The Effect Of Multiglycosides Tripterygium Wilfordii Hook. F. On Early Stage Male Germ Cells

Multiglycosides of Tripterygium wilfordii Hook. f. (GTW), a Chinese herb-derived medicine used as the remedy of rheumatoid arthritis, allergic dermatitis and so on, could cause influence on the male reproductive system to the different degree. It has been shown that long-term medicine taking would lead to the reduction of the number of sperm and make sperm activity decreased. However, the fertility will recover gradually after the cessation of medication. Thus in recent years this medicine attracted many researchers'attention and has been used for the research and development of male contraceptive. However, the underlying antifertility mechanism of GTW is still unclear. Previous studies focused on the late stage of spermatogenesis to research the mechanism. This study suggested that GTW could also affect the growth of spermatogonial stem cells (SSCs), which means that the anti-fertility effect of GTW could trace back to the initial stage of spermatogenesis. By the detection of histology and apoptosis we found a significant dosage-dependent decrease in the total number of germ cells in seminiferous tubules after the GTW treatment, and apoptotic cells were correspondingly increased from low-dosage to high-dosage group. In vitro detection on SSCs confirmed that GTW-triggered apoptosis could also take effects on SSCs, and was tending to be severe when the concentration or the treating time increased. We also detected the dimethylation level of histone H3 lysine 9 (H3K9me2) to examine the effect of GTW on the germline epigenetic state. Immunofluorescence assay showed that dimethylation level was declined in GTW-treated testes, and our in vitro detection on SSCs was corresponded to the observation in vivo. Thus we inferred that GTW could also influence the spermatogenesis of mice by inhibiting the epigenetic modification of H3K9 in male germ cells, which opened up a new way to study the antifertility mechanism of GTW and provided an important theoretical basis for further comprehensive study and clinical applications of this medicine.