Oxidative stress induction by T-2 toxin causes DNA damage and triggers apoptosis via caspase pathway in human cervical cancer cells

Indole-3-acetic acid induced cardiogenesis impairment in in-vivo zebrafish via oxidative stress and downregulation of cardiac morphogenic factors

Plant growth regulators (PGRs) are increasingly used to promote sustainable agriculture, but their unregulated use raises concerns about potential environmental risks. Indole-3-acetic acid (IAA), a commonly used PGR, has been the subject of research on its developmental toxicity in the in-vivo zebrafish model. IAA exposure to zebrafish embryos caused oxidative stress, lipid peroxidation, and cellular apoptosis. The study also revealed that critical antioxidant genes including sod, cat, and bcl2 were downregulated, while pro-apoptotic genes such as bax and p53 were upregulated. IAA exposure also hampered normal cardiogenesis by downregulating myl7, amhc, and vmhc genes and potentially influencing zebrafish neurobehavior. The accumulation of IAA was confirmed by HPLC analysis of IAA-exposed zebrafish tissues. These findings underscore the need for further study on the potential ecological consequences of IAA use and the need for sustainable agricultural practices.

Melatonin alleviates T-2 toxin-induced oxidative damage, inflammatory response, and apoptosis in piglet spleen and thymus

T-2 toxin, an unavoidable contaminant in animal feeds, can induce oxidative stress and damage immune organs. Melatonin (MT), a natural and potent antioxidant, has shown promise as a detoxifier for various mycotoxins. However, the detoxifying effect of MT on T-2 toxin has not been previously reported. In order to investigate the protective effect of MT added to diets on the immune system of T-2 toxin-exposed piglets, twenty piglets weaned at 28d of age were randomly divided into control, T-2 toxin (1 mg/kg), MT (5 mg/kg), and T-2 toxin (1 mg/kg) + MT (5 mg/kg) groups(n = 5 per group). Our results demonstrated that MT mitigated T-2 toxin-induced histoarchitectural alterations in the spleen and thymus, such as hemorrhage, decreased white pulp size in the spleen, and medullary cell sparing in the thymus. Further research revealed that MT promoted the expression of Nrf2 and increased the activities of antioxidant enzymes CAT and SOD, while reducing the production of the lipid peroxidation product MDA. Moreover, MT inhibited the NF-κB signaling pathway, regulated the expression of downstream cytokines IL-1β, IL-6, TNF-α, and TGF-β1. MT also suppressed the activation of caspase-3 while down-regulating the ratio of Bax/Bcl-2 to reduce apoptosis. Additionally, MT ameliorated the T-2 toxin-induced disorders of immune cells and immune molecules in the blood. In conclusion, our findings suggest that MT may effectively protect the immune system of piglets against T-2 toxin-induced damage by inhibiting oxidative stress, inflammatory response, and apoptosis in the spleen and thymus. Therefore, MT holds the potential as an antidote for T-2 toxin poisoning.

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Anticancer effect of umbelliferone on MKN-45 and MIA PaCa-2 cell lines

In this study, the anticancer activity of umbelliferone (7-hydroxycoumarin-UMB) was investigated in MKN-45 human gastric cancer and MIA PaCa-2 human pancreatic cancer cells. The cytotoxic effect of UMB on MKN-45 and MIA PaCa-2 cells was determined by WST-8 cell viability assay; the effect on colony formation and migration potential by colony forming assay and wound healing/cell migration assay. Apoptotic effect of UMB was determined by measuring the change in mitochondrial membrane potentials, reactive oxygen species levels, and Caspase-3 activities in cells. Anticancer drugs cisplatin and gemcitabine were used as positive controls in experiments, and NIH/Swiss 3 T3 mouse embryonic fibroblast cells were used as a healthy cell group. The results of this study showed that umbelliferone had a significant cytotoxic effect in MKN-45 and MIA PaCa-2 cells, especially after 72 h treatment, while its cytotoxic effect in NIH/3 T3 cells was low. Furthermore, UMB reduces significantly the potential of cells to colonize and migrate; it has been determined that it causes apoptosis by decreasing the mitochondrial membrane potential, increasing intracellular ROS levels and Caspase-3 activity. UMB was found to have more anticancer effect on MIA PaCa-2 cells compared to MKN-45 cells. This showed that UMB has a cell-selective effect.

Unraveling the Nrf2-ARE Signaling Pathway in the DF-1 Chicken Fibroblast Cell Line: Insights into T-2 Toxin-Induced Oxidative Stress Regulation

The T-2 toxin (T2) poses a major threat to the health and productivity of animals. The present study aimed to investigate the regulatory mechanism of Nrf2 derived from broilers against T2-induced oxidative damage. DF-1 cells, including those with normal characteristics, as well as those overexpressing or with a knockout of specific components, were exposed to a 24 h treatment of 50 nM T2. The primary objective was to evaluate the indicators associated with oxidative stress and the expression of downstream antioxidant factors regulated by the Nrf2-ARE signaling pathway, at both the mRNA and protein levels. The findings of this study demonstrated a noteworthy relationship between the up-regulation of the Nrf2 protein and a considerable reduction in the oxidative stress levels within DF-1 cells (p < 0.05). Furthermore, this up-regulation was associated with a notable increase in the mRNA and protein levels of antioxidant factors downstream of the Nrf2-ARE signaling pathway (p < 0.05). Conversely, the down-regulation of the Nrf2 protein was linked to a marked elevation in oxidative stress levels in DF-1 cells (p < 0.05). Additionally, this down-regulation resulted in a significant decrease in both the mRNA and protein expression of antioxidant factors (p < 0.05). This experiment lays a theoretical foundation for investigating the detrimental impacts of T2 on broiler chickens. It also establishes a research framework for employing the Nrf2 protein in broiler chicken production and breeding. Moreover, it introduces novel insights for the prospective management of oxidative stress-related ailments in the livestock and poultry industry.

From ribosome to ribotoxins: understanding the toxicity of deoxynivalenol and Shiga toxin, two food borne toxins

Ribosomes that synthesize proteins are among the most central and evolutionarily conserved organelles. Given the key role of proteins in cellular functions, prokaryotic and eukaryotic pathogens have evolved potent toxins to inhibit ribosomal functions and weaken their host. Many of these ribotoxin-producing pathogens are associated with food. For example, food can be contaminated with bacterial pathogens that produce the ribotoxin Shiga toxin, but also with the fungal ribotoxin deoxynivalenol. Shiga toxin cleaves ribosomal RNA, while deoxynivalenol binds to and inhibits the peptidyl transferase center. Despite their distinct modes of action, both groups of ribotoxins hinder protein translation, but also trigger other comparable toxic effects, which depend or not on the activation of the ribotoxic stress response. Ribotoxic stress response-dependent effects include inflammation and apoptosis, whereas ribotoxic stress response-independent effects include endoplasmic reticulum stress, oxidative stress, and autophagy. For other effects, such as cell cycle arrest and cytoskeleton modulation, the involvement of the ribotoxic stress response is still controversial. Ribotoxins affect one organelle yet induce multiple toxic effects with multiple consequences for the cell. The ribosome can therefore be considered as the cellular "Achilles heel" targeted by food borne ribotoxins. Considering the high toxicity of ribotoxins, they pose a substantial health risk, as humans are highly susceptible to widespread exposure to these toxins through contaminated food sources.

Protection of β-pancreatic cells from dysfunctionality of insulin using vitexin by apoptosis of INS-1 cells

AIMS

This study was performed to explore the possible beneficial effects of vitexin on high glucose (HG)-induced cytotoxicity in pancreatic β-cells.

METHODS

INS-1 pancreatic β-cell line has used this study. HG-induced (33 Mm) exposed INS-1 cell death; the apoptosis INS-1 cells treated vitexin 10, 20, 40, and 80 µg/mL for 24 hours. The anti-apoptosis properties were evaluated by MTT assay, glucose-stimulated insulin secretion assay, biochemical assay, annexin-V-FITC staining and western blot analysis.

RESULTS

These findings demonstrate that vitexin treatment improved the HG-exposure, reduced the INS-1 cell viability and significantly enhanced glucose-stimulated insulin secretion in a dose-dependent manner. The antioxidant studies revealed that vitexin treatment significantly decreased lipid peroxidation and reactive oxygen species and increased antioxidant level of INS-1 cell line in 24 hrs. The findings of the study suggested that in the vitexin treatment group, pancreatic apoptosis and Bax protein expression reduced significantly. At the same time, Bcl-2 protein expression increased, and NF-κB protein in HG-induced INS-cells was inhibited.

CONCLUSION

Therefore, our results suggest that vitexin can be successfully used to regulate the expression of Bcl-2 family proteins, reduce lipid peroxidation and to improve the secretion of antioxidants in pancreatic β-cell lines.

