived extracts are rich in plant secondary metabolites, such as polyphenols, with antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory properties that can be further exploited through microbe-driven fermentation processes. On this premise, this literature review aims to provide an informative summary of the most updated evidence on their interactions with skin commensals and pathogens and on their ability to manage inflammatory conditions and restore microbial biodiversity. The emerging research showcases the potential novel beneficial ingredients for addressing various skincare concerns and advancing the cosmeceutics field as well. Full article
►▼ Show Figures

Graphical abstract

14 pages, 1996 KiB  
Article
Cytocompatibility and Antibiofilm Activity of Calcium Hydroxide Mixed with Cyperus articulatus Essential Oil and Bio-C Temp Bioceramic Intracanal Medicament
by Cláudia Fernandes de Magalhães Silveira, Carlos Eduardo da Silveira Bueno and Angélica Zaninelli Schreiber
Antibiotics 2024, 13(7), 637; https://doi.org/10.3390/antibiotics13070637 - 10 Jul 2024
Cited by 1 | Viewed by 1782
Abstract
Calcium hydroxide represents the most commonly used intracanal dressing between sessions; however, it may not be effective against all types of microorganisms. Several compounds of plant origin have attracted increasing attention from researchers in recent years. The objective of this study was to [...] Read more.
Calcium hydroxide represents the most commonly used intracanal dressing between sessions; however, it may not be effective against all types of microorganisms. Several compounds of plant origin have attracted increasing attention from researchers in recent years. The objective of this study was to evaluate the cytocompatibility and antimicrobial activity of calcium hydroxide associated with the essential oil of Cyperus articulatus and the new bioceramic intracanal medicament Bio-C Temp®. Five experimental groups were designed: group Ca–C. articulatus essential oil; group CHPG-calcium hydroxide associated with propylene glycol; group CHCa-essential oil of C. articulatus associated with calcium hydroxide; and group U-UltraCal® XS; group BCT-Bio-C Temp®. The control group was a culture medium. Cytocompatibility was assessed by the methyltetrazolium (MTT) assay after exposure of the Saos-2 human osteoblast-like cell line to dilutions of commercial products/associations for 24 h and 72 h. The antimicrobial activity against mature Enterococcus faecalis biofilm was evaluated by the crystal violet assay. All commercial products/associations showed a cell viability similar to or even higher than the control group (p > 0.05) for both periods evaluated. C. articulatus essential oil associated or not with calcium hydroxide showed better antibiofilm capacity. C. articulatus associated or not with calcium hydroxide showed superior cytocompatibility and antimicrobial capacity, representing a promissory intracanal medicament. Full article
►▼ Show Figures

Figure 1

26 pages, 10235 KiB  
Article
In Vitro Evaluation of Colistin Conjugated with Chitosan-Capped Gold Nanoparticles as a Possible Formulation Applied in a Metered-Dose Inhaler
by Narumon Changsan, Apichart Atipairin, Poowadon Muenraya, Rutthapol Sritharadol, Teerapol Srichana, Neelam Balekar and Somchai Sawatdee
Antibiotics 2024, 13(7), 630; https://doi.org/10.3390/antibiotics13070630 - 6 Jul 2024
Cited by 6 | Viewed by 1836
Abstract
Inhaled colistin is used to treat pneumonia and respiratory infections through nebulization or dry powder inhalers. Nevertheless, the development of a metered-dose inhaler (MDI) for colistin, which could enhance patient convenience and treatment efficacy, has not yet been developed. Colistin is known for [...] Read more.
Inhaled colistin is used to treat pneumonia and respiratory infections through nebulization or dry powder inhalers. Nevertheless, the development of a metered-dose inhaler (MDI) for colistin, which could enhance patient convenience and treatment efficacy, has not yet been developed. Colistin is known for its ability to induce cellular toxicity. Gold nanoparticles (AuNPs) can potentially mitigate colistin toxicity. Therefore, this study aimed to evaluate the antimicrobial effectiveness of colistin conjugated with chitosan-capped gold nanoparticles (Col-CS-AuNPs) and their potential formulation for use with MDIs to deliver the aerosol directly to the deep lung. Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and elemental analysis were used to characterize the synthesized Col-CS-AuNPs. Drug release profiles fitted with the most suitable release kinetic model were evaluated. An MDI formulation containing 100 µg of colistin per puff was prepared. The aerosol properties used to determine the MDI performance included the fine particle fraction, mass median aerodynamic diameter, and geometric standard deviation, which were evaluated using the Andersen Cascade Impactor. The delivered dose uniformity was also determined. The antimicrobial efficacy of the Col-CS-AuNP formulation in the MDI was assessed. The chitosan-capped gold nanoparticles (CS-AuNPs) and Col-CS-AuNPs had particle sizes of 44.34 ± 1.02 and 174.50 ± 4.46 nm, respectively. CS-AuNPs effectively entrapped 76.4% of colistin. Col-CS-AuNPs exhibited an initial burst release of up to 60% colistin within the first 6 h. The release mechanism was accurately described by the Korsmeyer–Peppas model, with an R2 > 0.95. The aerosol properties of the Col-CS-AuNP formulation in the MDI revealed a high fine particle fraction of 61.08%, mass median aerodynamic diameter of 2.34 µm, and geometric standard deviation of 0.21, with a delivered dose uniformity within 75–125% of the labeled claim. The Col-CS-AuNP MDI formulation completely killed Escherichia coli at 5× and 10× minimum inhibitory concentrations after 6 and 12 h of incubation, respectively. The toxicity of CS-AuNP and Col-CS-AuNP MDI formulations in upper and lower respiratory tract cell lines was lower than that of free colistin. The stability of the Col-CS-AuNP MDI formulation was maintained for at least 3 months. The Col-CS-AuNP MDI formulation effectively eradicated bacteria over a 12-h period, showing promise for advancing lung infection treatments. Full article
►▼ Show Figures

