Experimental Ultraviolet Light-Carcinogenesis

Black, Homer S.; Chan, Joel

doi:10.1111/j.1751-1097.1977.tb07472.x

Cited by 54 publications

(14 citation statements)

References 183 publications

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“…Exposure of skin to UV-B (29C320 nm) radiation may result in the development of skin tumors (Black and Chan, 1977). It is thought that singlet oxygen and free radicals may also be involved in this process (Black and Chan, 1977). Carotenoids have been found to prevent or slow down the development of *Abbreviations: DPBF, 1,3 diphenylisobenzofuran; DMSO, dimethyl sulfoxide.…”

Section: Introductionmentioning

confidence: 99%

CAROTENOIDS QUENCH EVOLUTION OF EXCITED SPECIES IN EPIDERMIS EXPOSED TO UV‐B (290‐320 nm) LIGHT

Mathews-Roth

1986

Photochem & Photobiology

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Abstract— Reactions involving singlet oxygen and other free radicals have been identified in epidermis containing either exogenous or endogenous photosensitizers. soaked in a singlet oxygen/free radical trap, and then exposed to visible or UV‐A (320‐400 nm) light. Such reactions can be quenched by the presence of the carotenoid pigments β‐carotene and canthaxanthin which accumulate in epidermis after oral administration. We report here that the carotenoid pigments β‐carotene. canthaxanthin and phytoene accumulating in epidermis can also quench to some degree those photochemical reactions involving singlet oxygen and free radicals that occur when epidermis is exposed to the sunburn spectrum of light (UV‐B. 290–320 nm).

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Section: Introductionmentioning

confidence: 99%

CAROTENOIDS QUENCH EVOLUTION OF EXCITED SPECIES IN EPIDERMIS EXPOSED TO UV‐B (290‐320 nm) LIGHT

Mathews-Roth

1986

Photochem & Photobiology

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“…Several lines of evidence indicate that damage to DNA is the earliest event in a complex sequence that eventually leads to skin cancer in humans chronically exposed to sunlight (Setlow, 1974;Black and Chan, 1977;Cleaver, 1980). However, remarkably little is known about the interaction of natural solar UV radiation with nucleic acids and living cells (see Murphy, 1975, andGiese, 1976, for reviews).…”

Section: Introductionmentioning

confidence: 99%

Lethal Effects of Natural Solar Ultraviolet Radiation in Repair Proficient and Repair Deficient Strains of Escherichia Coli: Actions and Interactions

Tyrrell

Souza-Neto

1981

Photochem Photobiol

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Abstract— The inactivation of repair proficient (Escherichia coli K12 AB 1157, E. coli B/r) and repair deficient (E. coli K12 AB 1886 uvrA, AB 2463 recA and AB 2480 uvrA recA) strains of bacteria by noon sunlight has been measured. The use of biological dosimetry based on an ultraviolet (UV) sensitive strain of Bacillus subtilis spores has allowed a quantitative comparison of bacterial inactivation by solar, 254 and 302 nm radiations. Our analysis indicates that: (1) uvrA and recA gene products are involved in repair of a substantial portion of the solar DNA damage, (2) 302 nm is a more appropriate wavelength than 254 nm to represent the DNA‐damaging action of sunlight and that (3) repair proficient strains are inactivated by sunlight more rapidly than expected from the levels of DNA damage induced. When populations of repair proficient bacteria are exposed to noon sunlight for 20 min, they become sensitive to the lethal action of far‐UV (254 nm), MMS (0.1 M) and to a lesser extent, mild heat (52°C).

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“…Another study showed that antioxidants inhibited the formation of cholesterol-a-oxide in animals (49). Cholesterol-a-oxide, a known carcinogen and a photoproduct of cholesterol, is found in both human and hairless mouse skin on exposure to ultraviolet radiation (50,51). Despite early enthusiasm, it is most probably not ultimately responsible for ultravioletinduced carcinogenesis because (5 1): (i) Peak cutaneous levels are much lower than that required to produce tumors in mice (4 to 16 p g vs 20 mg); (ii) when introduced subcutaneously, only tumors of dermal origin are produced; and (iii) cholesterola-oxide levels found in antioxidant-fed animals should be lower than those on a regular diet, but this was not the case.…”

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confidence: 99%