DNA Damage Induced by T-2 Mycotoxin in Human Skin Fibroblast Cell Line-Hs68

T-2 mycotoxin is the most potent representative of the trichothecene group A and is produced by various Fusarium species, including F. sporotrichioides, F. poae, and F. acuminatum. T-2 toxin has been reported to have toxic effects on various tissues and organs, and humans and animals alike suffer a variety of pathological conditions after consumption of mycotoxin-contaminated food. The T-2 toxin's unique feature is dermal toxicity, characterized by skin inflammation. In this in vitro study, we investigated the molecular mechanism of T-2 toxin-induced genotoxicity in the human skin fibroblast-Hs68 cell line. For the purpose of investigation, the cells were treated with T-2 toxin in 0.1, 1, and 10 μM concentrations and incubated for 24 h and 48 h. Nuclear DNA (nDNA) is found within the nucleus of eukaryotic cells and has a double-helix structure. nDNA encodes the primary structure of proteins, consisting of the basic amino acid sequence. The alkaline comet assay results showed that T-2 toxin induces DNA alkali-labile sites. The DNA strand breaks in cells, and the DNA damage level is correlated with the increasing concentration and time of exposure to T-2 toxin. The evaluation of nDNA damage revealed that exposure to toxin resulted in an increasing lesion frequency in Hs68 cells with HPRT1 and TP53 genes. Further analyses were focused on mRNA expression changes in two groups of genes involved in the inflammatory and repair processes. The level of mRNA increased for all examined inflammatory genes (TNF, INFG, IL1A, and IL1B). In the second group of genes related to the repair process, changes in expression induced by toxin in genes-LIG3 and APEX were observed. The level of mRNA for LIG3 decreased, while that for APEX increased. In the case of LIG1, FEN, and XRCC1, no changes in mRNA level between the control and T-2 toxin probes were observed. In conclusion, the results of this study indicate that T-2 toxin shows genotoxic effects on Hs68 cells, and the molecular mechanism of this toxic effect is related to nDNA damage.

Deoxynivalenol affects cell metabolism in vivo and inhibits protein synthesis in IPEC-1 cells

Deoxynivalenol is present in forage crops in concentrations that endanger animal welfare but is also found in cereal-based food. The amphipathic nature of mycotoxins allows them to cross the cell membrane and interacts with different cell organelles such as mitochondria and ribosomes. In our study, we investigated the gene expression of several genes in vivo and in vitro that are related to the metabolism. We observed a significantly higher COX5B and MHCII expression in enterocytes of DON-fed pigs compared to CON-fed pigs and a marked increase in GAPDH and SLC7A11 in DON-fed pigs, but we could not confirm this in vitro in IPEC-1. In vitro, functional metabolic analyses were performed with a seahorse analyzer. A significant increase of non-mitochondrial respiration was observed in all DON-treatment groups (50-2000 ng/mL). The oxygen consumption of cells, which were cultured on membranes, was examined with a fiber-glass electrode. Here, we found significantly lower values for DON 200- and DON 2000-treatment group. The effect on ribosomes was investigated using biorthogonal non-canonical amino acid tagging (BONCAT) to tag newly synthesized proteins. A significantly reduced amount was found in almost all DON-treatment groups. Our findings clearly show that apical and basolateral DON-treatment of epithelial cell layer results in decreasing amounts of newly synthesized proteins. Furthermore, our study shows that DON affects enterocyte metabolism in vivo and in vitro.

Mitochondrial Damage Induced by T-2 Mycotoxin on Human Skin-Fibroblast Hs68 Cell Line

T-2 toxin is produced by different Fusarium species and belongs to the group of type A trichothecene mycotoxins. T-2 toxin contaminates various grains, such as wheat, barley, maize, or rice, thus posing a risk to human and animal health. The toxin has toxicological effects on human and animal digestive, immune, nervous and reproductive systems. In addition, the most significant toxic effect can be observed on the skin. This in vitro study focused on T-2 toxicity on human skin fibroblast Hs68 cell line mitochondria. In the first step of this study, T-2 toxin's effect on the cell mitochondrial membrane potential (MMP) was determined. The cells were exposed to T-2 toxin, which resulted in dose- and time-dependent changes and a decrease in MMP. The obtained results revealed that the changes of intracellular reactive oxygen species (ROS) in the Hs68 cells were not affected by T-2 toxin. A further mitochondrial genome analysis showed that T-2 toxin in a dose- and time-dependent manner decreased the number of mitochondrial DNA (mtDNA) copies in cells. In addition, T-2 toxin genotoxicity causing mtDNA damage was evaluated. It was found that incubation of Hs68 cells in the presence of T-2 toxin, in a dose- and time-dependent manner, increased the level of mtDNA damage in both tested mtDNA regions: NADH dehydrogenase subunit 1 (ND1) and NADH dehydrogenase subunit 5 (ND5). In conclusion, the results of the in vitro study revealed that T-2 toxin shows adverse effects on Hs68 cell mitochondria. T-2 toxin induces mitochondrial dysfunction and mtDNA damage, which may cause the disruption of adenosine triphosphate (ATP) synthesis and, in consequence, cell death.

Dietary T-2 toxin induces transcriptomic changes in hepatopancreas of Chinese mitten crab (Eriocheir sinensis) via nutrition metabolism and apoptosis-related pathways

Long-term feed route exposure to T-2 toxin was proved to elicit growth retarding effects and induction of oxidative stress and apoptosis in Chinese mitten crab (Eriocheir sinensis). However, no study with a holistic perspective has been conducted to date to further describe the in-depth toxicological mechanism of T-2 toxin in E.sinensis. In this study, an RNA-Sequencing (RNA-seq) was used in this study to investigate the effects of feed supplementation with 0 mg/kg and 4 mg/kg T-2 toxin on the hepatopancreas transcriptome of E.sinensis and establish a hepatopancreas transcriptome library of T-2 toxin chronically exposed crabs after five weeks, where 14 differentially expressed genes (DEGs) were screened out across antioxidant, apoptosis, autophagy, glucolipid metabolism and protein synthesis. The actual expression of all the DEGs (Caspase, ATG4, PERK, ACSL, CAT, BIRC2, HADHA, HADHB, ACOX, PFK, eEFe1, eIF4ɑ, RPL13Ae) was also analyzed by real-time quantitative PCR (RT-qPCR). It was demonstrated that long-term intake of large amounts of T-2 toxin could impair antioxidant enzyme activity, promote apoptosis and protective autophagy, disrupt lipid metabolism and inhibit protein synthesis in the hepatopancreas of E.sinensis. In conclusion, this study explored the toxicity mechanism of T-2 toxin on the hepatopancreas of E.sinensis at the mRNA level, which lays the foundation for further investigation of the molecular toxicity mechanism of T-2 toxin in aquatic crustaceans.

Toxicity and detoxification of T-2 toxin in poultry

This review summarizes the updated knowledge on the toxicity of T-2 on poultry, followed by potential strategies for detoxification of T-2 in poultry diet. The toxic effects of T-2 on poultry include cytotoxicity, genotoxicity, metabolism modulation, immunotoxicity, hepatotoxicity, gastrointestinal toxicity, skeletal toxicity, nephrotoxicity, reproductive toxicity, neurotoxicity, etc. Cytotoxicity is the primary toxicity of T-2, characterized by inhibiting protein and nucleic acid synthesis, altering the cell cycle, inducing oxidative stress, apoptosis and necrosis, which lead to damages of immune organs, liver, digestive tract, bone, kidney, etc., resulting in pathological changes and impaired physiological functions of these organs. Glutathione redox system, superoxide dismutase, catalase and autophagy are protective mechanisms against oxidative stress and apoptosis, and can compensate the pathological changes and physiological functions impaired by T-2 to some degree. T-2 detoxifying agents for poultry feeds include adsorbing agents (e.g., aluminosilicate-based clays and microbial cell wall), biotransforming agents (e.g., Eubacterium sp. BBSH 797 strain), and indirect detoxifying agents (e.g., plant-derived antioxidants). These T-2 detoxifying agents could alleviate different pathological changes to different degrees, and multi-component T-2 detoxifying agents can likely provide more comprehensive protection against the toxicity of T-2.

An update on T2-toxins: metabolism, immunotoxicity mechanism and human assessment exposure of intestinal microbiota

Mycotoxins are naturally produced secondary metabolites or low molecular organic compounds produced by fungus with high diversification, which cause mycotoxicosis (food contamination) in humans and animals. T-2 toxin is simply one of the metabolites belonging to fungi trichothecene mycotoxin. Specifically, Trichothecenes-2 (T-2) mycotoxin of genus fusarium is considered one of the most hotspot agricultural commodities and carcinogenic compounds worldwide. There are well-known examples of salmonellosis in mice and pigs, necrotic enteritis in chickens, catfish enteric septicemia and colibacillosis in pigs as T-2 toxic agent. On the other hand, it has shown a significant reduction in the Salmonella population's aptitude in the pig intestinal tract. Although the impact of the excess Fusarium contaminants on humans in creating infectious illness is less well-known, some toxins are harmful; for example, salmonellosis and colibacillosis have been frequently observed in humans. More than 20 different metabolites are synthesized and excreted after ingestion, but the T-2 toxin is one of the most protuberant metabolites. Less absorption of mycotoxins in intestinal tract results in biotransformation of toxic metabolites into less toxic variants. In addition to these, effects of microbiota on harmful mycotoxins are not limited to intestinal tract, it may harm the other human vital organs. However, detoxification of microbiota is considered as an alternative way to decontaminate the feed for both animals and humans. These transformations of toxic metabolites depend upon the formation of metabolites. This study is complete in all perspectives regarding interactions between microbiota and mycotoxins, their mechanism and practical applications based on experimental studies.

