The Study On Antitumor Activity Of Daidzein And Ruthenium(Ⅱ) Polypyridyl Complexes

Objectives: With the developing of molecular biology, pathogenesis of tumor was further understood. To enhance the efficacy and optimize the treatment of cancer, the integration of multimodal and multifunctional agents for systematic treatment has received considerable interest. Traditional Chinese medicine gains countless recognition for its low toxicity and extensive pharmacological activities. Though daidzein has been found that it possesses a variety of pharmacological effects, the research still limited to animal model study. The anti-tumor effect and mechanism about daidzein is not clear, so that it deserves further exploration. Metal complexes(ruthenium(II), Ir(III), etc.) act as important potential chemotherapeutic drugs, and synthetic design has made great progress so far. However, the antitumor activity and mechanism of new synthetic complexes remains to be further researched.Methods: Three series of ruthenium(II) pyridine complexes were synthesized, then we researched their antitumor activity and mechanism of apoptosis. MTT test was used to screen antitumor activity of daidzein and ruthenium complexs; AO/EB double dye, Hoechst 33258 dyeing and intracellular assay were taken to verify whether these complexes can cause cell apoptosis and observe the form of apoptotic cells; The proportion of cell apoptosis and cell cycle arrest were investigated by reactive oxygen species detection, mitochondrial membrane potential assay and flow cytometry test; Single cell gel electrophoresis assay was also taken to observe the degree of single cell DNA damage; The level of related protein expression in cells which were dealed with daidzein and ruthenium(II) polypyridyl complexes is detected through western blot analysis.Results: 1. In the same conditions, the synthetic ruthenium(II) metal complexes have obvious inhibition toward specific tumor cells. 2. Cell morphology test and flow cytometry show that the complexes can induce different degree of cell apoptosis and produce obviously apoptotic morphological features. Meanwhile, the drugs(e.g 3A, 4D) can lead to significant cell cycle arrest. 3. Comet assay suggests that the complexes can cause DNA damage of cancer cells; Wound healing assay proves that complexes(5A ~ 5D) can effectively inhibit tumor cells’ migration and proliferation. 4. Through western blotting analysis, the ratios of Bcl-2 and Bcl-x decreased significantly while protein expression of caspase-3/-7 increased, suggests complexes may induce cell apoptosis through mitochondrial signaling pathways.In conclusion, the antitumor mechanism of daidzein and ruthenium(II) polypyridyl complexes is presumed to lower the mitochondrial membrane potential, thus regulating downstream c-myc and related myc protein, activating the ROS-mediated mitochondrial dysfunction pathways finally.