Figure 2
Real time monitoring of O. labiatum effect on the viability of TZM-bl cells. Cells were exposed to 62.6 μg/mL of extract (A) and 112.6 μM compound (B), which were the CC50 values determined in a tetrazolium dye assay. Auranofin (iii) was used as a positive control for toxicity and caused cell death almost from the time of addition until end of incubation period (72 h). A unique growth pattern was observed in extract treated cells with uptake in the first 48 hours followed by extract content being metabolized by the cells resulting in an increase in cell index above that of untreated cells which following prolonged exposure is reduced to half cell index of control cells (i) at 72 h. RT-CES demonstrated low cytotoxicity for compound treated cells 72 h similar to that of untreated cells (i). For the compounds, uptake and metabolism was similar to that of extract however, elevated cell indices was maintained. Data was normalized against the time point before extract addition.