Anti-obesity compounds in green leaves of Eucommia ulmoides.

The anti-hypertensive effect of Eucommia leaves has been confirmed clinically, and the study of their anti-obesity properties has advanced. However, the compounds involved in their anti-obesity effect have not been fully elucidated. In this Letter, we examined the anti-obesity effect of Eucommia green leaf extract (EGLE) divided into five fractions with high porous polystyrene gel and of the compounds isolated, geniposidic acid, asperuloside and chlorogenic acid, respectively. A metabolic syndrome-like clinical model in mice was generated by feeding a 40% high-fat diet to examine the anti-obesity effects of chronic administration of test substance. After 4 weeks, body weight, white adipose tissue weight, plasma triglyceride levels and total cholesterol levels in the model mice were significantly inhibited by the 30% MeOH fraction (containing much higher levels of asperuloside than the other fractions), and these effects were similar to those of EGLE. Chronic administration of isolated asperuloside in Eucommia leaves suppressed increases in model mouse body weight, white adipose tissue weight, plasma triglyceride levels and free fatty acids levels. These results suggest that asperuloside in Eucommia leaves has important anti-obesity effects.