Effects of chronic ethanol consumption on brain synaptosomes and protective role of betaine.

To evaluate the cytotoxic effects of chronic ethanol consumption on brain cerebral synaptosomes and preventive role of betaine as a methyl donor and S-adenosylmethionine precursor, 24 male Wistar rats were divided into three groups: control, ethanol (8 g/kg/day) and ethanol plus betaine(0.5% w/v) group. Animals were fed 60 ml/diet per day for two months, then sacrificed. Malondialdehyde (MDA), protein carbonyl contents and adenosine deaminase (ADA) activities were determined in synaptosomal/mitochondrial enriched fraction isolated from rat cerebral cortexes. When compared to controls, ethanol containing diet significantly increased MDA levels (P < 0.05), also increased protein carbonyl levels and adenosine deaminase activities. But these were not statistically significant (P > 0.05). However, adding betaine to ethanol containing diet caused a significant decrease in MDA, protein carbonyl levels and adenosine deaminase activities (P < 0.05). These results indicate that betaine may appear as a protective nutritional agent against cytotoxic brain damage induced by chronic ethanol consumption.