β-glucan-containing polysaccharide extract from the grey oyster mushroom (Pleurotus sajor-caju (Fr.) Sing.) stimulates glucose uptake by the L6 myotubes

Mushroom β-glucan has the ability to affect many cellular functions, including cellular glucose uptake. Although cumulative evidence in literature suggests a connection between β-glucan and reduction of blood glucose concentration, a mechanism of how β-glucan affects cellular glucose uptake has not been demonstrated. In this study, we analyzed the effect of β-glucan containing polysaccharide extract from mushrooms on glucose uptake by the L6 myotubes. We extracted crude polysaccharide from fruiting bodies of the grey oyster mushroom (Pleurotus sajor-caju), using hot water and protein removed by the Sevag reagent. The presence of β-glucan in the extract was confirmed by FT-IR analysis. We found that the partially purified polysaccharide extract from the grey oyster mushroom stimulated glucose uptake by the rat L6 muscle cells. In addition, laminarin, a small soluble β-glucan, enhanced the cellular glucose uptake. Results from this study suggest that β-glucan in the extract might promote the effect to the cells. The effect of purified mushroom β-glucan on the L6 cells requires additional analyses, and mechanistically how the mushroom β-glucan affects blood glucose concentration becomes our future goal.