Search Results (468)

Chrome tanning of fish skins generates hazardous effluents and carcinogenic Cr(VI) residues; chromium-free routes to valorize collagen-rich by-products from aquaculture and coastal fisheries are therefore needed. We report a 12-stage ecological protocol employing acetic acid/NaCl pickling, Acacia mearnsii tannin, A. podalyriifolia retanning, mashed-papaya enzymatic bating, and cinnamon as antimicrobial/odor adjunct, scaled from bench to pilot using exclusively locally sourced inputs, for Nile tilapia (Oreochromis niloticus) and Patagonian flounder (Paralichthys patagonicus). Three trained operators evaluated macroscopic quality against five predefined criteria adapted from SATRA and ISO 3376 grading conventions, providing a structured feasibility baseline that does not substitute for the standardized instrumental testing designated as priority future work. Both species achieved satisfactory grain stability, complete tannin penetration, pliable handle, and cinnamon-dominant odor without residual amines; dark-brown coloration is a recognized practical limitation for fashion applications. In silico molecular docking (GNINA v1.0) was used to explore the mechanistic plausibility of each ecological substitution, generating testable hypotheses rather than definitive mechanistic conclusions: the multidentate polyphenol proxy (PGG) exhibited consistently superior collagen engagement over the flavanol monomer across both collagen constructs and all three scoring metrics (1CAG: Vina affinity −5.51 ± 0.13 vs. −3.54 ± 0.35 kcal/mol; CNNscore 0.874 ± 0.009 vs. 0.771 ± 0.010; 7CWK: Vina affinity −6.98 ± 1.43 vs. −4.37 ± 0.16 kcal/mol; CNNscore 0.858 ± 0.024 vs. 0.635 ± 0.094). Dipeptide probes were reproducibly accommodated in the papain catalytic cleft, with the closest configuration reaching 3.997 Å from the catalytic nucleophile (OCS25-SG). Trans-cinnamaldehyde occupied the quorum-sensing pocket with reproducible placement (CNNscore 0.718 ± 0.034) but without score-based selectivity over structural decoys, a result interpreted as hypothesis-generating for future microbiological validation. The protocol is reproducible from bench to pilot and generalizable across two species with distinct dermal architectures. Quantitative physical-mechanical testing (shrinkage temperature, tensile strength, elongation, tear load), CIELab colorimetric analysis, and effluent characterization (COD, BOD₅, total phenolics) are designated as priorities for future validation. Full article

Colored potato cultivars are rich in phenolic compounds that confer high antioxidant capacity; however, these beneficial metabolites could be susceptible to oxidation by polyphenol oxidases (PPOs), leading to enzymatic browning and the loss of antioxidant potential. Despite the agronomic relevance of this trade-off, the dynamics of the PPO gene family (StPPOs) gene expression in pigmented potatoes remains poorly characterized. Here, we present an integrated biochemical and molecular analysis of two purple-fleshed Peruvian landraces (Siriñacha and Angashungo), a partially pigmented landrace (Sapa), and non-pigmented cultivars, including the commercial cultivar Desirée. We quantified the total phenolic content, antioxidant capacity, and enzymatic browning index (EBI) using colorimetric and spectrophotometric methods. We also generated gene expression profiles of ten StPPO genes using semi-quantitative and digital PCR. Purple-fleshed cultivars exhibited significantly higher phenolic content and antioxidant capacity but also displayed accelerated browning kinetics compared to non- or partially pigmented genotypes. Expression analysis revealed cultivar-specific StPPO patterns, with StPPO2 and StPPO8 being markedly upregulated in pigmented materials, particularly StPPO8. These findings provide the first integrated biochemical and transcriptional evidence linking specific StPPO isoforms to enzymatic browning in colored potatoes, and highlight their potential for biotechnological applications. Full article

