Abstract: AIM: To investigate the protective affect of salvianolic acid A on palmitic acid-induced lipotoxicity in hepatocyte and its potential molecular mechanism.  METHODS: The lipotoxicity model of AML12 hepatocytes induced by PA was established. Different concentrations of Sal A (20, 40, 80, 120 μmol/L) were intervened. The hepatocyte injury was detected by the Lactate dehydrogenase (LDH) method, the intracellular triglyceride (TG) content was detected by enzyme assay and the lipid droplets were observed by Bodipy staining, cell viability was detected by MTT, Intracellular reactive oxygen species (ROS) were detected by 2'eci'- dichlorofluorescein diacetate (DCFH-DA) and fluorescence microscope. Mitochondrial membrane potential was detected by rhodamine 123 and fluorescence microscope. The expression of phosphorylation of AMP-activated protein kinase (AMPK) protein and silent information regulator 1 (SIRT1) protein were observed by Western blot. RESULTS: Model of hepatocyte lipotoxicity was established after intervented for 12 h in vitro with PA (0.5 mmol/L). Different concentrations of Sal A could significantly reduce the lipid deposition and hepatocytes injury induced by PA (P<0.05), and the protective effect was dose-dependent. Secondly, Sal A could significantly improve cell mitochondrial membrane potential (P<0.01) and abate the ROS level of hepatocytes induced by PA (P<0.01). In addition, PA could significantly inhibit AMPK and SIRT1 protein expression (P<0.05). Salvianolic acid A can significantly up-regulate SIRT1 and AMPK protein expression (P<0.05). CONCLUSION: Sal A improves PA induced lipotoxicity in hepatocyte, AMPK and SIRT1 may be a potential molecular target.

Key words: salvianolic acid A, lipotoxicity, AMP-activated protein kinase, silent information regulator 1