[Protective effect of Wuzi Yanzong recipe on testicular DNA damage and apoptosis in natural ageing rats].

To study the protective effect of Wuzi Yanzong recipe on testicular DNA damage and apoptosis in natural ageing rats, SPF grade 16-month-old SD male rats were randomly divided into three groups: ageing model group, low and high dose Wuzi Yanzong recipe groups (WZ, 1， 4 g·kg⁻¹). In addition, 2-month-old SD rats were used as adult control group (10 rats in each group). The ageing model group and the adult control group were fed with normal diet for 4 months. Wuzi Yanzong groups received medicated feed for 4 months. After fasting for 12 hours, the rats were sacrificed. Then testis tissues were taken and weighed to calculate the testis index. The change of testicular tissue morphology was observed by HE staining. Expression and localization of DNA damage-associated protein ATR were observed by immunofluorescence. The expressions of DNA damage-related proteins γ-H2AX, Chk1, p-p53 and apoptosis-related proteins Bcl-2 and Bax in testes were detected by Western blot. The apoptosis of testis tissue in rats was detected by using TUNEL. The results showed that as compared with the youth control group, the protein expression levels of γ-H2AX, Chk1, p-p53 and Bax were significantly increased while Bcl-2 protein expression level was significantly decreased intestis tissues of ageing model group. Wuzi Yanzong recipe significantly decreased protein expression levels of γ-H2AX, Chk1, p-p53 and Bax and increased Bcl-2 protein expression level as well as Bcl-2/Bax ratio. Immunofluorescence results showed that Wuzi Yanzong recipe could significantly decrease the ageing-induced ATR, increase in testis tissues. TUNEL results showed that Wuzi Yanzong recipe could significantly attenuate the germ cell apoptosis in testicular tissues. All the above results suggest that Wuzi Yanzong recipe could protect the germ cell in testicular tissues of natural ageing rates from DNA damage and apoptosis, and the mechanism may be associated with regulating p53 signaling pathway.