Extraction,Isolation,Purification And Bioactivity Of The Fucoidan From Laminaria Japonica

Laminaria japonica fucoidan is a kind of special water-soluble polysaccharide combined with some sulfate groups,and it has high pharmacological value.In this paper,fucoidan was isolated from Laminaria japonica,and the polysaccharide LF2 was collected through separation and purification.Then the monosaccharide composition,the structure,antioxidative and antitumor activity in vivo and in vitro were studied.All above studies can provide some theoretical basis for application,exploration and functional study of fucoidan.The contents and results are shown as follows:1.Among three extraction methods for Laminaria japonica fucoidan,compound enzymes treatment had the highest extracting ratio of crude fucoidan(4.96%).The crude fucoidan was purified by DEAE-52 and collected the solution named as LF2 by 0.5mol/L NaCl for further study,the polysaccharide yield was 58.7%.Then the Sephadex G-200 result showed that LF2 was pure.2.HPLC analysis indicated that LF2 containing mannose,rhamnose,glucuronic acid,glucose,galactose,xylose,fucose and its molar ratio was 1.253:0.341:0.298:0.275:0.932:0.316:1.106.Infrared spectrum analysis showed that LF2 contained the pyranose with beta glycosidic bond.3.According to the results of antioxidant assessment in vitro,LF2 had the best scavenging effect on hydroxyl free radical,the maximum was 64.88%.In the same concentration,the clearance rate on DPPH free radical was 31.97%.And the activity depended on the concentration of LF2 both of them.4.Compared with the aging model group,the activity of SOD,CAT and content of MDA in serum and liver of LF2 group all had significant difference.The activitiy of SOD increased by 33.70%and 65.78 respectively(P<0.01),the activity of CAT increased by 69.75%and 69.75%respectively(P<0.01),and the content of MDA was reduced by 41.73%and 41.73%respectively(P<0.01).5.The hightest inhibition rates of LF2 on HepG-2 and H22 were 40.05%and 31.26%respectively.And within 0～0.8 mg/mL,the inhibition rates depended on the concentration of LF2 both of them.And the apoptosis morphologic changes of HepG-22 cell were examined via AO/EB staining.6.Compared with the normal group,the spleen and thymus in the group of LF2 high dose increased by 48.52%and 48.52%respectively(P<0.01),the lever of IL-2,TNF-a increased by 49.18%and 49.18%respectively(P<0.01).And the life extension rate of ascites H22 mice was up to 44.2%.