TY - JOUR
T1 - Alternative methods to evaluate the protective ability of sunscreen against photo-genotoxicity
AU - Toyoshima, Megumi
AU - Hosoda, Kanako
AU - Hanamura, Miho
AU - Okamoto, Keinosuke
AU - Kobayashi, Hiroshi
AU - Negishi, Tomoe
N1 - Funding Information:
We are grateful to Dr. Hikoya Hayatsu (Professor Emeritus of Okayama University, Professor of Shujitsu University) for his valuable discussion and encouragement to carry out this study. This work was supported in part by the Cosmetology Research Foundation.
PY - 2004/1/23
Y1 - 2004/1/23
N2 - Numerous epidemiological investigations show that sunlight is carcinogenic to humans and that the use of sunscreen may be effective in decreasing the risk of skin cancer. The biological activity of a sunscreen is evaluated by its ability to protect human skin from erythema as represented by a Sun Protection Factor (SPF). We propose that the sunscreen's protective effect against sunlight-induced genotoxicity, including mutation, should also be taken into account. In this study we examined the protective ability of sunscreens against natural sunlight and UV-induced genotoxicity in Drosophila somatic cells. We prepared three kinds of sunscreen samples, each with an SPF value of 20, 40 or 60 and compared their protective activities with commercial sunscreens. When a sunscreen of SPF 20, 40 or 60 was pasted on the plastic cover of a petri dish in which Drosophila larvae were exposed to the sun or UV lamps, genotoxicity decreased as the SPF of the sunscreen increased, relative to levels of genotoxicity observed in samples without sunscreen. However, the protective abilities of sunscreens were unexpectedly not so different from each other. To reveal the relationship between the protective activity of sunscreen and the wavelength of light with which larvae were irradiated through the sunscreen, we measured the transmittance of light through the petri dish cover on which the sunscreen was pasted. Effective protection was demonstrated by removing components of light whose wavelengths were below 315 nm. We suggest, that the measurement of anti-genotoxic activity and the determination of the wavelengths of light transmitted through the sunscreen should be an alternative method for evaluating the effectiveness of a sunscreen.
AB - Numerous epidemiological investigations show that sunlight is carcinogenic to humans and that the use of sunscreen may be effective in decreasing the risk of skin cancer. The biological activity of a sunscreen is evaluated by its ability to protect human skin from erythema as represented by a Sun Protection Factor (SPF). We propose that the sunscreen's protective effect against sunlight-induced genotoxicity, including mutation, should also be taken into account. In this study we examined the protective ability of sunscreens against natural sunlight and UV-induced genotoxicity in Drosophila somatic cells. We prepared three kinds of sunscreen samples, each with an SPF value of 20, 40 or 60 and compared their protective activities with commercial sunscreens. When a sunscreen of SPF 20, 40 or 60 was pasted on the plastic cover of a petri dish in which Drosophila larvae were exposed to the sun or UV lamps, genotoxicity decreased as the SPF of the sunscreen increased, relative to levels of genotoxicity observed in samples without sunscreen. However, the protective abilities of sunscreens were unexpectedly not so different from each other. To reveal the relationship between the protective activity of sunscreen and the wavelength of light with which larvae were irradiated through the sunscreen, we measured the transmittance of light through the petri dish cover on which the sunscreen was pasted. Effective protection was demonstrated by removing components of light whose wavelengths were below 315 nm. We suggest, that the measurement of anti-genotoxic activity and the determination of the wavelengths of light transmitted through the sunscreen should be an alternative method for evaluating the effectiveness of a sunscreen.
KW - Drosophila melanogaster
KW - Genotoxicity
KW - Somatic cell mutation
KW - Sunlight
KW - Sunscreen
KW - Transmittance
KW - UVB
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U2 - 10.1016/j.jphotobiol.2003.09.005
DO - 10.1016/j.jphotobiol.2003.09.005
M3 - Article
C2 - 14732252
AN - SCOPUS:0742306120
SN - 1011-1344
VL - 73
SP - 59
EP - 66
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
IS - 1-2
ER -