Alpha-lipoic acid impairs body weight gain of young broiler chicks via modulating peripheral AMPK

Abstract

In mammals, the AMP-activated protein kinase (AMPK) pathways in the central and peripheral tissues coordinately integrate inputs from multiple sources to regulate energy balance. The present study was aimed to explore the potential role of hepatic AMPK in the energy homeostasis of broiler chickens. Diets with 0, 0.05% or 0.1% alpha-lipoic acid (α-LA), a known AMPK inhibitor were provided to broiler chicks for 7days. As a result, α-LA supplementation decreased the relative growth rate of broiler chicks. Hepatic AMPKα2 mRNA levels were significantly upregulated by dietary α-LA, in concert with the increased phosphorylated AMPKα protein levels. In addition, hepatic FAS mRNA levels together with the malonyl-CoA to total CoA ester ratio were reduced by α-LA supplementation. Moreover, the hepatic phosphorylated glycogen synthase levels were increased resulting in a markedly decreased hepatic glycogen content. In conclusion, dietary α-LA supplementation decreased the in vivo hepatic glycogenesis and lipogenesis via stimulating hepatic AMPKα mRNA levels and the phosphorylated gene product. The stimulatory effect of α-LA on hepatic AMPK mRNA and pAMPKα protein levels together with our previous observations regarding its inhibitory effect on hypothalamic AMPK may have altered the energy balance and hence impaired body weight gain of broiler chicks.