Antitumor potential of total alkaloid extract from Tabebuiarosea

Currently there is considerable scientific and commercial interest in the continuing discovery of new anticancer agents from plants. Here the in vitro antitumor potential of the total alkaloid extract from Tabebuia rosea (Bertol.) DC. leaves was evaluated by MTT (3-(4,5-dimethythiazol-2yl)2,5-diphenyl tetrazolium bromide) based cytotoxicity test using the human leukemic cells (MOLT-4) and the genotoxic potential of the extract was also tested using cytokinesis block in vitro micronucleus assay. Simultaneously, the cytotoxic and genotoxic potential of the extract were compared with mitogen stimulated T-lymphocyte cultures derived from peripheral blood of healthy volunteers. The MTT test revealed that the extract exhibited comparatively higher toxicity towards the cancer cells than the normal cells and the GI50 values at 24, 48 and 72 h exposure were found to be 46.95, 36.05, and 25.75 µg/ml/1×106 cells against cancer cells. The micronucleus assay showed that in both cultures the number of micronuclei obtained even at the highest exposure concentration tested was very low than that of the positive control mitomycin-C. The results of the present investigation demonstrate that the alkaloid extract from Tabebuia rosea leaves is preferentially cytotoxic to human T-cell leukemia (MOLT-4) cells in a dose and time dependent manner with the absence of genotoxicity. [Nature and Science 2010;8(9):77-85]. (ISSN: 1545-0740).