Coleus forskohlii shows anti-psoriatic activity in imiquimod-induced psoriasis rats

Objective: To evaluate anti-psoriatic activity of Coleus forskohlii in rats with imiquimod-induced psoriasis. Methods: Imiquimod was used to induce psoriasis in rats. Body weight, skin thickness, erythema, scaling, spleen weight, and histological alternations were measured to assess the effect of Coleus forskohlii. Furthermore, an emulgel formulation containing Coleus forskohlii 10% was prepared and characterized along with its ex vivo permeation studies. Results: The emulgel formulation containing Coleus forskohlii 10% had a pH of 5.40 +/- 0.36, with optimum spreadability of (31.67 +/- 2.08) g/(cms) and viscosity of (15 966.67 +/- 1 274.10) cps, and enhanced both the rate and the extent of drug permeation through psoriatic skin. In an ex vivo study, the quantity of drug permeated (19.18%), deposited (52.38%), and drug remaining in the donor compartments (28.31%) was satisfactory. Coleus forskohlii significantly alleviated imiquimod-induced psoriasis by increasing glutathione and superoxide dismutase activity, decreasing malondialdehyde and nitric oxide levels, and alleviating histological alternations in rat skin. Conclusions: Coleus forskohlii can alleviate imiquimod-induced psoriasis, which may be used as a therapeutic candidate for the treatment of psoriasis.