Figure 4

Trypan blue exclusion assay on Mode-K cells treated with different concentrations of SA for different time periods. SA at a concentration of 2 μg/ml only caused around 20% cell death when used at 24 h. SA at a concentration of 4 μg/ml was not cytotoxic when cells were incubated with SA for up to 8 h, but caused more than 50% cell toxicity at 16 and 24 h. At a concentration of 8 μg/ml, SA also didn't cause any significant cell death up to 8 h but caused high toxicity when cell were treated for 16 or 24 h.