Extraction And Optimization Of Polysaccharides From Root Of Oudemansiella Raphanipes And Its Effect On Ulcerative Colitis In Mice

As a rare variety of cultivated edible fungi,the Oudemansiella raphanipes has become more and more popular in the edible fungus cultivation industry due to its rich nutritional value and considerable profit.However,after the O.raphanipes is planted,the root remaining in the upper layer of the spawn culture medium is still part of the O.raphanipes fruiting body,but it has not been fully utilized at present.Combined with the biological activity of edible fungus polysaccharides and the high incidence of ulcerative colitis(UC)in China in recent years,we want to solve the problem of the utilization of the root and the treatment of ulcerative colitis.In this experiment,the optimal extraction conditions for polysaccharides from root of O.raphanipes(PRO)were tested through the extraction optimization experiment,the primary structure and in vitro antioxidant capacity were preliminarily explored,and through animal experiments,the treatment effect of PRO on 3%dextran sodium sulfate(DSS)-induced ulcerative colitis mouse model was explored.(1)Plackett-Burman designs(PB)test was used to select the 3 extraction datas that had the greatest influence on the yield of PRO from the 9 extraction datas.Then,the response surface methodology(RSM)showed that under the datas of extraction temperature 85.69?,ethanol concentration 86.99%,ethanol precipitation time 22.69h,PRO had the best yield of3.40%.The pairwise interaction between the 3 extraction datas was not significant,and had passed the actual test.(2)The weight-average molecular weight of PRO was 1.99×10⁴Da by high-performance gel-permeation chromatography(HPGPC).High performance liquid chromatography(HPLC)results showed that the monosaccharide composition of PRO was mannose,glucuronic acid,glucose,galactose,xylose and fucose with a percentage of 6.57%,0.66%,44.26%,40.24%,0.57%and 7.50%,and mole ration of 10.73:1.00:72.26:65.69:1.12:13.44.The results of Fourier transform infrared(FT-IR)analysis showed that the absorption peaks near 880cm^-1,800cm^-1 and 599cm^-1 indicated that PRO should be a pyranose with?-and?-configurations.(3)The measurement results showed that the scavenging rate of PRO on DPPH,hydroxyl,and superoxide anion free radicals at a concentration of 1000 mg/L reached66.2±2.61%,66.8±2.64%and 53.7±2.77%,and the reducing power of PRO was 0.819±0.059at the concentration of 1000mg/L,it showed good antioxidant capacity.(4)The regulatory effect of PRO on DSS-induced ulcerative colitis.In terms of body surface morphology,PRO could improve the phenomenon of body weight loss and DAI score increase in mice with ulcerative colitis.In terms of the morphological changes of the colon,PRO alleviated the tendency of the length shortening,repaired the mucosal tissue damage in the colon,reduced the deletion of glands,cryts and goblet cells,and inhibited the overflow of inflammatory factors.In the determination of the activity of serum inflammatory factors,PRO could significantly reduce the activities of tumor necrosis factor?(TNF-?),interleukin-6(IL-6),interferon-?(IFN-?)and the levels of nitric oxide(NO).From the perspective of oxidative stress state,PRO could reduce the activities of malondiadehyde(MDA),lipid peroxidase(LPO),myeloperoxidase(MPO)and reactive oxygen species(ROS)to improve oxidative stress in the colon tissue of mice.From the point of view of antioxidant enzyme system,PRO could improve the activity of antioxidant enzyme including glutathione peroxidase(GSH-Px),catalase(CAT),superoxide dismutase(SOD).In conclusion,PRO could play an effective role on the treatment of ulcerative colitis of mice by inhibiting the expression of inflammatory factors,regulating oxidative stress state and repairing antioxidant enzyme system.And this effect may be related to primary structures such as monosaccharide composition.Therefore,we can efficiently extract the polysaccharide from the root of O.raphanipes and use some processing methods,and then get the product that can regulate ulcerative colitis,so that the root of O.raphanipes can be fully utilized.