Compound Astragalus and Salvia miltiorrhiza extract inhibits hepatocarcinogenesis via modulating TGF-β/TβR and Imp7/8.

Abstract

Compound Astragalus and Salvia miltiorrhiza extract (CASE) is a Chinese herbal formula consisting of astragalosides, astragalus polysaccharide and salvianolic acids extracted from Astragalus membranaceus and Salvia miltiorhiza. Previous studies by our group have demonstrated that CASE effectively suppresses diethylinitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats via modulating transforming growth factor β/Mothers against decapentaplegic (TGFβ/Smad) signaling. To further elucidate the mechanism of CASE, the effects of CASE on TGF-β1, the serine/threonine kinase receptors of TGF-β [TGF-β receptor type-I (TβRI) and TβRII] and karyopherins [Importin 7 (Imp7) and Imp8], which are crucial for TGF-β/Smad signaling in fibro-hepatocarcinogenesis, were assessed in the present study using in vivo (DEN-induced HCC in rats) and in vitro [TGF-β1-stimulated rat myofibroblasts (MFBs) and HepG2 cells] models of fibro-hepatocarcinogenesis. Hematoxylin and eosin staining revealed that CASE may suppress inflammatory reactions and fibrosis in HCC as well as increasing the differentiation of HCC cells. Positive TGF-β1 staining was increased in HCC nodule areas and in adjacent normal liver tissues in DEN-treated rats, while TβRI staining was increased only in normal adjacent liver tissues. The elevated expression of TGF-β1, TβRI and TβRII was suppressed by CASE. CASE treatment also reduced glutathione S-transferase P 1 and Imp7/8 protein expression in fibro-hepatocarcinogenesis. In vitro experiments confirmed that CASE was able to decrease the expression of TβRI and TβRII in TGF-β1-stimulated MFBs and HepG2 cells. These results indicate that the anti-HCC effect of CASE may be achieved by mediating TGF-β/TβR and Imp7/8 protein expression, suggesting that CASE has multiple targets in HCC treatment.