Momordica charantia Ameliorates Insulin Resistance and Dyslipidemia with Altered Hepatic Glucose Production and Fatty Acid Synthesis and AMPK Phosphorylation in High-fat-fed Mice

Momordica charantia Linn. (Cucurbitaceae) fruit is commonly known as bitter melon. C57BL/6J mice were firstly divided randomly into two groups: the control (CON) group was fed with a low-fat diet, whereas the experimental group was fed a 45% high-fat (HF) diet for 8 weeks. Afterwards, the CON group was treated with vehicle, whereas the HF group was subdivided into five groups and still on HF diet and was given orally M. charantia extract (MCE) or rosiglitazone (Rosi) or not for 4 weeks. M. charantia decreased the weights of visceral fat and caused glucose lowering. AMP-activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. MCE significantly increases the hepatic protein contents of AMPK phosphorylation by 126.2-297.3% and reduces expression of phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Most importantly, MCE decreased expression of hepatic 11beta hydroxysteroid dehydroxygenase (11beta-HSD1) gene, which contributed in attenuating diabetic state. Furthermore, MCE lowered serum triglycerides (TGs) by inhibition of hepatic fatty acid synthesis by dampening sterol response element binding protein 1c and fatty acid synthase mRNA leading to reduction in TGs synthesis. This study demonstrates M. charantia ameliorates diabetic and hyperlipidemic state in HF-fed mice occurred by regulation of hepatic PEPCK, 11beta-HSD1 and AMPK phosphorylation. Copyright (c) 2013 John Wiley & Sons, Ltd.