INCREASING the cytotoxic effects of doxorubicin COMBINATION AND RED BETEL LEAF EXTRACT methanolic (Piper crocatum Ruiz & Pav.) IN CANCER CELLS INDUCED BY KOLON WIDR APOPTOSIS IN VITRO
ABSTRACT: Doxorubicin is a chemotherapeutic agent that causes a lot of side effects in high doses. Therefore, combination with co-chemotherapeutic agent which can increase its toxicity on cancer cells are needed to reduce its therapeutic dose. Red betel leaves (Piper crocatum Ruiz & Pav.) have been known to contain flavonoids and alkaloids that have anticancer activity. Previous research reported that red betel leaves have cytotoxic effect on T47D breast cancer cell lines and Hela cervical cancer cell lines. The aim of this study is to determine the cytotoxic effect and apoptosis induction of red betel leaves methanolic extract (RBM) and doxorubicin (dox) combination on WiDr cells as model of colon cancer. RBM extracted by soxhlet method using methanol. Qualitative analysis of active compound was conducted using thin layer chromatography (TLC). Cytotoxicity assay was performed using MTT assay for both single and combination treatments for 24 hours to determine IC50 and CI as their parameters. Apoptosis induction was analyzed by double staining method using ethidium bromide and acridine orange staining. TLC profile showed that RBM contained flavonoids and alkaloids. Treatment of RBM and dox on WiDr cells for 24 hours showed cytotoxic activity with IC50 100 μg/ml and 1.6 μM respectively. Combination of RBM and dox performed synergism effect with CI<0.9 (n=3; p<0.05). Combination of RBM (12.5 μg/ml) and dox (0.4 μM) increased the number of early apoptosis cells compared to each single treatment. These results showed that RBM had cytotoxic effect and their combination increased doxorubicin cytotoxicity through apoptosis induction on WiDr colon cancer cell lines.
