Anti-diabetic Activity Present in the Fruit Body of Grifola frondosa (Maitake). I

Abstract

The fruit body of Grifola frondosa (maitake), Basidiomycetes was confirmed to contain substances with anti-diabetic activity. When 1g/d of powdered fruit body of maitake was given orally to a genetically diabetic mouse (KK-A^y), blood glucose reduction was observed, in contrast to the control group in which the blood glucose increased with ageing. Moreover, levels of insulin and triglyceride in plasma demonstrated a change similar to blood glucose with feeding of maitake. Ether-ethanol-soluble (ES) and hot water-soluble (WS) fractions were prepared from the fruit body and their hypoglycemic activity was examined. Blood glucose-lowering activity was found when ES-fraction or WS-50% ethanol float (X) fraction was administered orally, but other WS-fractions were inactive. These results suggest that the anti-diabetic activity was present not only in the ES-fraction consisting of lipid but also in the X-fraction of peptidoglycan (sugar : protein=65 : 35).