Structural characterization and biological activities of sulfated polysaccharides from Antrodia cinnamomea

Abstract

Antrodia cinnamomea, an edible and medicinal mushroom, has been widely used for functional foods and dietary supplements in Taiwan. This study discovered β-1,6-linked sulfated galactoglucans with or without branches from A. cinnamomea mycelia, and elucidated their anti-inflammatory and anti-cancer potentials. Results showed that K1, a sulfated polysaccharide (SPS) isolated from A. cinnamomea mycelia cultured for 49 days with 1 mM potassium sulfate, possessed potential anti-inflammation in that K1 100 μg/ml suppressed tumor necrosis factor-α (TNF-α) production by 49%, and anti-cancer activity with K1 800 μg/ml suppressed lung cancer H1975 cells by 57%. Based on the molecular weight distribution, three SPS fractions (K1 F1, K1 F2, and K1 F3) were purified from K1. Among the three fractions, K1 F2 and K1 F3 were found to contain high sulfate content with values of 4.46 and 3.77 mmol/g, respectively. The representative repeating unit of K1 F2 contained a sulfated β-1,6-linked glucosyl backbone with a long α-/β-galactoglucose branch attached at the 3-O position of backbone, while the proposed repeating unit of K1 F3 included an unbranched sulfated β-1,6-linked glucosyl residue. K1 F2 and K1 F3 attenuated the LPS-induced inflammation in RAW264.7 cells via p38 and AKT pathways, respectively. K1 F2 possessed potential anti-cancer activity against H1975 lung cancer cells through TGFβRI and apoptotic pathways. In conclusion, K1 F2, a long-branched sulfated galactoglucan, and K1 F3, an unbranched sulfated glucan, may be good candidates for anti-inflammatory and anti-cancer applications.

Keywords: Anti-inflammation; Anti-lung cancer; Antrodia cinnamomea; Galactoglucan; Sulfated polysaccharide.