Dihydroartemisinin alleviates skin lesions in mouse of psoriasis by regulating Th17/Treg balance

ObjectiveTo evaluate whether dihydroartemisinin (DHA) can improve the skin lesions in mouse model of psoriasis induced by imiquimod (IMQ) and to further explore its mechanism.

MethodsA total of 24 female BALB/c mice were randomly divided into control group, model group, DHA-L group (treated with 25 mg/kg DHA), and DHA-H group (treated with 50 mg/kg DHA), with 6 mice in each group.The skin lesions were observed every day and eavaluated by PASI score.After 6 days of continuous DHA therapy, the skin morphology was examined by HE staining and subjected to immunohistochemical staining with Ki67.The Th17 cells and Treg cells in spleen were investigated by flow cytometry, and interleukin-17A(IL-17A) and tumor necrosis factor-α (TNF-α) in serum were detected by ELISA.

ResultsThe psoriatic mouse model was successfully induced by IMQ.After DHA treatment, both the skin lesions and pathological changes were improved, and the PASI score and Ki67 positive cells in the DHA-L and DHA-H groups were lower than those in the model group (P < 0.05).The proportion of splenic Th17 cells in the model group was higher than that in the control group (P < 0.05), and the proportion of Th17 cells in the DHA-L and DHA-H groups were lower than that in the model group (P < 0.05).The proportion of splenic Treg cells in the DHA-H group was higher than that in the model group (P < 0.05).The levels of IL-17A and TNF-α in the model group were higher than those in the control group (P < 0.05).The levels of IL-17A in the DHA-L and DHA-H groups were lower than those in the model group (P < 0.05), while the levels of TNF-α were lower only in the DHA-H group (P < 0.05).

ConclusionsDHA can alleviate IMQ-induced skin lesions in mouse of psoriasis, and its mechanism may be related to regulating Th17/Treg cells balance.