Ethanol-Induced Oxidative Stress and Cognitive Impairment in Rats: Neuroprotective Effects Of Silymarin As A Flavonoids.

Abstract

Objectives: Increased ethanol consumption amongst people leads to a wide spectrum of neurological disorders, including cognitive deficits, such as learning and memory impairment. Silymarin, flavonoids is reported to show antioxidant effect.  However, no report is available on the influence of silymarin on ethanol-induced memory impairment. Therefore, we investigate its influence against cognitive dysfunction in ethanol-induced rats.

Materials and Methods: Alcoholic dementia was induced by 15% w/v ethanol (2 g/kg) in double distilled water once a day, administered intraperitoneally, for 45 days. The rats serving as controls were given 1 ml/kg double distilled water (DDW) per oral (p.o.) and cognitive dysfunction in ethanol-induced rats using Morris water maze and elevated plus maze paradigm. Lipid peroxidation and glutathione levels as parameter of oxidative stress and cholinesterase (ChE) activity as a marker of cholinergic function were assessed in the cerebral cortex and hippocampus.

Results: Forty five days after ethanol treated rats showed a severe deficit in learning and memory associated with increased lipid peroxidation, decreased glutathione, and elevated ChE activity. In contrast, chronic treatment with silymarin (50-200 mg/kg, p.o., once a day for 45 days) improved cognitive performance, and lowered oxidative stress, and ChE activity in ethanol treated rats. Chronic treatment (45 days) with vitamin C during training trials also improved ethanol-induced memory impairment and reduced oxidative stress and/or cholinesterase activity.

Conclusion: The present study demonstrates that treatment with silymarin prevents the changes in oxidative stress and ChE activity, and consequently memory impairment in ethanol treated rats.