Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin

J Am Acad Dermatol. 2004 Jan;50(1):41-9. doi: 10.1016/s0190-9622(03)02732-4.


Background: 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.

Objective: We sought to assess oral Polypodium leucotomos (PL) extract in decreasing PUVA-induced phototoxicity of human skin on a clinical and histologic level.

Methods: 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.

Results: 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.

Conclusions: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Dermatitis, Phototoxic / etiology
  • Dermatitis, Phototoxic / pathology
  • Dermatitis, Phototoxic / prevention & control*
  • Female
  • Humans
  • Hyperpigmentation / etiology
  • Hyperpigmentation / pathology
  • Hyperpigmentation / prevention & control*
  • Male
  • Middle Aged
  • PUVA Therapy / adverse effects*
  • Phytotherapy*
  • Plant Extracts / administration & dosage*
  • Polypodium*
  • Psoriasis / drug therapy*
  • Skin / pathology
  • Skin / radiation effects


  • Plant Extracts