alfa-Lipoic acid (alfa-LA) is a natural occurring antioxidant with beneficial effects on obesity. The aim of this study was to investigate the putative effects of alfa-LA on triglyceride accumulation and lipogenesis in subcutaneous adipocytes from overweight/obese subjects and to determine the potential mechanisms involved.
Fully differentiated human subcutaneous adipocytes were treated with alfa-LA (100 and 250 µM) during 24 h for studying triglyceride content, de novo lipogenesis, and levels of key lipogenic enzymes. The involvement of AMP-activated protein kinase (AMPK) activation was also evaluated.
alfa-LA down-regulated triglyceride content by inhibiting fatty acid esterification and de novo lipogenesis. These effects were mediated by reduction in fatty acid synthase (FAS), stearoyl-coenzyme A desaturase 1, and diacylglycerol O-acyltransferase 1 protein levels. Interestingly, alfa-LA increased AMPK and acetyl CoA carboxylase phosphorylation, while the presence of the AMPK inhibitor Compound C reversed the inhibition observed on FAS protein levels.
alfa-LA down-regulates key lipogenic enzymes, inhibiting lipogenesis and reducing triglyceride accumulation through the activation of AMPK signaling pathway in human subcutaneous adipocytes from overweight/obese subjects.