A herbal extract with acetyl-coenzyme A carboxylase inhibitory activity and its potential for treating metabolic syndrome

Acetyl-coenzyme A carboxylase (ACC) plays a crucial role in fatty acid metabolism, and its inhibition is an effective approach for treating metabolic syndrome. Partially purified ACC from rat liver was used to screen herbs commonly used in Taiwanese folk medicine for ACC inhibitory effects. An ethanol extract of Polygonum hypoleucum Ohwi (EP), the Taiwan tuber fleece flower, was found to have the highest inhibitory activity (half-maximal inhibitory concentration = 30 mu g/mL). We then tested the physiologic effects of EP using high-fat (HF) diet-fed C57BL/6J mice. After 4 weeks, body weight and levels of blood glucose, insulin, triacylglycerol, total cholesterol, and leptin were significantly reduced (P < .05) in mice fed a 3% EP-containing HF diet. The EP also improved the glucose tolerance and insulin sensitivity of HF diet-fed mice. In addition, EP at concentrations of 0.0725 and 0.145 mg/mL (2.5- and 5-fold higher than the half-maximal inhibitory concentration) was also effective in decreasing ACC and fatty acid synthase activity and the triacylglycerol content of HepG2 cells incubated in high-glucose (30 mmol/L) medium. These results show that EP, acting by inhibiting ACC activity, is effective in alleviating the symptoms associated with metabolic disease. (C) 2009 Elsevier Inc. All rights reserved.