Synergistic cytotoxicity effect by combination of N-hexane fraction of the herbs (Peperomia pellucida) with doxorubicin against breast cancer cells (MCF-7)

Abstract

Doxorubicin is the first-line chemotherapy agent for breast cancer treatment. However, it's reported to cause cardiotoxicity and induce chemoresistance in breast cancer cells. Doxorubicin is able to induce Pgp (P-glycoprotein) overexpression through NF-kB activation resulting in efflux of chemotherapeutic agents in MCF-7 cells. One of the approaches being developed for cancer treatment is combination therapy by combining two or more anticancer agents that may reduce side effects and provide better effects than single therapy. Peperomia pellucida is reported to have anticancer activity and is widely used as a traditional medicine. This study aimed to investigate the cytotoxic activity of the n-hexane fraction of Peperomia pellucida (NFP) and its combination with doxorubicin (D) against MCF-7 cells. The selectivity of NFP was evaluated using vero cells as a comparator. The phytochemical properties of NFP were evaluated using TLC and LC-MS/MS methods. The cytotoxic activity was determined using the MTT assay. Combination Index (CI) calculations were performed to determine the effect of the combination. This study found that NFP contained about 30 identified compounds and had an IC50 of 96.68 ppm, while doxorubicin had an IC50 of 2.10 ppm. The combination of 24.2 ppm (1/4 IC50) of NFP with 0.26 ppm (1/8 IC50) of doxorubicin had a synergistic cytotoxic effect (CI=0.6) against MCF-7 cells. NFP was selective for MCF-7 cells with a selectivity index of 21.83. The results suggest that NFP may have the potential to enhance the therapeutic efficacy of doxorubicin in breast cancer treatment.