The Study Of Antioxidant Activity And Induced-apoptosis Efficacy On HepG2 Cells Of Ginkgo Biloba Leaf Polysaccharide

Primary liver cancer is a malignant tumor disease which does harm to human health and characterized by the onset of secret,long course,high mortality and other characteristics.At present,the main treatment of primary liver cancer are palliative surgical treatment,chemical drug treatment and other methods which have a certain therapeutic effect but also with high risk,side effects,serious damage to the body and other defects at the same time.Therefore,it is urgent to dig out the natural anti-tumor drugs with good effects and small side effects and applied them into clinical treatment.The development of these drugs will have great practical significance on the prevention and treatment of malignant tumor disease.Numerous studies have shown that antitumor activity is an important biological activity of plant active polysaccharides.Therefore,in this study,hepatocellular carcinoma HepG2 cells were used as indicator cells to study the molecular mechanism of Ginkgo biloba polysaccharide(GBLP)on HepG2 cell proliferation and apoptosis induction.The experimental results are as follows:In this study,GBLP was extracted by water extraction and alcohol precipitation method.After the discoloration,deproteinization,dialysis and other treatment,we can obtain a higher purity of GBLP and the content of polysaccharide was 82.60% tested by phenol sulfuric acid method.Infrared spectroscopy analysis showed that GBLP contained a characteristic absorption peak of polysaccharides.The in vitro antioxidant test showed that GBLP had a strong ability to scavenge DPPH ·,O2-· radical,H2O2 and had some ability of reducing iron ions which indicated that GBLP had good antioxidant activity in vitro and positively correlated with polysaccharide concentration relationship.In this study,different concentrations of GBLP solution and HepG2 were incubated for48 h.MTT assay showed that the inhibition rate of GBLP to HepG2 was 37.42% when the concentration of GBLP solution reached 1400μg / ml.When we used flow cytometry to detect the apoptotic rate of cells,we found that when the concentration of GBLP solution reached1400μg / ml,the apoptosis rate reached 13.3%.The above results indicate that GBLP has a significant inhibitory effect on the proliferation of HepG2 and has dose-dependent effect.The Western Blot is used to analyses the expressions of caspase-9,caspase-3 and PARP,detects the translational levels of Bcl-2 and Bax proteins and examines the expression level ofoncogenic protein Mutant-p53.The results showed that GBLP could effectively activate caspase-9,caspase-3 and cut PARP to promote the apoptosis of HepG2,could furtherly induce mitochondrial damage by down-regulation of Bcl-2 and up-regulation of Bax expression and could reduce the expression level of mutant-p53.Above all,GBLP has a good regulatory effect on proliferation and apoptosis of HepG2 cells.