Antioxidant And Anti-aging Activities Of Sulfated Polysaccharides From Flammulina Velutipes

Flammulina velutipes containing a variety of components such as polysaccharides,proteins,mineral elements and vitamins,has biological activities such as immune regulation,anti-fatigue,lowering cholesterol and anti-tumor and so on.In this paper,Plackett-Burman designs?PB?and Response surface methodology?RSM?were used to optimize the extraction conditions of F.velutipes polysaccharides?FPS?,and sulfated FPS?SFPS?was obtained after sulfation.The structures and the antioxidant activities in vitro of SFPS and FPS were analyzed.The D-galactose-induced aging model was established to explore the anti-aging and organ protection effects.The main results are as follows:?1?When the extraction conditions were temperature 86.77?,extraction time 2.30h and ethanol multiple 3.40,the theoretical yield of FPS was 3.69%.For the convenience of operation,the extraction temperature,extraction time and ethanol multiple were set as 87?,2.5h and 3,respectively,the theory yield of FPS was 3.64%and the actual yield was3.55±0.12%.?2?High performance gel permeation chromatography?HPGPC?analysis showed that the weight average molecular weight?Mw?of SFPS and FPS were 2.81×10³Da and6.96×10⁶Da,respectively.High performance liquid chromatography?HPLC?analysis indicated that SFPS contained mannose,ribose,glucose,galactose,xylose and fucose,with mass percentage of 9.27%,4.47%,47.55%,29.98%,3.78%and 4.93%,while the FPS was composed of mannose,ribose,rhamnose,glucuronic acid,glucosamine,glucose,galactose,xylose and fucose with mass percentage of 13.95%,1.98%,0.97%,0.82%,0.22%,53.35%,20.08%,3.24%and 5.39%.Fourier transform infrared spectroscopy?FT-IR?showed that both SFPS and FPS were typical polysaccharide,SFPS with?-glucoside linked pyranoses while FPS with?-glucoside linked pyranoses.In addition,the absorption peaks of SFPS at 1241cm^-1and 804cm^-1 were due to stretching vibration of S=O and C-O-S,respectively,while the FPS showed no performance,indicating that sulfation was successful and the substitution degree was 0.38.?3?At the concentration of 1000mg/L,the scavenging capacities of SFPS on hydroxyl,superoxide anion,and 1,1-diphenyl-2-picrylhydrazyl?DPPH?free radicals were 63.43±2.25%,68.58±2.42%,and 56.82±2.21%,higher than those of FPS by 22.59%,60.68%,and 45.99%,respectively.The reducing capacity of SFPS was 0.60±0.02,which was 106.90%higher than FPS.?4?The effects of SFPS on anti-aging and protective organ in vivo were investigated.The results showed that the high-dose SFPS group had the best anti-aging effect in liver tissues,significantly by increasing the activities of superoxide dismutase?SOD?,glutathione peroxidase?GSH-Px?,catalase?CAT?and total antioxidant capability?T-AOC?,and reducing the malondiadehyde?MDA?and lipid peroxidase?LPO?contents.SFPS could decrease creatinine?CRE?,blood urea nitrogen?BUN?and uric acid?UA?levels in serum,and obviously reduce alanine aminotransferase?ALT?,alkaline phosphatase?ALP?and aspartate aminotransferase?AST?activities.At the same time,SFPS could also improve the abnormality of lipoprotein metabolism by inhibiting the reduction of high density lipoprotein cholesterol?HDL-C?,and the elevation of low density lipoprotein cholesterol?LDL-C?.Additionally,SFPS clearly increased the activities of nitric oxide synthase?NOS?and inhibited acetylcholinesterase?Ach E?.The above experimental results suggested that SFPS had certain antioxidant and anti-aging activities,and could resist oxidative stress damage in aging mice.All the results could be demonstrated by histopathological observation of liver,kidney and brain in aging mice,which indicated that SFPS had the effect of organ protection and provided references for the development and utilization of natural functional substances.