The food packaging industry requires sustainable solutions to reduce plastic waste and replace synthetic additives. This study addresses the need for scalable methods to transform conventional polyethylene terephthalate (PET) packaging into active food preservation systems using natural biocides. Commercial PET packaging was surface-activated using industrial-scale corona treatment, followed by coating with natural biocides—carvacrol (CV) and trans-cinnamaldehyde (tCN). The resulting active packaging materials (PET-CV and PET-tCN) were characterized using XRD, FTIR, SEM, AFM, and desorption kinetics. Packaging properties including mechanical strength, oxygen barrier, antioxidant (DPPH), and antibacterial activity (against S. aureus and E. coli) were evaluated. Real-food preservation tests were conducted using fresh minced pork (4 °C, 6 days) and table olives (23 °C, 21 days), monitoring microbiological (TVC), colorimetric (CIE L*a*b*), and pH changes. Corona treatment successfully anchored both biocides through physical adsorption, with tCN exhibiting stronger surface interaction (desorption energy: 128.0 kJ/mol). Both coatings significantly improved oxygen barrier properties (61% reduction for PET-CV, 80% for PET-tCN). PET-tCN demonstrated superior antibacterial activity (inhibition zones: 15.0 mm against E. coli). In pork preservation, PET-tCN achieved a 2-log reduction in TVC, maintained meat redness (a*: 12.80 vs. 5.10 for control), and stabilized pH. For olives, PET-tCN reduced TVC by 2.35 log cycles and preserved green color. This corona-assisted coating approach, demonstrated here at laboratory scale, successfully transforms inert PET into multi-functional active packaging with potent antimicrobial, antioxidant, and barrier properties, significantly extending food shelf-life and offering a sustainable solution for reducing food waste. Full article

Camellia hakodae Ninh flowers are an endemic Vietnamese species with limited phytochemical and biological characterization. This study aimed to characterize the phytochemical profile and evaluate antioxidant and anti-inflammatory activities of the total flower extract. Ultrasonic-assisted extraction (UAE) and maceration with methanol and ethanol at different concentrations were carried out to evaluate the efficiency of extracting total phenolic content (TPC) and total flavonoid content (TFC), quantified by colorimetric assays, along with the antioxidant and anti-inflammatory activities of the resulting extracts. The highest TPC (94.9 ± 4.5 mg GAE/g) and TFC (3.1 ± 0.2 mg QE/g) were obtained using UAE with 70% methanol, while maceration with 70% ethanol showed comparable TPC values. The optimized extract exhibited strong antioxidant activity with an IC₅₀ of 29.06 µg/mL, close to that of ascorbic acid (28.16 µg/mL) and significant anti-inflammatory activity in the proteinase inhibition assay (IC₅₀ = 2.72 mg/mL) compared to acetylsalicylic acid (IC₅₀ = 3.16 mg/mL). GC-MS and LC-QTOF-MS/MS analyses revealed diverse metabolites, including phenolic acids, flavonoids, fatty acids, terpenoids, and nitrogen-containing compounds, with representative constituents, such as quinic acid, catechins, flavonol glycosides, and loliolide, providing strong chemical evidence for the observed bioactivities. This integrated study demonstrates that C. hakodae flower is a rich source of multifunctional bioactive compounds and highlights its strong potential for applications in nutraceuticals, functional foods, and cosmeceuticals. Full article

This study systematically investigated the characterization of 2Fe-CDs/12Mn-CeO₂ composites and the colorimetric sensing properties of H₂O₂, glucose (Glu), and glutathione (GSH). The morphology, structure, and optical properties of the 2Fe-CDs/12Mn-CeO₂ composite were analyzed in detail by XRD, FT-IR, SEM, TEM, XPS, and Raman spectroscopy, and its formation was supported by multiple complementary characterization techniques. The catalytic efficiency (kcat/Km) of the nanozyme is 152-fold higher than natural HRP under optimal conditions and remains 59-fold higher even after temperature normalization to 25 °C. In the colorimetric sensing experiments, the detection limits of Fe-CDs/Mn-CeO₂ were 0.21 μM, 2.7 μM, and 0.63 μM for H₂O₂, Glu, and GSH, respectively. Rapid and accurate determination of the concentrations of these biomolecules can be achieved by observing the color changes after Fe-CDs/Mn-CeO₂ reaction with the objects to be measured. The experimental results show that Fe-CDs/Mn-CeO₂ have high sensitivity and selectivity for H₂O₂, Glu, and GSH, which provides a solid theoretical and experimental basis for the application of Fe-CDs/Mn-CeO₂ in the field of biosensing and medical diagnosis. Full article

