The cytotoxicity effects from plant extracts on COS-7 and HepG2 cells. (A) The effect from hot water extract of C. longa (bulb), (B) The effects from buffer extracts and (C) The effects from 80% hydroalcoholic extracts. The white bars represent the percentage of cell viability of COS-7 cells whereas the black bars represent the percentage of cell viability of HepG2 cells. Bar graph represents a mean value whereas an error bar indicates the uncertainty value of three independent experiments. “*” and “**” indicated significant inhibitory effect when compared with both cell lines at p < 0.01 and p < 0.001 (by t-test) respectively.