Preparation Of Selenium Nanoparticles Decorated By Astragalus Polysacharins And Its Growth Inhibition On Human Breast Carcinoma Cells

Objective:Astragalus polysaccharide is widely used in the field of medicine because of its antitumor synergistic effect,anti-inflammatory,liver protection activities,and high safety.In this paper,a series of nanoparticles of selenium,silver,and gold with small particle size,uniformity,and high stability were obtained by using astragalus polysaccharides or other polysaccharides as protective reagent.Furthermore,the anticancer mechanisms of nanoparticles with the highest activity were studied by using molecular biology methods.Method:Astragalus polysaccharides,trehalose,inulin,maltitol,and D-tallowose were used as protective agents and modifiers.Ascorbic acid and sodium citrate were used as reducing agents to synthesize a series of nano-selenium,nano-gold,nano-silver particles.Laser particle size analyzer,ultraviolet spectrometer,Infrared spectrometer were used to characterize the structure of the synthesized nanoparticles.The MTT method was used to select the growth inhibitory effect of the nanoparticles on breast cancer,liver cancer,and lung cancer cells.The nanoparticles with the highest activity and the corresponding cells were selected for further study.Annexin V-FITC / PI staining flow cytometry analysis,Nao fluorescence method,mitochondrial mass method and ROS method were used to detect the effect of nanoparticles on apoptosis,and Western blot method was used to detect the expression of apoptosis-related proteins Bax,Bcl-2,Casepase 9 and autophagy-related proteins LC3,p62,Beclin-1.The effects of nanoparticles on cell autophagy and apoptosis were also evaluated morphologically by immunofluorescence.Result:Nanoparticles were synthesized using 5 kinds of polysaccharides as protective agents.Among them,the nanoparticles synthesized using astragalus polysaccharides as protective agent had the characteristics of smaller particle size and better stability.MTT results showed that Astragalus polysaccharide nano-selenium(AP-SeNPs)exhibited obvious growth inhibitory effects on human liver cancer cells,breast cancer cells,and lung cancer cells,and the highest inhibitory effect on human breast cancer cells.Further mechanism research found that AP-SeNPs caused a decrease in mitochondrial mass,mitochondrial membrane potential,and an increase in ROS levels in human breast cancer cells.The results of flow cytometry,immunofluorescence and Western blot experiments showed that after treating breast cancer cells with AP-SeNPs,the apoptosis rate was significantly increased,the nucleus shrank and was cleaved into fragments.The expression of Bax and Cleaved caspase 9 protein increased and the expression of Bcl-2 protein decreased,which indicated that AP-SeNPs induced the apoptosis of breast cancer cells through an endogenous pathway mediated by cellular mitochondria.Subsequently,the autophagy was investigated.The immunofluorescence experiment detected that part of the red fluorescence of the LC3 protein in the cytoplasm changed from a diffuse state to point-like aggregation and the fluorescence intensity increased.Western blot experiment showed the expression of LC3-?,p62 protein increased,which are autophagy marker proteins,and the expression of Beclin-1 protein decreased.After chloroquine and AP-SeNPs co-acted on breast cancer cells,the expression levels of LC3-?,p62 protein and apoptosis rate increased,indicating that AP-SeNPs can induce breast cancer cells Not completely autophagy.Conclusion:A series of modified nano-gold,nano-silver and nano-selenium were prepared in this paper.Astragalus polysaccharide nano-selenium showed growth inhibitory effect on human liver cancer cells,breast cancer cells and lung cancer cells,and highest effect on human breast cancer cells.It is further verified that it exerts anti-tumor effect by inhibiting late autophagy and inducing apoptosis.This paper provided further experimental and theoretical basis for nano-selenium as a potential drug candidate for cancer treatment.