Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin.
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.
Middelkamp-Hup
Maritza A
MA
Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
Pathak
Madhu A
MA
Parrado
Concepcion
C
Garcia-Caballero
Tomas
T
Rius-Díaz
Francisca
F
Fitzpatrick
Thomas B
TB
González
Salvador
S
D000284:Administration, Oral; D000328:Adult; D017484:Dermatitis, Phototoxic / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D017495:Hyperpigmentation / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011701:PUVA Therapy / Q000009:adverse effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage*; D032494:Polypodium; D011565:Psoriasis / Q000188:drug therapy*; D012867:Skin / Q000473:pathology / Q000528:radiation effects
D010936:Plant Extracts