Qilin pills alleviate oligoasthenospermia by inhibiting Bax-caspase-9 apoptosis pathway in the testes of model rats

At present, the treatment of oligoasthenospermia with western medicine is ineffective. Qilin pill (QLP) is a Chinese traditional medicine for treating male infertility. Recent multicenter clinical studies in China reported that QLPs markedly improved sperm quality. However, the mechanism of action of QLPs on oligoasthenospermia remains unknown. In this study, we investigated the mechanistic basis for improvement of semen parameters and reversal of testis damage by QLPs in a rat model of oligoasthenospermia induced by treatment with tripterygium glycosides (TGs) (40 mg/kg) once daily for 4 weeks. Rats were administered QLPs (1.62 g/kg or 3.24 g/kg) each day for 60 days, with untreated animals serving as controls. The concentration and motility of sperm extracted from rat epididymis were determined, whereas histopathological examination and immunohistochemical apoptosis analysis of rat testes was performed. Expression profiles of apoptosis-related genes were determined by microarray analysis; the results were validated by quantitative real-time PCR, western blotting, and immunohistochemistry. Sperm concentration and motility in the QLP treatment group were increased relative to those in control rats. Testis tissue and DNA damage were reversed by QLP treatment. The improvement function of QLPs on sperm and testis works mainly by suppressing mitochondrial apoptosis in the testis via modulation of B cell lymphoma (Bcl)-2, Bcl-2-associated X protein (Bax), cytochrome C, caspase-9 and caspase-3 expression. QLPs could improve sperm quality and testis damage in a rat model of oligoasthenospermia by inhibiting the Bax-Caspase-9 apoptosis pathway and exerting therapeutic effects.