Hypoglycemic and Hypolipidemic Effects of the Cracked-Cap Medicinal Mushroom Phellinus rimosus (Higher Basidiomycetes) in Streptozotocin-Induced Diabetic Rats

Phellinus rimosus is a parasitic host specific polypore mushroom with profound antioxidant, antihepatotoxic, anti-inflammatory, antitumor, and antimutagenic activities. This study investigated the hypoglycemic and hypolipidemic activities of the wood-inhabiting polypore mushroom Ph. rimosus in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by single intraperitoneal injection of STZ (45 mg/kg) to Wistar rats. The effects of 30 days treatment with Ph. rimosus (50 and 250 mg/kg) and glibenclamide (0.65 mg/kg) on blood glucose level, serum insulin, serum lipid profile, liver glycogen, liver function enzymes, and non-enzymic and enzymic antioxidants activities in pancreas, liver, and kidney were evaluated in STZ-induced diabetic rats. Oral administration of Ph. rimosus extract exhibited a significant reduction in blood glucose, triacylglycerol, total cholesterol, LDL-cholesterol, and liver function enzymes, and increased serum insulin, liver glycogen, and HDL-cholesterol levels in STZ-induced diabetic rats. Furthermore, Ph. rimosus treatment increased antioxidant status in pancreas, liver, and kidney tissues with concomitant decreases in levels of thiobarbituric acid-reactive substances. Results of this study indicated that Ph. rimosus possessed significant hypoglycemic and hypolipidemic activities and this effect may be related to its insulinogenic and antioxidant effect.