Polyphenols as novel treatment options for dermatological diseases: A systematic review of clinical trials

Background: Polyphenol phytochemicals demonstrate biological properties in vitro and in vivo that have led to the development of novel treatments for certain dermatological conditions. Objective: We sought to provide clinicians with an overview of clinical trials evaluating the effectiveness of polyphenol-based therapies and highlight novel treatments and the evidence available supporting their use. Methods: PubMed and Embase databases were systematically searched to 4 July 2014. Two independent reviewers reviewed published abstracts for inclusion. References were also manually searched for relevant studies. Data were extracted independently from eligible studies and discrepancies were adjudicated by consensus. Results: Our search yielded 356 unique abstracts, of which 17 studies met inclusion and exclusion criteria. Polyphenols were used in topical and oral forms. High-quality evidence suggests that green tea polyphenols may be effective in treating anogenital warts. Limited available evidence indicates that polyphenols may also benefit patients with alopecia, acne vulgaris, fungal infections, hyperpigmentation or photoaged skin. Conclusions and relevance: Evidence-based knowledge regarding the effectiveness, indications and side effects of polyphenol-based phytochemicals is needed as their clinical use increases within dermatology. We qualitatively conclude that polyphenols may be effective in treating certain dermatological conditions. Additional rigorously conducted clinical trials are needed to further evaluate efficacy.