Cytotoxic active ingredients from the seeds of Voacanga africana

Voacanga africana is a medicinal tree used in Ghana in West Africa for treatment of various diseases. Using MTT assay-guided separation, 6 compounds were isolated and identified. Compound 1 was a new compound, and the rest 5 compounds were 3-oxo-tabersonine (2), 3α- acetonylvoafrine B (3), lochnericine (4), 17,18-dehydrovincamine (5) and tabersonine (6). Amongst these compounds, tabersonine exhibited a remarkable cytotoxic activity and the IC50 value of tabersonine on 10 types of human cancer cell lines range from 4.8 ± 0.4 µg/mL to 22.5 ± 1.4 µg/mL. The cytotoxicity of tabersonine may be through inducing apoptosis. In conclusion, this study is the first report about the isolation and evaluation of anti-tumor components in Voacanga africana seeds. From these results, the alkaloid compound tabersonine could be considered as a potential anti-tumor agent.