Extraction optimization and antioxidant activity of intracellular selenium polysaccharide by Cordyceps sinensis SU-02

Central composite design (CCD) was used to optimize the extraction parameters of intracellular selenium polysaccharide (ISPS) from Cordyceps sinensis SU-02 mycelium in submerged culture. The optimum conditions for ISPS extraction were predicted to be, ultrasonic treatment for 15.11 min, extraction temperature at 59.26 °C and pH 7.17, and ISPS production was estimated at 11.52%. The in vivo antioxidant results of ISPS showed that the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) of mice blood were 2.36 ± 0.17 U and 477.92 ± 35.14 U, respectively, and malonaldehyde (MDA) level was 0.65 ± 0.04 μM/l. The in vitro inhibition effects of ISPS on superoxide anion radical and hydroxyl radical were 38.53 ± 3.19% and 43.22 ± 3.29%, respectively, and the reducing power of ISPS was 0.61 ± 0.04. The results suggested that the ISPS could be used as a potential antioxidant which enhances adaptive immune responses.