Search Results (1,211)

Background/Objectives: Stem base rot caused by Fusarium oxysporum is a devastating soil-borne disease, yet long-term chemical pesticide application has raised serious environmental and ecological concerns. Thymol, a plant-derived fungicide, demonstrates a favorable safety profile for humans and environmental systems while exhibiting broad-spectrum antifungal efficacy. This study aimed to evaluate the inhibitory effects of thymol against F. oxysporum and to elucidate its underlying mechanisms of action. Methods: The antifungal activity of thymol was assessed in vitro against F. oxysporum by measuring colony and mycelial growth inhibition, sporulation, and spore germination at varying concentrations. Microscopic examination was performed to observe morphological changes in hyphae. Biochemical assays were conducted to quantify soluble protein content, DNA synthesis, ergosterol levels, and fusaric acid production in treated mycelia. Dose–response data were used to calculate median effective concentrations (EC₅₀) for relevant parameters. Results: Thymol significantly inhibited F. oxysporum growth, with EC₅₀ values of 51.02 μg/mL for colony growth and 57.30 μg/mL for mycelial growth. Microscopy revealed abnormal, shorter, thicker hyphae with enlarged vacuoles. Sporulation and spore germination were also effectively suppressed, with EC₅₀ of 39.37 μg/mL and 53.55 μg/mL, respectively. At 100 μg/mL, thymol reduced soluble protein content by 36.73%, inhibited DNA synthesis by 47.29%, decreased ergosterol content by 48.11%, and reduced fusaric acid production by 76.86%. Conclusions: Thymol exerts multi-targeted inhibitory effects against F. oxysporum through disruption of cellular structure, impairment of macromolecular synthesis, interference with ergosterol biosynthesis, and suppression of toxin production. These findings provide a strong theoretical foundation for developing thymol as a novel biopesticide for sustainable management of stem base rot. Full article

Clostridioides difficile infection (CDI) remains a major cause of antibiotic-associated diarrhea, with recurrence largely driven by disruption of the gut microbiota and impaired colonization resistance. Bile acids have emerged as key mediators in this process, as primary conjugated bile acids promote C. difficile spore germination, whereas microbiota-derived secondary bile acids can inhibit germination, vegetative growth, and toxin activity. Diet further modulates CDI susceptibility by shaping microbial composition, short-chain fatty acid production, bile acid transformation, epithelial barrier integrity, and intestinal inflammation. Western-style diets, and low fiber intake, may favor dysbiosis and a bile acid profile permissive to CDI, while fiber-rich and Mediterranean-type dietary patterns may support beneficial anaerobes, microbial metabolites, and mucosal resilience. This narrative review summarizes current evidence on the bile acid–diet–microbiome axis in CDI pathogenesis, recurrence, and therapy. It also discusses standard treatment limitations, microbiome-based therapeutics, dietary interventions, and emerging bile acid-targeted strategies. Understanding this axis may support future precision approaches aimed not only at suppressing C. difficile, but also at restoring microbiota function and durable colonization resistance. Full article

Aflatoxins (AFs) are highly carcinogenic mycotoxins produced by toxigenic fungi, posing serious threats to food safety, animal production, and human health. Microbial aflatoxin control has recently emerged as a promising, sustainable, and environmentally friendly strategy for reducing aflatoxin contamination. However, growing evidence suggests that reductions in AF levels within microbial treatment systems may arise not only from direct toxin degradation, but also from inhibition of fungal growth, adsorption or sequestration processes, and suppression of AF biosynthesis. In microbial co-culture systems involving viable toxigenic fungi, exogenous microorganisms and their metabolites can establish persistent ecological stress through nutrient competition, oxidative stress, and interspecies signaling. These stresses activate fungal cell wall integrity pathways, MAPK signaling cascades, and transcriptional regulatory networks, leading to membrane remodeling, alterations in lipid and energy metabolism, and redistribution of cellular resources. As a consequence, fungal physiology progressively shifts from a growth- and toxin-production-oriented state toward a survival- and defense-oriented state, resulting in impaired growth and reduced AF biosynthesis. This review proposes the internal disintegration framework, which conceptualizes AF suppression as a progressive loss of toxin-producing capacity caused by sustained microbial-induced physiological remodeling rather than solely by fungal growth inhibition or toxin degradation. It will provide new perspectives for developing precise, efficient, and eco-friendly dual-target control strategies. Full article

