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

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 purifi ed 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.(c) 2023 Beijing Academy of Food Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).