Metabolic Disruption by Naturally Occurring Mycotoxins in Circulation: A Focus on Vascular and Bone Homeostasis Dysfunction

Naturally occurring food/feed contaminants have become a significant global issue due to animal and human health implications. Despite risk assessments and legislation setpoints on the mycotoxins' levels, exposure to lower amounts occurs, and it might affect cell homeostasis. However, the inflammatory consequences of this possible everyday exposure to toxins on the vascular microenvironment and arterial dysfunction are unexplored in detail. Circulation is the most accessible path for food-borne toxins, and the consequent metabolic and immune shifts affect systemic health, both on vascular apparatus and bone homeostasis. Their oxidative nature makes mycotoxins a plausible underlying source of low-level toxicity in the bone marrow microenvironment and arterial dysfunction. Mycotoxins could also influence the function of cardiomyocytes with possible injury to the heart. Co-occurrence of mycotoxins can modulate the metabolic pathways favoring osteoblast dysfunction and bone health losses. This review provides a novel insight into understanding the complex events of coexposure to mixed (low levels) mycotoxicosis and subsequent metabolic/immune disruptions contributing to chronic alterations in circulation.

PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity

T-2 toxin can cause mitochondrial impairment and subsequent renal damage. PINK1/Parkin-mediated mitophagy can mitigate renal impairment by alleviating mitochondrial damage. Nevertheless, the impact of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced renal injury remains unclear. Here, we studied the role of PINK1/Parkin-mediated mitophagy in T-2 toxin-induced nephrotoxicity. Mitochondrial damage was accompanied by NLRP3-inflammasome activation and PINK1/Parkin-mediated mitophagy in the kidney of T-2 toxin-exposed C57BL/6N mice. Knocking out Parkin inhibited the mitophagy but aggravated the structural and functional damage, NLRP3-inflammasome activation, mitochondrial damage, and apoptosis. Correlation analysis revealed that NLRP3-inflammasome activation was correlated with apoptosis. These results show that PINK1/Parkin-mediated mitophagy mitigates T-2 toxin-induced nephrotoxicity.

Low-Concentration T-2 Toxin Attenuates Pseudorabies Virus Replication in Porcine Kidney 15 Cells

Pseudorabies, caused by pseudorabies virus (PRV), is the main highly infectious disease that severely affects the pig industry globally. T-2 toxin (T2), a significant mycotoxin, is widely spread in food and feeds and shows high toxicity to mammals. The potential mechanism of the interaction between viruses and toxins is of great research value because revealing this mechanism may provide new ideas for their joint prevention and control. In this study, we investigated the effect of T2 on PRV replication and the mechanism of action. The results showed that at a low dose (10 nM), T2 had no significant effect on porcine kidney 15 (PK15) cell viability. However, this T2 concentration alleviated PRV-induced cell injury and increased cell survival time. Additionally, the number of PK15 cells infected with PRV significantly reduced by T2 treatment. Similarly, T2 significantly decreased the copy number of PRV. Investigation of the mechanism revealed that 10 nM T2 significantly inhibits PRV replication and leads to downregulation of oxidative stress- and apoptosis-related genes. These results suggest that oxidative stress and apoptosis are involved in the inhibition of PRV replication in PK15 cells by low-concentration T2. Taken together, we demonstrated the protective effects of T2 against PRV infection. A low T2 concentration inhibited the replication of PRV in PK15 cells, and this process was accompanied by downregulation of the oxidative stress and apoptosis signaling pathways. Our findings partly explain the interaction mechanism between T2 and PRV, relating to oxidative stress and apoptosis, though further research is required.

Apoptotic mechanism in human brain microvascular endothelial cells triggered by 4'-iodo-α-pyrrolidinononanophenone: Contribution of decrease in antioxidant properties

In this study, we newly synthesized four α-pyrrolidinononanophenone (α-PNP) derivatives [4'-halogenated derivatives and α-pyrrolidinodecanophenone (α-PDP)], and then performed the structure-cytotoxicity relationship analyses. The results showed the rank order for the cytotoxic effects, α-PNP < α-PDP < 4'-fluoro-α-PNP < 4'-chrolo-α-PNP < 4'-bromo-α-PNP < 4'-iodo-α-PNP (I-α-PNP), and suggest that cytotoxicities of 4'-halogenated derivatives were more intensive than that of elongation of the hydrocarbon chain (α-PDP). We also surveyed the apoptotic mechanism of I-α-PNP in brain microvascular endothelial (HBME) cells that are utilized as the in vitro model of the blood-brain barrier. HBME cell treatment with I-α-PNP facilitated the apoptotic events (caspase-3 activation, externalization of phosphatidylserine, and DNA fragmentation), which were almost completely abolished by pretreating with antioxidants. In addition, the immunofluorescent staining revealed the enhanced production of hydroxyl radical in mitochondria by the I-α-PNP treatment, inferring that the I-α-PNP treatment triggers the apoptotic mechanism dependent on the enhanced ROS production in mitochondria. The treatment with I-α-PNP increased the production of cytotoxic aldehyde 4-hydroxy-2-nonenal and decreased the amount of reduced glutathione. Additionally, the treatment decreased the 26S proteasome-based proteolytic activities and aggresome formation. These results suggest that decrease in the antioxidant properties is also ascribable to HBME cell apoptosis elicited by I-α-PNP.

Protective Effect of Selenomethionine on T-2 Toxin-Induced Rabbit Immunotoxicity

T-2 toxin is a trichothecene mycotoxin produced by fusarium species, which is mainly prevalent in grain and livestock feed. One of the main effects of this toxin is immunodepression. Previous studies have shown that T-2 toxin can cause damage to immune organs and impaired immune function in animals. However, selenomethionine (SeMet) as an organic selenium source can not only promote the growth and development of the body but also effectively improve the body's immune function. In this study, rabbits were exposed to 0.4-mg/kg T-2 toxin, and abnormal blood routine indicators were found in the rabbits. HE staining also showed obvious lesions in the spleen and thymus tissue structures, accompanied by a large number of bleeding points. In addition, rabbits showed strong oxidative stress and inflammatory response after T-2 toxin action. 0.2 mg/kg, 0.4 mg/kg, and 0.6 mg/kg organic selenium were added to the feed. However, it was found that 0.2 mg/kg selenium can effectively improve the abnormal changes of blood routine and spleen and thymus tissue of rabbits. On the other hand, it can significantly increase the expression of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in the spleen and thymus, and downregulate the expression of reactive oxygen species (ROS) and malondialdehyde (MDA). In addition, inflammatory factors interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in blood were also significantly inhibited; the expression of proliferating cell nuclear antigen (PCNA) in the spleen and thymus was also significantly increased after low-dose selenium treatment. Surprisingly, 0.4 mg/kg and 0.6 mg/kg of selenium did not effectively alleviate the immunotoxic effects caused by T-2 toxin, and cause damage to a certain extent. In summary, our results show that 0.2 mg/kg of SeMet can effectively alleviate the immunotoxicity caused by T-2 toxin. Selenium may protect rabbits from T-2 toxin by improving its antioxidant and anti-inflammatory capabilities.

The Protective Effect of Selenium on T-2-Induced Nephrotoxicity Is Related to the Inhibition of ROS-Mediated Apoptosis in Mice Kidney

T-2 toxin is produced by the Fusarium genus. Ingestion of food or feed contaminated by T-2 toxin will cause damage to kidney. Selenium (Se), an essential trace element, showed the significant protective effects against kidney and renal cell damage induced by toxic substances. To explore the protective effects and mechanisms of Se against T-2-induced renal lesions, forty-eight male Kunming mice were exposed to T-2 toxin (1.0 mg/kg) and/or Se (0.2 mg/kg) for 28 days. In this study, we found that Se alleviated T-2-induced nephrotoxicity, presenting as increasing the body weight and kidney coefficient, relieving the renal structure injury, decreasing the contents of renal function-related biomarkers, decreasing the levels of reactive oxygen species (ROS), and increasing the mitochondrial membrane potential in T-2 toxin-treated mice. In addition, inhibition of renal cell apoptosis by Se was associated with blocking the mitochondrial pathway in T-2 toxin-treated mice, presenting as decreasing the protein expression of cytochrome-c, activities of caspase-3/9, as well as regulating the protein and mRNA expressions of Bax and Bcl-2. These results documented that the alleviating effect of Se on T-2-induced nephrotoxicity is related to the inhibition of ROS-mediated renal apoptosis.

