Do oral carotenoids protect human skin against ultraviolet erythema, psoralen phototoxicity, and ultraviolet-induced DNA damage?
This study was performed in order to (1) assess the magnitude of a possible protective effect of oral carotenoids on ultraviolet B (UVB)-, ultraviolet A (UVA)-, and psoralen ultraviolet A (PUVA)-induced erythema in human skin and (2) to evaluate whether the postulated prevention of skin cancer by prophylactic administration of carotenoids is based on a decrease in UVB-induced DNA damage. Twenty-three healthy volunteers received oral carotenoids (150 mg/day) for 4 weeks. Serum levels were quantitated, and ranged from 390 to 1710 micrograms/dl. Before and after carotenoid administration, the UVA- and UVB-MEDs and the PUVA-MPD were determined by standard phototesting. DNA damage was assessed by autoradiographical measurement of unscheduled DNA synthesis (UDS) following UVB exposure before and after treatment. No statistically significant carotenoid-dependent protection was found against UVA, UVB, and PUVA erythema by comparing the pre- and postcarotenoid erythema doses. Also at the DNA level there was no indication of a protective effect that could be detected with the methods employed: the amount of UVB-induced UDS was not decreased after carotenoid treatment. We conclude that (1) carotenoids do not reduce UVB-, UVA-, or PUVA-induced erythema in human skin; that (2) reactive oxygen species may not be involved in PUVA-erythema production or, alternatively, carotenoids may not quench these radicals sufficiently in vivo; and that (3) carotenoid protection against UVB-induced carcinogenesis does not operate by reducing the number of mutagenic lesions in DNA.
Wolf
C
C
Department of Dermatology I, University of Vienna, Austria.
Steiner
A
A
Hönigsmann
H
H
D000284:Administration, Oral; D002338:Carotenoids / Q000008:administration & dosage* / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004249:DNA Damage; D004890:Erythema / Q000517:prevention & control; D006801:Humans; D011701:PUVA Therapy / Q000009:adverse effects*; D011837:Radiation-Protective Agents / Q000008:administration & dosage* / Q000494:pharmacology; D012867:Skin / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
D011837:Radiation-Protective Agents; D002338:Carotenoids; D004247:DNA