Cytotoxic effect of Senecio madagascariensis (Asteraceae) extracts on cancer derived cell lines

Species of the genus Senecio have been traditionally employed with medical purposes and it has been demonstrated that some of them have anti-proliferative activity on cancer-derived cell lines. In South America S. madagascariensis is one of the most important representatives of the genus. Almost all species contain pyrrolizidine alkaloids (PA), substances that can lead to hepatic damage. Thus, the aim of this work was to determine the cytotoxic activity of a low PAs extract of S. madagascariensis on a cancer-derived cell line. A chloroform extract from plant material was produced and it was demonstrated to have a PAs concentration lower than 200 µg/g (w/w). Two stock solutions were made with DMSO and acetone as solvents and were diluted in culture medium (DMEM). Cells from urinary bladder transitional cell carcinoma T24 were cultured in 96 well plates (10⁴ cells/well) and incubated for 24 hours with dilutions of the extracts at the following concentrations, 0.5 mg/mL, 0.25 mg/mL, 0.125 mg/mL and 0.06 mg/mL. Cell viability was evaluated by the MTT colorimetric technique. Both solutions of S. madagascariensis extracts (acetone and DMSO) showed cytotoxic activity. In both cases, the degree of cytotoxicity was dependent on the concentration of the solution.