[Screening combination ratio and exploring mechanism of Momordicae Semen and Epimedii Folium]

The aim of this paper was to obtain low toxicity and high efficiency anti-tumor Chinese medicine through screening the combination ratios of Momordicae Semen and Epimedii Folium, and to explore the anti-tumor mechanism of the combination of two drugs by observing their effect on apoptosis-related proteins in cancer cells. Methyl thiazolyl tetrazolium(MTT) assay was used to observe the effect of drug combination on the proliferation of tumor cells from different tissue sources. The effects of the combination of the two drugs on tumor cells were analyzed by Compusyn software. Plate cloning assay was used to observe the effect of combination of these two drugs on the proliferation of A549 cells in vitro. The expression of reactive oxygen species(ROS) and apoptotic proteins p53, Bcl-2 and Bax were compared by using ROS kit and Western blot. Lewis lung cancer model was used to observe the anti-tumor effect of drugs in vivo. The results showed that the anti-tumor effect of their ethanol extract was more significant than that of water extract, and the anti-proliferation effect was strongest when the ratio was 1∶1(P<0.05). Compusyn analysis showed that the combination of the two drugs had synergistic effect. Further studies showed that after combined use, the number of clonogen formation in A549 cells was significantly reduced(P<0.01); ROS production was increased; the expression of apoptosis-related protein p53 was up-regulated, and the ratio of Bcl-2/Bax was decreased. In vivo animal study showed that the tumor inhibition rate was 53.06%(P<0.05) in the high dose group. As compared with the single use of the two drugs, the combination of the two drugs had more significant anti-proliferative effect on tumors, and the optimum ratio was 1∶1. The combination of the two drugs at a ratio of 1∶1 inhibited the proliferation of various tumor cells, and had no significant effect on normal liver cells LO2 when compared with other ratios. Therefore, it can be preliminarily inferred that the combination of the two drugs may have the effect of synergism and detoxification. Further studies showed that the combination of the two drugs can significantly inhibit the proliferation of A549 cells, and its mechanism may be related to the activation of endogenous apoptotic pathway. In vivo experiments also showed that the tumor inhibition rate increased with the increase of drug concentration.