Objective: The objective of this study was to determine the safety of oral Polypodium leucotomos extract administered twice daily to healthy adults for 60 days and assess its ability to provide protection against exposure to ultraviolet radiation.
Design: This was a randomized, double-blind, placebo-controlled study.
Setting: A single clinical research center.
Participants: Healthy adult men and women between 18 and 65 years of age with Fitzpatrick skin types I to IV.
Measurements: Safety assessments included a physical examination, vital signs, and clinical laboratory parameters including hematology, comprehensive metabolic panel, and prothrombin time-partial thromboplastin time were obtained at baseline and at the end of the study. Reports of adverse events were recorded. Efficacy assessments were changes in minimal erythema dose testing, ultraviolet-induced erythema intensity response, and sunburn history during the prior 60 days.
Results: After two months of treatment, there were no changes in any safety assessments. The subjects in the placebo group showed a greater likelihood of experiencing >1 episodes of sunburn (2 vs. 8 subjects; p=0.04) At Day 28, Polypodium leucotomos extract-treated subjects showed greater likelihood of an increased minimal erythema dose (8 vs. 1 subject; p=0.01) and greater likelihood of decreased ultraviolet-induced erythema intensity (10 subjects vs. 3 subjects; p<0.01).
Conclusion: Polypodium leucotomos extract 240mg taken twice daily for 60 days was a safe and effective means for reducing the damaging effects of ultraviolet radiation. Based on the excellent safety profile of Polypodium leucotomos, additional studies using higher doses may be warranted.