Toxicol Appl Pharmacol. 2002 Jul; 182(1): 27-33.

Salvia miltiorrhiza inhibits biliary obstruction-induced hepatocyte apoptosis by cytoplasmic sequestration of p53.

Oh SH, Nan JX, Sohn DW, Kim YC, Lee BH.

College of Pharmacy and Medicinal Resources Research Center, Wonkwang University, Iksan, Jeonbuk, 570-749, Korea.

Cholestatic liver injury is caused by hepatocellular apoptosis induced by toxic bile salts. We have studied the effects of a traditional Chinese herbal medicine, Salvia miltiorrhiza, on apoptotic cell death in bile duct-ligated (BDL) rats. We also attempted to clarify the molecular mechanisms of the hepatoprotective effects of S. miltiorrhiza in this animal model. A water extract of S. miltiorrhiza (Sm-X; 200 mg/kg; po) was administered to BDL rats for 10 days. Rats were euthanized and apoptosis was detected in liver tissue by TUNEL staining. Western blot analysis and immunostaining for alpha-smooth muscle actin (alpha-SMA), Bax, Bcl-2, and p53 were performed. Results show that the treatment of BDL rats with Sm-X significantly improved the liver function parameters, although the expression of alpha-SMA, a marker of hepatic stellate cell activation, was not affected. Treatment with Sm-X significantly reduced the number of apoptotic cells. A time-dependent decrease in Bax protein level and an increase in Bcl-2 protein level were observed in BDL rats treated with Sm-X. Immunohistochemical analysis demonstrated that p53 was strongly positive in hepatocyte nuclei of BDL rats but that treatment with Sm-X induced a cytoplasmic sequestration of p53. Taken together, hepatoprotective effects of Sm-X partially ascribe to the antiapoptotic property in hepatocytes. Treatment of Sm-X-induced cytoplasmic sequestration of p53, downregulation of Bax, and upregulation of Bcl-2 protein. This study identifies and delineates signaling factors involved in the antiapoptotic properties of Sm-X and suggests a potential application of S. miltiorrhiza in the clinical management of hepatic disease induced by toxic bile salts following biliary obstruction.