Immune-stimulatory potential of hot water extracts of selected edible mushrooms

Abstract

Polysaccharides isolated from mushrooms have recently attracted attention due to its potential immune-stimulatory activity. The aim of this study was to validate the in vitro immune-stimulatory activities of various mushroom extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that Pleurotus eryngii, with the highest β-glucan (18.94%) content, displayed highest viability on macrophage cells of 62.59% at 200 μg/ml concentration. Pleurotus cystidiosus, with 18.16% β-glucan, content showed highest activation of NF-kB (0.7 µg/ml) at a concentration of 100 µg/ml. Termitomyces heimii, with the lowest percentage of β-glucan (0.51%), exhibited highest phagocytosis index of 9.38 at 12.5 µg/ml. The brown strain of Agaricus bisporus with 1.54% of β-glucan stimulates the highest nitric oxide (NO) production of 12.39 µM nitrite oxide at 100 µg/ml. This study revealed that hot water extracts of mushrooms have different β-glucan contents and produced varying immune-stimulatory activities. Among these, Pleurotus spp. demonstrated the highest percentage of β-glucan content and viability of macrophage cells. Pleurotus spp. are deemed immune-stimulatory by increasing phagocytic activity, NO production, and triggered the activation of NF-kB.