Abstract: AIM: To reveal the ameliorative effect of salvianolic acid A on palmitie acid-induced lipotoxicity in H9C2 cells and to explore its potential molecular mechanisms preliminarily.  METHODS: H9C2 cell were induced by palmitie acid to establish a lipotoxicity model, while salvianolic acid A was added prior to palmitie acid treatment. Lactate dehydrogenase (LDH) was employed to detect cell damage. Cell counting Kit-8 was used to detect cell viability. The changes of mitochondrial membrane potential in cardiomyocyte were observed by rhodamine 123 staining. The molecular mechanisms of the ameliorative effect of salvianolic acid A was analyzed by Western Blotting. RESULTS: Palmitie acid at a concentration of 400 μmol/L significantly caused lipotoxicity damage to H9C2 cells (P<0.05). There was no cytotoxic effect of different concentrations of salvianolic acid A (10, 20, 40, 80 μmol/L) treatment on H9C2 cells (P>0.05). Salvianolic acid A intervention significantly improved lipotoxicity-induced cell death and reduction of cell mitochondrial membrane potential (P<0.05). The activation of toll-like receptor 4 (TLR4) significantly enhanced lipotoxicity-induced cell damage (P<0.05), while inhibition of TLR4 significantly reduced palmitie acid-induced lipotoxicity (P<0.05). In addition, salvianolic acid A effectively inhibited the upregulation of TLR4 and the downstream c-Jun N-terminal kinase (JNK MAPK) of TLR4 by palmitie acid treatment (P<0.05). CONCLUSION: Salvianolic acid A effectively improves lipotoxicity-induced cardiomyocyte damage. The inhibition of p38 signaling pathway is potentially involved in its protective effect. The protective effect may be related to the inhibition of TLR4/JNK MAPK signaling pathway, providing a potential molecular target for the prevention and treatment of lipotoxic cardiomyopathy.

Key words: salvianolic acid A, palmitie acid, Toll-like receptor 4, lipotoxicity, cardiomyocyte