Alkaline extractive crude polysaccharide from Russula senecis possesses antioxidant potential and stimulates innate immunity response.

OBJECTIVES: Over past decades, investigation on bioactive polysaccharides extracted from mushroom by heated water reflux has been an emerging field of biomedicine especially in the area of immune stimulation. While studies with macromolecules isolated from remainder residue of aqueous extraction are scarce. In this context, crude polysaccharide from a traditionally edible macrofungus, Russula senecis, was prepared (RuseCap) by alkaline solvent using leftover residue of that conventional process and its structural along with therapeutic properties were evaluated.

KEY FINDINGS: Investigation by FT-IR, HPTLC, GC-MS and spectrophotometry showed that the fraction was mainly consisted of carbohydrate with backbone of xylose, rhamnose, mannose and glucose (mostly β-glucan). Besides, RuseCap exhibited strong antioxidant activity evident by radical scavenging (superoxide, hydroxyl, DPPH, ABTS), chelating ability and reduction power where EC50 values ranged from 257 to 4068 μg/ml concentration. In addition, it also exhibited immune-boosting potentiality as the treatment effectively induced proliferation, phagocytosis, nitric oxide production, intracellular reactive oxygen species generation, morphological changes and increased transcription level of iNOS, COX-2, TNF-α, IL-6 genes in macrophage cells.

CONCLUSIONS: Overall, the study provided blueprint for extended utilization of R. senecis basidiocarps beyond hot water process and defined use of RuseCap as potent therapeutic agent against free radicals as well as deprived immunity.