The effects of melatonin and Ginkgo biloba extract on memory loss and choline acetyltransferase activities in the brain of rats infused intracerebroventricularly with β-amyloid 1-40

Abstract

Intraventricular infusion of rats with β-amyloid for 14 days resulted in memory deficit in the water maze as well as decreases in choline acetyltransferase activities and somatostatin levels in the cerebral cortex and hippocampus. These changes were not altered by daily intraperitoneal injection of 20 mg/Kg melatonin. Orally administered Ginkgo biloba extract, however, partially reversed the memory deficit and the decrease in choline actyltransferase activities in the hippocampus. The latter treatment failed to reverse the decrease in somatostatin levels. The results indicate that orally administered Ginkgo biloba extract can protect the brain against β-amyloid from changes leading to memory deficit through its effect on the cholinergic system. © 2002 Elsevier Science Inc. All rights reserved.