In vitro anticancer activity and cytotoxicity of some papaver alkaloids on cancer and normal cell lines

Background: The purpose of this study is to determine the effect of in vitro anticancer activity and cytotoxicity of 13 Papaver alkaloids (amurine, armepavine, berberine, isocorydine, isothebaine, macranthine, mecambrine, mecambridine, narkotine, orientalidine, oripavine, salutaridine and thebaine) against the human cervical cancer cell line (HeLa) compared to the normal African green monkey kidney epithelial cell line (Vero) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Materials and Methods: The Vero and HeLa cell lines were treated with various concentrations (1-300 μg/mL) of alkaloids for 48 h. Values for cytotoxicity measured by MTT assay were expressed as the concentration that causes a 50% decrease in cell viability (IC50) (μg/mL). Results: Berberine and macranthine were the most active alkaloids. Salutaridine exhibited no cytotoxic activity against two types of cell lines. Dose-dependent studies presented IC50 of 12.08 μg/mL and IC50 of 71.14 μg/mL for berberine and IC50 of 24.16 μg/mL and IC50 of >300 μg/mL for macranthine on the HeLa cells and the Vero cells respectively. Conclusion: The degree of selectivity of the compounds can be expressed by its Selectivity Index (SI) value. High SI value (>2) of a compound gives a selective toxicity towards cancer cells (SI = IC50 for normal cells/IC50 for cancer cells). Two alkaloids showed significant SI values, which are 12.42 for macranthine and 5.89 for berberine. Hence, macranthine and berberine display potential to be further exploited in the discovery and development of new anticancer agents.