The Antioxidant Activity Of Total Flavonoids,Structural Characterization And Immunomodulatory Activity Of Polysaccharides From Eurycoma Longifolia

Eurycoma longifolia?known as tongkat ali?,is a flowering plant of the family Simaroubaceae,native to Southeast Asia.A novel polysaccharide fraction named Ali-1 and the flavonoids was isolated from the roots of Malaysia's E.longifolia in the study.Its structural characterization and analysis were carried out respectively.Biological activities were evaluated by different cell models,such as the chemical and cellular CAA antioxidant activity of the flavonoids,the anti-inflammatory activity of Ali-1 and the anti-AAPH oxidative hemolytic activity.The total flavonoids of E.longifolia were separated by AB-8 macroporous adsorption resin,and the adsorption rate was 76.57%.The total flavonoids of E.longifolia are obtained after concentrated lyophilization.Then,the functional groups and their characteristics were analyzed by UV scanning and FT-IR.The result of chemical antioxidant capacity show that the total flavonoids has a good scavenging effect on DPPH free radicals and superoxide radicals,and has good reducing power for iron ions.The result of ORAC value and the antioxidant activity of HepG2 cells indicated that the value of ORAC was 2302.48?mol TE/g,the value of EC₅₀0 was 192.27?g/mL,and the value of CAA was 4.10?mol QE/100?mol of total flavonoid.Comparing with the value of ORAC and cellular antioxidant activity in common plant flavonoids,the total flavonoids of E.longifolia is at a superior antioxidant level.The crude polysaccharides of E.longifolia was obtained by the way of water extraction-alcoholprecipitation and lyophilization.The yield is 6.93%.The fraction of Ali-1was further purified by DEAE-Sepharose Fast Flow column and G-50 gel column.The purity of the sample was determined to be 95.42%.The average molecular weight of Ali-1 is 14.3 ku by the determetion of HPGPC.The result of FT-IR indicated hat Ali-1 contained the characteristic absorption peak of polysaccharide.it is composed of arabinose?14.31%?,xylose?57.69%?,galacturonic acid?13.03%?,and glucuronic acid?14.86%?by the determination of monosaccharide composition.The main chain comprises?1?4?-linked xylose residues.It has branch points in the main chain;?1?2,4?-linked xylose residues,1,2-linked glucuronic acid residues,and 1,2-linked arabinose residues form the branches,and the branches are terminated with T-linked galacturonic acid residues and T-linked arabinose residues.Ali-1 has a sheet-like appearance and that ovoid-shaped particles were randomly distributed throughout its microstructure from the imges of SEM.Finally,the phagocyte RAW264.7 model demonstrated that Ali-1 can promote the secretion of cytokines NO,TNF-?and IL-6 by mouse macrophages with dose-effect relationship.The results indicate that Ali-1 has good anti-inflammatory activity.The antioxidant model of red blood cell was used to evaluate the antioxidant activity of Ali-1 in vitro.Ali-1 could protect human red blood cells from AAPH damage and has certain antioxidant activity within a certain sample concentration range.