Phosphatidylserine Topically Attenuates Imiquimod-induced Psoriasis Through Inflammation Inhibition in Mice.

Background: Psoriasis is a chronic skin condition that is associated with persistent inflammation and skin lesions. Topical therapy has been a promising approach to the alleviation of psoriasis through the application of anti-inflammatory agents. Phosphatidylserine (PS) administration has shown anti-inflammatory effects in the trials. Consequently, the objective of this study was to evaluate the effects of topical PS on the potential improvement of an imiquimod (IMQ)-induced psoriasis model. Additionally, cyclosporine A was utilized as a comparative anti-psoriatic agent in our study.

Methods: The psoriasis model was established by topically applying IMQ to the dorsal skin of mice once daily for five consecutive days. The efficacy of topical PS was assessed using the Psoriasis Area and Severity Index (PASI) score to evaluate skin lesions. Subsequently, the skin samples were analyzed using Baker's scoring system, Masson's trichrome staining, immunohistochemistry, and real-time PCR analysis.

Results: IMQ-induced plaque-type psoriasis resulted in a significant increase (P<0.05) in dermal thickness, hyperkeratosis, PASI score, and inflammatory cytokines at the lesion site. The topical PS and cyclosporine A significantly (P<0.05) reduced PASI score and dermal thickness, while also alleviating erythema and scaling when compared to untreated mice. Furthermore, biomolecular assessments revealed that PS significantly (P<0.05) inhibited the gene expression of IL-17, IL-23, and TNF-α cytokines in the IMQ-induced lesions.

Conclusion: Topical PS may pointedly alleviate psoriasis through the inhibition of inflammation. The beneficial effects of the PS recommend further investigation in both experimental and clinical studies in the control of skin psoriasis.