OBJECTIVE Oxidative sress is one of the key factor responsible for occurrence and development of hepatic fibrosis,a common consequence of chronic liver injury of multiple etiology.Nuclear factor erythroid 2-related factor 2(Nrf2)serves as a major regulator of a celular defense system against oxidative stress.Xiaochaihutang(XCHT),a compound of seven botanical extracts used for liver diseases traditionally in East Asia.However,few studies have investigated its anti-hepatic fibrosis effects and pathophysiological mechanism of action.The present study was designed to confirm the anti-hepatic fibrosis effects and explore its potential mechanism of action by investigating the intervention of Nrf2 pathway.METHODS Liver fibrosis was induced by repeated injection of Carbon tetrachloride(CCl4) over a period of 9 weeks.Starting from the 6 th week,the animals in treatment groups were given the appropriate dose of XCHT granules and silybin.Biochemical parameters,histological changes of the liver and alpha-smooth muscle actin(α-SMA) were determined.The expressions of Nrf2,Keap1,Nqo1,HO-1,Gclc and Gclm were assessed by RT-PCR and Western blot.RESULTS CCl4 caused a significant fibrosis damage in the rat liver and the liver functions and fibrosis degree were significantly improved by XCHT(5 g·kg~(-1) and 10 g·kg~(-1)).XCHT(5 g·kg~(-1) and 10 g·kg~(-1)) treatment significantly decreased the number of cells labeled with α-SMA antibodies.Moreover,XCHT(5 g·kg~(-1) and 10 g·kg~(-1))significantly increase Nqo1,HO-1,Gclc and Gclm expressions in the liver.CONCLUSION T hese studies establish XCHT is a potentially useful therapeutic agent for treatment of hepatic fibrosis and it might be via regulation of Nrf2 pathway in rats against oxidative stress,making further efforts to inhibiting the activated HSCs.Activation or up-regulation of Nrf2 pathway may be an alternative treatment strategy for liver fibrosis. OBJECTIVE Oxidative sress is one of the key factor responsible for occurrence and development of hepatic fibrosis, a common consequence of chronic liver injury of multiple etiology. Nuclear factor erythroid 2-related factor 2 (Nrf2) serves as a major regulator of a celular defense system against oxidative stress. Xiaochaihutang (XCHT), a compound of seven botanical extracts used for liver diseases traditionally in East Asia. Yet, a few studies have investigated its anti-hepatic fibrosis effects and pathophysiological mechanism of action. The present study was designed to confirm the anti-hepatic fibrosis effects and explore its potential mechanism of action by investigating the intervention of Nrf2 pathway. METHHODS Liver fibrosis was induced by repeated injection of Carbon tetrachloride (CCl4) over a period of 9 weeks. Starting from the 6th week, the animals in treatment groups were given the appropriate dose of XCHT granules and silybin.Biochemical parameters, histological changes of the liver an The expressions of Nrf2, Keap1, Nqo1, HO-1, Gclc and Gclm were assessed by RT-PCR and Western blot .RESULTS CCl4 caused a significant fibrosis damage in the rat liver and the liver functions and fibrosis degree were significantly improved by XCHT (5 g · kg -1 and 10 g · kg -1) kg -1 significantly increased the number of cells labeled with α-SMA antibodies. Moreover, XCHT (5 g · kg -1 and 10 g · kg -1) significantly increased Nqo1, HO -1, Gclc and Gclm expressions in the liver. CONCLUSION T hese studies establish XCHT is a potentially useful therapeutic agent for treatment of hepatic fibrosis and it might be via regulation of Nrf2 pathway in rats against oxidative stress, making further efforts to inhibit the activated HSCs.Activation or up-regulation of Nrf2 pathway may be an alternative treatment strategy for liver fibrosis.