T-2 toxin causes dysfunction of Sertoli cells by inducing oxidative stress

T-2 toxin is an inevitable mycotoxin in food products and feeds. It is a proven toxicant impairing the male reproductive system. However, previous studies have concentrated on the toxic effect of T-2 toxin on Leydig cells, with little attention on the Sertoli cell cytotoxicity. Therefore, this study aimed to establish the toxic mechanism of T-2 toxin on Sertoli cells. The Sertoli cell line (TM4 cell) was cultured and exposed to different concentrations of T-2 toxin with/without N-acetyl-L-cysteine (NAC) for 24 h. A CCK-8 assay then measured the cell viability. In addition, the expression of TM4 cell biomarkers (FSHR and ABP) and functional factors (occludin (Ocln), zonula occluden-1 (ZO-1), Connexin 43 (Cx-43), and N-Cadherin (N-cad)) were measured by qRT-PCR and Western blotting. The oxidative stress status (ROS, MDA, CAT, and SOD) and apoptosis rate, including the caspase-9, 8, and 3 activities in TM4 cells, were analyzed. We established that (1): T-2 toxin decreased TM4 cells viability and the half-maximal inhibitory concentration was 8.10 nM. (2): T-2 toxin-induced oxidative stress, evidenced by increased ROS and MDA contents, and inhibited CAT and SOD activities. (3): T-2 toxin inhibited FSHR, ABP, ocln, ZO-1, Cx-43, and N-Cad expressions. (4): T-2 toxin promoted TM4 cell apoptosis and caspase-9, 8, and 3 activities. (5): N-acetyl-L-cysteine relieved oxidative stress, functional impairment, and apoptosis in TM4 cells treated with T-2 toxin. Thus, T-2 toxin induced TM4 cell dysfunction through ROS-induced apoptosis.

Effects of Molecular Iodine/Chemotherapy in the Immune Component of Breast Cancer Tumoral Microenvironment

Molecular iodine (I₂) induces apoptotic, antiangiogenic, and antiproliferative effects in breast cancer cells. Little is known about its effects on the tumor immune microenvironment. We studied the effect of oral (5 mg/day) I₂ supplementation alone (I₂) or together with conventional chemotherapy (Cht+I₂) on the immune component of breast cancer tumors from a previously published pilot study conducted in Mexico. RNA-seq, I₂ and Cht+I₂ samples showed significant increases in the expression of Th1 and Th17 pathways. Tumor immune composition determined by deconvolution analysis revealed significant increases in M0 macrophages and B lymphocytes in both I₂ groups. Real-time RT-PCR showed that I₂ tumors overexpress T-BET (p = 0.019) and interferon-gamma (IFNγ; p = 0.020) and silence tumor growth factor-beta (TGFβ; p = 0.049), whereas in Cht+I₂ tumors, GATA3 is silenced (p = 0.014). Preliminary methylation analysis shows that I₂ activates IFNγ gene promoter (by increasing its unmethylated form) and silences TGFβ in Cht+I₂. In conclusion, our data showed that I₂ supplements induce the activation of the immune response and that when combined with Cht, the Th1 pathways are stimulated. The molecular mechanisms involved in these responses are being analyzed, but preliminary data suggest that methylation/demethylation mechanisms could also participate.

Betulinic acid protects against renal damage by attenuation of oxidative stress and inflammation via Nrf2 signaling pathway in T-2 toxin-induced mice

Betulinic acid (BA) is a pentacyclic triterpenoid compound with potential antioxidant and anti-inflammatory effects. In this study, T-2 toxin was injected intraperitoneally in mice to establish kidney damage model and to evaluate the protective effects of BA and further reveal the molecular mechanism. BA pretreatment inhibited the T-2 toxin-stimulated increase in serum Crea, but showed no significant effect on serum Urea. BA pretreatment alleviated excessive glomerular hemorrhage and inflammatory cell infiltration in kidneys caused by T-2 toxin. Moreover, pretreatment with BA mitigated T-2 toxin-induced renal oxidative damage by up-regulating the activities of SOD and CAT, and the content of GSH, while down-regulating the accumulation of ROS and MDA. Meanwhile, BA pretreatment markedly attenuated T-2 toxin-induced renal inflammatory response by decreasing the mRNA expression of IL-1β, TNF-α and IL-10, and increasing IL-6 mRNA expression. Furthermore, mechanism research found that pretreatment with BA could activate Nrf2 signaling pathway. It was suggested that BA ameliorated the oxidative stress and inflammatory response of T-2 toxin-triggered renal damage by activating the Nrf2 signaling pathway.

T-2 Toxin Induces Oxidative Stress at Low Doses via Atf3ΔZip2a/2b-Mediated Ubiquitination and Degradation of Nrf2

T-2 toxin is mainly produced by Fusarium species, which is an extremely toxic mycotoxin to humans and animals. It is well known that T-2 toxin induces oxidative stress, but the molecular mechanism is still unknown. In this study, we found that T-2 toxin significantly promoted reactive oxygen species (ROS) accumulation in MCF-7 cells at low doses which maintains cell viability at least 80%. Further analysis showed that T-2 toxin downregulated the expression of the master regulator of antioxidant defense gene, nuclear factor erythroid 2-related factor (Nrf2), and its targeted antioxidant genes. Overexpression of Nrf2 or its target gene heme oxygenase 1 (HO1) significantly blocked the ROS accumulation in MCF-7 cells under T-2 toxin treatment. Moreover, we found that T-2 toxin downregulated the antioxidant genes via inducing the expression of ATF3ΔZip2a/2b. Importantly, overexpression of ATF3ΔZip2a/2b promoted the ubiquitination and degradation of Nrf2. Altogether, our results demonstrated that T-2 toxin-induced ROS accumulation via ATF3ΔZip2a/2b mediated ubiquitination and degradation of Nrf2, which provided a new insight into the mechanism of T-2 toxin-induced oxidative stress.

Spirulina platensis (Arthrospira platensis) attenuates Cyclophosphamide-induced reproductive toxicity in male Wistar rats: Evidence for sperm apoptosis and p53/Bcl-2 expression

Cyclophosphamide is an antitumor agent that causes disorders in fertility. This study aimed to evaluate the protective effects of Spirulina platensis against Cyclophosphamide-induced testicular toxicity. 42 male Wistar rats were randomly divided into six groups. Experimental groups included three groups. The first experimental group received Cyclophosphamide at a dose of 5 mg/kg body weight (BW) orally. The second and third experimental groups received 5 mg/kg BW Cyclophosphamide and 500 and 1,000 mg/kg BW S. platensis orally, respectively. The control groups included a control group, and two S. platensis control groups. Following 28 days, two flow cytometry techniques were used to determine sperm apoptosis and testicular protein expression of tumor protein (p53) and B-cell lymphoma 2 (Bcl-2). p53 is a tumor suppressor protein that causes the cell to enter the apoptosis cycle after DNA damage and Bcl-2 is an anti-apoptotic protein that acts through the mitochondrial pathway of apoptosis. FITC-Annexin V assay was used for sperm apoptosis evaluation. For protein expression assay, primary and secondary antibodies staining were performed. The Cyclophosphamide group showed a significant increase in sperm apoptosis compared to the control group. Cyclophosphamide significantly increased p53 and decreased Bcl-2 expression compared to the control group. S. platensis co-treated groups exhibited a significant decrease in sperm apoptosis compared to the Cyclophosphamide group. Moreover, S. platensis co-treated groups displayed a significant decreasing in p53 and increasing in Bcl-2 expression compared to the Cyclophosphamide group. The results of this study indicated that S. platensis protected rats against Cyclophosphamide-induced reproductive toxicity. PRACTICAL APPLICATIONS: Cyclophosphamide is the chemotherapy agent used to treat different cancers. Cyclophosphamide has side effects on the male reproductive system. Spirulina plantesis has a protective effect because of its antioxidant and anti-apoptotic properties. Co-administration of Spirulina plantesis with Cyclophosphamide reduces sperm apoptosis also decreases P53 protein expression and increases Bcl-2 protein expression. This study validated the anti-apoptotic potential of Spirulina plantesis against Cyclophosphamide-induced male reproductive toxicity.

Neuroimmune disruptions from naturally occurring levels of mycotoxins

Substantial pieces of evidence support the potential of exogenous toxins in disrupting neuroimmune homeostasis. It appears that mycotoxins are one of the noticeable sources of naturally occurring substances dysregulating the immune system, which involves the physiology of many organs, such as the central nervous system (CNS). The induction of inflammatory responses in microglial cells and astrocytes, the CNS resident cells with immunological characteristics, could interrupt the hemostasis upon even with low-level exposure to mycotoxins. The inevitable widespread occurrence of a low level of mycotoxins in foods and feed is likely increasing worldwide, predisposing individuals to potential neuroimmunological dysregulations. This paper reviews the current understanding of mycotoxins' neuro-immunotoxic features under low-dose exposure and the possible ways for detoxification and clearance as a perspective.

