Study On Biological Activity And Mechanism Of Chinese Yam (Dioscorea Opposite Thunb.) Tuber Polysaccharide

Chinese yam tuber polysaccharides bioactive functions was studied in this paper. Antioxidant activity, physiological property and Antioxidant activity in vivo of drosophila, antibacterial effect and immunological competence was investigated respectively,.i Yam tubers polysaccharide was extracted by the method of water extract and alcohol precipitate.①O2-,ABTS, DPPH free radicals and FRAP was investigated respectively of polysaccharide in vitro antioxidant activity.② Different mass ratio of coarse polysaccharide was added in the basal medium include 0(CK),0.1%,0.3%,0.5%,1.0%and 1.5%. Drosophila’s lifespan(50 percent individuals lethal date, average life, maximum lifespan), flying ability, sexual vitality(the time of mating latency, mating duration),fecundity (number of F1, F2) and weight was investigated respectively on 0(CK),0.1%,0.5%,1.0% and 1.5% coarse polysaccharide. The influence of physiological characteristics on drosophila of yam coarse polysaccharide was evaluated.③ Drosophila was feed in the basic medium for 30d, then feed in the basic medium and different concentration of coarse polysaccharide medium for 10d respectively. Tissue of slurry of male and female drosophila feed in different group was extracted respectively.④ The inhibition effect of polysaccharides to fungi and bacteria was determined respectively. Material for common strains included Escherichia col, Staphylococcus aureus, Bacillus subtilis, Rhizopus, Penicillium, Aspergillus nige.⑤ The cellular morphology of macrophage RAW264.7 was observed. The activity of macrophage, excreted factor and metabolic enzymes was investigated respectively.Finally, yam polysaccharide comprehensive bioactivity was evaluated. Main results were as follows:1. Yam polysaccharide antioxidant in vitro was determined in the experiment. The results showed:when the concentration of yam tuber of coarse polysaccharide of 12 g/L, the capacity of cleared the O2- up to 0.53, when the concentration of yam tuber of coarse polysaccharide of 16 g/L, the capacity of cleared the ABTS up to 0.55, The capacity of cleared the DPPH-was stronger than Vc, up to 0.77, FRAP maximum 0.84 when the concentration of yam tuber of coarse polysaccharide on 20 g/L2. Drosophila’s life span, flight ability, sexual vitality, fecundity was enhanced respectively.3. The antioxidant enzyme activity was enhanced and the MDA was decreased respectively on the function of Chinese yam polysaccharide and the effect result was different in deferent concentrations.4. The antibacterial activity of yam polysaccharide reached 31.25% and 22.56% on Penicillium and Aspergillus niger and reached 34.55%,41.42%,21.33% on Bacillus subtilis, Staphylococcus aureus and Escherichia coli respectively, yam polysaccharide has different degrees of inhibition between bacteria and fungi.5. The mice macrophage RAW264.7 was incubated in vitro by the different mass ratio of coarse polysaccharide added in the dulbecco’s modified eagle medium. The result showed:The activity of macrophages was maintained and enhanced and the content of secrete factors NO and the activity of acid phosphatase enzymes was increased respectively on different content of yam polysaccharide. The activity of cell macrophages inflammation model by LPS was inhibited by yam coarse polysaccharide. Yam polysaccharide expressed the immune function of a two-way adjustment the activity of macrophages.