| Aging is an extremely complex systematic process.In aged organism,the function of antioxidant system reduces,the balance of internal environment redox is disrupted and age-related diseases are induced.Nrf2(nuclear factor erythroid2-related factor 2)is a positive regulatory factor of the antioxidant response element and involves in the regulation of the expressions of over 500 genes,including the genes of antioxidant enzymes,and dexoxification enzymes.Among the older individuals,the overall level of Nrf2 signaling pathway with the protective effect up-regulates in the longevity individuals.It enhances the defense capabilities of older individuals,and delays the aging process.Therefore,scientists believe that Nrf2 is a protector of health and longevity.Sargassum fusiforme has a "longevity food" regulation.It has been reported that the polysaccharides from S.fusiforme have many biological functions,such as antioxidant activities.But the mechanisms of antioxidant activities and delaying the aging of S.fusiforme polysaccharides have not been reported.In this study,polysaccharides from S.fusiforme were extracted by hot water or cold and hot water in turn,obtained three polysaccharides,determine their physical and chemical properties and screened their antioxidant activities by scavenging free radicals.Then the model of natural aged mice was establish S.fusiforme polysaccharide at the concentration of 100mg/kg/d was fed to the natural aged mice.The antioxidant enzymes and genes related to aging index in the livers of the natural aged mice and the influence of SFPS on them were determined to analyze if S.fusiforme polysaccharide play a role in anti-aging through Nrf2/ARE(anti-oxidation response element)signaling pathway.The cold-water solube polysaccharide(SFCP)and hot-water soluble polysaccharide(SFHP)were obtained from S.fusiforme by cold and hot water treatments successively.The total water soluble polysaccharide(SFPS)was obtained from S.fusiforme by hot water treatment.According to the result of scavenging free radicals,the relationship between the concentration of three polysaccharides and the scavenging rate was positively correlated.Among these three polysaccharides,SFPS have the highest DPPH free radical scavenging ability.However,there is no significant difference in the hydroxyl radical scavenging ability these three S.fusiforme polysaccharides.SFPS was a sulfated polysaccharide mainly composed of nine kinds of monosaccharides such as guluronic acid and fucose.It contained more uronic acid(41.2%)and its total sugar content was 77.2%.Studies showed that 9-month-old mice can be used as natural aged mice for significantly decrease in Nrf2,related antioxidant enzyme genes? expression and activities of antioxidant enzymes and so on.Intragastric administration of SFPS enhanced the expression and the antioxidant capacity of Nrf2 system of 9 months aged mice,including the enzyme activity of T-AOC,T-SOD and CAT and the expression of GCLC,GCLM and GPx1.It can be concluded that SFPS is a good natural antioxidant,which up-regulate Nrf2/ARE signaling pathway to enhance the body's antioxidant capacity and delay aging. |
PDF Full Text Request