Protective effect of selenomethionine on T-2 toxin-induced liver injury in New Zealand rabbits

Background

T-2 toxin is a mycotoxin produced by Fusarium species that is highly toxic to animals. Recent studies have indicated that Selenomethionine (SeMet) have protective effect against mycotoxins-induced toxicity. The aim of the present study was to investigate the protective effect of SeMet on T-2-toxin-induced liver injury in rabbit and explore its molecular mechanism. Fifty rabbits (30 d, 0.5 ± 0.1 kg) were randomly divided into 5 groups: control group, T-2 toxin group, low, medium and high dose SeMet treatment group. The SeMet-treated group was orally pretreated with SeMet (containing selenium 0.2 mg/kg, 0.4 mg/kg and 0.6 mg/kg) for 21 days. On the 17th day, T-2 toxin group and SeMet-treated group were orally administered with T-2 toxin (0.4 mg/kg body weight) for 5 consecutive days.

Results

The results showed that low-dose SeMet significantly improved T-2 toxin-induced liver injury. We found that low-dose SeMet can reduce the level of oxidative stress and the number of hepatocyte apoptosis. Moreover, the levels of Bax, caspase-3 and caspase-9 were significantly reduced and the levels of Bcl-2 were increased.

Conclusions

Therefore, we confirmed that low-dose SeMet may protect rabbit hepatocytes from T-2 toxin by inhibiting the mitochondrial-caspase apoptosis pathway.

Cadmium triggers oxidative stress and mitochondrial injury mediated apoptosis in human extravillous trophoblast HTR-8/SVneo cells

Cadmium (Cd) is a bioaccumulative heavy metal element with potential placental toxicity during pregnancy. Up to now, however, the precise toxic effects of Cd on human placentae, particularly as they pertain to trophoblast cells remain obscure. We therefore sought to investigate the cytotoxic effects of Cd on human extravillous trophoblast HTR-8/SVneo cells and the mechanisms involved in the processes. Results in this present study showed that CdCl2 treatment significantly suppressed cell viability and induced noticeable oxidative stress in HTR-8/SVneo cells. Further studies showed that CdCl2 treatment caused distortion of mitochondrial structure, reduction of mitochondrial membrane potential (Δψm), DNA damage and G0/G1 phase arrest. Under the same condition, CdCl2 treatment increased Bax/Bcl-2 ratios by up-regulating Bax expression and down-regulating Bcl-2 expression, and activated apoptotic executive molecule caspase-3, which irreversibly induced HTR-8/SVneo cell apoptosis. N-acetyl-l-cysteine (NAC), ROS scavenger, significantly attenuated CdCl2-caused mitochondrial injury, DNA damage, G0/G1 phase arrest and apoptosis. In addition, in vivo assay suggested that CdCl2 induced trophoblast cells apoptosis but not other cells in mice placental tissue. Taken together, these data suggest that Cd selectively triggers oxidative stress and mitochondrial injury mediated apoptosis in trophoblast cells, which might contribute to placentae impairment and placental-related disorders after Cd exposure. These findings may provide new insights to understand adverse effects of Cd on placentae during pregnancy.

HT-2 toxin affects cell viability of goat spermatogonial stem cells through AMPK-ULK1 autophagy pathways

HT-2 toxin is widely found in moldy crops and is the major metabolite of T-2 toxin, which has been shown to exert various toxic effects in farm animals. However, little is known about the effects of HT-2 toxin on male reproduction, particularly spermatogenesis. This study aims to investigate the toxic effects of HT-2 toxin on goat spermatogonial stem cells (SSCs) and related autophagy-regulated mechanisms. Our results showed that HT-2 toxin exposure resulted in decreased cell viability and proliferation, disrupted SSCs self-renewal, and reduced germ cell-related gene expression. HT-2 toxin exposure also induced oxidative stress and cell apoptosis, as shown by ROS accumulation, increased antioxidant enzyme activity levels, decreased the mitochondrial membrane potential, and increased caspase-9 mRNA and Bcl/bax protein levels. Additionally, HT-2 toxin exposure increased the expression of the autophagy-inducing genes Atg5, Atg7 and Beclin1 and the number of autophagosomes, which indicated that HT-2 toxin induced autophagy in the goat SSCs. Moreover, we also examined a possible mechanism by which HT-2 toxin exposure induced higher expression of AMPK, mTOR and ULK at both the mRNA and protein levels. our results indicated that HT-2 toxin caused apoptosis and autophagy by activating AMPK-mTOR-ULK1 pathway, which further affected SSCs viability.

Betulinic Acid Alleviates Spleen Oxidative Damage Induced by Acute Intraperitoneal Exposure to T-2 Toxin by Activating Nrf2 and Inhibiting MAPK Signaling Pathways

T-2 toxin, which is mainly produced by specific strains of Fusarium in nature, can induce immunotoxicity and oxidative stress, resulting in immune organ dysfunction and apoptosis. Betulinic acid (BA), a pentacyclic triterpenoids from nature plants, has been demonstrated to possess immunomodulating and antioxidative bioactivities. The purpose of the study was to explore the effect of BA on T-2 toxin-challenged spleen oxidative damage and further elucidate the underlying mechanism. We found that BA not only ameliorated the contents of serum total cholesterol (TC) and triglyceride (TG) but also restored the number of lymphocytes in T-2 toxin-induced mice. BA dose-dependently reduced the accumulation of reactive oxygen species (ROS), enhanced superoxide dismutase (SOD) activity, and decreased malondialdehyde (MDA) content, as well as increased the total antioxidant capacity (T-AOC) in the spleen of T-2-toxin-exposed mice. Moreover, BA reduced inflammatory cell infiltration in the spleen, improved the morphology of mitochondria and enriched the number of organelles in splenocytes, and dramatically attenuated T-2 toxin-triggered splenocyte apoptosis. Furthermore, administration of BA alleviated the protein phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK); decreased the protein expression of kelch-like erythroid cell-derived protein with CNC homology [ECH]-associated protein1 (Keap1); and increased the protein expression of nuclear factor erythroid 2 [NF-E2]-related factor (Nrf2) and heme oxygenase-1 (HO-1) in the spleen. These findings demonstrate that BA defends against spleen oxidative damage associated with T-2 toxin injection by decreasing ROS accumulation and activating the Nrf2 signaling pathway, as well as inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway.

Novel colorimetric aptasensor based on unmodified gold nanoparticle and ssDNA for rapid and sensitive detection of T-2 toxin

A novel colorimetric aptasensor based on unmodified gold nanoparticle (AuNPs) and single-strand DNA (ssDNA) aptamer was developed for the rapid and sensitive detection of T-2 toxin. In the absence of T-2, the AuNPs were wrapped by the aptamer to avoid the salt-induced aggregation and the solution remains red. In the presence of T-2, the aptamer was bound with T-2 and released from the surface of AuNPs, resulting in the aggregation of AuNPs under proper salt solution and the color change from red to purple-blue. The aptasensor exhibited a high sensitivity and selectivity for the detection of T-2. The range of linearity and detection limit were 0.1 ng/mL-5000 ng/mL (0.21435 nM-10717.5 nM) and 57.8 pg/mL (0.124 nM), respectively. The aptasensor developed here was applicable to assay T-2 in wheat and corn samples. These results implied that the colorimetric aptasensor was potentially useful in food detection.

The Impact of Fermented Wheat Germ Extract on Porcine Epithelial Cell Line Exposed to Deoxynivalenol and T-2 Mycotoxins

The effect of fermented wheat germ extract (FWGE) (Immunovet®) was evaluated with cotreatments with deoxynivalenol (DON) and T-2 toxin (T-2). These mycotoxins are produced by Fusarium mold species. The effects of FWGE on IPEC-J2 with DON and T-2 have not been studied until now. The IPEC-J2 porcine, nontumorigenic cell line was selected to investigate the outcome of the individually and simultaneously added compounds, as it has in vivo-like properties. The cells were treated for 24 h with the selected solutions; then, the IPEC-J2 cells were allowed to regenerate in a culture medium for an additional 24 h. In our results, DON and T-2 significantly increased the adverse impacts on cell viability and integrity of the cell monolayer. To elucidate the extent of oxidative stress, extracellular H₂O₂ concentrations and intracellular reactive oxygen species (ROS) were measured. FWGE appeared to be beneficial to IPEC-J2 cells given the separately and significantly decreased ROS levels. 1% and 2% FWGE could significantly reduce mycotoxin-induced oxidative stress. In conclusion, the results demonstrate that FWGE exerted protective effects to counteract the oxidative stress-provoking properties of applied fusariotoxins in the nontumorigenic IPEC-J2 cell line.

