| 摘要 |
PROBLEM TO BE SOLVED: To obtain a blood glucose level increase inhibitor or a hypoglycemic agent that has no side-effect and contains corosolic acid in a specific proportion as a hot water extract from dried leaves of a plant, Lagerstroemia speciosa in Lythraceae Myrtales as a main ingredient, and causes no acute increase of blood sugar even when its administration is discontinued, while brings about no hypoglycemia even when a person of normal blood sugar takes it. SOLUTION: Dried leaves of a plant, Lagerstroemia speciosa, are extracted with hot water or an alcohol and the concentrate of the extract is used as a main ingredient to give the objective composition containing 0.1-15 mg, preferably 0.2-12 mg, particularly preferably 0.5-10 mg of corosolic acid per 100 mg of the concentrate. In a preferred embodiment, this composition is prepared to tablet forms for oral administration. The above alcohol extract is obtain by repeating the extraction of dried and crushed plant leaves with ethanol or aqueous ethanol, preferably in an amount 8-10 times of the dried leaves, preferably at about 50-85 deg.C for 30 minutes to 2 hours twice or three times. |
