Obesity preventive function of novel edible mushroom, Basidiomycetes-X (Echigoshirayukidake): Manipulations of insulin resistance and lipid metabolism

Echigoshirayukidake is an edible mushroom found in Uonuma, Japan in 1994. It was assigned to a new species of Basidiomycetes (BDM-X) but is uniquely defect of forming bashidium. The high antioxidant activity and β-glucan content of BDM-X suggest possible functions preventing type 2 diabetes. In the present study, anti-obesity and insulin resistance preventive functions of BDM-X were examined using genetically defined obese model rat, OLETF (Otsuka Long Evans Tokushima Fatty) by feeding regular diet with and without supplementation of 5% dried BDM-X powder (BDMP) for 15 weeks. BDMP supplementation to the diet significantly (p < 0.01) suppressed the body weight gain and also visceral fat accumulation during the feeding period compared to control diet. Simultaneously, the insulin resistance and the plasma levels of adiponectin and triglycerides were significantly (p = 0.003) ameliorated in the BDMP supplemented diet group. A statistical multivariate analysis showed the weight of three types of adipose tissue (epididymal, retroperirenal, and mesenteric fat) positively correlated with HOMA-IR (Homeostasis Model Assessment of Insulin Resistance), and negatively correlated with plasma adiponectin. These results indicate BDM-X is a new resource applicable to the functional foods or the complementary biomedicines to prevent metabolic syndromes leading to type 2 diabetes.