Venoms of African spitting cobras, including Naja mossambica, N. nigricincta, and N. pallida, are widely recognised for their cytotoxicity. However, their effects on platelets and blood coagulation remain poorly characterised. To address this gap, we characterised their enzymatic profiles and evaluated their effects on haemostasis and cell viability using functional blood-based and cellular assays, respectively. All three venoms markedly impaired haemostatic regulation by affecting intrinsic coagulation, significantly inhibiting platelet function, and inducing haemolysis. They also exerted potent myotoxic effects on cultured myoblasts/myotubes while causing only minimal cytotoxicity towards platelets. Fractionation by reversed-phase HPLC followed by mass spectrometry identified three-finger toxins that reproduced the potent platelet-inhibitory and myotoxic activities of the crude venoms but only partially accounted for the haemolytic and anticoagulant effects. These findings demonstrate that African spitting cobra venoms induce coordinated, multifaceted effects on human blood, with three-finger toxins serving as key functional mediators alongside other potential venom components. Overall, this study advances our understanding of the effects of spitting cobra envenoming, provides a foundation for developing improved snakebite therapies, and highlights venom-derived components as potential scaffolds for developing novel antithrombotic agents. Full article

T-2 toxin is a typical fusarium mycotoxin that induces reproductive injury. As a male reproductive toxicant, impaired testosterone biosynthesis is the primary reproductive toxic effect induced by T-2 toxin. Therefore, clarifying how T-2 toxin disrupts testosterone synthesis at the molecular level and screening natural plant extracts that can alleviate this reproductive toxicity are of great importance. Lycopene (LYC) is a natural carotenoid known for its reproductive protective properties. Hence, this work assessed the protective efficacy and molecular mechanisms of LYC against T-2 toxin-caused testosterone synthesis disruption. Our results showed that LYC supplementation significantly alleviated testicular structural injury, restored testicular organ coefficients, and rescued serum and intracellular testosterone levels via transcriptional and translational upregulation of key steroidogenic proteins. Mechanistically, LYC suppressed T-2 toxin-triggered reactive oxygen species (ROS) accumulation, inhibited MAPK pathway activation, and prevented ROS/p38/TORC2/CREB axis activation, thereby restoring TORC2/CREB transcriptional activity and steroidogenesis. Pharmacological validation using SB203580 and NAC confirmed the central role of the ROS/p38/TORC2/CREB axis. Taken together, LYC alleviates T-2 toxin-triggered disruption of testosterone synthesis by inhibiting the ROS/p38/TORC2/CREB axis, and we identify LYC as a promising nutritional strategy against mycotoxin-caused reproductive toxicity. Full article

Chronic kidney disease (CKD) is sustained by a network of sterile inflammation, oxidative and metabolic stress, uremic toxin retention, gut barrier dysfunction, and maladaptive immune activation. These processes contribute to kidney fibrosis, cardiovascular injury, wasting, and excess mortality, but inflammatory biomarkers do not by themselves establish therapeutic causality. This narrative review integrates mechanistic and therapeutic evidence using an explicit three-layer translational hierarchy. Renin–angiotensin system inhibitors, sodium–glucose cotransporter-2 inhibitors, finerenone, and glucagon-like peptide-1 receptor agonists improve cardiorenal outcomes and have plausible anti-inflammatory actions, although inflammatory mediation remains unproven. Interleukin-1 blockade provides cardiovascular proof of principle and small dialysis feasibility data. Interleukin-6 ligand inhibition produces marked human target engagement; however, headline results from the completed phase 3 ZEUS trial showed no reduction in three-point major adverse cardiovascular events with ziltivekimab despite biomarker suppression, while serious infections were more frequent. POSIBIL6ESKD continues to test clazakizumab in inflamed dialysis patients. Direct NLRP3 inhibition has entered early human CKD development, whereas senescence-directed and microbiota-based approaches remain less mature. Future progress requires inflammatory endotyping, repeated biomarker assessment, mechanistically aligned outcomes, and rigorous infection surveillance. ZEUS underscores that pathway suppression must deliver clinical benefit beyond contemporary standard therapy. Full article