Figure 1

11 pages, 2383 KiB  
Article
Therapeutic Potential of Mangosteen Pericarp Extract-Loaded Liposomes against Superficial Skin Infection Caused by Staphylococcus pseudintermedius in a Murine Model
by Seong-Yeop Kim, Seong-Yong Park, Jung-Hwa Lee, Nayeong Kim, Ha-Na Oh, So-Young Yoo, Dae-Sung Lee and Je-Chul Lee
Antibiotics 2024, 13(7), 612; https://doi.org/10.3390/antibiotics13070612 - 1 Jul 2024
Viewed by 1622
Abstract
α-mangostin (α-MG) demonstrates antibacterial activity against Staphylococcus species. Therefore, this study aimed to explore the antibacterial activity of α-MG-rich mangosteen pericarp extract (MPE)-loaded liposomes against Staphylococcus isolates from companion animal skin diseases in vitro and evaluated their therapeutic potential in a murine model [...] Read more.
α-mangostin (α-MG) demonstrates antibacterial activity against Staphylococcus species. Therefore, this study aimed to explore the antibacterial activity of α-MG-rich mangosteen pericarp extract (MPE)-loaded liposomes against Staphylococcus isolates from companion animal skin diseases in vitro and evaluated their therapeutic potential in a murine model of superficial skin infection caused by S. pseudintermedius. α-MG-rich extract was purified from mangosteen pericarp and then complexed with γ-cyclodextrin (γ-CD), forming the inclusion complexes. Nanoliposomes containing MPE and γ-CD complexes were prepared by adding lecithin and casein. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of MPE-loaded liposomes were determined using agar dilution and broth microdilution methods. The therapeutic potential of MPE-loaded liposomes was evaluated in vivo on tape-stripped skin lesions infected with S. pseudintermedius. Purified MPE and MPE-loaded liposomes contained 402.43 mg/g and 18.18 mg/g α-MG, respectively. MPE-loaded liposomes showed antibacterial activity against clinical Staphylococcus isolates in vitro but did not show antibacterial activity against Gram-negative bacterial isolates. MPE-loaded liposomes demonstrated consistent MICs and MBCs against Staphylococcus isolates. These liposomes significantly reduced bacterial numbers and lesional sizes in a superficial skin infection model. Moreover, they reconstructed the epidermal barrier in skin lesions. The therapeutic concentrations of MPE-loaded liposomes did not induce cytotoxicity in canine progenitor epidermal keratinocyte cells. In conclusion, MPE-loaded liposomes hold promise for the development of a prospective topical formulation to treat superficial pyoderma in companion animals. Full article
►▼ Show Figures

Figure 1

11 pages, 1536 KiB  
Article
Antimicrobial and Antibiofilm Effects of Bithionol against Mycobacterium abscessus
by Dan Cao, Xin Yuan, Xiuzhi Jiang, Tiantian Wu, Yanghui Xiang, Zhongkang Ji, Jiaying Liu, Xu Dong, Kefan Bi, Tone Tønjum, Kaijin Xu and Ying Zhang
Antibiotics 2024, 13(6), 529; https://doi.org/10.3390/antibiotics13060529 - 5 Jun 2024
Cited by 3 | Viewed by 1911
Abstract
Mycobacterium abscessus (M. abscessus) is a multidrug-resistant nontuberculous mycobacterium (NTM) that is responsible for a wide spectrum of infections in humans. The lack of effective bactericidal drugs and the formation of biofilm make its clinical treatment very difficult. The FDA-approved drug [...] Read more.
Mycobacterium abscessus (M. abscessus) is a multidrug-resistant nontuberculous mycobacterium (NTM) that is responsible for a wide spectrum of infections in humans. The lack of effective bactericidal drugs and the formation of biofilm make its clinical treatment very difficult. The FDA-approved drug library containing 3048 marketed and pharmacopeial drugs or compounds was screened at 20 μM against M. abscessus type strain 19977 in 7H9 medium, and 62 hits with potential antimicrobial activity against M. abscessus were identified. Among them, bithionol, a clinically approved antiparasitic agent, showed excellent antibacterial activity and inhibited the growth of three different subtypes of M. abscessus from 0.625 μM to 2.5 μM. We confirmed the bactericidal activity of bithionol by the MBC/MIC ratio being ≤4 and the time–kill curve study and also electron microscopy study. Interestingly, it was found that at 128 μg/mL, bithionol could completely eliminate biofilms after 48h, demonstrating an outstanding antibiofilm capability compared to commonly used antibiotics. Additionally, bithionol could eliminate 99.9% of biofilm bacteria at 64 μg/mL, 99% at 32 μg/mL, and 90% at 16 μg/mL. Therefore, bithionol may be a potential candidate for the treatment of M. abscessus infections due to its significant antimicrobial and antibiofilm activities. Full article
►▼ Show Figures

Figure 1

Back to TopTop