Effects of WBM leaf extracts on UV-induced ROS production and cytotoxicity in HaCaT keratinocytes. After exposure of UVB (80 mJ/cm2), the cells were further incubated at 37°C for 30 min and then ROS generation was determined by flow cytometry. ROS production was represented as % of control without UVB irradiation. (A) After exposure of UVB (80 mJ/cm2), the cells were further incubated at 37°C for 30 min (B) or 16 h (C) and then cell viability was measured using the MTT assay. Non-irradiated HaCaT keratinocytes were used as the control. Cell viability is expressed as the percentage of control. Data are presented as the mean ± SD of triplicate determinations. Values with the same letter are not significantly different as determined by Duncan’s multiple range tests.