Extraction And Antioxidant Activities Of Exopolysaccharide And Intracellular Polysaccharide By Pholiota Nameko W-01

Pholiota nameko, a nutritional and medicinal mushroom with refreshing fragrance,belongs to Basidiomycotina, Agaricales, Strophariaceae, Pholiota. It contains manybiological active materials, such as polysaccharides, protein, trace elements, vitamins, etc.The P. nameko polysaccharides have the functions of antitumour, fatigue resistance, antivirus.In this paper, the extraction conditions of P. nameko W-01exopolysaccharide (EPS) andintrecellular polysaccharide (IPS) in submerged culture were optimized on the basis ofPlackett-Burman (PB) design and response surface methodology (RSM). The in vitro and invivo antioxidant activities of EPS and IPS were evaluated.(1) Optimization of EPS extractionThe results of PB experiments for EPS extraction were pH9, concentration multiple3,concentration temperature60C, ethanol multiple4, ethanol concentration75%, precipitationtemperature-4°C and precipitation time12h, while the EPS production was1904.60mg/L.The RSM results showed that the conditions of EPS extraction were pH8.80,concentration multiple1.02, and ethanol concentration90%. while the expected EPSproduction was3935.57mg/L. In view of the operating convenience, the optimal extractionparameters were determined to be pH9, concentration multiple1, ethanol concentration90%,and the actual value was3933.02mg/L.(2) Optimization of IPS extractionThe optimal conditions of IPS extraction by PB tests were water multiple20, pH9,ultrasonic power400W, ultrasonic treatment time800s, extraction temperature90C,extraction time1h, extraction number3, ethanol concentration95%, ethanol multiple4,precipitation temperature-4°C and precipitation time12h, while the IPS production was2.85%.The results of RSM experiments for IPS extraction were water multiple20.31, ultrasonic treatment time623s and extraction number2.87, while the expected IPS production was3.92%. The optimal extraction parameters were determined to be water multiple20,ultrasonic treatment time623s and extraction number3, and the actual value was3.92%.(3) Antioxidant activity of EPS and IPS in vitroAt a dosage of500mg/L, the reducing power of EPS was0.526, the scavenging effectson hydroxyl, superoxide anion, DPPH radicals were45.23%,58.37%, and52.55%,respectively. The EC50values of EPS scavenging hydroxyl, superoxide anion and DPPHradicals were536.13mg/L,388.09mg/L, and435.54mg/L, respectively.At a dosage of500mg/L, the reducing power of IPS was0.593, the scavenging effectson hydroxyl, superoxide anion, DPPH radicals were53.11%,63.24%and59.33%,respectively. The EC50values of IPS scavenging hydroxyl, superoxide anion and DPPHradicals were421.83mg/L,322.39m/L, and392.37mg/L, respectively。(4) Antioxidant activity of EPS and IPS in vivoThe EPS and IPS of P. nameko W-01at a dosage of0-200mg/kg had significantantioxidant activities in blood, heart, liver, spleen and kidney of mice by increasing theactivities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), alaninetrasaminase (ALT) and catalase (CAT), and by reducing the content of malondialdehyde(MDA). The in vivo activity capacity of IPS was superior to that of EPS.(5) Isolation and purification of EPS and IPSTwo components, named EPS-1and EPS-2, were obtained from EPS byDEAE-Cellulose, and three components, named EPS-2a, EPS-2b and EPS-2c, were purifiedfrom EPS-2by Sephadex G-100.Four components, named IPS-1, IPS-2, IPS-3and IPS-4, were obtained from IPS byDEAE-Cellulose, and only one component was from IPS-2.The results suggested that the EPS and IPS of P. nameko W-01had significantlyantioxidant activity in vitro and in vivo, which could be used as natural and potentialantioxidants.