Objective: To explore the effect of Sini Decoction (SND) on learning and memory ability of vascular dementia (VD) in rats and the related mechanism. Method: VD model of rat was established by repeated cerebral ischemia/reperfusion after the decrease in blood pressure induced by sodium nitroprusside. Thirty rats were randomly divided into Sham-operated group; VD model group and SND group (3.5 g ·kg-1

ig 28 d). The learning and memory ability was tested with Y-maze and water maze. The production of NOS

NO and glutathione peroxidase (GSH-Px) in cerebral cortex and hippocampus was detected. Result: Learning and memory abilities were decreased

NOS and NO were increased

the activities of GSH-Px were reduced in VD group

compared with those in the sham-operated group (P<0.05). In SND group

the learning and memory ability was increased

NOS and NO were decreased and the activity of GSH-Px was increased

comparedwith those in the VD group (P<0.01). Conclusion: These findings suggested that SND could improve the learning and memory ability in VD rats

which may be due to the increased anti-oxidative ability of brain tissue.