Skeletal muscle regeneration is often impaired after acute muscle damage induced by viperid snake venoms, such as that of Bothrops asper, a medically relevant species in Latin America. It has been shown that traces of venom that remain in the damaged muscle affect myogenic cells in culture, raising the possibility of inhibiting these toxins during the regenerative process to improve regeneration. Using a mouse model of myonecrosis and regeneration, we evaluated the effects of Varespladib (a phospholipase A₂ inhibitor) or Marimastat (a metalloproteinase inhibitor) on muscle regeneration when administered intravenously 24 h after the onset of myonecrosis, i.e., after muscle damage has occurred. The regenerative process was evaluated 14 and 28 days after venom injection. Marimastat, or a combination of both inhibitors, increased the number and diameter of regenerating muscle fibers and reduced tissue fibrosis compared to tissues from mice receiving only venom, as judged by qualitative and quantitative histological assessment. These initial results underscore the deleterious role of traces of venom components, especially metalloproteinases, in damaged muscles during muscle regeneration. Full article

Staphylococcus aureus (S. aureus) is a prominent foodborne pathogen that poses a continuous threat to global public health and food safety due to its possession of a variety of toxins and its multidrug resistance. Medium-chain fatty acids (MCFAs), notably lauric acid (LA), exhibit strong antimicrobial properties, but their application is heavily constrained by poor water solubility. In this study, optimized LA emulsions stabilized by chitosan (CS) and polyvinyl alcohol (PVA) were evaluated for their antibacterial activity and detailed mode of action against S. aureus ATCC 6538. The antibacterial activities were evaluated by the maximum inhibition zone, with the 20 CS-PVA/DLTA-LA formulation exhibiting stable dispersion and potent antibacterial activity at 1%. The underlying antibacterial mechanisms against S. aureus were specifically focused on cell membranes and peptidoglycan. Therein, the binding of emulsion droplets to the anionic bacterial surface was driven by electrostatic attraction. Membrane degradation was also observed with membrane dysfunctions involving membrane depolarization, increased permeability, and fluidity reduction triggered by their subsequent insertion into the lipid bilayer, which may cause cell dysmetabolism, disintegration, and eventual cell death. Overall, these findings substantiate that LA emulsions disrupt S. aureus by operating potentially multi-targeted effects involving cell membrane disruption and peptidoglycan interference, offering a promising alternative approach warranting further investigation for foodborne pathogen control. Full article

Vascular calcification (VC) is a major complication of chronic kidney disease (CKD) that is strongly associated with cardiovascular mortality. While indoxyl sulfate (IS), a protein-bound uremic toxin, has been implicated in the progression of VC, the underlying molecular mechanisms remain unclear. We investigated the procalcific effects of IS using a two-step nephrectomy-induced CKD mouse model and cultured vascular smooth muscle cells. In vivo, progressive renal impairment was associated with elevated circulating IS levels and enhanced VC. In vitro, IS dose- and time-dependently induced calcium deposition, increased reactive oxygen species (ROS) production, and upregulated osteogenic markers, including runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2), and osteocalcin (OCN), whereas N-acetyl-L-cysteine (NAC) partially attenuated IS-induced ROS accumulation and cell injury. Mechanistically, IS exposure activated extracellular signal-regulated kinase (ERK) and Wnt/β-catenin signaling while suppressing nuclear factor erythroid 2-related factor 2 (Nrf2)-related antioxidant responses, as reflected by reductions in the phosphorylated Nrf2 (pNrf2) to total Nrf2 and heme oxygenase-1 (HO-1) expression. Pharmacological inhibition of ERK and Wnt/β-catenin signaling attenuated IS-induced osteogenic responses. These findings indicate that IS promotes VC in association with increased oxidative stress, activation of ERK and Wnt/β-catenin signaling, and impaired Nrf2-related antioxidant defense. These integrated findings provide mechanistic insight into IS-associated VC and highlight oxidative stress-related signaling networks as potential therapeutic targets in CKD. Full article

