Combined Effects Of DHA And Cucurbitacin B On Cell Proliferation And Apoptosis Of Human Gastric Cancer BGC-823 Cells

Objective:To investigate the combined effects of docosahexaenoic acid(DHA)and Cucurbitacin B on cells proliferation and apoptosis of human gastric cancer BGC-823 cells.Methods:1 Experiment Grouping: Make 4 groups of medium RPMI 1640 with different consistencies of DHA dissolved with absolute ethanol, and final consistencies are 10、20、30、40μg/m L. Put absolute ethanol into control groups(<0.5%,V/V); Make 5 groups of medium RPMI 1640 with different consistencies of Cucurbitacin B dissolved with DMSO, and final consistencies are 0.01、0.1、1、10、100μg/m L. The blank control group is a medium with the same volume and put DMSO into the control group(<2%,V/V). You will have IC50 of different drugs. Select DHA( 20μg/m L) and combined Cucurbitacin B(10μg/m L), the IC50 of which are lower than each drug, and act on human gastric cancer BGC-823 cells. Add absolute ethanol(<0.5%,V/V)and DMSO(<2%,V/V)into the control group.2 Observe the morphological changes of human gastric cancer BGC-823 cells after adding DHA(20μg/m L)、Cucurbitacin B(10μg/m L) and DHA(20μg/m L)、combined Cucurbitacin B(10μg/m L) respectively with NADH enzyme staining microscopy.3 Observe the morphological changes of human gastric cancer BGC-823 cells after adding DHA(20μg/m L)、Cucurbitacin B(10μg/m L) and DHA(20μg/m L)、combined Cucurbitacin B(10μg/m L) respectively with Giemsa staining microscopy.4 Adopt the method of MTT, and study the effect on proliferation of human gastric cancer BGC-823 cells of DHA group(10、20、30、40μg/m L), Cucurbitacin B group(0.01、0.1、1、10、100μg/m L)and DHA(20μg/m L)combined Cucurbitacin B(0.01、0.1、1、10、100μg/m L).5 Study the cell period and apoptosis of DHA group(20μg/m L), Cucurbitacin B group( 10μg/m L) and DHA( 20μg/m L) combined Cucurbitacin B(10μg/m L) group with flow cytometry detection method.6 All data will be presented in the form of mean±SD. Adopt the single factor analysis of variance with SPSS16. Adopt the double factor analysis of variance and Pearson related analysis in certain experiments. It is statistically meaningful when P<0.05.Results:1 With Giemsa staining microscopy, within the same time run when the consistency of drugs increases, cell apoptosis of the group of DHA(20μg/m L)and Cucurbitacin B(10μg/m L)is more obvious. And cell apoptosis of the group of DHA(20μg/m L)combined Cucurbitacin B of different consistencies is more complete than the group of DHA(20μg/m L)and Cucurbitacin B(10μg/m L).2 With NADH enzyme staining microscopy, within the same time run when the consistency of drugs increases, cell apoptosis of the group of DHA(20μg/m L)and Cucurbitacin B(10μg/m L)is more obvious. And cell apoptosis of the group of DHA(20μg/m L)combined Cucurbitacin B of different consistencies is more complete than the group of DHA(20μg/m L)and Cucurbitacin B(10μg/m L).3 According the method of MTT, within the control time run, the inhibition of cell proliferation of the DHA group, the Cucurbitacin B group and the DHA(20μg/m L)combined Cucurbitacin B of different consistencies group has dose-dependent effect. The combined group has more significant inhibition effect on cell proliferation than the DHA group and the Cucurbitacin B group. The combined group also reduces the cell survival rate effectively. And also, the higher the consistency is, the better the effect is. The effect can be calculated with the equation(CI)=AB%/A%×B%(when CI=1,it means adding; when <1, synergy; when >1, antagonism). CI of DHA(20μg/m L)combined Cucurbitacin B(10μg/m L)on cell inhibition is 0.591±0.105, which means drug combination has synergistic effect.4 When detecting tumor cells with flow cytometry, in the group of DHA combined Cucurbitacin B, number of cell G0/G1 increases significantly and number of cell G2/M and S decreases significantly.Conclusion:According to the grouping experiment, the combined treatment of DHA and Cucurbitacin B can inhibit the growth and induce the apoptosis of human gastric cancer BGC-823 cells. Within the same time, when the drug consistency increases, the effect improves accordingly. The combination has synergistic effect.