Protective effect of berberine, an isoquinoline alkaloid ameliorates ethanol-induced oxidative stress and memory dysfunction in rats

Memory impairment induced by ethanol in rats is a consequence of changes in the CNS that are secondary to impaired oxidative stress and cholinergic dysfunction. Treatment with antioxidants and cholinergic agonists are reported to produce beneficial effects in this model. Berberine, an isoquinoline alkaloid is reported to exhibit antioxidant effect and cholinesterase (ChE) inhibitor activity. However, no report is available on the influence of berberine on ethanol-induced memory impairment. Therefore, we tested its influence against cognitive dysfunction in ethanol-induced rats using Morris water 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. 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 berberine (25-100 mg/kg, p.o., once a day for 45 days) improved cognitive performance, and lowered oxidative stress and ChE activity in ethanol treated rats. In another set of experiments, berberine (100 mg/kg) treatment during training trials also improved learning and memory, and lowered oxidative stress and ChE activity. Chronic treatment (45 days) with vitamin C, and donepezil during training trials also improved ethanol-induced memory impairment and reduced oxidative stress and/or cholinesterase activity. In conclusion, the present study demonstrates that treatment with berberine prevents the changes in oxidative stress and ChE activity, and consequently memory impairment in ethanol treated rats.