Objective: To study the effect of Icariin on rat Leydig cells with TGF-β1-induced injury.
Methods: We determined the optimal concentration of Icariin for protecting primarily cultured Leydig cells against TGF-β1-induced injury by methyl thiazolyl tetrazolium assay. We detected the effects of Icariin on the secretion of estradiol (E2) and activity of aromatase in the injured Leydig cells by radioimmunoassay and Tritium water release experiment and its effect on the gap junctional intercellular communication (GJIC) between the Leydig cells by fluorescence distribution after photobleaching.
Results: Different concentrations of Icariin showed different degrees of protective effect on the TGF-β1-treated Leydig cells, the effect observed at 20 μg/ml and at its optimum at 160 μg/ml. After treatment of the injured Leydig cells with Icariin at 160 μg/ml, significant improvement was observed in the E2 secretion and aromatase activity (P<0.01) as well as in the GJIC between the Leydig cells (P<0.01).
Conclusions: Icariin can effectively protect rat Leydig cells against TGF-β1-induced injury, which is largely attributed to its effects of increasing E2 synthesis, enhancing aromatase activity, and improving GJIC between Leydig cells.
目的： 研究淫羊藿苷（Icariin）对转化生长因子-β1（TGF-β1）诱导的大鼠睾丸间质细胞损伤的保护作用。方法： 利用4-甲偶氮唑蓝法筛选Icariin对TGF-β1诱导的间质细 胞损伤保护作用的最适浓度，用放射免疫法和3H释放实验检测Icariin作用前后损伤的间质细胞中雌激素（E2）含量和芳香化酶P450arom活性，采用荧光漂白后恢复实验检测 Icariin 对损伤 的间质细胞间缝隙连接通讯（GJIC)功能的影响。结果： 不同浓度 Icariin 均可提高 TGF-β1 作用后睾丸间质细胞的活细胞率，其中，20 μg/ml 时即可发挥作用，而160 μg/ml 时达到 最佳；用160 μg/ml浓度Icariin干预TGF-β1 损伤的睾丸间质细胞后，间质细胞中E2的生成和芳香化酶活性显著增加（P<0.01），且间质细胞间的荧光恢复率也明显提高（P<0.01）。结论 ： Icariin 可通过增加 E2合成有效阻止 TGF-β1 对间质细胞的损伤，这种影响可能通过部分上调雌激素合成的关键酶P450arom活性实现；且Icariin 还具有改善间质细胞间 GJIC 功能的 作用。.
Keywords: Icariin; Leydig cell; TGF-β1; estradiol; gap junctional intercellular communication; testis.