Reports: Supplemental β-Carotene, Smoking, and Urinary F2-Isoprostane Excretion in Patients With Prior Early Stage Head and Neck Cancer
| Autor: | Susan T. Mayne, Brenda Cartmel, W. Jarrard Goodwin, Mary F. Walter, Jeffrey B. Blumberg |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Adult
Cancer Research medicine.medical_specialty medicine.medical_treatment Urinary system Medicine (miscellaneous) Physiology Urine Placebo Antioxidants Gas Chromatography-Mass Spectrometry Placebos Lipid peroxidation Excretion chemistry.chemical_compound Double-Blind Method In vivo Internal medicine medicine Anticarcinogenic Agents Humans Longitudinal Studies Lung cancer Aged F2-Isoprostanes Nutrition and Dietetics business.industry Smoking Carotene Neoplasms Second Primary Middle Aged beta Carotene medicine.disease Endocrinology Oncology chemistry Head and Neck Neoplasms Dietary Supplements Lipid Peroxidation Neoplasm Recurrence Local business |
| Zdroj: | Nutrition and Cancer. 49:1-6 |
| ISSN: | 1532-7914 0163-5581 |
| DOI: | 10.1207/s15327914nc4901_1 |
| Popis: | Supplemental beta-carotene has been shown to increase lung cancer risk in recent chemoprevention trials, especially in current smokers. Several possible mechanisms for this effect have been suggested based upon in vitro and animal studies, but mechanistic data from human studies to explain the excess risk are lacking. beta-Carotene has both antioxidant and prooxidant effects in vitro; therefore, we evaluated whether or not high-dose supplemental beta-carotene might have prooxidant effects in vivo, especially in current smokers taking high-dose supplemental beta-carotene for several years (median 4.0 yr). Urine samples (n = 55 total) were collected from both smokers and nonsmokers participating in a multiyear randomized chemoprevention trial of supplemental beta-carotene (50 mg/day) versus placebo. Samples were analyzed by GC/MS for total isoprostanes and for 8-iso-prostaglandin F2 (8-iso-PGF2), stable end products of lipid peroxidation in vivo. Smokers had higher levels of both total isoprostanes and 8-iso-PGF2. Smokers and nonsmokers randomized to beta-carotene had nonsignificantly lower concentrations of total isoprostanes and of 8-iso-PGF2 [mean +- SD 8-iso-PGF2/ml = 2.00 +- 1.72 (placebo smoker); 1.72 +- 1.66 (beta-carotene smoker); 1.22 +- 0.68 (placebo nonsmoker); 0.97 +- 0.62 (beta-carotene nonsmoker)]. These results indicate that supplemental beta-carotene, even when given at high doses for many years, does not have prooxidant effects in either smokers or nonsmokers, as measured by urinary excretion of F2-isoprostanes. |
| Databáze: | OpenAIRE |
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