Effect of (Poly)phenolics as Potential Agents in the Treatment of Psoriasis: A Systematic Review of the Evidence and Future Applications

Psoriasis is a chronic inflammatory autoimmune skin disease with current treatments often causing significant side effects. This study systematically evaluated the therapeutic potential and mechanisms of polyphenolic compounds in psoriasis treatment. Following PRISMA guidelines, we searched PubMed, Google Scholar, and ScienceDirect databases between January 2008 and September 2023. Studies investigating polyphenolic effects on psoriasis through in vitro, animal, or clinical models were included. Twenty-five studies met inclusion criteria: nine in vitro studies, eleven animal studies, and five clinical trials. Curcumin was most extensively studied, demonstrating 30–60% reductions in inflammatory markers (TNF-alpha, IL-17, IL-22) and significant PASI score improvements. Mechanistic analysis revealed polyphenols primarily target NF-kappaB pathway inhibition and IL-17/Th17 axis suppression, addressing fundamental inflammatory processes in psoriatic pathophysiology. However, limited clinical evidence represents a significant implementation barrier. Polyphenols show potential as adjunctive therapies to conventional topical and systemic treatments. Future research should prioritize large-scale randomized controlled trials with standardized formulations and combination therapy investigations to establish clinical efficacy and overcome bioavailability challenges.