Potato peel waste (PPW) represents a low-cost and eco-friendly by-product with potential for use as a fermentation substrate for the production of antibacterial metabolites by Bacillus species. This study evaluated PPW as a fermentation matrix for Bacillus velezensis and demonstrated that 2% PPW supported optimal production of antibacterial compounds. The cell-free supernatant obtained after 96 h of fermentation exhibited the strongest activity against E. coli 18/22, with a MIC of 62.5 µg/mL. The ethyl acetate extract exhibited rapid bactericidal activity, killing E. coli 18/22 within 30 min at 2× MIC and within 120 min at MIC. The antibacterial activity remained stable up to 80 °C, across pH 4–12, and after treatment with pepsin and chymotrypsin. LC/HR-ESI-MS analysis identified oxydifficidin and surfactins C14 and C15 as the main active compounds. Molecular docking revealed that oxydifficidin and surfactin C15 exhibited the strongest binding affinity toward Shiga toxin II, while surfactin C14 displayed a weaker interaction, suggesting the role of acyl chain length in toxin binding. Both oxydifficidin and surfactins interacted with key residues within the catalytic pocket of the AcrB subunit of the AcrAB–TolC multidrug efflux pump, indicating potential inhibition of multidrug resistance mechanisms. To our knowledge, this is the first report describing the use of PPW as a fermentation substrate for Bacillus velezensis B38 to produce oxydifficidin and surfactin C14 and C15 exhibiting antimicrobial activity against multidrug-resistant E. coli. These findings provide a promising strategy for transforming agro-industrial waste into value-added antimicrobial metabolites, contributing to the circular bioeconomy strategies within the One Health framework. Full article

Chronic kidney disease is associated with neurovascular complications including cognitive impairment, potentially involving blood–brain barrier (BBB) impairment. The protein-bound uremic toxin indoxyl sulfate (IS) promotes endothelial injury, but its effects on human brain microvascular endothelial cells remain incompletely understood. Human cerebral microvascular endothelial cells (hCMEC/D3) were exposed to IS 200 and 900 μM. BBB integrity was assessed by the FITC-dextran (4 kDa) transwell permeability assay and claudin-5 immunofluorescence. Transcriptional responses were quantified by qPCR for aryl hydrocarbon (AhR) target genes, oxidative stress-associated and inflammatory markers, senescence, and junction-associated genes. Senescence-associated phenotypic changes were evaluated by SA-β-galactosidase staining and cytokine array profiling. IS increased endothelial permeability at 24 and 48 h (~1.5-fold relative to control) without evidence of cytotoxicity and reduced claudin-5 staining intensity. IS strongly upregulated AhR target genes, including CYP1A1, CYP1B1, and CYP1A2. NFE2L2 and IDO1 increased, while NFKB1 remained unchanged. SA-β-gal positivity increased, accompanied by elevated GM-CSF and G-CSF secretion, while CDKN1A decreased at IS 900 µM and CDKN2A remained unchanged. CDH5 was downregulated, TJP1 increased at 900 µM, and CLDN5 remained unchanged. These findings indicate that IS exposure is associated with impaired BBB integrity, AhR-related transcriptional responses, oxidative stress-associated transcriptional changes, junctional remodeling, and senescence-like endothelial features. However, causal attribution to individual pathways requires inhibition or knockdown studies. Full article

Post-stroke spasticity involves both neural and non-neural mechanisms, including structural alterations of muscles and surrounding fascia. Although botulinum toxin type A (BoNT-A) is widely used to treat focal spasticity, its effects on fascial tissue remain unclear. This retrospective observational study investigated longitudinal changes in fascial thickness after BoNT-A injection using ultrasonography. Thirty-seven patients with post-stroke spasticity were included. Fascial thickness was measured at baseline, 3 weeks, and 3 months after treatment in the injected muscle regions. Clinical outcomes were assessed using the Modified Ashworth Scale (MAS), Fugl–Meyer Assessment (FMA), and Brunnstrom stages. Repeated-measures analysis demonstrated significant reductions in fascial thickness across all evaluated regions. Pairwise comparisons showed significant decreases from baseline to week 3 and month 3, whereas continued reductions between week 3 and month 3 were observed only in the flexor digitorum superficialis fascia, the flexor digitorum superficialis–flexor digitorum profundus interfascial layer, and the deep brachialis fascia. MAS scores and upper extremity Fugl–Meyer scores improved significantly, whereas Brunnstrom stages remained unchanged. These findings suggest that the therapeutic effects of BoNT-A may extend beyond neural inhibition to include fascial remodeling. Ultrasonographic assessment of fascial thickness may represent a potential imaging biomarker for monitoring structural treatment responses in post-stroke spasticity. Full article