Quercetin mitigates the deoxynivalenol mycotoxin induced apoptosis in SH-SY5Y cells by modulating the oxidative stress mediators

Deoxynivalenol (DON) is Fusarium mycotoxin that is frequently found in many cereal-based foods, and its ingestion has a deleterious impact on human health. In this investigation, we studied the mechanism of DON-induced neurotoxicity and followed by cytoprotective efficacy of quercetin (QUE) in contradiction of DON-induced neurotoxicity through assessing the oxidative stress and apoptotic demise in the human neuronal model, i.e. SH-SY5Y cells. DON diminished the proliferation of cells in the manner of dose and time-dependent as revealed by cell viability investigations, i.e. MTT and lactate dehydrogenase assays. Additional studies, such as intracellular reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), DNA damage, cell cycle, and neuronal biomarkers (amino acid decarboxylase, tyrosine hydroxylase, and brain-derived neurotrophic factor) demonstrated that DON induces apoptotic demise in neuronal cells through oxidative stress intermediaries. On another hand, pre-treatment of neuronal cells with 1 mM of quercetin (QUE) showed decent viability upon exposure to 100 µM of DON. In detailed studies demonstrated that QUE (1 mM) pre-treated cells show strong attenuation efficiency against DON-induced ROS generation, LPO, MMP loss, DNA impairment, cell cycle arrest, and down-regulation of neuronal biomarkers. The consequences of the investigation concluded that QUE mitigates the DON-induced stress viz., decreased ROS production and LPO generation, upholding MMP and DNA integrity and regulation of neuronal biomarker gene expression in SH-SY5Y cells.

Preparation of T‑2 toxin‑containing pH‑sensitive liposome and its antitumor activity

T‑2 toxin is a type A trichothecene mycotoxin. In order to reduce the side effects of T‑2 toxin and increase the tumor targeting ability, a pH‑sensitive liposome of T‑2 toxin (LP‑pHS‑T2) was prepared and characterized in the present study. The cytotoxicity of LP‑pHS‑T2 on A549, Hep‑G2, MKN‑45, K562 and L929 cell lines was tested by 3‑(4,5‑dimethylthiazolyl‑2)‑2,5‑diphenyltetrazolium bromide assay, with T‑2 toxin as the control. The apoptotic and migratory effects of LP‑pHS‑T2 on Hep‑G2 cells were investigated. The preparation process of LP‑pHS‑T2 involved the following parameters: Dipalmitoyl phosphatidylcholine: dioleoylphosphatidylethanolamine, 1:2; total phospholipid concentration, 20 mg/ml; phospholipid:cholesterol, 3:1; 4‑(2‑hydroxyethyl)‑1‑piperazineethanesulfonic acid buffer (pH 7.4), 10 ml; drug:lipid ratio, 2:1; followed by ultrasound for 10 min and extrusion. The encapsulation efficiency reached 95±2.43%. The average particle size of LP‑pHS‑T2 after extrusion was 100 nm; transmission electron microscopy showed that the shape of LP‑pHS‑T2 was round or oval and of uniform size. The release profile demonstrated a two‑phase downward trend, with fast leakage of T‑2 toxin in the first 6 h (~20% released), followed by sustained release up to 48 h (~46% released). From 48‑72 h, the leakage rate increased (~76% released), until reaching a minimum at 72 h. When LP‑pHS‑T2 was immersed in 0.2 mol/l disodium phosphate‑sodium dihydrogen phosphate buffers (pH 6.5), the release speed was significantly increased and the release rate reached 91.2%, demonstrating strong pH sensitivity. Overall, antitumor tests showed that LP‑pHS‑T2 could promote the apoptosis and inhibit the migration of Hep‑G2 cells. The present study provided a new approach for the development of T‑2 toxin‑based anti‑cancer drugs.

An update on T-2 toxin and its modified forms: metabolism, immunotoxicity mechanism, and human exposure assessment

T-2 toxin is the most toxic trichothecene mycotoxin, and it exerts potent toxic effects, including immunotoxicity, neurotoxicity, and reproductive toxicity. Recently, several novel metabolites, including 3',4'-dihydroxy-T-2 toxin and 4',4'-dihydroxy-T-2 toxin, have been uncovered. The enzymes CYP3A4 and carboxylesterase contribute to T-2 toxin metabolism, with 3'-hydroxy-T-2 toxin and HT-2 toxin as the corresponding primary products. Modified forms of T-2 toxin, including T-2-3-glucoside, exert their immunotoxic effects by signaling through JAK/STAT but not MAPK. T-2-3-glucoside results from hydrolyzation of the corresponding parent mycotoxin and other metabolites by the intestinal microbiota, which leads to enhanced toxicity. Increasing evidence has shown that autophagy, hypoxia-inducible factors, and exosomes are involved in T-2 toxin-induced immunotoxicity. Autophagy promotes the immunosuppression induced by T-2 toxin, and a complex crosstalk between apoptosis and autophagy exists. Very recently, "immune evasion" activity was reported to be associated with this toxin; this activity is initiated inside cells and allows pathogens to escape the host immune response. Moreover, T-2 toxin has the potential to trigger hypoxia in cells, which is related to activation of hypoxia-inducible factor and the release of exosomes, leading to immunotoxicity. Based on the data from a series of human exposure studies, free T-2 toxin, HT-2 toxin, and HT-2-4-glucuronide should be considered human T-2 toxin biomarkers in the urine. The present review focuses on novel findings related to the metabolism, immunotoxicity, and human exposure assessment of T-2 toxin and its modified forms. In particular, the immunotoxicity mechanisms of T-2 toxin and the toxicity mechanism of its modified form, as well as human T-2 toxin biomarkers, are discussed. This work will contribute to an improved understanding of the immunotoxicity mechanism of T-2 toxin and its modified forms.

Protective Effects of Boron on Cyclophosphamide-Induced Bladder Damage and Oxidative Stress in Rats

This study aims to investigate protective effects of boron against cyclophosphamide-induced bladder toxicity that produces oxidative stress and leads to apoptosis of the cells. In total, 24 rats were divided into 4 equal groups. The control group received saline. The 2nd experimental group received 200 mg kg of cyclophosphamide i.p. on the 4th day while the 3rd group was given only boron (200 mg kg, i.p.) for 6 days. In the 4th group, boron was given for 6 days and cyclophosphamide (200 mg kg, i.p.) was administrated on the 4th day. Twenty-four hours after the last boron or cyclophosphamide administration, rats were sacrificed under anesthesia. Bladder tissues of rats were taken for histological and immunohistochemical (apoptotic markers such as caspase-3, bcl-2, and bax) and blood was taken for the biochemical (serum total thiol, serum natural thiol, serum thiol-disulfide) analysis. Transient epithelial thinning, edema, marked inflammatory reaction, and bleeding were observed in bladders of the group that received cyclophosphamide. Also, the activity of bax and caspase-3-positive cells increased while the number of bcl-2-positive cells decreased. In the same group, serum natural thiol and total thiol levels decreased while serum disulfide levels increased, which indicates oxidative stress. On the other hand, in the boron+cyclophosphamide group pretreatment with boron protected, the bladder tissue and the number of bcl-2-positive cells increased, and bax and caspase-3-positive cells decreased, showing antiapoptotic effects of boron against cyclophosphamide-induced toxicity. In parallel with the findings of this group, native thiol and total thiol levels increased and serum disulfide levels decreased pointing out to a decreased oxidative stress. Our results indicate that boron pretreatment significantly protects rat bladder against cyclophosphamide-induced bladder damage due to its antiapoptotic and antioxidant properties.

Betulinic Acid Attenuates Oxidative Stress in the Thymus Induced by Acute Exposure to T-2 Toxin via Regulation of the MAPK/Nrf2 Signaling Pathway

T-2 toxin, the most toxic of the trichothecenes, is widely found in grains and feeds, and its intake poses serious risks to the health of humans and animals. An important cytotoxicity mechanism of T-2 toxin is the production of excess free radicals, which in turn leads to oxidative stress. Betulinic acid (BA) has many biological activities, including antioxidant activity, which is a plant-derived pentacyclic triterpenoid. The protective effects and mechanisms of BA in blocking oxidative stress caused by acute exposure to T-2 toxin in the thymus of mice was studied. BA pretreatment reduced ROS production, decreased the MDA content, and increased the content of IgG in serum and the levels of SOD and GSH in the thymus. BA pretreatment also reduced the degree of congestion observed in histopathological tissue sections of the thymus induced by T-2 toxin. Besides, BA downregulated the phosphorylation of the p38, JNK, and ERK proteins, while it upregulated the expression of the Nrf2 and HO-1 proteins in thymus tissues. The results indicated that BA could protect the thymus against the oxidative damage challenged by T-2 toxin by activating Nrf2 and suppressing the MAPK signaling pathway.

Protective effect of selenomethionine on intestinal injury induced by T- 2 toxin

T-2 toxin is the most toxic as a type A trichothecenes, which could contaminate grains, especially in wheat and corn. It can cause immune suppression, neurotoxicity, the apoptosis of cells and even induce tumorigenesis. Recent studies have indicated that selenium (Se) have protective effect against mycotoxins-induced toxicity. The present studies was designed to investigate the protective role of Selenomethionine (SeMet) on T-2 toxin-induced toxicity in rabbit's jejunum. 50 New Zealand rabbits were divided into five group (Control group, T-2 group, low-dose Se + T-2 group, medium-dose + T-2 group and high-dose Se + T-2 group). New Zealand rabbits were orally administered with SeMet (0.2, 0.4 and 0.6 mg/kg, Adding diet) for 21 days. On 17th days, each group began to take 0.4 mg/kg of T-2 toxin orally every day for 5 days. We found that rabbit exposed to T-2 toxin could increase the levels of ROS, and decrease activities of antioxidant enzymes and the expression of Occludin and ZO-1. In addition, T-2 toxin could trigger jejunal inflammatory response and enhance the expression of IL-1β, IL-6 and TNF-α. After SeMet pretreatment, our results indicated that Se attenuated the T-2 toxin-induced oxidative stress, decreasing the level of ROS, MDA and enhancing the activity of SOD and GSH-Px. Moreover, SeMet can alleviate jejunal inflammatory response, and protect the integrity of the intestinal barrier through up-regulating the expression of ZO-1 and Occludin. In the present research, supplementation of 0.2 mg/kg SeMet in the diet could effectively alleviate the T-2 toxin poisoning in rabbits.

