Figure 1.

Cell proliferation of (A) epidermal keratinocytes and (B) dermal fibroblasts in response to lupeol. Cells were seeded in a 96-well plate. After overnight attachment, different concentrations of lupeol were added, and the cells were left for 24 h at 37 °C. Cell proliferation was measured by crystal violet assay and calculated by a comparison of the values from the lupeol treatment group with the control group. Data are expressed as mean ± standard error of the mean (SEM). * p < 0.05, ** p < 0.01, and *** p < 0.001 versus control group.