Abstract: Objective To investigate the effects of the main compositions of Astragalus on testicular Leydig cells and their synthesis of estradiol(E₂), P450arom under TGF-β1 induction. Methods Leydig cells were divided into three groups: control group, model group and Chinese herbal medicine intervention group. Results Compared with the control group, Leydig cells in the model group showed abnormal morphology and less cells(P＜0.01).TGF-β1 significantly inhibited the synthesis of E₂ and P450arom by Leydig cells (P＜0.05). Total Astragalus flavone, total Astragalus saponin and total astragalus polysaccharide all resulted in pathological changes of Leydig cells induced by TGF-β1. Compared with the model group, the number of cells increased significantly (P＜0.01) and all of them alleviated the inhibitory effect of TGF-β 1 on the synthesis of E₂ in Leydig cells induced by TGF-β1, and the effect of concentration of 20 mg/L total saponin of Astragalus was the most significant. Conclusions Total Astragalus saponin is the most effective component in Astragalus to exert TGF-β1 inhibitory effect on E₂ synthesis by Leydig cells.

Key words: Astragalus, Leydig cells of testis, estradiol(E₂)