Plague, caused by Yersinia pestis, remains a significant public health concern, yet the determinants of many toxin-associated proteins encoded by this pathogen remain poorly understood. Here, we characterized two previously unexplored Rearrangement hotspot (Rhs) proteins, YPO3609 and YPO3615, using a combination of bioinformatic analyses, bacterial toxicity assays, DNA degradation assays, SOS reporter assays, and RT-qPCR analysis. The C-terminal domains of YPO3609 and YPO3615 confer nuclease toxicity, with YPO3609 containing a WHH motif of the HNH nuclease superfamily and YPO3615 harboring a restriction endonuclease-like aspartate dyad. Heterologous expression of these C-terminal toxin domains in Escherichia coli inhibited growth, caused DNA degradation, elicited SOS-related responses, and induced cellular filamentation. Co-expression experiments identified YPO3610 and YPO3616 as the cognate immunity proteins of YPO3609 and YPO3615, respectively, while site-directed mutagenesis further showed that H411 and D1442/D1447 contribute to the nuclease-associated activities of the two toxins. Homologs of both toxin domains were broadly distributed in Pseudomonadota, with the C-terminal domain of YPO3609 showing a wider distribution. These findings characterize two functional Rhs toxin–immunity modules encoded by Y. pestis, and provide new insights into Rhs-associated nuclease toxins and their related homologs. Full article

The emergence of multidrug-resistant (MDR) bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA), represents a major global health challenge by limiting the current therapeutic options. In this context, antimicrobial peptides (AMPs) have been widely studied for their potent antimicrobial properties. In this study, we evaluated the anti-MRSA effect of a novel AMP, LyeTx I mnΔKL, derived from a toxin of Lycosa erythrognatha. Its activity was evaluated in vitro by minimal inhibitory and bactericidal concentrations (MIC and MBC), antibiofilm effect, membrane interaction, cytotoxicity, synergistic interaction with vancomycin, and in vivo in an MRSA murine wound/abscess infection model. LyeTx I mnΔKL showed enhanced antimicrobial activity against clinical MRSA isolates compared to its prototype (LyeTx I mnΔK), with MIC₅₀ and MBC₅₀ of 2 and 8 µM and 16 and 32 µM, respectively. Furthermore, LyeTx I mnΔKL exhibited a rapid bactericidal effect and a pronounced ability to inhibit biofilm formation and disrupt mature biofilms. LyeTx I mnΔKL interacts with bacterial membranes, adopts an α-helical structure, and induces membrane disruption and leakage of intracellular material. In vivo, topical treatment with LyeTx I mnΔKL reduced MRSA burden compared with LyeTx I mnΔK and untreated controls (log₁₀ CFU/g of wound of 2.4, 4.4, and 6.5 for LyeTx I mnΔKL, LyeTx I mnΔK, and the saline group, respectively). However, increased cytotoxicity remains a significant limitation. Overall, LyeTx I mnΔKL is a promising anti-MRSA candidate for topical use with potent antibiofilm and in vivo activity. Full article

Mechanisms for the maintenance of chronic viruses are poorly understood, particularly for archaeal viruses. Here, we identify the product of Sulfolobus spindle-shaped virus 1 (SSV1) ORF a291 as a putative virally encoded toxin required for growth inhibition but dispensable for viral replication and virion production. Viruses lacking ORF a291 replicated their genomes and formed morphologically normal spindle-shaped particles, yet failed to inhibit the growth of uninfected Saccharolobus solfataricus. Substitution of residues at a predicted N-terminal signal peptide cleavage site abolished growth suppression without affecting replication, suggesting that secretion is essential for toxin function. Despite primary sequence divergence among fusellovirus toxin candidates, analysis of protein structure predictions revealed a conserved hydrolase-like fold across SSV1, SSV9 and SSV10 toxins. These findings demonstrate functional separation of viral replication and host growth suppression and support a model in which chronic archaeal viruses modulate host competition through antagonistic factors. This work expands the known diversity of putative viral toxins and suggests that fuselloviruses employ conserved strategies to promote persistence in extreme environments. Full article