Keywords: 
• procyanidins /
• vascular dementia /
• oxidative stress /
• apoptosis

Abstract: Objective To investigate the effects and possible mechanisms of procyanidins, a polyphenol extracted from grape seeds, on spatial learning and memory in rats model of vascular dementia(VD). Methods Modified Pulsinelli's 4-vessel occlusion (4-VO) method was used for replicating vascular dementia in rats. The male Wistar rats were divided equally into 5 experimental groups: in one the rats were subjected to sham-operated, and in the other four the rats was subjected to the 4-VO surgery followed by oral administration of vehicle, Ginkgo leaf extract(24 mg/kg), procyanidins(50 or 150 mg/kg) respectively. The spatial learning and memory performance was recorded as the acquisition trial and probe trial in the Morris water maze. The levels of malondialdehyde(MDA), glutathione(GSH), total antioxidant capacity(T-AOC) and the activity of superoxidedismutase(SOD) in the brain tissue were determined by colorimetric Assay Kit. The gene expression of Bax and Bcl-2 in the rat hippocampus was detected by real-time PCR. Results The vascular dementia rats treated with procyanidins showed decreased escaped latency during acquisition training, especially at the dose of 150 mg/kg, procyanidins also increased exploration time and frequency of crossing in the target quadrant during probe trial. The administration of procyanidins induced increase in GSH, T-AOC contents and SOD activities with lowering MDA levels in the brain. In addition, procyanidins upregulated the Bcl-2/Bax ratio of mRNA expression in the rat hippocampus. Conclusion Procyanidins could have potentials for improving the spatial cognition with VD,which was possibly due to the antioxidative and anti-apoptotic effects of polyphenol.