Extraction And Antioxidant Activity Of Exopolysaccharide And Intracellular Polysaccharide By Hypsizigus Marmoreus SK-01

Hypsizigus marmoreus, a large wooden saprophytic fungi, belongs to Basidiomycota, Basidiomycetes, Agaricales, Tricholomataceae, Hypsizigus. It contains many biological active materials, such as polysaccharides, protein, trace elements, vitamins, etc, and is a kind of health food with high protein, low fat and low calorie, which has significant effects on scavenging free radical, stimulating the immune system, prolonging life and anti-aging.In this paper, the extraction conditions of H. marmoreus SK-01exopolysaccharide (EPS) and intrecellular polysaccharide (IPS) in submerged culture were optimized on the basis of plackett-burman (PB) design and response surface methodology (RSM). The in vitro and in vivo antioxidant activities of EPS and IPS were evaluated. The results were as follows:(1) Optimization of EPS extractionThe results showed that the optimal conditions of EPS extraction were concentration multiple2.72, pH8.26, and ethanol multiple2.85, while the expected value of EPS was4.72mg/mL. In view of the operating convenience, the optimal extraction parameters were determined to be concentration multiple3, pH8.3, ethanol multiple3, while the predicted value of EPS extraction was4.71mg/mL. The real extraction value of EPS performed under the determined conditions was4.66mg/mL.(2) Optimization of IPS extractionThe optimal conditions of IPS extraction were pH7.57, ultrasonic treatment time618.07s and extraction temperature84.53℃, while the expected IPS production was6.84%. The optimum extraction parameters were determined to be pH7.6, ultrasonic treatment time620s and extraction temperature85℃, and the actual rate of IPS extraction was6.93%.(3) Antioxidant activity of EPS and IPS in vitroAt a dosage of lg/L, the reducing power of EPS was1.02, the scavenging effects on hydroxyl, superoxide anion, DPPH radicals were92.31%,71.12%, and69.11%, respectively. The EC50values of EPS scavenging hydroxyl, superoxide anion and DPPH radicals were0.19g/L,0.53g/L, and0.47g/L, respectively.At a dosage of lg/L, the reducing power of IPS was0.74, the scavenging effects on hydroxyl, superoxide anion, DPPH radicals were52.63%,68.21%and63.43%, respectively. The EC50values of IPS scavenging hydroxyl, superoxide anion and DPPH radicals were0.85g/L,0.47g/L, and0.62g/L, respectively。(4) Antioxidant activity of EPS and IPS in vivoThe EPS and IPS of H. marmoreus SK-01at a dosage of0-400mg/kg had significant effects on increasing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and on reducing the contents of malondialdehyde (MDA) and lipid peroxidation (LPO) in blood, heart, liver, spleen and kidney of mice. The in vivo activity capacity of EPS was superior to that of IPS.(5) Isolation and purification of EPS and IPSThree components, named EPS-Ⅰ、EPS-Ⅱ and EPS-Ⅲ, were obtained from EPS by DEAE-Cellulose, and only one component was from EPS-Ⅱ.Four components, named IPS-Ⅰ、IPS-Ⅱ、IPS-Ⅲ and IPS-Ⅳ, were obtained from IPS by DEAE-Cellulose, and two components, named IPS-Ⅰa and IPS-Ⅰb, were purified from IPS-Ⅰ by Sephadex G-100.The results obtained in this work suggested that the EPS and IPS of H. marmoreus SK-01had significantly antioxidant activity in vitro and in vivo, which could be used as the natural and potential antioxidants.