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Chronic alcohol consumption causes numerous biochemical and biophysical changes in the central nervous system, in which mitochondria is the primary organelle affected. In the present study, we hypothesized that alcohol alters the mitochondrial membrane properties and leads to mitochondrial dysfunction via mitochondrial reactive oxygen species (mROS) and reactive nitrogen species (RNS). Alcohol-induced hypoxia further enhances these effects. Administration of alcohol to rats significantly increased the mitochondrial lipid peroxidation and protein oxidation with decreased SOD2 mRNA and protein expression was decreased, while nitric oxide (NO) levels and expression of iNOS and nNOS in brain cortex were increased. In addition, alcohol augmented HIF-1α mRNA and protein expression in the brain cortex. Results from this study showed that alcohol administration to rats decreased mitochondrial complex I, III, IV activities, Na(+)/K(+)-ATPase activity and cardiolipin content with increased anisotropic value. Cardiolipin regulates numerous enzyme activities, especially those related to oxidative phosphorylation and coupled respiration. In the present study, decreased cardiolipin could be ascribed to ROS/RNS-induced damage. In conclusion, alcohol-induced ROS/RNS is responsible for the altered mitochondrial membrane properties, and alcohol-induced hypoxia further enhance these alterations, which ultimately leads to mitochondrial dysfunction.

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The fruit of Emblica officinalis has been used in the Ayurvedic system of medicine for the treatment of different ailments and is also an ingredient of various traditional medicinal herbal formulations in India and other countries. To investigate the protective effect of Emblica officinalis fruit extract (EFE) against alcohol-induced brain mitochondrial dysfunction, male Wistar rats were orally administered 20% alcohol (5 g/kg of body weight/day) and EFE (250 mg/kg of body weight/day) for 60 days. Alcohol-treated rats showed significantly lowered activities of mitochondrial antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and reduced glutathione compared with those of experimental control rats. Furthermore, alcohol feeding lowered the activities of NADH dehydrogenase, succinate dehydrogenase (SDH), and cytochrome c oxidase and the content of cytochromes followed by increased levels of nitric oxide (NO), thiobarbituric acid-reactive substances, and protein carbonyls. No significant change was observed in membrane potential. Administration of EFE to alcohol-treated rats, lowered the levels of NO, protein carbonyls, and lipid peroxidation and elevated the activities of the antioxidant enzymes SDH, NADH dehydrogenase, and cytochrome c oxidase and the content of cytochromes. The active tannoid principles present in EFE with its antioxidant as well as NO scavenging properties might have contributed to the observed protection against alcohol-induced brain mitochondrial dysfunction.