Physiological responses to a natural antioxidant flavonoid mixture, silymarin, in BALB/c mice: I induction of transforming growth factor beta1 and c-myc in liver with marginal effects on other genes.

Silymarin, a mixture of flavonolignans isolated from Silybum marianum, is known for its hepatoprotective properties. We investigated the expression of cytokines in mouse liver following treatment with 0, 10, 50, and 250 mg/kg of silymarin once daily for 5 days. A dose-related but insignificant decrease of circulating alanine aminotransferase and aspartate aminotransferase after silymarin treatment was observed, suggesting that silymarin treatment did not induce hepatic damage. Silymarin treatment caused significant increases in the expressions of transforming growth factor (TGF) beta1 and c-myc in liver. No significant difference was detected among these treatments in the expression of hepatocyte growth factor, interferon gamma, tumor necrosis factor alpha, and class II major histocompatibility complex. These results suggest that alterations of TGFbeta1 and c-myc expression in the liver may be involved in the hepatoprotective effects of silymarin observed in other studies.