RÉSUMÉ
Psoriasis is an auto-immune skin disease, which is characterized by the excessive generation of plaques on the skin with typically a long-lasting red, itchy and scaly symptoms. Imiquimod, which has been used for the treatment of external genital warts, actinic keratosis, and superficial basal cell carcinoma, induced of psoriasis-like skin disorders with skin erythema and thickness in mice. In the present study, we tried to find the bioactive herbal extract against imiquimod-induced psoriasis-like skin disorder in mice. During the searching of the herbal extract with anti-psoriatic effect, the ethanolic extract of Cnidium officinale ameliorated imiquimodinduced psoriasis-like skin disorder in mice. The morphological evaluation, H&E staining and Psoriasis Area and Severity Index (PASI) score showed that ear and back thickness, and erythema induced by imiquimod were significantly reversed after the treatment of the cream of the ethanolic extract of C. officinale. The overexpressed myeloperoxidase (MPO) and keratin 6A levels were decreased by the treatment of C. officinale cream. Also, IFN-γ, c-fos and IκB-α mRNA levels, which are related to the progression of psoriasis, were reduced by C. officinale cream. Thus, the ethanolic extract of C. officinale ameliorated psoriasis-like skin disorder induced by imiquimod and might be the therapeutic agent for psoriasis.