Orally Administered Polypodium Leucotomos Extract Decreases Psoralen-uva-induced Phototoxicity, Pigmentation, and Damage of Human Skin.
Middelkamp – Hup MA1, Pathak MA, et al.
A study has shown that reduction in melanin intensity was 68% greater in users consuming PLE + topical sunscreen as compared to Placebo + topical sunscreen.
The use of psoralen-UVA (PUVA) in patients of skin phototype I to II is limited by side effects of acute phototoxicity and possible long-term carcinogenesis.
We sought to assess oral Polypodium Leucotomos (PL) extract in decreasing PUVA-induced phototoxicity of human skin on a clinical and histologic level.
A total of 10 healthy patients with skin phototypes II to III were exposed to PUVA alone (using 0.6 mg/kg oral 8-methoxypsoralen) and to PUVA with 7.5 mg/kg of oral PL.
Clinically, phototoxicity was always lower in PL-treated skin after 48 to 72 hours (P<.005), and pigmentation was also reduced 4 months later. Histologically, PL-treated skin showed a significant numeric reduction of sunburn cells (P=.05), preservation of Langerhans cells (P< or =.01), decrease of tryptase-positive mast cell infiltration (P<.05), and decrease of vasodilation (P< or =.01). No differences were found in Ki-67+ proliferating cells.
PL is an effective chemophotoprotector against PUVA-induced skin phototoxicity and leads to substantial benefits of skin protection against damaging effects of PUVA as evidenced by histology.