Imiquimod (IMQ) induced human-like
psoriasis in mice has been shown to be effective in testing and development of novel treatments. The IMQ
psoriasis model has become widely used animal model, however, it is not completely characterized in different rat strains. We aimed to evaluate IMQ and
betamethasone treatment for induction and reversal of psoriatic lesions on macroscopic, histological, genetic as well as
cytokines and
chemokines activation levels. Wistar rats were treated topically with IMQ. Adopted
Psoriasis Area Severity Index (PASI) was calculated at the baseline, after the IMQ-symptoms induction and after
betamethasone-symptoms reversal. Systematic effects were studied on
cytokines and
chemokines levels in plasma. Skin biopsy was taken to assess histological symptoms and selected inflammatory
cytokines and receptors genes expression levels. Reversal of skin lesions, after
betamethasone treatment, was significant (p = 0.03). Histological differences between untreated and IMQ-treated skin were significant for some markers (p < 0.05) though not significantly decreased by
betamethasone treatment. Fourteen genes were significantly up-regulated after the IMQ and four genes were down-regulated after skin lesions reversal by
betamethasone. This work provides new insights on
biological effects of
imiquimod induced
psoriasis and its reversal by
betamethasone treatment in Wistar rats. It also contributes to general knowledge of the rat model usage for testing of novel anti-
psoriasis drugs.