| Zinc is one of the most essential trace elements in human body and links with nearly 300 kinds of enzymes in the body,and also can improve the immunity,increase the antioxidant abilities and promote development of the human body.Approximately 50% of the world’s population is at risk of inadequate zinc intake.Pleurotus nebrodensis is a kind of efficient biotransformer with high heavy metal enrichment conversion ability,and it can transform inorganic zinc into organic zinc,which digests and absorbs in human body and increases the utilization efficiency of the zinc.The mycelia zinc polysaccharide(MZPS)of P.nebrodensis was obtained by liquid fermentation,and ackalic-extractable MZPS(Ac-MZPS),alkalic-extractable MZPS(Al-MZPS)and enzymatic-extractable MZPS(En-MZPS)were determined in this work.The monosaccharide compositions,antioxidant properties and the antihyperlipidemic activities were investigated.(1)Separation and purification of MZPS: Ac-MZPS,Al-MZPS and En-MZPS were purified by DEAE-52 cellulose column,two fractions(Ac-MZPS-1 and Ac-MZPS-2)of Ac-MZPS;two fractions(Al-MZPS-1 and Al-MZPS-2)of Al-MZPS;one fraction(En-MZPS-1)of En-MZPS were obtained.The results of gas chromatography(GC)showed that Ac-MZPS contained mannose,galactose and glucose with a ratio of 4.0:1.90:5.79(33.70%,16.01% and 50.29%);and Al-MZPS contained mannose,galactose and glucose,with a ratio of 1.3:1.0:3.8(20.8%,19.1% and 60.82%);and En-MZPS contained arabinose,mannose,galactose and glucose,monosaccharides(10.1%,15.6%,7.80%,and 66.5%)with a molar ratio of 11.0:14.0:6.8:58.(2)The antioxidant activities in vitro of MZPS showed that Ac-MZPS,Al-MZPS and En-MZPS exhibited higher antioxidant activities on reducing power,scavenging abilities on hydroxyl and DPPH radicals.Ac-MZPS exhibited higher antioxidant activities on reducing power and the scavenging activities against hydroxyl radicals;En-MZPS showed the highest antioxidant capacity on reducing power and the scavenging activities against DPPH radicals.(3)The antihyperlipidemic activities of MZPS showed that the administration of Ac-MZPS,Al-MZPS and En-MZPS improved activities of glutathione peroxidase(GSH-Px),superoxide dismutase(SOD),catalase(CAT)and total antioxidant capability(T-AOC),and reduce the lipid peroxide(LPO)and malondialdehyde(MDA)contents in liver of mice.Three MZPS decreased the activities of alanine transaminase(ALT),aspertate aminotransferase(AST)and alkaline phosphatase(ALP)and the levels of low-density lipoprotein cholesterol(LDL-C),very low-density lipoprotein cholesterol(VLDL-C),triglycerides(TG),total cholesterol(TC)and increased the level of high-density lipoprotein cholesterol(HDL-C)in serum.The histopathological observations of mice livers indicated that the MZPS could attenuate liver injury.These results demonstrated that MZPS could improve the lipid metabolism of hyperglycemia mice induced by high fat emulsion.In addition,The Ac-MZPS showed superior recovery effects than that of Al-MZPS and En-MZPS,demonstrating that Ac-MZPS had the protective effects on antihyperlipidemic,hepatoprotection and liver damage. |
