Abstract: LI Yuan-yuan，LI Lin-feng. Department of Dermatology, Peking University Third Hospital, Beijing 100191, China Corresponding author: LI Lin-feng, Email: zoonl@tom.com 【Abstract】 Objective To investigate the effect of a topical Tibetan medicine, Qingpeng ointment, on atopic dermatitis in mice and its possible mechanisms. Methods A model of atopic dermatitis was established in 180 7-week-old BALB/c mice by repeatedly applying 100 μl of 0.15% 2, 4-dinitrofluorobenzene （DNFB） to shaved ventral skin and 50 μl of 0.15% DNFB to shaved dorsal skin. After the establishment of model, the mice were divided into 5 groups, i.e., model group receiving no treatment，three Qingpeng groups treated with 100%, 75% and 50% Qingpeng ointment respectively, vehicle control group treated with the vehicle of Qingpeng ointment. Thirty-six mice receiving neither DNFB sensitization nor Qingpeng ointment or vehicle treatment served as the blank control group. The treatment lasted 14 days. On day 8 and 15, serum samples and dorsal skin tissue samples were obtained from these mice. Skin samples underwent the measurement of thickness and weightness, observation of histopathological changes by using hematoxylin and eosin （HE） staining, enumeration of inflammatory cells infiltrating the dermis. Enzyme linked immunosorbent assay （ELISA） was carried out to determine the levels of several cytokines, including interleukin （IL）-2, -4 and -5, interferon （IFN）-γ, tumor necrosis factor （TNF）-α, in the sera and homogenate of the skin samples. Results All the 3 concentrations of Qingpeng ointment significantly inhibited skin inflammation induced by DNFB on day 8 and 15, with a decrease in the degree of edema and number of lymphocytes infiltrating the dermis. Compared with the model mice and vehicle-treated mice, those treated with 100% and 75% Qingpeng ointment showed a significantly lower level of IL-4 and IL-5 in both sera and homogenates of skin lesions on day 8 and 15 after the start of treatment （all P < 0.05）. On day 15, a statistical increase was observed in IL-2, IFN-γ and TNF-α in sera as well as in IFN-γ and TNF-α in homogenates of skin lesions from mice treated with 100% Qingpeng ointment compared with the model mice and vehicle control mice（all P < 0.05）. Conclusion Qingpeng ointment can inhibit the inflammation in mouse model of atopic dermatitis, likely by modulating the balance between type 1 and type 2 T helper cells. 【Key words】 Dermatitis, atopic; Dinitrofluorobenzene; Cytokines; Qingpeng ointment

Key words: Cytokines