Extraction And Antioxidant Activities Of Exopolysaccharide And Intracellular Polysaccharide By Pholiota Adiposa

Pholiota adiposa, which belongs to Basidiomycotina, Hymenomycetes, Agaricales, Strophariaceae. P. adiposa, is a nutritional and medicinal mushroom with refreshing fragrance. It contains many biological active materials, such as polysaccharides, protein, trace elements, dietary fiber and vitamins, etc. The polysaccharides from P. adiposa had the functions of antitumour, fatigue resistance, antivirus and immunoregulation.In this paper, the extraction conditions for P. adiposa SX-02 exopolysaccharide (EPS) and intracellular polysaccharide (IPS) in submerged culture were optimized on the basis of Plackett–Burman (PB) design and response surface methodology (RSM). The in vitro antioxiant activities of EPS and IPS and in vivo antioxiant activities of EPS were evaluated.1. Extraction optimization of IPSThe optimum extraction conditions for IPS production were ultrasonic power 561.26W, precipitation time 30.18h, and pH8.28, while the production of IPS was predicted to be 20.73%. In view of the operating convenience, the optimal extraction parameters were determined to be ultrasonic power 560W, precipitation time 30h and pH8.3, the expected EPS production was 20.70%, slightly lower than that of the maximum predicted value.2. Antioxidant activity of IPS in vitroResults showed that the IPS had significantly scavenging effects on superoxide anion, hydroxyl, and DPPH radicals. IPS also shows considerable reducing power. The EC50 values of EPS scavenging superoxide anion, hydroxyl and DPPH radicals were 19.61±1.25 mg/L, 47.37±3.72 mg/L, and 24.83.61±2.16 mg/L, respectively.3. Extraction optimization of EPSThe optimum extraction conditions for EPS production were concentration temperature 87.36℃, precipitation time 35.18h, and pH8.81, while the production of EPS was predicted to be 8.81mg/mL. In view of the operating convenience, the optimal extraction parameters were determined to be concentration temperature 87℃, precipitation time 35h and pH8.8, and the predicted EPS production was 8.79mg/mL, slightly lower than that of the maximum predicted value.4. Antioxidant activity of EPS in vitroResults showed that the EPS had significantly scavenging effects on superoxide anion, hydroxyl and DPPH radicals and reducing power. The EC50 values of EPS scavenging superoxide anion, hydroxyl and DPPH radicals were 28.65±2.55 mg/L, 119.24±10.05 mg/L, and 10.85±0.57 mg/L, respectively.5. Antioxidant activities of EPS in vivoThe effect of EPS on antioxidation capacity of mice was observed by measuring the superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, and the content of malondialdehyde (MDA). The in vivo results showed that EPS could significantly elevate the activity of SOD and GSH-Px, and the decrease MDA content in mice tissue (heart, liver, kidney, spleen) and blood.The results suggest that the EPS and IPS of P. adiposa had significantly antioxidant activity in vivo and in vitro, which could be used as natural and potential antioxidants.