Traditional Chinese medicine Bao Gan Ning increase phosphorylation of CREB in liver fibrosis in vivo and in vitro

Abstract

Previous studies have demonstrated that traditional Chinese medicine Bao Gan Ning, which contains six different drugs: Trionyx sinensis Wiegmann shell, Prunus persica (L.) Batsch seed, Salvia miltiorrhiza Bge. root, Mallotus opelta (Lour.) Muell-Arg root, Astragalus membranaceus (Fisch.) Bge. var. mongho-licus (Bge.) Hsiao root and Scutellaria baicalensis Georgi root, was able to protect liver against fibrosis in CCL 4 models. In an effort to elucidate molecular mechanisms by which Bao Gan Ning exerts its anti-fibrosis activity, effects of Bao Gan Ning on liver fibrosis and cAMP response element binding protein (CREB), an important transcription factor involved in liver fibrosis, were evaluated in animal and cell models in this work. Results showed that Bao Gan Ning (2.16 or 4.32 g/kg/day) significantly decreased alanine aminotransferase (ALT) and hyaluronidase levels and reversed liver fibrosis in rat liver fibrosis models. The proliferation of HSC-T6, a hepatic stellate cell line, was also significantly inhibited by incubation with serums that were prepared from rats fed with Bao Gan Ning. Most interestingly, results from Western blot, immunohistochemistry and electrophoretic mobility shift assay (EMSA) showed that Bao Gan Ning up-regulated CREB phosphorylation both in rat liver fibrosis models and in HSC-T6 cells, but did not affect protein level of CREB and the DNA binding activity of CREB. These results suggested that up-regulation of CREB phosphorylation may be involved in anti-fibrosis activity of Chinese medicine Bao Gan Ning.