Background: Ovarian cancer (OC) is characterized by aggressive progression, high metastatic potential, and frequent resistance to conventional chemotherapy, highlighting the need for novel combination-based therapeutic strategies. Metformin has emerged as a promising antineoplastic agent; however, its efficacy may be enhanced through combination with bioactive compounds. This study aimed to investigate the antineoplastic effects of metformin in SKOV3 human OC cells and to evaluate whether these effects could be potentiated by boric acid (BA) and resveratrol, with particular emphasis on their modulatory impact on key inflammatory and tumor-associated biomarkers, including interleukin-17 (IL-17), nuclear factor kappa-B (NF-κB), and midkine (MDK). Methods: SKOV3 cells were treated with metformin, BA, and resveratrol as monotherapies or in combination. Cell viability was assessed using a colorimetric assay, while migratory capacity was evaluated by wound healing analysis. The expression levels of IL-17, NF-κB, and MDK were quantified in cell lysates, and p21 protein expression was analyzed by immunocytochemistry. Results: All treatments induced concentration- and time-dependent reductions in cell viability. Combination treatments, particularly metformin with boric acid or resveratrol, produced more pronounced inhibitory effects on cell survival and migration compared with single-agent treatments. Inflammatory and tumor-associated biomarkers, including IL-17, NF-κB, and MDK, were significantly modulated following treatment. Additionally, increased p21 expression was observed in treated cells, indicating enhanced cell cycle regulatory activity. Conclusions: These findings indicate that BA and resveratrol enhance the antineoplastic activity of metformin in SKOV3 OC cells by suppressing proliferative and migratory capacities and modulating inflammatory mediators such as IL-17, NF-κB, and MDK. However, since toxicity assessments in non-cancerous cells were not performed, the safety profile of this combination remains unclear and requires further investigation in non-cancerous models. Full article

Catalpol, one of the primary bioactive components in Rehmannia glutinosa, is an iridoid glycoside with significant pharmacological activities. To expand the microbial sources of catalpol, endophytic bacteria were isolated from R. glutinosa (cultivated in Jiaozuo, China) using the dilution plating method combined with vanillin–sulfuric acid colorimetric assay. High-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC-MS) were employed for screening and identification. The isolated strain was identified through morphological characterization and 16S rDNA gene sequence analysis, while single-factor experiments coupled with response surface methodology were utilized to optimize its fermentation conditions. Results indicated that the strain DH14 formed circular, cream-white, opaque colonies and was Gram-negative. It was identified as Brevundimonas olei. The optimal fermentation conditions were determined to be 190 rpm, pH 7.6, 31 °C, and 0% NaCl. Meanwhile, the results revealed a positive correlation between the pH of the fermentation broth and catalpol production. Under the optimized conditions, the maximum catalpol yield reached 0.142 mg/mL after 3 days of cultivation. This study provides a promising microbial resource and optimized fermentation parameters for the microbial production of catalpol. Full article

pH-responsive indicator films for intelligent food packaging applications are based on the embedding of a natural or synthetic dye in a polymeric substrate, preferably biobased and biodegradable. Although natural colorants like anthocyanins were extensively investigated in this respect, nature-inspired synthetic flavylium compounds could represent an alternative based on their higher stability. In this work, five novel synthetic 4′-aminoflavylium derivatives with different substitution patterns in the benzopyrylium core (compounds 1–5) were synthesized and characterized. Polyvinyl alcohol (PVA), as well as chitosan–PVA and chitosan–starch blends, were used to prepare pH-responsive indicator films having inserted each of the synthesized flavylium dyes or a natural onion peel extract. The PVA films with compounds 1 and 3, and the PVA–chitosan film with compound 1, exhibited antioxidant activity, highlighting their potential for active packaging applications. All indicator films showed pH responsiveness in the range of 2 to 12 and were subsequently tested in contact with the packaging atmosphere or in direct contact with pork and fish meat, at different temperatures (4 °C, 20 °C, and 40 °C) for 24 h to assess their colorimetric response to progressive spoilage. Although the differences were small, the films with the 7-hydroxy-4′-aminoflavylium derivative exhibited the earliest and most intense color change during storage of meat, starting from direct contact at 4 °C for 24 h, being able to identify the initial stages of meat spoilage, while the performance of the dihydroxy-substituted derivative was attenuated by incorporation in polymer matrices. This behavior was comparable to that of onion peel extract, but the synthetic flavylium derivative was more stable. The results can provide new opportunities for intelligent food packaging applications using biopolymer indicator films with 4′-aminoflavylium derivatives. Full article

