Effect of resveratrol on apoptosis and cell cycle of human keratinocytes irradiated by ultraviolet B / 中华皮肤科杂志

ABSTRACT

Objective:To evaluate the effect of resveratrol on apoptosis and cell cycle of human epidermal keratinocytes (HEKs) after ultraviolet B (UVB) irradiation.Methods:After 12-hour treatment with 0 (control group) , 25, 50, 100, 150 and 200 μmol/L resveratrol, cell counting kit-8 (CCK8) assay, bromodeoxyuridine (BrdU) assay and lactate dehydrogenase (LDH) assay were performed to evaluate the effect of resveratrol on proliferative activity and death of HEKs. Some HEKs were divided into 4 groups normal control group receiving no treatment, resveratrol group treated with 100 μmol/L resveratrol, UVB group irradiated with 50 mJ/cm 2 UVB, and UVB+resveratrol group irradiated with 50 mJ/cm 2 UVB followed by 12-hour treatment with 100 μmol/L resveratrol. Western blot analysis was conducted to determine the expression of apoptosis-related proteins poly (ADP-ribose) polymerase (PARP) and caspase-3, as well as cell cycle-related proteins cyclin B1 and cyclin E1, and flow cytometry to detect the apoptosis and determine cell cycle distribution. One-way analysis of variance was used for comparisons among multiple groups, and least significant difference- t test for multiple comparisons. Results:The proliferative activity of HEKs significantly differed among the 25-, 50-, 100-, 150-, 200-μmol/L resveratrol groups and control group ( F=46.52, P < 0.001) , and was significantly lower in these resveratrol groups than in the control group (all P < 0.001) ; the DNA synthesis activity of HEKs was significantly lower in the 100-μmol/L resveratrol group (0.761 ± 0.141) than in the control group (2.226 ± 0.141, t=17.92, P < 0.001) ; there was no significant difference in cell death rate among the 25-, 50-, 100- and 200-μmol/L resveratrol groups ( F=1.938, P > 0.05) . After treatment with or without UVB and/or resveratrol, there were significant differences in the apoptosis rate, proportion of cells at G1, G2 and S phases, expression of PARP, caspase-3, cyclin B1 and cyclin E1 among the 4 groups (all P < 0.05) . The UVB group showed significantly increased apoptosis rates (24.69% ± 3.54%) and cleavage levels of PARP and caspase-3 (2.190 ± 0.349, 0.090 ± 0.016, respectively) compared with the normal control group and UVB+resveratrol group (4.00% ± 0.81%, 0.926 ± 0.040, 0.024 ± 0.019, respectively, all P < 0.05) ; the UVB group showed significantly decreased protein expression of cyclin E1 and cyclin B1 (0.116 ± 0.017, 0.775 ± 0.080, respectively) compared with the normal control group, and the UVB+resveratrol group showed significantly increased expression of cyclin E1 (0.287 ± 0.047) , but decreased expression of cyclin B1 (0.504 ± 0.009) compared with the UVB group (all P < 0.05) ; the UVB group showed significantly decreased proportion of S-phase cells, but increased proportion of G1- and G2-phase cells compared with the UVB+resveratrol group (all P < 0.05) . Conclusion:Resveratrol can decrease the proliferative activity of HEKs, inhibit apoptosis induced by UVB radiation, and regulate cell cycle progression.