OBJECTIVE To study the role of Ginkgo biloba extract-761(EGb-761)in the recovery of gait abnormality and its neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlu-sion in rats.METHODS Male Sprague Dawley rats(n=200,240-305 g)were anesthetized with 0.2%pentobarbital sodium diluted in physiological saline(2.0 m L·kg-1,ip).Then a monofilament coated with poly-L-lysine,was used to occlude the origin of the middle cerebral artery.It was inserted into the internal carotid artery lumen until it met mild resistance,approximately 20mm beyond the common carotid artery bifurcation.The suture was secured with a ligature and maintained in place until sacrifice.The same surgical procedure was conducted in sham-operated rats in which the middle cerebral artery was not occluded.Motor and behavioral changes were assessed after surgery using a five point scale.The rats securing the point scale above 2 were included in the study.The rats were randomly divided into control,and treated groups:EGb-761(20,50,and 100 mg·kg-1).The treated groups were oral y administered(10 mL·kg-1)for 28 d.On 7th,14th,21st,and 28th day the neurological scores,rotar rod test and gait assessment(the automated computer-assisted method)were performed.The brains were collected for TTC staining and histopathological analysis.RESULTS 1)Weight:On 28th day,EGb-761(20 mg·kg-1,)significantly increased the weight of the rat by~8%as compared to control(~300 g).However,at 50 mg·kg-1,and 100 mg·kg-1,a significant increase of~7-7.6%(control:~232 g),and~7.3-7%,respectively from 14 to 28 days was noted.2)Neurological scores:On 28thday,EGb-761(20,50,and 100 mg·kg-1)significantly decreased the neurological scores by~18%,~22%,~21%,respectively as compared to control(~2.07).3)Rotar rod test:On 28thday,EGb-761(50,and100 mg·kg-1)significantly increased by~69.1%,~74.1%,respectively as compared to control(~28.2).4)Gait assessment:On 7th,14th,21st,and 28thday,EGb-761(20,50,and 100 m·kg-1)significantly reduced the average body angle,on 7th,14th,21st,and 28thday,EGb-761(100 mg·kg-1)significantly increased the walk speed and reduced the average walking cycle,EGb-761(50,and 100 mg·kg-1)significantly the area of the left brain/right brain area percentage and reduced tissue pathologic neuron injury.CONCLUSION Ginkgo biloba extract EGb-761 has obvious improve behavior disorders,and has a protective neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlusion. OBJECTIVE To study the role of Ginkgo biloba extract-761 (EGb-761) in the recovery of gait abnormality and its neuroprotective effect against the brain injury induced by permanent middle cerebral artery occlu-sion in rats. METHODS Male Sprague Dawley rats (n = 200, 240-305 g) were anesthetized with 0.2% pentobarbital sodium diluted in physiological saline (2.0 m L · kg-1, ip). Then a monofilament coated with poly-L-lysine, was used to occlude the origin of the middle cerebral artery .It was inserted into the internal carotid artery lumen until it met mild resistance, approximately 20mm beyond the common carotid artery bifurcation. Suture was secured with a ligature and maintained in place until sacrifice.The same surgical procedure was conducted in sham-operated rats in which the middle cerebral artery was not occluded. Motor and behavioral changes were evaluated after surgery using a five point scale. rats stable at point scale above 2 were included in the study. The rats were randomly divided into control, and treated groups: EGb-761 (20,50, and 100 mg · kg -1). The treated groups were orally administered with 10 mL · kg -1 for 28 d. On 7th, 14th, 21st, and 28th day the neurological scores, rotar rod test and gait assessment (the automated computer-assisted method) were performed.The brains were collected for TTC staining and histopathological analysis .RESULTS 1) Weight: On 28th day, EGb-761 (20 mg · Kg -1, significantly increased the weight of the rat by ~ 8% as compared to control (~ 300 g) .However, at 50 mg · kg -1, and 100 mg · kg -1, a significant increase of ~ 7-7.6% (control: ~ 232 g), and ~ 7.3-7% respectively from 14 to 28 days ago.2) Neurological scores: On 28thday, EGb-761 (20,50 and 100 mg · kg- 1) significantly decreased the neurological scores by ~ 18%, ~ 22%, ~ 21%, respectively as compared to control (~ 2.07) .3) Rotarod test: On 28thday, EGb- Gait assessment: On 7th, 14th, 21st, and 28th day, EGb-761 (20, 50, and 100 m · Kg-1) sisignificantly increased the walk speed and reduced the average walking cycle, EGb-761 (50, and 100 mg · kg -1) kg-1) significantly the area of ​​the left brain / right brain area percentage and reduced tissue pathologic neuron injury. CONCLUSION Ginkgo biloba extract EGb-761 has obvious improve behavior disorders, and has a protective neuroprotective effect against the brain injury induced by permanent middle Cerebral artery occlusion.