Fig. 4: UVB irradiation could injure HaCaT cells.

HaCaT cells were exposed to different doses of UVB (0–300 mJ/cm2). After that, the cells were incubated with MTT for 4 h. Cell viability was measured by the absorbance of dissolved MTT crystals using an ELISA reader (n = 5). All data were analyzed by software GraphPad Prism 9.5.0 and presented as mean ± SD from three independent experiments. Statistical significance between the indicated groups were calculated by using one-way ANOVA and multiple comparisons. Adjustments were made for multiple comparisons. Significance is presented as ****p < 0.0001 (adjusted p value) versus the control (0 mJ/cm2) group.