Cytotoxic effect of Agaricus bisporus and Lactarius rufus β-d-glucans on HepG2 cells

Abstract The cytotoxic activity of β- d -glucans isolated from Agaricus bisporus and Lactarius rufus fruiting bodies was evaluated on human hepatocellular carcinoma cells (HepG2). NMR and methylation analysis suggest that these β- d -glucans were composed of a linear (1→6)-linked and a branched (1→3), (1→6)-linked backbone, respectively. They both decreased cell viability at concentrations of up to 100 μg mL −1 , as shown by MTT assay. The amount of LDH released and the analysis of cell morphology corroborated these values and also showed that the β- d -glucan of L. rufus was more cytotoxic to HepG2 cells than that of A. bisporus . The treatment of HepG2 cells with L. rufus and A. bisporus β- d -glucans at a dose of 200 μg mL −1 for 24 h promoted an increase of cytochrome c release and a decrease of ATP content, suggesting that these polysaccharides could promote cell death by apoptosis. Both β- d -glucans were tested against murine primary hepatocytes at a dose of 200 μg mL −1 . The results suggest that the L. rufus β- d -glucan was as cytotoxic for hepatocytes as for HepG2 cells, whereas the A. bisporus β- d -glucan, under the same conditions, was cytotoxic only for HepG2 cells, suggesting cell selectivity. These results open new possibilities for use of mushroom β- d -glucans in cancer therapy.