2006 Fiscal Year Final Research Report Summary
Evaluation of the efficacy and safety of antioxidant supplements on the basis of oxidative DNA damage profiles
| Project/Area Number |
17590528
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Hygiene
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| Research Institution | Tsu City College |
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Principal Investigator |
ITO Kimiko Tsu City College, Life Science, Associate Professor, 生活科学科, 准教授 (90369611)
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| Co-Investigator(Kenkyū-buntansha) |
MURATA Mariko Mie University, Faculty of Medicine, Professor, 医学部, 教授 (10171141)
HIRAKU Yusuke Mie University, Faculty of Medicine, Lecturer, 医学部, 講師 (30324510)
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| Project Period (FY) |
2005 – 2006
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| Keywords | antioxidant supplements / coenzyme Q10 / oxidative DNA damage / 8-oxodG |
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| Research Abstract |
Oxidative stress has been implicated in the pathogenesis of various health disorders including cancer. It has been therefore suggested that antioxidant supplementation provides potential health benefits and disease prevention strategies by ameliorating oxidative stress. Particularly, antioxidants derived from dietary sources are now taken to the public widely, because they have very long history of use without any significant adverse effects. However, no conclusive evidence of the efficacy and safety of antioxidant supplements has been provided yet. Moreover, epidemiological studies demonstrated that β-carotene increased the incidences of lung cancer in smokers. This work was performed to systematically evaluate the beneficial and harmful effects of antioxidant supplements such as coenzyme Q10 (CoQ10) on human health. We found that UVA irradiation of CoQ10 induced damage to isolated DNA fragments obtained from human c-Ha-ras-1 protooncogene. The photosensitized DNA damage by CoQ10 was also observed in the presence of Cu(II) and the cleavage pattern was different from that induced in the absence of Cu(II). In addition, the reduced form of CoQ10 in the presence of Cu(II) increased the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a marker of oxidative DNA damage, in calf thymus DNA. The effect of CoQ10 supplementation on the urinary levels of 8-oxodG was also investigated in a cross-over study with 31 healthy volunteers. Participants received 3-weeks of CoQ10 (60 mg/ day) and the urinary 8-oxodG levels were measured by HPLC-ECD. The results revealed that the 8-oxodG level was significantly reduced in CoQ10 supplementation period compared to the control period (paired t-test, p<0.05).
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