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

Abstract

Background Systemic antioxidants, such as oral Polypodium leucotomos extract (PLE), have been found to have photoprotective properties. Objective This study was designed to objectively evaluate the molecular and photobiologic effects of oral administration of PLE. Methods 22 subjects with Fitzpatrick skin phototype I–III were enrolled. On day 1, subjects were irradiated with visible light, ultraviolet A1 (UVA1) and ultraviolet B (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 out 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–III only were studied. Conclusion This is the first demonstration that PLE has objective measurable suppressive effects on UVB-induced erythema within 2 hours of administration. The results suggest that PLE can potentially be utilized as an adjunctive therapy to lessen the negative photobiologic effects of UVB. In addition, this is the first study to demonstrate the potential correlation between non-invasive colorimetry outcomes and UVB induced molecular damage.

Synergistic effects of long-wavelength ultraviolet A1 and visible light on pigmentation and erythema

“…Colorimetry and DRS are noninvasive objective assessment techniques used to quantitatively assess erythema and pigmentation . The details of the equipment have been described previously and are also included in Materials and Methods S1 (see Supporting Information) . In this study, colorimetric analysis focused on the magnitude of the change in L* (−ΔL*).…”

“…9,10 The details of the equipment have been described previously and are also included in Materials and Methods S1 (see Supporting Information). 11,12 In this study, colorimetric analysis focused on the magnitude of the change in L* (ÀDL*). The greater the magnitude of ÀDL*, the darker the lesion.…”

Chemoprevention agents for melanoma: A path forward into phase 3 clinical trials

“…Participants had significantly higher MED post-treatment (i.e., their skin required a higher UV dose to induce redness) compared to pre-treatment. In a recent study, Kohli et al reported on the clinical and histological effects of oral PLE on irradiation with a combination of UVA/UVB and visible light 142 . On day 1, 22 patients (Fitzpatrick skin type I–III) were irradiated and MED determinations were made on day 2.…”

Photoprotection of the future: challenges and opportunities

“…As an example, oral intake of nicotinamide prevents photo-immunosuppression and development of actinic keratoses and keratinocyte cancers in humans, 50,51 and oral intake of carotenoids, or Polypodium leucocotmos can reduce UVB-induced erythema. 52,53 We believe that the photoprotective potential of oral photoprotection has not yet been fully realized and should be further investigated. For regulatory reasons, in the past the emphasis has been on the prevention of UVB-induced erythema, similar to sunscreens.…”

“…Nutritional supplements may contain one or more actives that promote skin photoprotection through different mechanisms and could thereby complement topical sunscreens. As an example, oral intake of nicotinamide prevents photo‐immunosuppression and development of actinic keratoses and keratinocyte cancers in humans, and oral intake of carotenoids, or Polypodium leucocotmos can reduce UVB‐induced erythema . We believe that the photoprotective potential of oral photoprotection has not yet been fully realized and should be further investigated.…”