Composition analysis of acid hydrolysates from Cucurbita moschata Duch.polysaccharides and their effect on oxidative stress resistance of Caenorhabditis elegans

摘要

Pumpkin polysaccharides(PPe)have a variety of bioactive effects and our previous research showed the acid hydrolysate(PPe-S,a mixture)from PPe had an antioxidative capacity both in vitro and in viro.The aim of this study was to purify PPe-S and investigate the antioxidant stress effects of 2 purified components(PPe-S-1 and PPe-S-2)using Caenorhabditis elegans as model organism.The results showed that PPe-S-2 had a notable antioxidant effect,and could significantly enhance the activities of antioxidant enzymes including superoxide dismutase(SOD)(P<0.01),catalase(CAT)(P<0.01)and glutathione reductase(GR)(P<0.05),and increase the level of glutathione(GSH)(P<0.01),and decreased the content of malondialdehyde(MDA)(P<0.05).PPe-S-2 could significantly extend the survival time of C.elegans(P<0.01),which were stress-induced by hydrogen peroxide and methyl viologen.PPe-S-2 was a heteropolys accharide composed of glucose,arabinose,rhamnose and galactose with the molar ratio of 1.00:0.03:0.02:0.14.The molecular weight of PPe-S-2 was 0.73 kDa detected by high performance liquid chromatography.These studies demonstrated that PPe-S-2 obtained by the acid hydrolysis of PPe had a prominent protective effect to the damage induced by the intracellular free radical generating agents.