We examined the prevention effect of red clover (Trifolium pratense L.) sprout on metabolic syndrome using a high-carbohydrate and high-fat diet (Western diet; WD)-induced male C57BL/6J obese model mouse. Red clover sprout-lyophilized powder (RC) contained 3.5 mg/g dry-weight of formononetin as a major phenolic compound, as analyzed by high performance liquid chromatography. Supplementation of 0.3% (w/w) RC in a WD (WD+RC) showed an anti-obesity effect and ameliorated lipid metabolism in the obese model mice. Additionally, fasting plasma glucose levels were significantly reduced in the WD+RC group. Administration of 0.1 mg/kg formononetin reduced the postprandial blood glucose level, as assessed using the oral maltose tolerance test. However, no significant formononetin intake effect was observed on the plasma insulin level. These results suggest that the formononetin contained in red clover sprout inhibits α-glucosidase and thereby contributes to reducing the postprandial blood glucose response in mice.
Keywords: anti-metabolic syndrome; formononetin; postprandial blood glucose; red clover sprout; α-glucosidase inhibitor.