| Pleurotus nebrodensis is a kind of fungus with great edible and medicinal value.It is rich in polysaccharides and other active ingredients.Among them,Pleurotus nebrodensis polysaccharides have been proved to have biological activities such as anti-tumor,immune enhancement and anti-oxidation.The purpose of this study was to explore the anti-aging activity and mechanism of Pleurotus nebrodensis polysaccharide by using the model of Caenorhabditis elegans.Experimental methods: after the concentration of polysaccharide was first determined,it was proved that polysaccharide could prolong the life of nematodes,and the changes of physiological characteristics of wild-type nematodes were measured.The changes of life span,active oxygen content,superoxide dismutase and catalase activities,lipofuscin content and lipid peroxide malondialdehyde content of nematodes under normal and stress conditions were further determined to judge the effect of Pleurotus nebrodensis polysaccharide on the biochemical characterization of nematodes.According to the neurodegenerative disease model of nematodes,the effects of polysaccharides on the life span,paralysis rate,chemosensory behavior,toxic protein aggregation and other changes in the nervous system of transgenic nematodes were investigated.Combined with the longevity,nuclear localization of transcription factors and gene expression of mutant nematodes,the anti-aging mechanism of polysaccharides was preliminarily determined.The results showed that polysaccharide from Pleurotus nebrodensis could prolong the life span of wild-type nematodes,and the average life span increased by 24.43%.Polysaccharide treatment not only prolonged the life span of wild-type nematodes under heat stress and oxidative stress,but also increased the activity of antioxidant enzymes under different stress conditions,and decreased the level of reactive oxygen species and the content of malondialdehyde.Polysaccharide treatment of Pleurotus nebrodensis reduced the accumulation of lipofuscin by 14%.Further experiments showed that β-In the amyloid mediated neurodegenerative disease nematode model,Pleurotus nebrodensis polysaccharide can prolong the life of transgenic nematodes,delay paralysis and reduce the dysfunction of chemical sensory behavior.It can be determined that the protection of nerve by polysaccharide is related to its anti-aging activity.Based on the analysis of nuclear localization,mutant longevity and key gene expression level,we preliminarily judged that the anti-aging mechanism of Pleurotus nebrodensis polysaccharide is to increase the nucleation rate of daf-16/FOXO,stimulate the expression of DAF-16 and its downstream target genes,improve the antioxidant capacity,reduce the damage associated with aging,and prolong the survival time of nematodes.Intestinal microbiological analysis showed that polysaccharide treatment had different effects on the intestinal flora of young and aging nematodes,but there was no inevitable relationship between the changes of intestinal flora affected by polysaccharide and the aging of nematodes. |
PDF Full Text Request