The impact of oral Polypodium leucotomos extract on ultraviolet B response: A human clinical study.

BACKGROUND: There is a rationale for adding systemic photoprotective agents to the current photoprotection regimen.

OBJECTIVE: This study was designed to objectively evaluate the molecular and photobiologic effects of oral administration of Polypodium leucotomos extract (PLE).

METHODS: In all, 22 subjects with Fitzpatrick skin phototype I to III were enrolled. On day 1, subjects were irradiated with visible light, ultraviolet (UV) A1, and UVB (using 308-nm excimer laser). Evaluation was done immediately and 24 hours after irradiation. On days 3 and 4, irradiation and evaluation process was repeated after ingestion of PLE.

RESULTS: Clinical assessments and colorimetry data showed a decrease in UVB-induced changes in 17 of 22 subjects post-PLE administration; histology findings demonstrated such a decrease in all 22 subjects.

LIMITATIONS: Only 2 doses of PLE were given. Furthermore, subjects with skin phototypes I to III only were studied.

CONCLUSION: The results suggest that PLE can potentially be used as an adjunctive agent to lessen the negative photobiologic effects of UVB.