Extraction optimization and bioactivity of exopolysaccharides from Agaricus bisporus

Response surface methodology was used to optimize the extraction parameters of EPS produced by Agaricus bisporus MJ-0811 in submerged culture. The optimal levels for ethanol concentration (85%, v/v), pH (8) and precipitation time (22 h) were determined, and EPS production was estimated at 2.71 g/L. The actual yield of EPS under these conditions was 2.69 g/L. In addition, the antioxidant activity of EPS was investigated by measuring its scavenging ability on superoxide radicals and hydroxyl radicals in vitro. Furthermore, the hypoglycemic activity of EPS was investigated by measuring its effects on body weights and blood glucose of diabetic mice. The study suggests that EPS has beneficial antioxidant activities (hydroxyl radical-scavenging activities, superoxide radical-scavenging activities) in vitro, anti-diabetic effect on alloxan induced diabetic mice. The EPS from A. bisporus may be a novel resource of natural antioxidants and anti-diabetic agents for use in the functional food or medicine.