The role of mitochondria in sterigmatocystin-induced apoptosis on SH-SY5Y cells

Mitochondria are cellular organelles involved in many crucial functions, such as generation of energy (ATP) and initiation of apoptosis. The aim of the present study was to evaluate the role of mitochondria in the toxicity induced by sterigmatocystin (STE), a mycotoxin produced by fungi of the genus Aspergillus, on SH-SY5Y cells. Our results showed that STE exposure decreased cell viability in a time- and concentration-dependent manner by MTT assay and caused mitochondrial dysfunction, as highlighted by the increase of STE cytotoxicity in cells forced to rely on mitochondrial oxidative phosphorylation. Furthermore, intracellular ATP depletion and increased mitochondrial reactive oxygen species were also observed. Since mitochondria play a pivotal role in apoptosis, the induction of this process in response to STE exposure was decided to study. Our results showed an increase in apoptotic cell population by flow cytometry, further confirmed by the up-regulation of the expression levels of the pro-apoptotic genes Bax and Casp-3 and the down-regulation of the anti-apoptotic gene Bcl-2 by qPCR technique. Taken together, our results provide novel insights in the signalling pathways of the cell death process induced by STE in SH-SY5Y cells, highlighting the key role played by mitochondria in STE toxicity.

Does low concentration mycotoxin exposure induce toxicity in HepG2 cells through oxidative stress?

The purpose of this study was to determine whether exposure to low concentrations of deoxynivalenol (DON), T-2 toxin (T-2) and patulin (PAT) in a human hepatocellular carcinoma cell line (HepG2) exerts toxic effects through mechanisms related to oxidative stress, and how cells deal with such exposure. Cell viability was determined by the MTT and protein content (PC) assays over 24, 48 and 72 h. The IC₅₀ values detected ranged from >10 to 2.53 ± 0.21 μM (DON), 0.050 ± 0.025 to 0.034 ± 0.007 μM (T-2) and 2.66 ± 0.66 to 1.17 ± 0.21 µM (PAT). The key players in oxidative stress are the generation of reactive oxygen species (ROS), lipid peroxidation (LPO) and mitochondrial membrane potential (MMP) dysfunction. The results obtained showed that PAT, DON and T-2 did not significantly increase LPO or ROS production with respect to the controls. Moreover, PAT and DON did not alter MMP, though T-2 increased MMP at the higher concentrations tested (17 and 34 nM). In conclusion, the exposure of HepG2 cells to nontoxic concentrations of T-2 condition them against subsequent cellular oxidative conditions induced by even higher concentrations of mycotoxin.

R, Basalingappa KM. Toxicopathological studies on the effects of T-2 mycotoxin and their interaction in juvenile goats

Food and feeds contaminated with mycotoxins have been a threat to the rearing industry by causing some of the most fatal toxic reactions not only in the farm animals but also in humans who consume them. Toxicity to juvenile goats was induced by feed contamination with T-2 toxin (at 10 and 20 ppm dosage; group I and II, respectively). The toxicity impact was assessed on days 15 and 30 post treatment with respect to growth performance, oxidative stress, apoptotic studies and detailed pathomorphology. The study revealed that apart from the obvious clinical toxicosis (weakness, lethargy, and retardation in growth), the toxin fed groups also exhibited significant haematological (reduced hemoglobin, total leukocyte and thrombocyte counts) and biochemical changes (increased levels of oxidative stress markers with concomitant decrease in levels of serum and tissue catalase and superoxide dismutase). The pathomorphological and histological alterations suggested that the liver and intestine were the most affected organs. Ultra-structurally, varying degrees of degeneration, cytoplasmic vacuolations and pleomorphic mitochondria were observed in the hepatocytes and the enterocytes of the intestine. Kidney also revealed extensive degeneration of the cytoplasmic organelles with similar condensation of the heterochromatin whereas the neuronal degeneration was characterized by circular, whirling structures. In addition, the central vein and portal triad of the hepatocytes, cryptic epithelial cells of the intestine, MLNs in the lymphoid follicles, PCT and DCT of the nephronal tissues and the white pulp of the spleen exhibited extensive apoptosis. In this study, it was also observed that the expression of HSPs, pro-apoptotic proteins and pro-inflammatory cytokines were significantly upregulated in response to the toxin treatment. These results suggest that the pathogenesis of T-2 toxicosis in goats employs oxidative, apoptotic and inflammatory mechanisms.

Cellular Effects of T-2 Toxin on Primary Hepatic Cell Culture Models of Chickens

Trichothecene mycotoxins such as T-2 toxin cause severe problems for agriculture, as well as for veterinary medicine. As liver is one of the key organs in metabolism, the main aim of our study was to investigate the immunomodulatory and cytotoxic effects of T-2 toxin, using primary hepatocyte mono-culture and hepatocyte-nonparenchymal cell (predominantly Kupffer cell) co-culture models of chicken. Cultures were exposed to 10 (T10 group), 100 (T100 group) and 1000 (T1000 group) nmol/L T-2 toxin treatment for 8 or 24 h. Alterations of cellular metabolic activity, the production of reactive oxygen species (extracellular H2O2), heat shock protein 70 (HSP70), and the concentration of different inflammatory cytokines such as interleukin (IL-)6 and IL-8 were investigated. Metabolic activity was intensely decreased by T-2 toxin administration in all of the cell culture models, in every applied concentration and incubation time. Concentrations of HSP70 and IL-8 were significantly increased in hepatocyte mono-cultures exposed to higher T-2 toxin levels (both in T100 and T1000 groups for HSP70 and in T1000 group for IL-8, respectively) compared to controls after 24 h incubation. Similarly, IL-6 levels were also significantly elevated in the T100 and T1000 groups in both of mono- and co-cultures, but only after 8 h of incubation time. In spite of the general harmful effects of T-2 toxin treatment, no significant differences were observed on reactive oxygen species production. Furthermore, the two cell culture models showed different levels of H2O2, HSP70, and IL-8 concentrations independently of T-2 toxin supplementation. In conclusion, the established primary cell cultures derived from chicken proved to be proper models to study the specific molecular effects caused by T-2 toxin. Metabolic activity and immune status of the different examined cell cultures were intensively affected; however, no changes were found in H2O2 levels.

T-2 Toxin-Induced Oxidative Stress Leads to Imbalance of Mitochondrial Fission and Fusion to Activate Cellular Apoptosis in the Human Liver 7702 Cell Line

T-2 toxin, as a highly toxic mycotoxin to humans and animals, induces oxidative stress and apoptosis in various cells and tissues. Apoptosis and mitochondrial fusion/fission are two tightly interconnected processes that are crucial for maintaining physiological homeostasis. However, the role of mitochondrial fusion/fission in apoptosis of T-2 toxin remains unknown. Hence, we aimed to explore the putative role of mitochondrial fusion/fission on T-2 toxin induced apoptosis in normal human liver (HL-7702) cells. T-2 toxin treatment (0, 0.1, 1.0, or 10 μg/L) for 24 h caused decreased cell viability and ATP concentration and increased production of (ROS), as seen by a loss of mitochondrial membrane potential (∆Ψm) and increase in mitochondrial fragmentation. Subsequently, the mitochondrial dynamic imbalance was activated, evidenced by a dose-dependent decrease and increase in the protein expression of mitochondrial fusion (OPA1, Mfn1, and Mfn2) and fission (Drp1 and Fis1), respectively. Furthermore, the T-2 toxin promoted the release of cytochrome c from mitochondria to cytoplasm and induced cell apoptosis triggered by upregulation of Bax and Bax/Bcl-2 ratios, and further activated the caspase pathways. Taken together, these results indicate that altered mitochondrial dynamics induced by oxidative stress with T-2 toxin exposure likely contribute to mitochondrial injury and HL-7702 cell apoptosis.

