T-2 mycotoxin slows down the development of mouse blastocysts, decreases their blastomere number and increases chromatin damage

Review of the Reproductive Toxicity of T-2 Toxin

T-2 toxin, an inevitable environmental pollutant, is the most toxic type A trichothecene mycotoxin. Reproductive disruption is a key adverse effect of T-2 toxin. Herein, this paper reviews the reproductive toxicity of T-2 toxin and its mechanisms in male and female members of different species. The reproductive toxicity of T-2 toxin is evidenced by decreased fertility, disrupted structures and functions of reproductive organs, and loss of gametogenesis in males and females. T-2 toxin disrupts the reproductive endocrine axis and inhibits reproductive hormone synthesis. Furthermore, exposure to T-2 toxin during pregnancy results in embryotoxicity and the abnormal development of offspring. We also summarize the research progress in counteracting the reproductive toxicity of T-2 toxin. This review provides information toward a comprehensive understanding of the reproductive toxicity mechanisms of T-2 toxin.

Effects of T-2 and Fumonisin B1 combined treatment on in vitro mouse embryo development and blastocyst quality

In the temperate region, most common mycotoxins are members of fusariotoxins. It often happens that food and forage are contaminated with two or more fusariotoxins at the same time. Effects of co-contamination are poorly documented, especially in the field of reproduction. The aim of our study was to assess the combined effect of the two common fusariotoxins, T-2 toxin (T-2) and Fumonisin B1 on early mouse embryo development in vitro. Embryo culture media contained either (1) 0.5 ng/ml T-2; 1, 2, or 10 ng/ml FB1 (group A, B, and C, respectively); or (2) 0.5 ng/ml T-2 and 1, 2, or 10 ng/ml FB1 (group TA, TB, and TC, respectively). Developmental rate, blastocoel expansion, cell number, and micronucleus rate were measured following 96 h culture. Although the developmental rate was similar to the control group (86.43% vs. 83.33, 78.79, 85.98, and 86.67%, respectively) in the case of single toxin treatments, the combined treatments induced significant decreases (14.5, 33.6, and 22.8% in TA, TB, and TC, respectively). The proportion of late blastocysts was lower in all treatments compared to control (83.6% vs. 0–83.6%). Combined treatment resulted in a significantly lower proportion of late blastocysts (25% in TA and 0% in TB and TC). Cell numbers decreased in all toxin-treated groups with a higher rate after combined treatments. No differences were detected in the micronucleus rate in the single or combined treatments compared to control. Our study shows that T-2 and FB1 toxins do not necessarily decrease the developmental rate, but co-contamination results in a significantly lower blastocyst rate and disturbs the blastocoel expansion as well. One possible explanation of this observation could be that the presence of two mycotoxins in the culture media intensifies their negative effects. All toxin treatments decreased the cell number in the blastocysts and this negative effect was more expressed after combined treatment.

HT-2 toxin affects development of porcine parthenotes by altering DNA and histone methylation in oocytes matured in vitro

T-2 toxin is a type A mycotoxin produced by various Fusarium species, while HT-2 toxin is a major metabolite of T-2 toxin. Both T-2 toxin and HT-2 toxin are known to have deleterious effects on animals. Our previous work showed that HT-2 treatment caused the failure of porcine oocyte maturation. In this study, we reported that HT-2 also affected porcine embryo development. In HT-2 toxin treated group, all the percentages of embryos in 2-cell, 4-cell and blastocyst stage were significantly lower compared with those in control groups. We then explored the causes from the epigenetic modification aspect of the oocytes. The analysis of fluorescence intensity showed that 5-methyl cytosine (5 mC) level was increased after exposure to HT-2 toxin in porcine oocytes, indicating that the general DNA methylation level increased in the treated porcine oocytes. In addition, histone modifications were also affected, since our results showed that H3K4me2 and H3K9me2 levels were increased in the oocytes from HT-2-treated group. Therefore, our results indicated that HT-2 toxin decreased porcine embryo developmental competence through altering the epigenetic modifications of oocytes.

T-2 mycotoxin: toxicological effects and decontamination strategies

Mycotoxins are highly diverse secondary metabolites produced in nature by a wide variety of fungus which causes food contamination, resulting in mycotoxicosis in animals and humans. In particular, trichothecenes mycotoxin produced by genus fusarium is agriculturally more important worldwide due to the potential health hazards they pose. It is mainly metabolized and eliminated after ingestion, yielding more than 20 metabolites with the hydroxy trichothecenes-2 toxin being the major metabolite. Trichothecene is hazardously intoxicating due to their additional potential to be topically absorbed, and their metabolites affect the gastrointestinal tract, skin, kidney, liver, and immune and hematopoietic progenitor cellular systems. Sensitivity to this type of toxin varying from dairy cattle to pigs, with the most sensitive endpoints being neural, reproductive, immunological and hematological effects. The mechanism of action mainly consists of the inhibition of protein synthesis and oxidative damage to cells followed by the disruption of nucleic acid synthesis and ensuing apoptosis. In this review, the possible hazards, historical significance, toxicokinetics, and the genotoxic and cytotoxic effects along with regulatory guidelines and recommendations pertaining to the trichothecene mycotoxin are discussed. Furthermore, various techniques utilized for toxin determination, pathophysiology, prophylaxis and treatment using herbal antioxidant compounds and regulatory guidelines and recommendations are reviewed. The prospects of the trichothecene as potential hazardous agents, decontamination strategies and future perspectives along with plausible therapeutic uses are comprehensively described.