Abstract: The present inventors produced lotus leaf extracts, and discovered that quercetin is one of the active ingredients. As a result of treating ?3-adrenergic receptor-expressing cells and feeding diabetes model mice with quercetin and evaluating its effects, the present inventors discovered specifically that quercetin produces obesity-improving effects and antidiabetic effects by acting as a ?3-adrenergic receptor agonist.

Abstract: The present inventors focused on the lotus plant and prepared lotus extracts. When ?-glucosidase and its substrate sucrose were reacted with the lotus extracts to examine the effect of adding the extracts on the enzymatic reaction, the lotus extracts were found to have ?-glucosidase inhibitory activity. Furthermore, when the lotus extract and sucrose were administered to mice and their blood glucose levels were measured, the lotus extracts were found to suppress blood glucose levels. More specifically, the present inventors discovered that the lotus extracts have ?-glucosidase inhibitory activity and can be used to control blood glucose levels.

Abstract: Extract of at least one selected from GAJUTSU (zedoariae rhizoma), KYOUOU (curcumae rhizoma) and ICHO leaves (ginko leaves) obtained using polar solvent, and composition containing the extract are disclosed; since the extract has an excellent effect on lowering the level of blood triglyceride, is derived from natural material and has an excellent level of safety, the extract and the composition can be used as or in drink, food or medicine.