Critical role of caveolin-1 in aflatoxin B1-induced hepatotoxicity via the regulation of oxidation and autophagy

Aflatoxin B1 (AFB1) is a potent hepatocarcinogen in humans and exposure to AFB1 is known to cause both acute and chronic hepatocellular injury. As the liver is known to be the main target organ of aflatoxin, it is important to identify the key molecules that participate in AFB1-induced hepatotoxicity and to investigate their underlying mechanisms. In this study, the critical role of caveolin-1 in AFB1-induced hepatic cell apoptosis was examined. We found a decrease in cell viability and an increase in oxidation and apoptosis in human hepatocyte L02 cells after AFB1 exposure. In addition, the intracellular expression of caveolin-1 was increased in response to AFB1 treatment. Downregulation of caveolin-1 significantly alleviated AFB1-induced apoptosis and decreased cell viability, whereas overexpression of caveolin-1 reversed these effects. Further functional analysis showed that caveolin-1 participates in AFB1-induced oxidative stress through its interaction with Nrf2, leading to the downregulation of cellular antioxidant enzymes and the promotion of oxidative stress-induced apoptosis. In addition, caveolin-1 was found to regulate AFB1-induced autophagy. This finding was supported by the effect that caveolin-1 deficiency promoted autophagy after AFB1 treatment, leading to the inhibition of apoptosis, whereas overexpression of caveolin-1 inhibited autophagy and accelerated apoptosis. Interestingly, further investigation showed that caveolin-1 participates in AFB1-induced autophagy by regulating the EGFR/PI3K-AKT/mTOR signaling pathway. Taken together, our data reveal that caveolin-1 plays a crucial role in AFB1-induced hepatic cell apoptosis via the regulation of oxidation and autophagy, which provides a potential target for the development of novel treatments to combat AFB1 hepatotoxicity.

Betulinic Acid Attenuates T-2-Toxin-Induced Testis Oxidative Damage Through Regulation of the JAK2/STAT3 Signaling Pathway in Mice

T-2 toxin is one of the most toxic type A trichothecene mycotoxins in nature, and it exhibits reproductive toxicity. Betulinic acid (BA) is a natural pentacyclic triterpene compound found in species of Betula, and it has been reported to have antioxidant activity. The aim of the present study was to investigate the protective effect of BA on T-2-toxin-induced testicular injury in mice and explore its molecular mechanism. Sixty adult male mice were randomly divided into groups. The mice were pretreated orally with BA (0.25, 0.5, and 1.0 mg/kg) daily for 14 days, and the T-2 toxin (4 mg/kg body weight) was administered via intraperitoneal injection to induce oxidative stress after the last administration of BA. BA pretreatment significantly increased the secreted levels of testosterone and sperm motility. Moreover, BA pretreatment significantly increased the total antioxidant capacity (T-AOC), the activity of SOD and CAT, and the content of GSH, and it reduced the content of MDA. Furthermore, BA relieved testicular injury and reduced the number of apoptotic cells, and it significantly decreased the protein expression of Janus kinase 2 (JAK2), signal transducers and activators of transcription 3 (STAT3), caspsae-3, and Bcl-2-associated X protein (Bax). BA also increased the expression of B-cell lymphoma-2 (Bcl-2). We suggest that BA reduced the oxidative damage induced by T-2 toxin, and that these protective effects may be partially mediated by the JAK2/STAT3 signaling pathway.

Oxidative Stress and Apoptotic Changes in Broiler Chicken Splenocytes Exposed to T-2 Toxin

T-2 toxin is a trichothecene mycotoxin produced by fungi which are known to contaminate cereals, especially in wheat and corn. T-2 toxin is known to cause a range of toxic effects in humans and animals, including immunosuppression and carcinogenesis. Although the effects of T-2 toxin on condition of chickens' spleens have been reported, there has been no systematic study of damage to the spleen of broiler chickens exposed to T-2 toxin. The purpose of the present study was to assess the effects of T-2 toxin on pathology, rates of apoptosis, oxidative stress, and T-lymphocyte subsets in the spleen of broiler chickens. One hundred and twenty male broiler chickens were randomly assigned to one of four groups (30 birds per group), fed 0 mg/kg (control), 0.5 mg/kg, 1 mg/kg, or 2 mg/kg T-2 toxin, respectively. After 21 days, chickens exposed to T-2 toxin demonstrated decreased relative weight and size of the spleen, increased percentage of apoptotic splenocytes, and evident lesions. Concentrations of reactive oxygen species and MDA content increased in splenocytes during T-2 toxin treatments, whereas activities of SOD, CAT, and GSH-PX decreased. The ratio of CD4+/CD8+ T cells also decreased as the dose of T-2 toxin increased. Overall, these results suggest that T-2 toxin causes oxidative stress, leading to increased rates of splenocyte apoptosis and might impair the splenic immune function of broiler chickens.

T-2 toxin upregulates the expression of human cytochrome P450 1A1 (CYP1A1) by enhancing NRF1 and Sp1 interaction

T-2 toxin is a major pollutant in crops and feedstuffs. Due to its high toxicity in a variety of organisms, T-2 toxin is of great concern as a threat to humans and to animal breeding. Overexpression of CYP1A1 may contribute to carcinogenesis, and CYP1A1 may be a promising target for the prevention and treatment of human malignancies. Therefore, it is essential to understand the regulatory mechanism by which T-2 toxin induces CYP1A1 expression in human cells. In this study, we confirmed that T-2 toxin (100 ng/mL) induced the expression of CYP1A1 in HepG2 cells through NRF1 and Sp1 bound to the promoter instead of through the well-recognized Aromatic hydrocarbon receptors (AhR). In cells treated with T-2 toxin, Sp1, but not NRF1, was significantly upregulated. However, T-2 toxin apparently promoted the interaction between NRF1 and Sp1 proteins, as revealed by IP analysis. Furthermore, in T-2 toxin-treated HepG2 cells, nuclear translocation of NRF1 was enhanced, while knockdown of Sp1 ablated NRF1 nuclear enrichment. Our results revealed that the upregulation of CYP1A1 by T-2 toxin in HepG2 cells depended on enhanced interaction between Sp1 and NRF1. This finding suggests the tumorigenic features of T-2 toxin might be related to the CYP1A1, which provides new insights to understand the toxicological effect of T-2 toxin.

T-2 toxin neurotoxicity: role of oxidative stress and mitochondrial dysfunction

Mycotoxins are highly diverse secondary metabolites produced in nature by a wide variety of fungi. Mycotoxins cause animal feed and food contamination, resulting in mycotoxicosis. T-2 toxin is one of the most common and toxic trichothecene mycotoxins. For the last decade, it has garnered considerable attention due to its potent neurotoxicity. Worryingly, T-2 toxin can cross the blood-brain barrier and accumulate in the central nervous system (CNS) to cause neurotoxicity. This review covers the current knowledge base on the molecular mechanisms of T-2 toxin-induced oxidative stress and mitochondrial dysfunction in the CNS. In vitro and animal data have shown that induction of reactive oxygen species (ROS) and oxidative stress plays a critical role during T-2 toxin-induced neurotoxicity. Mitochondrial dysfunction and cascade signaling pathways including p53, MAPK, Akt/mTOR, PKA/CREB and NF-κB contribute to T-2 toxin-induced neuronal cell death. T-2 toxin exposure can also result in perturbations of mitochondrial respiratory chain complex and mitochondrial biogenesis. T-2 toxin exposure decreases the mitochondria unfolded protein response and dampens mitochondrial energy metabolism. Antioxidants such as N-acetylcysteine (NAC), activation of Nrf2/HO-1 and autophagy have been shown to provide a protective effect against these detrimental effects. Clearly, translational research and the discovery of effective treatment strategies are urgently required against this common food-borne threat to human health and livestock.

Probucol Protects Against Contrast-Induced Acute Kidney Injury via the Extracellular Signal-Regulated Kinases 1 and 2 (ERK1/2)/JNK-Caspase 3 Pathway in Diabetic Rats

Background

Contrast-induced acute kidney injury is an important clinical problem, yet its pathogenic mechanisms are incompletely understood. In this study we explored the potential beneficial effects of probucol as treatment of contrast-induced acute kidney injury in diabetic rats.

Material/Methods

Rats were divided into 3 groups: i) diabetic control, ii) diabetic with contrast, and iii) probucol treatment groups. Probucol was administered by gavage and the contrast diatrizoate (60%) was injected via femoral vein. After 24 h, the rats were sacrificed and samples were taken to measure biochemical indicators. Pathological damage of renal tubules was evaluated by HE staining. Expression of Bcl-2, Bax, p-ERKs, and p-JNK proteins in the kidneys was examined by Western blotting, whereas expression level of caspase-3 in kidneys was detected by immunohistochemistry.

Results

Compared to the probucol treatment group, the diabetes with contrast group showed higher serum creatinine and lower creatinine clearance. The pathological changes of kidneys in the probucol treatment group were improved compared with the contrast group. Moreover, Western blot analyses revealed that use of contrast agent led to lower p-ERK1/2, higher p-JNK, lower Bcl-2, and higher Bax levels, which were reversed by probucol. Finally, immunohistochemical findings revealed higher caspase-3 after contrast use, which was partially reversed by probucol.

Conclusions

Probucol exerts protective effects on contrast-induced acute kidney injury in diabetic rats by inhibition of renal cell apoptosis. This is achieved by reducing mitochondrial caspase-3 expression through increasing and decreasing the expression of the upstream mediators p-ERK1/2 and p-JNK, respectively.