Antidiabetic activity of polysaccharides from Suillellus luridus in streptozotocin-induced diabetic mice

Three polysaccharides were extracted from Suillellus luridus (Suilu.A, Suilu.C and Suilu.S) by the hot water-extraction (1:40, w/v) and ethanol precipitation. Their preliminary structures were characterized and their antidiabetic activities were evaluated to obtain the most active component. The results of high performance gel permeation chromatography (HPGPC) and gas chromatograph (GC) showed that the main molecular weight of Suilu.A, Suilu.C and Suilu.S were 6383, 8172, 10,710 Da, and these polysaccharides were composed of arabinose, xylose, mannose, glucose and galactose, with the highest glucose contents (41.90%-49.09%) and the lowest xylose contents (2.06%-4.36%). Besides, the structures of them were proved by Fourier transform infrared (FT-IR). Further, the antidiabetic effects of three polysaccharides were evaluated in diabetic mice (induced by injecting streptozotocin, 100 mg/kg, i.p). The results showed that these polysaccharides all exhibited potential antidiabetic effects. Especially, when diabetic mice were treated with Suilu.C (150 mg/kg·bw), all antidiabetic indexes and pathologic morphologies of liver, kidney were normalized, which indicated Suilu.C possessed higher antidiabetic activity than other two polysaccharides and was valuable for the diabetes treatment.