Adverse events and potential herb-drug interactions of plants used for psoriasis: A systematic review

Context: Medicinal plants have been widely used for psoriasis management for centuries. However, their safety profiles remain insufficiently documented. Aims: To systematically evaluate adverse events (AEs) and potential pharmacokinetic interactions of antipsoriatic herbal treatments. Methods: A PRISMA-compliant review was conducted using PubMed, Cochrane, Google Scholar, Web of Science, and Scopus databases (January 2015-December 2022). Clinical trials, case reports, and ethnomedicinal studies reporting AEs of single plant antipsoriatic preparations were included. CONSORT criteria for herbal medicines were applied to assess study quality. Results: Eleven studies covering nine herbal treatments were included. While most of reported AEs were mild, severe cases involving Indigo naturalis, Psoralea corylifolia, and Ranunculus arvensis were documented. Several herbal metabolites (indirubin, psoralen, curcumin, triptolide) showed potential pharmacokinetic interactions with conventional drugs. Conclusions: While generally well tolerated, antipsoriatic herbal therapies can induce mild to severe AEs and may alter drug metabolism. Long-term, high-quality randomized trials are needed to establish their safety profile.