[Dihydroartemisinin alleviates atopic dermatitis in mice by inhibiting mast cell infiltration].

OBJECTIVE:To observe the therapeutic effect of different doses of dihydroartemisinin (DHA) on atopic dermatitis (AD) in mice and explore the mechanism. METHODS:Forty-two C57BL/6 mice were randomly divided into 7 groups (n=6), including a blank control group, a 2, 4-dinitrochlorobenzene (DNCB)-induced AD model group, a solvent-treated group, 3 DHA treatment groups treated with 25, 75, and 125 mg/kg DHA, and a dexamethasone treatment group. The counts of skin scratches were recorded and the lesion scores were evaluated on a daily basis. After 7 consecutive days of treatment, skin tissues were sampled from the lesions on the back and ear of the mice for pathological examination with HE staining, Masson staining and toluidine blue staining. RESULTS:Treatment with 25, 75, and 125 mg/kg DHA and dexamethasone all alleviated AD symptoms of mice, reduced the severity scores of skin lesions, and ameliorated pathological changes of the skin tissue. DHA at 125 mg/kg produced the most obvious therapeutic effect and significantly alleviated mast cell infiltration in the lesions as compared with the other treatment groups (P < 0.05). CONCLUSIONS:DHA is effective for the treatment of AD in mice with an optimal dose of 125 mg/kg. The therapeutic effect of DHA is achieved probably through regulation of local immunity by inhibiting mast cell infiltration in the lesions.