Effects of phytoestrogens on the deposition of α-SMA in 5/6 nephrectomized rats and its related mechanism

Abstract

Objective To study the effect of genistein and daidzein, the 2 main phytoestrogens, on the deposition of α-smooth muscle actin (α-SMA) in 5/6 nephrectomized rats and its related mechanism. Methods The 5/6 nephrectomized rats were randomly divided into the genistein group (n=9), the daidzein group (n=10), the control group (n=8), and still another 8 rats with sham-operation were used as control. Urinary protein, serum albumin, total protein, creatinine, urea were measured both before operation and 4 and 8 weeks after operation. Pathologic changes in the kidney were investigated. Immunohistochemistry was employed to investigate the expression of α-SMA. RT-PCR and Western Blot were also used to measure mRNA transcription and protein expression of transforming growth factor-β1 ( TGF-β1 ) respectively. Results Urinary albumin excretion, serum creatinine and urea in the genistein and daidzein groups decreased substantially when compared with those of the control group (P<0.01). Pathological lesion of the genistein group was less serious than that of the control group. The deposition of α-SMA was lower than that of the control group. Protein expression and mRNA transcription of TGF-β1 in the operated groups were attenuated by genistein and daidzein (P<0.05). Conclusions Genistein and daidzein could decrease the deposition of α-SMA, and this might be associated with the inhibition of the expression of TGF-β1. Key words: Phytoestrogens; Genistein; Daidzein; α-smooth muscle actin; Transforming growth factor beta 1