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Ginkgo leaf extract Spatial memory. Motor function Chronic cerebral insufficiency
Abstract
The main goal of the curren study was to investigate the effects of two Ginkgo leaf extracts, EGb 761 and an extract of local Ginkgo leaf (LGb), on the memory and motor functions of rats with chronic cerebral insufficiency (produced by bilateral common carotid artery ligation). After the operation, spatial memory and motor functions were tested for over 80 days. Tests included (1) radial-arm maze test for testing spatial memory and locomotor activity and (2) muscle force and hind limbs for escape. The results indicate that both EGb 761 and LGb improved spatial memory from the second week after operation, but only EGb 761 delayed deterioration of motor functions from the fifth week after operation.
Introduction
Ginkgo extracts have been used for therapy of cardiopulmonary diseases in traditional Chinese medicine for thousands of years. Since different proportions of components are obtained by different methods, the effects of this plant leaf extract depend on the method of extraction. A widely used Ginkgo leaf extract (EGb 761 by Ipsen, France) has been extensively investigated. The possible mechanisms of its effects include actions on blood viscoelasticity [1], free radical scavenging, antiplatelet and calcium ion [2]. Many animal and clinical studies showed that EGb 761 had favorable effects on memory, attention, learning and behavior in aged, cerebral ischemic or brain injury subjects [3]. Studies also showed that EGb 761 had beneficial effects on the motor functions. EGb 761 ameliorated motor performance in hemiplegic rats caused by ablation of a portion of the somatomotor cortex [4].
Most of the past animal studies focused on the effects of Ginkgo leaf extract in transient ischemia or acute injury, which was not applicable to the situation of chronic cerebrovascular diseases frequently encountered in clinical practice. The main goal of the current study is to investigate the effects of two Ginkgo leaf extracts, EGb 761 and a local Gjinkgo leaf extract (LGb), on the memory and motor functions of rats with chronic cerebral insufficiency.
Animals and Materials
Six- to eight-week-old male Wistar rats were used in this study. The animals were maintained at the animal center and principles of laboratory animal care were followed. The animals were kept...