Dermatologic Applications of Polypodium leucotomos: A Literature Review

BACKGROUND: Polypodium leucotomos (PL) is a natural extract from tropical fern leaves with antioxidant and anti-inflammatory properties. It has been implicated as a potential treatment agent in multiple dermatologic conditions. OBJECTIVE: Here, we review the mechanism of action and current dermatologic applications of PL and extrapolate potential future dermatologic applications of PL. DESIGN: An extensive literature review on Pubmed was conducted in search of relevant background information and human studies utilizing PL for the treatment of dermatologic conditions. METHODS: Using the PubMed database, a literature search was conducted to identify relevant publications. "Polypodium leucotomos" was input as the key search criterion. The results were filtered by species (human) and language (English). Only papers with dermatologic applications were selected. Additionally, relevant publications found in the reference sections of selected articles were manually searched and selected. Included articles explore the origin, basic science mechanism, and various dermatologic applications of PL studied in humans. Each article was thoroughly studied by all authors and applicable data from each was used for the compilation of this review article. RESULTS: See Table 1 for a summary of dermatologic applications of PL based on available human clinical studies. LIMITATIONS: There was a limited number of human studies concerning the use of PL for treatment of dermatologic conditions and, of the available studies, many were of a small sample size. CONCLUSION: PL has a clinically significant role for the treatment and prevention of certain dermatologic conditions including: photoprotection, photocarcinogenesis, photoaging, vitiligo, melasma, and polymorphic light eruption. There is supporting evidence for its use in malignant melanoma high-risk patients, for enhanced actinic keratosis clearance following photodynamic therapy, and for symptomatic relief in atopic dermatitis. Potential clinical uses that require additional human clinical studies include solar urticaria, post-inflammatory hyperpigmentation, cutaneous lupus erythematosus, and other photosensitive cutaneous disorders.