Canine leishmaniasis (CanL) is a major vector-borne disease with zoonotic potential, and oxidative stress plays an important role in its pathogenesis. CanL is a chronic, progressive disease in which clinical signs may develop gradually over months or even years, depending on host immune response and parasite burden. This study aimed to evaluate oxidative DNA damage in dogs with CanL by measuring urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels and oxidative stress markers. A total of 54 dogs, including 34 dogs with CanL and 20 healthy controls, were included. Urinary 8-OHdG and serum malondialdehyde (MDA) were measured using ELISA method, whereas serum TAC and TOC were determined using automated colorimetric method. Dogs with CanL showed significantly higher TAC (1.30 ± 0.05 vs. 1.04 ± 0.06 mmol/L, p = 0.001) and TOC levels (18.91 ± 3.29 vs. 8.23 ± 1.61 μmol H₂O₂ Eq/L, p = 0.002) compared with healthy controls. Although urinary 8-OHdG and MDA levels were higher in infected dogs, these differences were not statistically significant (p > 0.05). These findings indicate a disturbance in oxidative balance in dogs with CanL, characterized by simultaneous increases in both oxidant and antioxidant parameters, while urinary 8-OHdG, as measured by ELISA, may have limited ability to reflect cellular oxidative DNA damage in dogs with CanL, rather than indicating an absence of DNA damage. Full article

Background: Oxidative stress plays a critical role in cancer initiation and progression. Although vitamin D exhibits multiple anti-tumorigenic properties, its antioxidant effects across different cancer types remain incompletely characterized. This study aimed to evaluate the antioxidant role of vitamin D in cancer. Methods: This in vitro study was conducted using breast (MCF-7, MDA-MB-231), colorectal (HCT-116, HT-29), and head and neck (Detroit-562, FaDu) cancer cell lines. Cells were treated with 1,25-dihydroxyvitamin D₃ (1 nM, 10 nM, and 100 nM) for 48 h. Reactive oxygen species (ROS) were quantified using the ROS-Glo™ H₂O₂ assay. Oxidative stress biomarkers were assessed by measuring 8-hydroxy-2′-deoxyguanosine (8-OHdG) using enzyme-linked immunosorbent assay (ELISA), while thiobarbituric acid reactive substances (TBARS) and protein carbonyls (PC) were measured using colorimetric assays. Xanthine oxidase (XOD) protein levels were determined by ELISA, whereas superoxide dismutase (SOD) and catalase (CAT) activity and/or expression were evaluated using colorimetric assays. Results: Vitamin D significantly reduced ROS levels in all investigated cell lines in a dose-dependent manner compared with control cells (p < 0.05). Levels of 8-OHdG and TBARS were significantly decreased across all cell lines, whereas reductions in PC and XOD were cell-type-dependent. Vitamin D significantly increased SOD activity and protein expression in all cell lines, while CAT activity was elevated in most cell lines. Conclusions: This study provides proof-of-concept evidence that vitamin D exerts dose-dependent and cell-specific antioxidant effects in cancer. These findings suggest potential antioxidant roles for vitamin D in the prevention or treatment of breast, colorectal, and head and neck cancers. Full article

This study presents a non-invasive, integrated and multidisciplinary diagnostic approach applied to the analysis of the altarpiece Coronation of the Virgin, attributed to Michele di Matteo (15th century). The investigation focused on the evaluation of a restoration intervention carried out in 2023 using quantitative colorimetric measurements to assess chromatic variations induced by surface treatments. Other non-invasive techniques, including multispectral imaging, hyperspectral imaging, Raman spectroscopy, and visible reflectance spectroscopy, were employed to investigate the painted surface, examine underlying features, and support the characterization and spatial distribution of pictorial materials through comparison with reference standards. Finally, the proteinaceous binding media used by the artist were investigated using nano-liquid chromatography coupled with tandem mass spectrometry (nLC-MS/MS), a sensitive, high-resolution analytical approach in the field of cultural heritage studies. Overall, the integrated approach documented chromatic changes induced by cleaning, revealed the preparatory drawing and previously unknown decorative elements by infrared reflectography, and confirmed the presence of pigments previously identified in earlier studies, allowing, in some cases, for an investigation of their distribution across the painted surface. The characterization of proteinaceous binding media further contributed to a deeper understanding of the materials and techniques employed by the artist. Full article

