Study On Hypoglycemic Activity Of Artemisia Sphaerocephala Polysaccharide And The Derivatives In Vitro

Artemisia sphaerocephala polysaccharide(ASP) is a polysaccharose substance from waste residue when Artemisia sphaerocephala Krasch. seeds are oil pressed, essential constituent of which is galactomannan, a linear macromolecule with many branched chains and it has been studied for well hypoglycemic effect and antioxidant activity. Sulfated derivatives of ASP(SASP), Phosphated derivatives of ASP(PASP) and Selenide of ASP(SeASP) are prepared using ASP as raw materials by chemical structure modified of sulfation, phosphorylation and selenite respectively, antioxidant activity of which is higher than ASP in vitro. Therefore, this thesis is to investigate the hypoglycemic activity of ASP, SASP, PASP and SeASP using liver cancer HepG2 cells in vitro. it is discussed that action characteristics of ASP, SASP, PASP and SeASP on phase of cell growth by observing influence of ASP, SASP, PASP and SeASP on HepG2 cell seven days'growing curve.Hypoglycemic effect and poisoning effect are preliminarily explored by glucose comsumption assay and methyl thiazolyl tetrazolium(MTT) colorimetric method separately. In addition, insulin resistant HepG2 cell model is induced by means of high concentration of insulin, induction conditions of which are optimized for its stability. To probe enhanced sensitivity for insulin and hypoglycemic activity respectively, glucose comsumption was detected on insulin resistant HepG2 cells treated with ASP, SASP, PASP and SeASP. The results indicate that:1. Low concentration(0.02mg/ml and 0.05mg/ml) of ASP, SASP, PASP and SeASP can stimulate the proliferation of HepG2 cells, and the first three days are logarithmic growth phase when HepG2 cells are treated. In the range of 0.02～1mg/ml, ASP, SASP, PASP and SeASP also can decrease HepG2 cell survival rate differently, and the rate of cell viability is inversely proportional to the dose of samples. High concentration(1mg/ml) of SASP has the most evident cell toxicity with 86.749% cell viability. while, highest cell survival rate is 99.863% at low concentration of SASP.2. ASP, SASP, PASP and SeASP can increase HepG2 cells glucose uptake in different extent. 0.1mg/ml of samples have the best hypoglycemic effect, and the glucose uptake rate is 146.942%, 154.393%, 145.521% and 116.968% respectively.Deduction of impact on cell viability, hypoglycemic activity of SASP is the best(p<0.01), secondly for ASP and PASP(p<0.05). It shows that ASP, SASP and PASP have certain significance on developing and investigating anti-diabetes agent.3. Considering effect on cell survival rate,the optimum establishment conditions of insulin resistant HepG2 cell model are 10-7mol/L insulin acting on HepG2 cells for 36h. Moreover, the characteristics of insulin resistance model can be kept for 48h.4. 0.1mg/ml ASP, SASP, PASP and SeASP have different ameliorative effect on insulin resistant HepG2 cellsin increasing glucose utilization, and the potency is in sequence of SASP>ASP> PASP >SeASP, which may be mainly related to their structural differences. SASP has the best obvious effect(p<0.01) on insulin resistant HepG2 cell model for 36h or 48h, which can be used as insulin sensitizer to study on improving hyperglycemia.