Extraction And Antitumor Activities Of Polysaccharides From The Root Of Pleurotus Nebrodensis

Pleurotus nebrodensis is a rare kind of medicinal and edible fungus.The success of artificial cultivation is undoubtedly the development of this biologica 1 resources to provide a good prospect.With the development of Bailing Mus-hroom industrialization in China,Pleurotus nebrodensis root scrap waste.Pleur-otus nebrodensis root containing polysaccharides and other bioactive substances,is a potential valuable resource.Therefore,it is a hot spot to improve the ad-ded value of Pleurotus nebrodensis.In order to improve the extraction rate of Pleurotus nebrodensis root exudates,the extraction conditions were optimized,and then the separation and purification were carried out.The physicochemical properties and structure identification of the polysaccharides were investigated.Finally,the growth of HepG-2 cells was carried out.On the basis of single-factor experiment,the ratio of water to material,extraction temperature and extraction time were selected as experimental single factors.Based on the experimental design principle of Box-Benhnken(BBD),the experiment was carried out to analyze the response surface and interaction of various factors.Based on the analysis of the significance and interaction of the three selected single factors,the optimum extraction conditions of the polysaccharides from the root of were as follows:the ratio of water to material 39.22:1,extraction temperature 90.3℃ and extraction time 3.06 h.Under these conditions,the predicted value of polysaccharide extraction rate of Pleurotus nebrodensis root was 1.98%.According to the experimental conditions,the ratio of water to material was adjusted to 40:1,the extraction temperature was adjusted to 90℃,and the extraction rate of polysaccharide was 2.01%.The purified polysaccharides were obtained from the root of Pleurotus nebrodensis by ion chromatography and gel filtration.The in vitro cell proliferation assay was used to detect the inhibitory rate of PN75,and the molecular weight of PN75-2 was 2.90 ×105 Da.The physicochemical properties of PN75-2 showed that PN75-2 had a pyran-type α-glycosidic bond structure with a sugar content of 92.5%,protein content of 3.6%,uronic acid content of 0.6%,without the presence of sulfuric acid group,with more side chains and branches,flocculent arrangement under the scanning electron microscope.The physical and chemical properties such as optical rotation,thermal properties and rheology were investigated,too.HepG-2 cells were treated with PN75-2 at the concentration of 200 μg/mL.MTT assay was used to study the inhibitory effect of PN75-2,a polysaccharide fraction from Pleurotus nebrodensis root exudates.The inhibition rate was 38.3%.Scanning electron microscopy(SEM)and AO/EB staining of HepG-2 cells were observed.The results showed that Pleurotus nebrodensis root polysaccharide PN75-2 could induce the apoptosis of HepG-2 cells.