The ginkgo biloba extract EGb761 improves memory loss and cognitive impairments in patients with senile dementia. It also promotes proliferation of neural stem cells in the subventricular zone in Parkinson＇s disease ...The ginkgo biloba extract EGb761 improves memory loss and cognitive impairments in patients with senile dementia. It also promotes proliferation of neural stem cells in the subventricular zone in Parkinson＇s disease model mice and in the hippocampal zone of young epileptic rats. However, it remains unclear whether EGb761 enhances proliferation of endogenous neural stem cells in the brain of rats with vascular dementia. In this study, a vascular dementia model was established by repeatedly clipping and reperfusing the bilateral common carotid arteries of rats in combination with an intraperitoneal injection of a sodium nitroprusside solution. Seven days after establishing the model, rats were intragastrically given EGb761 at 50 mg/kg per day. Learning and memory abilities were assessed using the Morris water maze and proliferation of endogenous neural stem cells in the subventricular zone and dentate gyrus were labeled by 5-bromo-2-deoxyuridine immunofluorescence in all rats at 15 days, and 1, 2, and 4 months after model establishment. The escape latencies in Morris water maze tests of rats with vascular dementia after EGb761 treatment were significantly shorter than the model group. Immunofluorescence staining showed that the number and proliferation of 5-bromo-2-deoxyuridine-positive cells in the subventricular zone and dentate gyrus of the EGb761-treated group were significantly higher than in the model group. These experimental findings suggest that EGb761 enhances proliferation of neural stem cells in the subventricular zone and dentate gyrus, and significantly improves learning and memory in rats with vascular dementia.展开更多
Objective:The aim of this study was to study the effect of Ginkgo biloba extract(EGb761) on metabolism of aflatoxin B1(AFB1) in Wistar rats.Methods:Seventy one Wistar rats were assigned at random to groups A,B and C.R...Objective:The aim of this study was to study the effect of Ginkgo biloba extract(EGb761) on metabolism of aflatoxin B1(AFB1) in Wistar rats.Methods:Seventy one Wistar rats were assigned at random to groups A,B and C.Rats in groups A,B were injected with AFB1(intraperitoneal,100-200 μg/kg body weight,1-3 times/week).Group C was normal control.Rats in group B were fed in food with EGb761,while rats in groups A,C were given normal food.Blood samples were collected and liver biopsies were performed on the 14th,28th and 42nd week.All the rats were sacrificed on the 64th week.The incidence of hepatocarcinoma was investigated.The hepatic phase I drug-metabolizing enzyme Cytochrome-P450(CYP450) and phase II metabolizing enzyme glutathione S-transferase(GST) were analyzed with spectrometry.Serum AFB1lysine adduct levels were assessed with high performance liquid chromatography(HPLC).The expression of 8-hydroxydeoxyguanosine(8-OHdG) was measured with immunohistochemistry.Results:The incidence of hepatocellular carcinoma(HCC) in group B was significantly lower than that in group A(26.92% vs 76.00%,P < 0.001).No HCC developed in group C.EGb761 showed no effects on the activities of CYP450 and GST in rat liver tissues.The level of AFB1-lysine adduct reached the peak(4356.01 pg/mg albumin) at the 14th week in group A.EGb761 significantly inhibited the formation of AFB1-lysine adduct in serum by 13.07% at the 14th week(P = 0.033),and 73.63% at the 42nd week(P = 0.002).The expression of 8-OHdG protein in rat liver tissues in group B was significantly lower than that in group A at the 28th,42nd,and 64th week(P < 0.05).Conclusion:The main mechanism underlying the effect of EGb761 in blocking hepatocarcinogenesis induced by AFB1 may not be fully attributable to its influence on the activity of liver phase I and phase II metabolizing enzymes.EGb761 inhibits the production of AFB1-lysine adducts,decreases the expression of 8-OHdG protein,and finally alleviates the DNA oxidative injury,which may be one of the mechanisms for the effects of EGb761 in inhibiting or delaying AFB1-induced hepatocarcinogenesis.展开更多
目的研究细胞外信号调节激酶(ERK1/2)在缺糖缺氧/复糖复氧神经元中的表达以及银杏叶提取物的调节作用。方法利用原代培养的皮层神经元,通过去除培养液中的糖和氧(oxygen and glucose deprivation,OGD)模拟缺血缺氧,恢复糖氧供给模拟再...目的研究细胞外信号调节激酶(ERK1/2)在缺糖缺氧/复糖复氧神经元中的表达以及银杏叶提取物的调节作用。方法利用原代培养的皮层神经元,通过去除培养液中的糖和氧(oxygen and glucose deprivation,OGD)模拟缺血缺氧,恢复糖氧供给模拟再灌注。通过免疫蛋白印迹法测定ERK1/2、p-ERK1/2蛋白的表达。再灌注时加用银杏叶提取物(EGB761)观察其对神经元保护作用以及时ERK1/2表达的调节作用。结果缺糖缺氧/复糖复氧后神经元p-ERK1/2表达明显下降,EGB761可剂量依赖地保护神经元活性,并可上调p-ERK1/2蛋白的表达。结论EGB761对培养的神经元缺糖缺氧/复糖复氧损伤有保护作用,该作用可能与激活ERK信号转导通路有关。展开更多
