Astragalus and Angelica mixture ameliorates renal interstitial fibrosis by a multiple manner

Aim The mixture of Chinese herbs,Astragalus Angelica(AA) has been found that has antifibrotic effect in rats.Methods To elucidate themechanisms underlying the renoprotective effects of AA in the process of renal interstitial fibrosis,we investigated the pathology changes of kidneys in unilateral ureteral obstruction(UUO) rats.In the study,Wistar rats were randomly divided into CON,Sham,UUO and UUA(UUO+AA) groups.After administration of AA(12 g·kg·d~(-1)) for 0,3,7 and 10 d,renal damage including interstitial cell infiltration,tubular atrophy and interstitial fibrosis were quantified on HE and Masson stained tissue sections.The expression of α-smooth muscle actin(α-SMA),transforming growth factor-β_1(TGF-β_1) and fibronectin(FN) was measured using computer image analysis of immunohistochemistry staining sections,ELISA and Western Blot.Results Renal damage and the expression of α-SMA,TGF-β_1 and FN were all significantly exacerbated in UUO group compared with those of Sham group(P0.001) at each time point.Interstitial cell infiltration,tubular atrophy and interstitial fibrosis,expression of TGF-β_1 were alleviated by AA treatment at d 3(P0.05),although AA had no effect upon the expression of α-SMA and FN,but at d 7,in contrast to UUO rats,UAA group had a persist reduction in cell infiltration,tubular atrophy and interstitial fibrosis,as well as suppressed expression of TGF-β_1.At same time,the expression of α-SMA(P0.05) and FN(P0.05) in renal interstitial area were also significantly suppressed.After 10 days of AA administration,tubular atrophy and interstitial fibrosis,overexpression of TGF-β_1,α-SMA,FN were alleviated by 18.95%,28.7%,39.6%,26% compared to UUO group,respectively.Conclusion Renal protective effects of AA in UUO rats started from the early phase of renal injury,reached the peak at d 7 and persisted to d 10 after the treatment with AA.Its antifibrotic effects are characterized to prevent interstitial cell infiltration and inhibit expression of TGF-β_1,following suppression of interstitial myofibroblast and a subsequently reduction of ECM accumulation in renal interstitium.