Physicochemical characterization of polysaccharides from Chlorella pyrenoidosa and its anti-ageing effects in Drosophila melanogaster

The physicochemical characteristics and in vitro antioxidant and in vivo anti-ageing activities of partial purified Chlorella pyrenoidosa polysaccharides (PCPPs) were investigated. The building blocks of PCPPs were mainly composed of D-glucose, D-galactose and D-mannose. The average molecular weight of PCPPs was 9,950 Da. In vitro antioxidant activity assays showed that PCPPs could effectively scavenge hydroxyl, 1,1-diphenyl-2-picrylhydrazyl, and superoxide radicals, with stronger effect on hydroxyl radicals. Furthermore, the mean lifespan of the male and female Drosophila melanogaster was extended by 11.5% and 10.6%, respectively. This was accompanied by an increase in the total activity of the endogenous antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and catalase in young or old D. melanogaster administered with PCPPs. Moreover, a gender-dependent difference was observed both in lifespan and antioxidant enzyme activities in D. melanogaster. The results indicated that C. pyrenoidosa polysaccharides are potential natural antioxidants in extending lifespan.