Synergistic Interaction Between Evodiamine And Chemotherapeutic Agents Such As Oxaliplatin In Vitro And Its Potential Mechanism

Propose:To study the interactions between Evodiamine (Evo) and chemotherapy drugs, such as Oxaliplatin (Oxa), Fluorouracil (5-Fu) on human colon cancer cell lines SW480, human gastric cancer cell lines SGC-7901 and human esophageal cancer cell lines TE1, and to investigate its possible mechanisms.Method:1) Using the MTT method to determine each single drug’s IC50 of Evo,Oxa and 5-Fu on the proliferation index phase of human colon cancer cell lines SW480, human gastric cancer cell lines SGC-7901 and human esophageal cancer cell lines TE1;2) According to the single drug IC50 to determine the combined effects of the drug concentration gradient, and using the MTT method again to evaluate the effect of Evo combined with Oxa or 5-Fu on the above three tumor cells;3) Using the median-effect principle to draw the inhibition of the proliferation curve of each single drug and two drugs combined with medication on three tumor cell lines,in order to analyze the interaction between the two drugs combined medication;4) Using flow cytometry(FCM) analysis is suitable to detect the two drugs synergistic effect on cell apoptosis and cell cycle in different concentration.Results:1) Human colon cancer cell lines SW480:The three single drugs all had proliferation inhibition effect on SW480 cells,the IC50 respectively after 48 hours was:Evo:(10.295±0.568)μg/ml, Oxa:(9.438±1.750)μg/ml,5-Fu:(6.8754±2.733)ug/ml. Analysis through median-effect principle, the synergistic effect was observed when Fa<0.65 for Evo and Oxa,while the synergistic effect was observed when Fa<0.75 for Evo and 5-Fu.2) Human gastric cancer cell lines SGC-7901:The three single drugs all had proliferation inhibition effect on SGC-7901 cells,the IC50 respectively after 48 hours was:Evo: (9.114±1.261)μg/ml, Oxa:(9.895±0.432)μg/ml,5-Fu:(15.149±2.903)μg/ml. Analysis through median-effect principle, the synergistic effect was observed when Fa< 0.45 for Evo and Oxa,while the synergistic effect was observed when Fa>0.45 for Evo and 5-Fu.3) Human esophageal cancer cell lines TE1:The three single drugs all had proliferatio n inhibition effect on SW480 cells,the IC50 respectively after 48 hours was:5-fu(25.840 ±6.422)μg/ml,Evo(6.935±0.698)(μg/ml,Oxa(21.679±7.201)(μg/ml,.Analysis through median-eff ect principle, the synergistic effect was observed whether in the higher concentration, or i n the low concentration for Evo and Oxa,while the synergistic effect was observed whe n Fa<0.80 for Evo and 5-Fu.4) Cell apoptosis analyzed by flow cytometry:TE1 cells treated with single drugs at a 1 ow cytotoxic dose of IC25 (Evo:4μg/ml,Oxa:10μg/ml) and both drugs (Evo+Oxa:(4+10)μ g/ml), compared with the the control group and the single durgs, the combined group h ad a higher cell apoptosis(45.7%), in which the early cell apoptosis was 41.1%5) Cell cycle analyzed by flow cytometry:TE1 cells treated with single drugs at a low cytotoxic dose of IC25 (Evo:4μg/ml,Oxa:10μg/ml) and both drugs (Evo+Oxa:(4+10)μg/ml), the G0/G1 stage of the cell cycle with Evo was increased to (54.25%) compared by the control group (27.54%), further increased to (71.30%) when combined with Oxa.Conclusion:1) Evo inhibited the proliferation of SW480, SGC-7901 and TE1 cells,and TE1 cells were the most sensitive to Evo.2) Evo combined with Oxa or 5-Fu on SW480 cells, both had the synergistic effect at a lower concentration, the concentration of the synergistic effect respectively was:Evo<(7.328±0.905) μg/mk Oxa<(9.160±1.132) μg/ml and Evo<(21.033±2.308) μg/ml、5-Fu<(442.010±229.117) μg/ml.3) Evo combined with Oxa or 5-Fu on SGC-7901 cells,both had synergistic effect,the concentration of the synergistic effect was:Evo<(7.892±1.295)μg/ml,Oxa<(8.686±0.462) μg/ml and Evo>(7.892±1.295)μg/ml,5-Fu>(7.631±1.598) ug/ml respectively.4) Only the synergistic effect was observed whether in the higher concentration, or in the low concentration for Evo and Oxa on TE1 cells. Evo combined with 5-Fu on TE1 cells had synergistic effect, the concentration of the synergistic effect was:Evo<(16.939±1.292) μg/ml,5-Fu<(5678.333±6957.135) μg/ml.5) Evo combined with Oxa had the obvious synergistic effect at low cytotoxic dose on TE1 cells, and its mechanism might be through: ① inducing cell apoptosis, especially the late apoptosis; ② arresting the cell cycle in G0/G1 phase.