The use of psoralen-UVA (PUVA) in patients of skin phototype I to II is limited to phototoxicity and possible long-term carcinogenesis. A total of 10 healthy patients with skin phototypes II to III were exposed to PUVA alone and to PUVA with oral Polypodium leucotomos (PL) extract. The study sought to assess oral Polypodium leucotomos extract in decreasing PUVA-induced phototoxicity of human skin.
Clinically, phototoxicity was always lower in PL-treated skin after 48 to 72 hours, and pigmentation was also reduced 4 months later. Histologically, PL-treated skin showed a significant numeric reduction of sunburn cells, reduced phototoxicity, and less pain and burning sensations. 642-637
In conclusion, PL is the first oral agent to decrease the acute phototoxicity and the subsequent development of hyperpigmentation induced by PUVA and leads to a significant Langerhans cell preservation, decrease of sunburn cell formation, etc.