Protective effect of exogenous biliverdin on ultraviolet B-induced photodamage to keratinocytes and its mechanisms / 中华皮肤科杂志

ABSTRACT

Objective:To evaluate the protective effect of exogenous biliverdin on ultraviolet B (UVB) -induced photodamage to keratinocytes, and to explore its mechanisms.Methods:HaCaT cells were divided into 5 groups UVB group irradiated with 30 mJ/cm 2 UVB alone, 0.1-, 1- and 10-μmol/L UVB groups treated with 0.1, 1 and 10 μmol/L biliverdin respectively and irradiated with 30 mJ/cm 2 UVB, and control group receiving no treatment. After irradiation, cells in the above groups continued to be cultured for 24 hours. Then, the reactive oxygen species (ROS) level, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected in HaCaT cells, and enzyme-linked immunosorbent assay (ELISA) was performed to detect levels of the inflammatory factors interleukin 6 (IL-6) and IL-8 in the culture supernatants of HaCaT cells. One-way analysis of variance was used for comparison of means among multiple groups, and least significant difference (LSD) - t test was used for multiple comparisons. Results:Significant differences were observed among the UVB group, 0.1-, 1- and 10-μmol/L UVB groups and control group in the ROS levels (3 613.33 ± 206.61, 2 958.67 ± 193.87, 2 678.33 ± 178.24, 2 274.67 ± 118.81, 1 905.67 ± 250.25, respectively, F = 34.02, P < 0.05), SOD activity (24.41 ± 1.78, 28.96 ± 2.21, 29.75 ± 1.75, 30.19 ± 2.29, 37.52 ± 2.31, respectively, F = 57.36, P < 0.05), MDA contents (5.61 ± 0.32, 5.46 ± 0.55, 4.65 ± 0.22, 2.55 ± 0.93, 1.31 ± 0.05, respectively, F = 214.09, P < 0.05), and supernatant levels of IL-6 ( F = 29.73, P < 0.05) and IL-8 ( F = 11.40, P < 0.05). The UVB group showed significantly increased levels of ROS, IL-6 and IL-8, and MDA contents compared with the other 4 groups (all P < 0.05), but significantly decreased SOD activity compared with the other 4 groups ( P < 0.05) . Conclusion:Exogenous biliverdin has some protective effect on UVB-induced photodamage, likely by reducing oxidative damage to cells, attenuating inflammatory reactions and suppressing lipid peroxidation.