基金financially sponsored by the Natural Science Foundation of Shandong Province,No.Y2008C32Scientific Research Funds of Shandong Provincial Education Ministry,No.J01K09
文摘The ginkgo biloba extract EGb761 improves memory loss and cognitive impairments in patients with senile dementia. It also promotes proliferation of neural stem cells in the subventricular zone in Parkinson＇s disease model mice and in the hippocampal zone of young epileptic rats. However, it remains unclear whether EGb761 enhances proliferation of endogenous neural stem cells in the brain of rats with vascular dementia. In this study, a vascular dementia model was established by repeatedly clipping and reperfusing the bilateral common carotid arteries of rats in combination with an intraperitoneal injection of a sodium nitroprusside solution. Seven days after establishing the model, rats were intragastrically given EGb761 at 50 mg/kg per day. Learning and memory abilities were assessed using the Morris water maze and proliferation of endogenous neural stem cells in the subventricular zone and dentate gyrus were labeled by 5-bromo-2-deoxyuridine immunofluorescence in all rats at 15 days, and 1, 2, and 4 months after model establishment. The escape latencies in Morris water maze tests of rats with vascular dementia after EGb761 treatment were significantly shorter than the model group. Immunofluorescence staining showed that the number and proliferation of 5-bromo-2-deoxyuridine-positive cells in the subventricular zone and dentate gyrus of the EGb761-treated group were significantly higher than in the model group. These experimental findings suggest that EGb761 enhances proliferation of neural stem cells in the subventricular zone and dentate gyrus, and significantly improves learning and memory in rats with vascular dementia.
文摘Objective:The aim of this study was to study the effect of Ginkgo biloba extract(EGb761) on metabolism of aflatoxin B1(AFB1) in Wistar rats.Methods:Seventy one Wistar rats were assigned at random to groups A,B and C.Rats in groups A,B were injected with AFB1(intraperitoneal,100-200 μg/kg body weight,1-3 times/week).Group C was normal control.Rats in group B were fed in food with EGb761,while rats in groups A,C were given normal food.Blood samples were collected and liver biopsies were performed on the 14th,28th and 42nd week.All the rats were sacrificed on the 64th week.The incidence of hepatocarcinoma was investigated.The hepatic phase I drug-metabolizing enzyme Cytochrome-P450(CYP450) and phase II metabolizing enzyme glutathione S-transferase(GST) were analyzed with spectrometry.Serum AFB1lysine adduct levels were assessed with high performance liquid chromatography(HPLC).The expression of 8-hydroxydeoxyguanosine(8-OHdG) was measured with immunohistochemistry.Results:The incidence of hepatocellular carcinoma(HCC) in group B was significantly lower than that in group A(26.92% vs 76.00%,P < 0.001).No HCC developed in group C.EGb761 showed no effects on the activities of CYP450 and GST in rat liver tissues.The level of AFB1-lysine adduct reached the peak(4356.01 pg/mg albumin) at the 14th week in group A.EGb761 significantly inhibited the formation of AFB1-lysine adduct in serum by 13.07% at the 14th week(P = 0.033),and 73.63% at the 42nd week(P = 0.002).The expression of 8-OHdG protein in rat liver tissues in group B was significantly lower than that in group A at the 28th,42nd,and 64th week(P < 0.05).Conclusion:The main mechanism underlying the effect of EGb761 in blocking hepatocarcinogenesis induced by AFB1 may not be fully attributable to its influence on the activity of liver phase I and phase II metabolizing enzymes.EGb761 inhibits the production of AFB1-lysine adducts,decreases the expression of 8-OHdG protein,and finally alleviates the DNA oxidative injury,which may be one of the mechanisms for the effects of EGb761 in inhibiting or delaying AFB1-induced hepatocarcinogenesis.
文摘目的研究细胞外信号调节激酶(ERK1/2)在缺糖缺氧/复糖复氧神经元中的表达以及银杏叶提取物的调节作用。方法利用原代培养的皮层神经元,通过去除培养液中的糖和氧(oxygen and glucose deprivation,OGD)模拟缺血缺氧,恢复糖氧供给模拟再灌注。通过免疫蛋白印迹法测定ERK1/2、p-ERK1/2蛋白的表达。再灌注时加用银杏叶提取物(EGB761)观察其对神经元保护作用以及时ERK1/2表达的调节作用。结果缺糖缺氧/复糖复氧后神经元p-ERK1/2表达明显下降,EGB761可剂量依赖地保护神经元活性,并可上调p-ERK1/2蛋白的表达。结论EGB761对培养的神经元缺糖缺氧/复糖复氧损伤有保护作用,该作用可能与激活ERK信号转导通路有关。
