Acetyl-L-carnitine inhibits TNF-α-induced insulin resistance via AMPK pathway in rat skeletal muscle cells

In this study, we demonstrated effects of acetyl-L-carnitine (ALC) on insulin resistance induced by tumor necrosis factor-alpha (TNF-alpha) in rat L6 cells. TNF-alpha downregulated insulin-stimulated glucose uptake and increased Serine 307 phosphorylation of insulin receptor substrate-1 (IRS-1). However, the treatment of ALC improved insulin-stimulated glucose uptake via AMP-activated protein kinase (AMPK) activation in a dose-dependent manner. Together, our data suggest that ALC inhibits TNF-alpha-induced insulin resistance through AMPK pathway in skeletal muscle cells. (C) 2008 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.