Anti-obesity effects of Garcinia indica high pressure ethanolic extract in vitro

Abstract

Obesity is one of the most common metabolic diseases that often lead to cardiovascular diseases, type II diabetes, cancer, and osteoarthritis. Inhibition of adipogenesis is a therapeutic target for reducing obesity and obesity-related disorders. We have investigated the anti-adipogenic effect of a supercritical ethanolic extract of dried fruits of Garcinia indica in-vitro. Chemical analysis of the high pressure ethanolic (HPE) extract showed that it has 36.7% hydroxy citric acid (HCA), 2.5% garcinol, 1.5% xanthochymol, 0.38% isogarcinol, and trace amounts of α-mangostin and cyaanidin-3-0-glucoside. G. indica HPE extract has an IC50 values of 112 ug/ml in 3T3-L1 pre-adipocytes and 140 ug/ml in differentiated adipocytes in the cytotoxicity assays. The HPE extract inhibited the adipocyte differentiation significantly in a dose-dependent manner with increasing concentrations of extract in 3T3-L1 preadipocytes. Treatment of HepG2 liver cells with G. indica HPE extract down regulated mRNA expression of mTOR, GLUT3 and HIF-1α genes and up regulated AMPKα genes very significantly. Similarly, down regulation of mTOR, HIF-1α and AKT1 mRNA expression was noticed in extract-treated 3T3-L1 pre-adipocytes. On the other hand, SIRT1 and AMPKα mRNA mRNA expression were up regulated in 3T3-L1 pre-adipocytes. G. indica HPE extract also down regulated genes such as FXR and SHP, and up regulated PPAR- gene that are associated with fat metabolism in HepG2 cells. These results show that the anti-obesity effect of G. indica HPE extract is mainly through signaling pathways affecting the expression of genes associated with weight control and fat metabolism.