Abstract: CHEN Huang, LI Yuan-hong, XU Xue-gang, WU Yan*. *Department of Dermatology, No.1 Hospital of China Medical University, Shenyang 110001, China Corresponding author: WU Yan, Email: jlwuyan@126.com 【Abstract】 Objective To investigate the protective effect of resveratrol on ultraviolet A （UVA）-irradiated human fibroblasts and its mechanism. Methods Fibroblasts were isolated from normal human foreskin and subjected to primary culture and four passages of subculture. Then, some fibroblasts were incubated with various concentrations （0.01, 0.1, 0.5 and 1.0 mmol/L） of resveratrol for 6, 24, 48 and 72 hours separately, followed by methyl thiazolyl tetrazolium （MTT） assay for the evaluation of cell proliferation. Some fibroblasts were classified into four groups: blank control group remaining untreated, UVA group irradiated with UVA only, 0.01 and 0.1 mmol/L resveratrol groups receiving UVA irradiation immediately followed by treatment with resveratrol of 0.01 and 0.1 mmol/L respectively. The dose of UVA irradiation was consistently 10 J/cm2 in these groups. After additional culture for 6, 24, 48 and 72 hours, MTT assay was conducted to evaluate cell proliferation, enzyme-linked immunosorbent assay （ELISA） to measure the levels of interleukin （IL）-1α, IL-1β, and IL-6 in the culture supernatant. Results Resveratrol at 0.5 and 1.0 mmol/L significantly inhibited the proliferation of fibroblasts, with the strongest inhibitory effect observed at 72 hours when the cell survival rate was 31.99% ± 8.29% and 21.15% ± 5.76%, respectively. After irradiation with UVA of 10 J/cm2, the survival rate of fibroblasts was 78.01% ± 12.74% at 6 hours and 80.64% ± 36.12% at 72 hours, compared to 100.04% ± 10.78% and 99.95% ± 12.23% in the blank control group respectively （both P < 0.05）; the supernatant levels of IL-1α, IL-1β and IL-6 were significantly increased compared with the blank control group at 6 hours （（58.39 ± 0.67） vs. （48.51 ± 6.20） ng/L, （1294.37 ± 92.51） vs. （1023.25 ± 86.40） pg/L, （197.81 ± 6.37） vs. （160.45 ± 7.19） ng/L, all P < 0.05）, and the increase still existed at 72 hours for IL-1β （（1236.76 ± 56.49） vs. （1045.55 ± 48.14） pg/L, P < 0.05） and IL-6 （（215.65 ± 3.78） vs. （195.09 ± 1.78） ng/L, P < 0.05）. Compared with the UVA group, the 0.01 mmol/L resveratrol group showed significantly higher survival rates at all the four time points （all P < 0.05）, but lower supernatant levels of IL-1α at 6, 24 and 48 （（43.89 ± 3.60） vs. （51.77 ± 1.77） ng/L, P < 0.05） hours as well as IL-1β and IL-6 at all the four time points （all P < 0.05）, while the 0.1 mmol/L resveratrol group experienced no significant changes in cell survival rate at any of the time points, with a significant decrease only in the supernatant level of IL-6 at 6 and 24 （（182.90 ± 6.67） vs. （240.62 ± 1.42） ng/L, P < 0.05） hours. In detail, the survival rate of fibroblasts was 91.93% ± 12.90%, with the supernatant level being （1110.12 ± 51.91） pg/L for IL-1β and （201.94 ± 4.71） ng/L for IL-6 at 72 hours in the 0.01 mmol/L resveratrol group, compared to 80.64% ± 36.12%, （1236.76 ± 56.49） pg/L and （215.65 ± 3.78） ng/L respectively in the UVA group （all P < 0.05）. Conclusion Resveratrol at 0.01 mmol/L has a protective effect on UVA-irradiated fibroblasts, likely by inhibiting the secretion of IL-1α, IL-1β and IL-6. 【Key words】 Ultraviolet rays; Fibroblasts; Cytokines; Resveratrol

Key words: fibrodblast, Cytokines