Toxic Effects and Possible Mechanisms of Deoxynivalenol Exposure on Sperm and Testicular Damage in BALB/c Mice

Deoxynivalenol (DON, vomitoxin) is the most common mycotoxin in cereals and grains. DON contamination can cause a serious health threat to humans and farm animals. DON has been reported to exert significant toxicity effects on the male reproductive system. However, the causes and mechanisms underlying efforts of DON on sperm and testicular damage remain largely unclear. In the present study, we thoroughly investigated this issue. Eighty male BALB/c mice were randomly divided into a control group (n = 40) and DON treatment group (2.4 mg/kg of body weight, n = 40). The ratio of testes and seminal vesicle to body, sperm survival and motility, and morphology of sperm and testis were observed in DON-treated and control mice. In addition, the concentrations of reactive oxygen species (ROS) and malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione (GSH), and also the expression levels of JNK/c-Jun signaling and apoptotic factors such as caspase-3, caspase-8, caspase-9, Bim, and Bid were analyzed and compared between the two groups. The results demonstrated that a single topical application of DON significantly increased the percentage of abnormal sperm and decreased the motility of sperm, indicating the sperms are damaged by DON. Additionally, the reduced relative body weight of testis and severe destruction of testicular morphology were observed. Moreover, the increased levels of ROS and MDA levels and decreased activities of SOD and GSH were found in testicular tissues, suggesting that oxidative stress is induced by DON treatment. Furthermore, DON upregulated the expression of stress-induced JNK/c-Jun signaling pathway proteins as well as JNK/c-Jun phosphorylation proteins. In addition, DON could enhance testicular apoptosis by increasing expression levels of apoptotic genes including Bim, cytochrome c, caspase 3, caspase 8, and caspase 9. These results suggest that DON exposure can cause sperm damage, oxidative stress, testicular apoptosis, and phosphorylation of JNK/c-Jun signaling pathway. The underlying mechanisms may be that DON induces sperm damage by exacerbating oxidative stress-mediated testicular apoptosis via JNK/c-Jun signaling pathway.