Effect of beta-carotene supplementation on rats submitted to chronic ethanol ingestion.
Chronic alcohol consumption is directly related to the induction of liver damage. The continuous use of ethanol induces the isoenzyme cytochrome P450CYP2E1, which promotes the formation of free radicals, resulting in lipid peroxidation. Among the main antioxidants are vitamin E, reduced glutathione (GSH), vitamin C, and beta-carotene. beta-Carotene has antioxidant activity per se, with a probable protective effect against different types of cancer. However, some studies have shown an increased number of cancer cells when beta-carotene is administered in the presence of chronic ethanol ingestion. On this basis, the objective of the present study was to assess the effect of beta-carotene supplementation on rats chronically treated with a hydroalcoholic solution by determining the levels of vitamin E, beta-carotene, GSH, and thiobarbituric acid reactive species (TBARS). Both the plasma and liver concentrations of beta-carotene were higher in the supplemented groups. Plasma vitamin E levels were decreased in the control group and liver vitamin E levels were significantly decreased (p < 0.05) in all groups compared to basal levels. GSH levels were increased over basal values in the group supplemented with beta-carotene for 14 days. TBARS values were increased as much as four-fold in the control group at 14 days, and declined again at 28 days, whereas they were increased in the supplemented group, with the increase remaining until the end of the experiment. The study indicates that beta-carotene had no beneficial effect as an antioxidant on rats submitted to chronic alcohol intake, and could be act as prooxidant when administered with ethanol.
Portari
G V
GV
Nutrition Division, Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-190 Ribeirão Preto, SP, Brazil.
Jordão Júnior
A A
AA
Meirelles
M S
MS
Marchini
J S
JS
Vannucchi
H
H
D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D001835:Body Weight; D019392:Cytochrome P-450 CYP2E1; D004334:Drug Administration Schedule; D004435:Eating; D000431:Ethanol / Q000008:administration & dosage* / Q000633:toxicity*; D005978:Glutathione / Q000097:blood / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008113:Liver Neoplasms / Q000139:chemically induced; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D019207:beta Carotene; D014810:Vitamin E; D000431:Ethanol; D019392:Cytochrome P-450 CYP2E1; D005978:Glutathione