Effects of α-tocopherol supplementation on liver of rats chronically exposed to ethanol.
OBJECTIVE
Chronic alcoholism is characterized by hepatotoxicity associated with antioxidant and redox status imbalance. Continuous ethanol intake induces free radical synthesis, resulting in the depletion of antioxidants, especially α-tocopherol, which has an important role in lipid peroxidation. This study aimed to evaluate if α-tocopherol supplementation can restore liver phenotype in rats chronically exposed to ethanol.


METHODS
α-Tocopherol levels were determined and histologic analysis of liver was performed. Hepatic gene expression was analyzed through oligonucleotide microarray and real-time PCR.


RESULTS
Alcohol exposure for 6 weeks did not decrease hepatic α-tocopherol levels; however, both groups exposed to ethanol (supplemented or not with α-tocopherol) displayed fatty liver. The antioxidant supplementation prevented Mallory bodies and inflammatory infiltration, but not apoptosis, in liver of the rats exposed to ethanol. Gene expression analysis showed evidence of adaptive response to chronic alcohol consumption, where antioxidant components were not regulated. Nevertheless, differentially expressed genes reflected the change in cellular homeostasis.


CONCLUSIONS
The hepatic α-tocopherol content was coherent with the antioxidant gene expression in this study. Cells are likely to have adapted and restored their antioxidant status after long-term ethanol exposure, which might be the reason for such conflicting reports concerning α-tocopherol status in chronic alcoholism.
Division of Nutrition, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Camila S
CS
Silva
Thaís H
TH
Monteiro
Lívia M C
LM
Simões-Ambrósio
Daniele Y
DY
Sunaga
João F R
JF
Cardoso
Kelly S
KS
Furtado
Thomas P
TP
Ong
Fernando S
FS
Moreno
Sérgio
S
Zucoloto
Helio
H
Vannucchi
D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D019587:Dietary Supplements; D000431:Ethanol / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000473:pathology; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D013056:Spectrophotometry, Ultraviolet; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000494:pharmacology
D017931:DNA Primers; D000431:Ethanol; D024502:alpha-Tocopherol