Neovascularization Induced By Isoflavone Puerarin In Rat Middle Cerebral Artery Occlusion Model

Object:In the present study, we investigated the effects of puerarin on cerebral infarction and its influence on neurovascualization in middle cerebral artery occlusion (MCAO) rats.Method:Male SD rats were subjected to MCAO for 90 min followed by reperfusion for 1, 3,7, and 14 days. Puerarin (50mg/kg, 100mg/kg,200mg/kg) was continuously administered at the onset of MCAO until the animals were sacrificed. Bromodeoxyuridine (BrdU) (50 mg/kg) intraperitoneally was injected daily from the onset to sacrifice. Neurological deficits were evaluated. Gene expression (VEGF, Tie-2 and Ang-1) was performed by realtime qPCR. Immunofluorescent technique was be used to detect Brdu and Glut1.Results:Puerarin (50,100 mg/kg) markedly improved the neurological functions in 50mg/kg and 100mg/kg groups at early stage (day 1,3,7), compared with MCAO+saline group (P＜0.05), but not in 200mg/kg group. Gene expression in ischemia region showed that VEGF mRNA levels had significant higher expression in puerarin treatments on day 7 and 14 (P＜0.05), but only 50 mg/kg treatment group on day 3 (P＜0.001). Tie-2 in 50 mg/kg treatment group had higher expression on day 7 (P＜0.001). Ang-1 in 200mg/kg group had a higher expression in day 1 only, compared with other groups. Cells with double staining by BrdU and GLUT1 (endothelial cells marker) were counted as immuno-positive stained cells (BrdU-FITC and Glut-1-PE) in day 14 after puerarin treatment. Data showed that dosage 50mg/kg of puerarin treatment could achieve the best results, compared with saline group (30±4, P＜0.001, n=6), strongly indicating that puerarin treatment could enhance the formation of new endothelial cells in ischemia region, but not in non-ischemia region.Conclusions:We demonstrate that puerarin is a potent agent for up-regulation of genes mediating neovascularization which is beneficial on MCAO-induced focal cerebral ischemia in vivo and Promote angiogenesis and neural function recovery of middle cerebral artery occlusion rats. Especially Puerarin (50 mg/kg) can get the best treatment effect.