Suillellus luridus (formerly Boletus luridus belongs to the genus Suillellus of the family Boletaceae) is a wellknown delicacy for centuries. It not only has high contents of carbohydrate and protein, low contents of crude fat, but also contains a variety of biological active compounds. In a study conducted by Liu et al., the aqueous extract of S. luridus showed the highest in-vitro antioxidant and antihyperglycemic activities among various boletus mushroom samples (Liu et al., 2016). In this study polysaccharides were identified as the major constituent of the aqueous extract, indicating that the high bioactivities of S. luridus aqueous extracts may be related to the effects of the polysaccharides in it.
Another study demonstrated that polysaccharides from S. luridus exhibited antihyperglycaemic, antihyperlipide, and protective effects in streptomycin-induced diabetic mice by decreasing blood glucose levels, reducing serum lipid levels, improving antioxidant status and attenuating kidney and liver injures (Zhang et al., 2018).