Identification of AMPK activator from twelve pure compounds isolated from <i>Aralia Taibaiensis</i>: implication in antihyperglycemic and hypolipidemic activities

Identification of AMPK activator from twelve pure compounds isolated from <i>Aralia Taibaiensis</i>: implication in antihyperglycemic and hypolipidemic activities

The root bark extract of <i>Aralia taibaiensis</i> is used traditionally for the treatment of diabetes mellitus in China. The total saponin extracted from <i>Aralia Taibaiensis</i> (sAT) has effective combined antihyperglycemic and hypolipidemic activities in experimental type 2 diabetic rats. However, the active compounds have not yet been fully investigated. In the present study, we examined effects of twelve triterpenoid saponins on AMP-activated protein kinase (AMPK) activation, and found that compound 28-O-β-D-glucopyranosyl ester (AT12) significantly increased phosphorylation of AMPK and Acetyl-CoA carboxylase (ACC). AT12 effectively decreased blood glucose, triglyceride (TG), free fatty acid (FFA) and low density lipoprotein-cholesterol (LDL-C) levels in the rat model of type 2 diabetes mellitus (T2DM). The mechanism by which AT12 activated AMPK was subsequently investigated. Intracellular ATP level and oxygen consumption were significantly reduced by AT12 treatment. The findings suggested AT12 was a novel AMPK activator, and could be useful for the treatment of metabolic diseases.