Substantial amounts of beta-carotene are being administered to thousands of volunteers in ongoing preventive studies and are being consumed by the general public in an uncontrolled undocumented fashion. Beta-carotene is being taken for its anti-cancer effects or as a precursor of (and substitute for) vitamin A, which has known intrinsic hepatotoxicity, exacerbated by ethanol. However, recent experimental studies and epidemiological observations in man revealed toxic interactions between ethanol and beta-carotene. Since moderate alcohol consumption is being advocated as possible health benefits, we determine such intake can adversely interact with beta-carotene supplementation. Established animal models in rats and nonhuman primates, as well as judicious clinical studies, will be used to determine the minimally effective dose of beta- carotene needed to restore hepatic vitamin A levels, whether this is affected by associated moderate alcohol consumption (1 or 2 drinks per day), whether beta-carotene, given in amounts commonly used at present, is influenced by moderate alcohol consumption in terms of absorption, disposition, and possible toxic manifestations, and whether the latter are exacerbated by beta-carotene beadlets. We will further ascertain the activity of the enzyme responsible for intestinal cleavage of beta-carotene is altered by chronic supplementation of beta-carotene and/or associated ethanol usage. Toxic manifestations will be assessed by measurements of circulating liver enzymes (AST, ALT) and of glutamic dehydrogenase (GDH), a marker of mitochondrial injury, as well as by ultrastructural changes in hepatic tissue. Additional experiments will be conducted to determine whether beta-carotene can attenuate the oxidant stress associated with alcohol (with or without iron), while avoiding toxic ethanol/beta-carotene interactions. Parameters of lipid peroxidation, such as F2-isoprostanes and 4-hydroxynonenal, determined by GC/MS will be assessed, Beta Carotene and other carotenoids will be measured by a state-of-the art HPLC method. Associated vitamin E changes will also be evaluated since beta-carotene may act as an antioxidant either directly (by trapping singlet-oxygen or other free radicals) or indirectly, by enhancing tissue and plasma, vitamin E. Possible synergism between beta-carotene and vitamin E supplementation will be evaluated. Ubiquinones 9, 10 (reduced and oxidized forms) shown to be affected earlier than the tocopherols in the plasma of humans exposed to oxidant stress, will also be measured by HPLC and electrochemical detection. The ultimate goal is to define the interactions between ethanol (especially moderate intake) with beta-carotene in terms of bioavailability and possible toxicity, to assess the advantages and possible disadvantages of beta-carotene substitution for vitamin A, and to formulate recommendations for optimal supplementation for that vast segment of our population drinking alcohol, albeit moderately.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA011160-02
Application #
2516849
Study Section
Special Emphasis Panel (SRCA (59))
Project Start
1996-09-29
Project End
1999-08-31
Budget Start
1997-09-01
Budget End
1998-08-31
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Type
Schools of Medicine
DUNS #
114400633
City
New York
State
NY
Country
United States
Zip Code
10029
Lieber, C S (2001) Liver diseases by alcohol and hepatitis C: early detection and new insights in pathogenesis lead to improved treatment. Am J Addict 10 Suppl:29-50
Lieber, C S (2001) Alcoholic liver injury: pathogenesis and therapy in 2001. Pathol Biol (Paris) 49:738-52
Kessova, I G; Leo, M A; Lieber, C S (2001) Effect of beta-carotene on hepatic cytochrome P-450 in ethanol-fed rats. Alcohol Clin Exp Res 25:1368-72
Ni, R; Leo, M A; Zhao, J et al. (2001) Toxicity of beta-carotene and its exacerbation by acetaldehyde in HepG2 cells. Alcohol Alcohol 36:281-5
Aleynik, S I; Leo, M A; Aleynik, M K et al. (2000) Polyenylphosphatidylcholine protects against alcohol but not iron-induced oxidative stress in the liver. Alcohol Clin Exp Res 24:196-206
Lieber, C S (2000) Alcoholic liver disease: new insights in pathogenesis lead to new treatments. J Hepatol 32:113-28
Lieber, C S (2000) Hepatic, metabolic, and nutritional disorders of alcoholism: from pathogenesis to therapy. Crit Rev Clin Lab Sci 37:551-84
Aleynik, S I; Leo, M A; Takeshige, U et al. (1999) Dilinoleoylphosphatidylcholine is the active antioxidant of polyenylphosphatidylcholine. J Investig Med 47:507-12
Lieber, C S (1999) Microsomal ethanol-oxidizing system (MEOS): the first 30 years (1968-1998)--a review. Alcohol Clin Exp Res 23:991-1007
Aleynik, S I; Leo, M A; Aleynik, M K et al. (1999) Alcohol-induced pancreatic oxidative stress: protection by phospholipid repletion. Free Radic Biol Med 26:609-19

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