Abstract:

Guo Jianmei, Zhong Shaomin, Tao Rong, Miao Xiaolin, Wu Yan. Department of Dermatology, Peking University First Hospital, Beijing 100034, China Corresponding author: Wu Yan, Email: adelewu@medmail.com.cn 【Abstract】 Objective To evaluate the inhibitory effect of butyl flufenamate （BT） on ultraviolet （UV）-induced acute skin phototoxic reaction, and to investigate its possible mechanisms. Methods Eight SKH-1 hairless mice were included in this study. The back of each SKH-1 hairless mouse was divided into six regions, which were then randomly classified into six groups: blank group receiving no treatment, UV group receiving UV radiation only, BT + UV group and vehicle + UV group topically treated with BT ointment and vehicle respectively followed by UV radiation, UV + BT group and UV + vehicle group topically treated with BT ointment and vehicle respectively after UV radiation. Skin samples were obtained from these mice at 24 hours after treatment. Subsequently, hematoxylin-eosin （HE） staining was performed, real-time PCR was carried out to detect mRNA expressions of caspase-3, p53, COX-2, PGER1, interleukin （IL）-1β, IL-6, and an immunofluorescence assay was conducted to observe the expression of caspase-3. Statistical analysis was carried out by repeated-measures analysis of variance （ANOVA）. Results Compared with the UV group, both BT + UV group and UV + BT group showed a decrease in the degree of skin edema and number of apoptotic cells at 24 hours after UV radiation. Real-time PCR showed that the mRNA expressions of caspase-3, p53, COX-2, PGER1, IL-1β and IL-6 were significantly higher in the UV group than in the blank group （all P < 0.05）, but significantly lower in the BT + UV group than in the UV group （all P < 0.05）, and only the expressions of caspase-3 and p53 mRNAs were significantly decreased in the UV + BT group compared with the UV group （both P < 0.05）. The immunofluorescence assay revealed that the expression of caspase-3 increased in the UV group compared with the blank group, but decreased in both BT + UV group and UV + BT group compared with the UV group. Conclusion BT could partially inhibit UV-induced acute skin phototoxicity in SKH-1 hairless mice.