Evaluation of Echinacea Leaf Extract and Allantoin Based Topical Formulations in an Imiquimod-Induced Psoriasis-like Model

Background/Objectives: Psoriasis is a chronic inflammatory disorder characterized by epidermal hyperproliferation and immune dysregulation. This study evaluated the topical efficacy of Echinacea leaf extract and allantoin compared to a corticosteroid (mometasone furoate) in an imiquimod (IMQ)-induced psoriasis-like model in Sprague-Dawley rats. Methods: Psoriasiform lesions were induced by daily application of 5% IMQ for six days, followed by six weeks of treatment with one of the following formulations: Echinacea cream or gel, allantoin cream or gel, and mometasone. Disease severity was assessed using a modified Psoriasis Area and Severity Index (PASI) and histological analysis. Results: All groups developed psoriasis-like lesions; however, Echinacea cream produced the most pronounced and sustained reduction in PASI scores, with near-complete macroscopic recovery. Echinacea gel and allantoin cream showed moderate effects, while allantoin gel and mometasone exhibited limited efficacy. Histological findings supported these results, with Echinacea cream restoring near-normal epidermal architecture. Conclusions: In conclusion, topical Echinacea leaf extract formulations, particularly the cream formulation, demonstrated superior efficacy in reducing psoriasis-like skin inflammation and restoring epidermal structure compared to allantoin based treatments and mometasone. These findings suggest that Echinacea-derived bioactive compounds may represent promising candidates for the development of alternative or adjunctive therapies for inflammatory skin diseases.