目的 基于P53/P21和碱基切除修复（BER）通路研究五子衍宗方对自然衰老大鼠睾丸DNA损伤的保护作用。方法 将16月龄SPF级SD雄性大鼠随机分为3组，衰老模型组、五子衍宗方低剂量组（1 g/kg）和高剂量组（4 g/kg），另取2月龄SD雄性大鼠作为青年对照组，每组8只。给予普通饲料或含药饲料饲养4个月后，处死大鼠，取出睾丸组织。免疫荧光检测大鼠睾丸组织中DNA损伤相关蛋白γ-H2AX及BER相关蛋白脱嘌呤脱嘧啶核酸内切酶（APE1）、8-羟基鸟嘌呤DNA糖苷酶1（OGG1）和X线修复交错互补基因1（XRCC1）的表达和定位；ELISA法检测大鼠睾丸组织中8-羟基脱氧鸟苷（8-OHdG）的量；Western blotting法检测大鼠睾丸组织中p-P53和P21蛋白的表达水平。结果 与衰老模型组相比，五子衍宗方能明显降低睾丸DNA损伤相关蛋白γ-H2AX和BER相关蛋白OGG1、APE1和XRCC1的表达水平；ELISA检测结果显示，与衰老模型组相比，五子衍宗方能显著下调8-OHdG的量；Western blotting结果显示，五子衍宗方能显著降低自然衰老大鼠睾丸p-P53、P21的蛋白表达水平。结论 五子衍宗方可通过调节P53/P21和BER通路减轻自然衰老大鼠睾丸DNA损伤。

Objective To study the protective effect of Wuzi Yanzong Prescription (WYP) on DNA damage in testis of natural ageing rats based on P53/P21 signaling pathway and base excision repair (BER). Methods SPF grade 16-month-old male SD rats were randomly divided into three groups with eight rats in each group:ageing model group, low and high dose of WYP groups (1 and 4 g/kg). In addition, 2-month-old SD male rats were used as adult control group. The ageing model group and the adult control group were fed with normal diet for four months. Rats in the WYP groups were given the medicated feed for four months. After fasting for 12 h, the rats were sacrificed. Then, the testes were immediately removed from rats. The expression and localization of DNA damage-related protein γH2AX and BER-related proteins OGG1, APE1, and XRCC1 were detected by immunofluorescence, and the content of 8-OHdG in testis was detected by ELISA. Also, the protein expression levels of p-P53 and P21 were detected by Western blotting. Results Compared with the ageing model group, immunofluorescence results showed WYP significantly decreased the expression levels of DNA damage-related protein γH2AX and BER-related proteins OGG1, APE1, and XRCC1 in testis of natural ageing rats. ELISA results showed that WYP significantly downregulated 8-OHdG levels, compared with the ageing model group. Moreover, Western blotting results showed that WYP significantly decreased the protein expression levels of p-P53 and P21 of the testis when compared with the ageing model group. Conclusion WYP reduced the DNA damage of testes in ageing related rats via P53/P21 and BER pathways.

国家自然科学基金资助项目（81573931，81373881，81774316，81503334）