Rhein inhibits liver fibrosis induced by carbon tetrachloride in rats

To investigate the effect of rhein on liver fibrosis induced by the exposure of carbon tetrachloride (CCl4)/ethanol in rats.

Male Wistar rats were divided into four study groups (n=10 each group): healthy controls, CCl4/ethanol-injured rats left untreated, and CCl4/ethanol-injured rats treated with rhein of low-dose (25 mg/kg) and high-dose (100 mg/kg). Rhein was given once a day since rat received CCl4/ethanol injury. After administration of rhein for 6 weeks rats were killed. The following parameters were determined: the activity of alanine aminotransferase (ALT), hyalauronic acid (HA) and procollagen type III (PC-III) concentrations in serum, liver malondialdehyde (MDA) level, the degree of liver fibrosis, and the expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta1 (TGF-beta1) in liver tissue.

The treatment of rhein markedly reduced the ALT activity, HA and PC-III concentrations, and liver MDA level in CCl4/ethanol-injured rats (P<0.01). It also improved significantly histological changes of fibrosis and decreased the expression of alpha-SMA and TGF-beta1 in liver of these rats (P<0.05 or P<0.01).

Rhein has protective effect on liver injury and can inhibit liver fibrosis induced by CCl4/ethanol in rats. The mechanisms possibly contribute to its action of antioxidant and anti-inflammatory activity, also associated with its effect of inhibiting TGF-beta1 and suppressing the activation of hepatic stellate cells.