Gray oyster mushroom, a common edible mushroom in Thailand, has been used as a source for polysaccharide extraction and purification. In this study, we extracted polysaccharides from the gray oyster mushroom through hot water, ammonium oxalate, and alkaline extraction methods. The extracts were further purified using enzymatic digestion, solvent extraction, and column chromatography. Fourier‐transform infrared spectroscopy reveals that the selected fractions contain β‐(1→3) glucan and mannan. Monosaccharide composition analysis suggests that glucose and mannose are the major constituents of all analyzed fractions. Interestingly, only the gel‐like fraction, namely SG1‐1 could enhance neutrophils’ killing activity on Candida albicans. In addition, the purified fractions stimulated glucose uptake activity in the L6 myotubes in a dose‐dependent manner.
Practical applications
The ability of those polysaccharides to stimulate glucose uptake in the muscle cells and enhance a neutrophil’s killing activity implicates the antidiabetic and immunostimulatory activities, respectively. Thus, these polysaccharides could be potentially developed into an immunostimulating agent and an alternative medicine for treating diabetes mellitus.
Functional mushroom polysaccharides have been known to the Asian traditional medicine for many years. The antiobesity activity of mushroom polysaccharides has been illustrated both in vivo and in vitro. However, the effect of pure polysaccharides on isolated fat cells has not been demonstrated. In this study, we used hot water and ammonium oxalate to extract polysaccharides from gray oyster mushroom [Pleurotus sajor-caju (Fr.) Sing.] and subsequently purified with enzymatic digestion, solvent extraction and ion-exchange chromatography. One of the fractions, 7S1-1, has the highest yield and purity and contains polysaccharides with the molecular weight around 500 kDa. In addition, Fourier transformed infrared spectroscopy (FTIR) and monosaccharide composition analyses showed that this 7S1-1 sample contains mostly β-glucan and some mannan. We find that the 7S1-1 fraction does not affect the total amount of triglycerides in the 3T3-L1 adipocytes but promotes a release of glycerol of the fat cells, suggesting that the fraction does not inhibit adipogenesis but stimulates lipolysis. Laminarin, a small β-glucan, confers similar results to the 7S1-1 sample, but it could not stimulate lipolysis as well as the 7S1-1 sample. Therefore, these results suggest a potential antiobesity activity of the mushroom polysaccharides.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.