BHT blocks NF-kappaB activation and ethanol-induced brain damage.
BACKGROUND
Binge ethanol administration causes corticolimbic brain damage that models alcoholic neurodegeneration. The mechanism of binge ethanol-induced degeneration is unknown, but is not simple glutamate-N-methyl-D-aspartate (NMDA) excitotoxicity. To test the hypothesis that oxidative stress and inflammation are mechanisms of binge ethanol-induced brain damage, we administered 4 antioxidants, e.g., butylated hydroxytoluene (BHT), ebselen (Eb), vitamin E (VE), and blueberry (BB) extract, during binge ethanol treatment and assessed various measures of neurodegeneration.


METHODS
Adult Sprague-Dawley rats were treated with intragastric ethanol 3 times per day (8-12 g/kg/d) alone or in combination with antioxidants or isocaloric diet for 4 days. Animals were killed, and brains were perfused and extracted for histochemical silver stain determination of brain damage, markers of neurogenesis, or other immunohistochemistry. Some animals were used for determination of nuclear factor kappa B (NF-kappaB)-DNA binding by electrophoretic mobility shift assay (EMSA) or for reverse transcription-polymerase chain reaction (RT-PCR) of cyclooxygenase 2 (COX2).


RESULTS
Binge ethanol induced corticolimbic brain damage and reduced neurogenesis. Treatment with BHT reversed binge induced brain damage and blocked ethanol inhibition of neurogenesis in all regions studied. Interestingly, the other antioxidants studied, e.g., Eb, VE, and BB, did not protect against binge-induced brain damage. Binge ethanol treatment also caused microglia activation, increased NF-kappaB-DNA binding and COX2 expression. Butylated hydroxytoluene reduced binge-induced NF-kappaB-DNA binding and COX2 expression.


CONCLUSIONS
Binge-induced brain damage and activation of NF-kappaB-DNA binding are blocked by BHT. These studies support a neuroinflammatory mechanism of binge ethanol-induced brain damage.
Crews
Fulton
F
Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, CB 7178, Chapel Hill, NC 27599, USA. ftcrews@med.unc.edu
Nixon
Kimberly
K
Kim
Daniel
D
Joseph
James
J
Shukitt-Hale
Barbara
B
Qin
Liya
L
Zou
Jian
J
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001711:Biotransformation / Q000187:drug effects; D001925:Brain Damage, Chronic / Q000139:chemically induced* / Q000517:prevention & control*; D002084:Butylated Hydroxytoluene / Q000494:pharmacology*; D002492:Central Nervous System Depressants / Q000037:antagonists & inhibitors / Q000633:toxicity*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D018891:Dentate Gyrus / Q000473:pathology; D024202:Electrophoretic Mobility Shift Assay; D000431:Ethanol / Q000037:antagonists & inhibitors / Q000633:toxicity*; D007150:Immunohistochemistry; D008297:Male; D016328:NF-kappa B / Q000378:metabolism*; D009410:Nerve Degeneration / Q000139:chemically induced / Q000523:psychology; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016622:Silver Staining; D013234:Stem Cells / Q000187:drug effects / Q000473:pathology
D000975:Antioxidants; D002492:Central Nervous System Depressants; D016328:NF-kappa B; D002084:Butylated Hydroxytoluene; D000431:Ethanol; D012313:RNA; D051546:Cyclooxygenase 2