The Alleviative Effects of Nude Pack Containing Black Tea Water Extract on Inflammation and Skin Barrier Damage in Hairless Mice

The aim of this study was to evaluate the alleviative effects of nude pack containing black tea water extract (NPBT) on inflammation and skin barrier damage in hairless mice. Skin inflammation and skin barrier damage were induced by UVB irradiation to the backs of hairless mice for 5 weeks. And at the same time, saline (C), NPBT (1%: E1, 2%: E2) and 0.01% retinoic acid diluted with polyethylene glycol (PC) were applied topically twice a day, 5 days a week for 5 weeks. The skin erythema indices of E1 and E2 groups were significantly lower (p<0.05) than the C group through 1 week after beginning of the experiment. Meanwhile, water contents of E1 and E2 groups were significantly higher (p<0.05) than the C group through 2 weeks after beginning of the experiment. Epidermis and dermis of C group were remarkably thickened in comparison with PC, E1, or E2 group. In the C group, many inflammatory cells including neutrophils and lymphocytes were infiltrated in dermis and a large number of mast cells were found in dermis and hypodermis, and the degree of degranulation was remarkable. However, these phenomena were alleviated in PC, E1, and E2 groups. Therefore, NPBT could have a considerable inhibitory efficacy on the inflammation and skin barrier damage induced by UVB irradiation.