Bacillus thuringiensis is the most extensively studied entomopathogenic bacterium worldwide; however, its sublethal effects on beetles remain poorly characterized. The aim of this study was to evaluate the toxicity of a previously selected Argentine strain of B. thuringiensis on second-instar Alphitobius diaperinus larvae during an initial 14 days of exposure, and to assess its effects at day 14 and throughout the remainder of the life cycle until death. Three treatments were applied: control, LC₃₀, and LC₅₀. Larval, pupal, and adult weight and body surface area were recorded, and nutritional composition was quantified using colorimetric methods. Insect status was monitored every 48–72 h over a total period of 540 days, until the death of the last individual. Among the evaluated variables, statistically significant differences between control and treatment groups were detected in larval area and weight, in the survival analysis and in two nutritional components: total protein and lipid content per larva. Overall, the results demonstrate that initial sublethal exposure to B. thuringiensis induces chronic lethal effects with delayed mortality in A. diaperinus, indicating irreversible physiological damage. This provides valuable information not only for understanding the biology of this insect but also for stakeholders involved in the productive scaling of beetle-targeted bioinputs. Full article

Background/Objectives: Oxidative stress and extracellular redox alterations are involved in the pathophysiology of essential hypertension, but their clinical assessment is limited by the invasiveness and preanalytical complexity of blood-based measurements. Urine represents an attractive non-invasive biological matrix; however, the relationship between urinary and plasma DTNB-reactive reduced thiols in hypertensive patients remains insufficiently characterized. This study aimed to evaluate the association between plasma and urinary reduced thiols in essential hypertension. Methods: In this paired observational study, plasma and urine samples were obtained from 40 patients with treated essential hypertension. Reduced thiols were quantified using a DTNB-based colorimetric assay under identical analytical conditions. Plasma thiols were normalized to total plasma protein concentration, and urinary thiols were normalized to creatinine. Associations between plasma and urinary thiols were assessed using non-parametric correlation analyses. Results: Protein-normalized plasma thiols and creatinine-normalized urinary thiols showed a significant positive correlation (Spearman’s ρ ≈ 0.7, p < 0.001). Conclusions: In patients with essential hypertension, creatinine-normalized urinary reduced thiols are strongly associated with protein-normalized plasma reduced thiols, as measured by the DTNB reaction method. These findings provide hypothesis-generating evidence that urinary thiols may reflect extracellular thiol-related redox alterations, warranting further validation in independent and more diverse cohorts. Full article

This paper presents the development of an Intelligent Virtual Instrument (VI) for detecting and characterizing corrosion on aluminum and steel surfaces. Implemented within the LabVIEW^® environment, the system utilizes colorimetric computer vision techniques tailored for the metalworking industry. The methodology integrates colorimetric and roughness analysis with Artificial Intelligence, specifically employing Fuzzy Logic for decision-making and Deep Learning algorithms for image processing. This system enables personnel without specialized training to perform rapid, objective diagnostics. The results demonstrate a high correlation between the color spectra of processed images and standard industry patterns, validating the instrument as an efficient and reliable alternative for diverse industrial environments. Full article

The rise of multidrug-resistant tuberculosis (TB) necessitates alternative therapeutic sources. This study investigated the polyphenolic content and the antioxidant, antimycobacterial, and anti-virulence activities of selected medicinal plants traditionally used to treat TB and related symptoms. Total phenolics, tannins, and flavonoids were quantified using colorimetric assays. Antioxidant capacity was assessed via DPPH and ferric-reducing power assays. Antimycobacterial activity against Mycobacterium smegmatis was evaluated using broth microdilution, growth kinetics, cell constituent leakage, and respiratory chain dehydrogenase inhibition assays. Anti-virulence effects were examined using crystal violet biofilm and swarming motility assays. Tarchonanthus camphoratus showed the highest polyphenolic levels and, together with Combretum hereroense, strong antioxidant activity. Extracts of Senecio macroglossus, Nerium oleander, and Tetradenia riparia displayed potent antimycobacterial activity (MIC = 0.16 mg/mL), characterized by delayed exponential growth, membrane damage, and metabolic inhibition. Tabernaemontana elegans exhibited the weakest activity (MIC > 2.5 mg/mL). Most extracts also significantly impaired motility (12–100%) and early-stage biofilm formation. Polyphenolic-rich plant extracts demonstrated promising antimycobacterial and anti-virulence properties against M. smegmatis, highlighting their potential as leads for developing novel anti-TB agents. Full article