Effects of ingested fruiting bodies, submerged culture biomass, and acidic polysaccharide glucuronoxylomannan of Tremella mesenterica Retz.:Fr. on glycemic responses in normal and diabetic rats.

Mushroom polysaccharides have been shown to regulate glucose metabolism. Using male Wistar rats injected with saline (normal rats), streptozotocin (STZ-NT rats), or streptozotocin plus nicotinamide (STZ+NT rats), we investigated the hypoglycemic activity of orally ingested fruiting bodies (FB), submerged culture biomass (CM), or the acidic polysaccharide glucuronoxylomannan (GXM) of Tremella mesenterica, an edible jelly mushroom. Our results demonstrated that FB ingestion significantly attenuated the elevated blood glucose levels in an oral glucose tolerance test (OGTT) in STZ-NT rats. However, in STZ+NT rats, FB, CM, and GXM ingestion significantly attenuated the increases in food and water intake, 2-h postprandial blood glucose concentrations, and blood glucose levels in OGTT. Moreover, FB and GXM ingestion significantly decreased serum concentration of fructosamine in STZ+NT rats. Our results indicated that T. mesenterica might be developed as a potential oral hypoglycemic agent or functional food for diabetic patients and for persons with high risk for diabetes mellitus.