To investigate the protective mechanism of berberine against Polygonum multiflorum thunb.induced liver injury.

SD rats were randomly divided into sham group, PM (Polygonum multiflorum thunb. 40 g·kg^-1) group, PM+NS (saline 1 mL) group, PM+BBR (berberine 50 mg·kg^-1) group (n=12 in each group). Another 24 rats were divided into PM+BBR+sh-PPAR-γ group and PM+BBR+sh-NC group, which were injected with 100 μL of shRNA-PPAR-γ and 100 μL of shRNA-NC into the tail vein. The administration of each group lasted for 8 weeks. HE staining was used to observe the pathological changes in liver tissue, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) levels and the levels of IL-1β, IL-6 and IL-10 in liver tissues were detected by ELISA. PPAR-γ expression was knockdown by transfecting shRNA-PPARγ into rats. The expression levels of PPAR-γ in rat liver tissues was detected by RT-qPCR and Western blot.

Compared with the sham group, the levels of serum ALT, AST, ALP were significantly increased, the levels of IL-1β, IL-6 in liver tissue were increased and IL-10 level was decreased, and PPAR-γ expression was significantly downregulated in the PM group and PM+NS group (all P<0.05). Compared with the PM+NS group, serum ALT, AST, ALP levels were significantly decreased, IL-1β and IL-6 levels were significantly decreased, IL-10 level was significantly increased, and PPAR-γ expression was significantly increased in the PM+BBR group (all P<0.05). Compared with the PM+BBR+sh-NC group, PPAR-γ expression was significantly decreased, serum ALT, AST, ALP levels were significantly increased, IL-1β and IL-6 levels were significantly increased, IL-10 level was significantly decreased in the PM+BBR+sh-PPAR-γ group (all P<0.05).

Berberine may alleviate hepatic injury induced by Polygonum multiflorum thunb. by up-regulating PPAR-γ expression.