Effect of Aescin in Psoriatic-Induced Animal Model: Immunohistochemical and Pathological Study

Background: Aescin is a mixture of the triterpene saponins extracted from the seeds of the horse chestnut tree Aesculus hippocastanum. Aescin has a venotonic, anti-inflammatory, antioxidant and anti-edematous characteristics that are mostly connected to the agent molecular mechanism. Objective: The present study aim to investigate the potential effects of Aescin on psoriasis induced by Imiquimod in male rats, ncluding its effect on the level of tumor necrosis factor alpha, Ki-67 and the histopathologic features of the psoriatic skin. Methods: Thirty-six albino male rats were divided into six groups each group containing 6 animals, psoriasis was induced by Imiquimod to five of the groups, while for the last group vasaline was applied and the group served as a control group. The animals were then treated with topical Aescin, topical clobetasol, combination of topical Aescin and clobetasol and oral Aescin, finally all animals were sacrificed and the dorsal back skin was taken to perform histopathological and immunohistochemical analysis. Results: regarding the level of Ki-67, Strong expression of Ki-67 was seen in the group who received Imiquimod only, where the scoring of Ki-67 was notably lowered among the other groups. However, the lowest expression was noticed in the group that were treated with the combination of topical Aescin and clobetasol. While the number of TNF-α positive cells and the intensity of immunostaining were higher in the induction group who received Imiquimod only and the lowest among the group who received the combination of topical Aescin and Clobetasol. Lastly the histopathologic analysis shows that the histopathologic features of psoriasis was markedly affected by the anti-inflammatory effect of Aescin and clobetasol, which was noticed through inhibition of proinflammatory markers, and the decrease in capillary permeability. Conclusion: Topical Aescin alone or in combination with clobetasol reduced Ki-67 expression successfully; furthermore, the combination of topical Aescin and Clobetasol decreased TNF- score and had the strongest anti-inflammatory activity more than the other groups. Lastly Aescin was able to alter the histopathologic features of the psoriatic skin through its anti-inflammatory, venotonic and anti-edematous activity.