Synergistic Effect of Saccharin and Caffeine on Antiproliferative Activity in Human Ovarian Carcinoma Ovcar-3 Cells

The purpose of this study was to confirm the antiproliferative and apoptotic induction potential of a saccharin and caffeine combination in ovarian cancer cells. The cell line used was Ovcar-3, and the cell viability was measured through a WST-8 assay, while a Chou–Talalay assay was used to confirm the synergistic effect of saccharin and caffeine on the ovarian cancer cells. A clonogenic assay, annexin V-FITC/PI-PE double-staining, and RT-PCR were performed to confirm the expression of genes that induce colony formation, cell viability, and apoptosis in ovarian cancer cells treated with the saccharin–caffeine combination. It was demonstrated that both saccharin and caffeine decreased the viability of Ovcar-3 cells, and the cell viability decreased even more significantly when the cells were treated with the combination of saccharin and caffeine. The clonogenic assay results showed that the number of colonies decreased the most when saccharin and caffeine were combined, and the number of colonies also significantly decreased compared to the single-treatment groups. Based on flow cytometry analysis using annexin V-FITC/PI-PE double-staining, it was confirmed that the decrease in cell viability caused by the combination of saccharin and caffeine was correlated with the induction of apoptosis. The results of the RT-PCR confirmed that the combined treatment of saccharin and caffeine promoted cell apoptosis by regulating the expression of apoptosis-inducing genes. These results demonstrate that the combination of saccharin and caffeine more efficiently inhibits the proliferation of Ovcar-3 cells and induces apoptosis in vitro.