Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment

Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.

Ginkgo biloba leaf extract improves the cognitive abilities of rats with D-galactose induced dementia

Standardized Ginkgo biloba leaf extract has been used in clinical trials for its beneficial effects on brain func- tions, particularly in dementia. Substantial experimental evidences indicated that Ginkgo biloba leaf extract （EGB） protected neuronal cells from a variety of insults. We investigated the effect of EGB on cognitive ability and protein kinase B （PKB） activity in hippocampal neuronal cells of dementia model rats. Rats received an intra- peritoneal injection of D-galactose to induce dementia. Forty-eight Spraque-Dawley rats were randomly divided into six groups, including the control group, D-galactose group （Gal）, low-dose EGB group （EGB-L）, mid-dose EGB group （EGB-M）, high-dose EGB group （EGB-H） and treatment group. The EGB-L, EGB-M and EGB-H groups were administered with EGB and D-galactose simultaneously. Y-maze, cresyl violet staining, TUNEL assays and immunohistochemistry staining were performed to detect learning and memory abilities, morpho- logical changes in the hippocampus, neuronal apoptosis and the expressing level of phospho-PKB, respectively. Rats in the Gal group showed decreased abilities of learning and memory, and hippocampal pyramidal cell layer was damaged, while EGB administration improved learning and memory abilities. The Gal group exhibited many stained, condensed nuclei and micronuclei, either isolated or within the cytoplasm of cells （39.5 ± 1.4）. Apoptotic cells decreased in the groups of EGB-L （35.9±0.9）, EGB-M （16.8± 1.0） and EGB-H （10.1±0.8）, and there were statistical significances compared with the Gal group. Immunoreactivity of phospho-PKB was localized diffusely throughout the cytosol of cells in all groups, while the immunoreactivity of the Gal group was weak. EGB signifi- cantly attenuated learning and memory impairment in a dose-dependent manner, while it could decrease the nmber of TUNEL-positive cells, and increase the activity of PKB. Our results demonstrated that EGB attenuated memory impairment and cell apoptosis in galactose-induced dementia model rats by activating PKB.

Effects of Ginkgo biloba extract on expression of biomarkers during aflatoxin B_1-induced hepatocarcinogenesis in Wistar rats

Objective： The aim of this study was to study the effect of Ginkgo biloba extract （EGb761） on metabolism of afiatoxin 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 ug/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 AFB1- lysine adduct levels were assessed with high performance liquid chromatography （HPLC）. The expression of 8-hydroxydeoxy- guanosine （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.

Hyperbaric Oxygen and Ginkgo Biloba Extract Ameliorate Cognitive and Memory Impairment via Nuclear Factor Kappa-B Pathway in Rat Model of Alzheimer＇s Disease

Background： Hyperbaric oxygen （HBO） and Ginkgo biloba extract （e.g., EGB 761） were shown to ameliorate cognitive and memory impairment in Alzheimcr＇s disease （AD）. However, the exact mechanism remains elusive. The aim of the present study was to investigate the possible mechanisms of HBO and EGB 761 via the function of nuclear factor kappa-B （NF-κB） pathway. Methods： AD rats were induced by injecting β-amyloid 25-35 into the hippocampus. All animals were divided into six groups： Normal. sham. AD model, HBO （2 atmosphere absolute： 60 min/d）, EGB 761 （20 mg·kg^-1 ·d ^-1）, and HBO/EGB 761 groups. Morris water maze tests were used to assess cognitive, and memory capacities of rats： TdT-mediated dUTP Nick-End Labeling staining and Western blotting were used to analyze apoptosis and NF-κB pathway-related proteins in hippocampus tissues. Results： Morris water maze tests revealed that EGB 761 and HBO significantly improved the cognitive and memory ability of AD rats. In addition, the protective effect of combinational therapy （HBO/EGB 761 ） was superior to either HBO or EGB 761 alone. In line. redticed apoptosis with NF-κB pathway activation was observed in hippocampus neurons treated by HBO and EGB 761. Conclusions： Our results suggested that HBO and EGB 761 improve cognitive and memory capacity in a rat model of AD. The protective effects are associated with the reduced apoptosis with NF-κB pathway activation in hippocampus neurons.

银杏叶提取物对胰岛素抵抗大鼠骨骼肌蛋白激酶B表达的影响

目的观察银杏叶提取物(EGB)对胰岛素抵抗(IR)大鼠骨骼肌蛋白激酶B(PKB)表达的影响,探讨EGB改善胰岛素敏感性的分子机制。方法采用高脂喂养的方法建立IR大鼠模型,并给予为期4周的不同剂量EGB腹腔注射干预,以罗格列酮作为阳性对照。本研究共涉及6个组,分别是正常对照组(NC组,基础饲料喂养,腹腔注射0.9%氯化钠注射液8 mg·kg-1·d-1)、模型对照组(MC组,IR大鼠,腹腔注射0.9%氯化钠注射液8 mg·kg-1·d-1)、银杏叶1组(EGB1组,IR大鼠,腹腔注射舒血宁注射液4 mg·kg-1·d-1)、银杏叶2组(EGB2组,IR大鼠,腹腔注射舒血宁注射液8 mg·kg-1·d-1)、银杏叶3组(EGB3组,IR大鼠,腹腔注射舒血宁注射液12 mg·kg-1·d-1)、罗格列酮组(RSG组,IR大鼠,马来酸罗格列酮0.9%氯化钠注射液混悬液3 mg·kg-1·d-1灌胃)。干预后测定各组大鼠血清总胆固醇(TC)、三酰甘油(TG)、空腹血糖(FBG)、空腹胰岛素(FINS)等指标的水平,用高胰岛素-正常葡萄糖钳夹实验测定葡萄糖输注率(GIR)。用Western Blot法测定大鼠骨骼肌PKB水平,实时荧光定量RT-PCR测定大鼠骨骼肌PKB mRNA表达。结果(1)实验第8周末,6组大鼠体质量间差异无统计学意义(P>0.05)。MC组大鼠血清TC、TG、FBG、FINS水平及GIR与NC组比较,差异均有统计学意义(P<0.05)。经药物干预,RSG组、EGB2组和EGB3组大鼠血清TC、TG、FBG、FINS水平及GIR与MC组比较,差异均有统计学意义(P<0.01)。(2)与NC组比较,MC组大鼠骨骼肌PKB表达量呈下降趋势,但差异无统计学意义(P=0.063)。EGB2组、EGB3组大鼠骨骼肌PKB水平与MC组比较,差异有统计学意义(P<0.01)。MC组大鼠骨骼肌PKB mRNA表达量与NC组比较,差异有统计学意义(P<0.05)。RSG组、EGB2、EGB3组大鼠骨骼肌PKB mRNA表达量与MC组比较,差异有统计学意义(P<0.05)。结论EGB能够改善高脂饮食诱导的IR状态,其胰岛素增敏机制可能与其增加骨骼肌PKB的表达有关。

银杏叶提取物对高同型半胱氨酸血症血管内皮NF-κBp65、iNOS、MCP-1表达影响的实验研究

目的探讨银杏叶提取物(GBE)对高同型半胱氨酸血症(HHcy)、血管内皮核转录因子(NF-κBp65)、诱导型一氧化氮合酶(iNOS)、单核细胞趋化因子-1(MCP-1)表达的干预作用。方法雄性Wistar大鼠51只随机分为空白对照组、模型组、叶酸组和银杏叶4组,采用液相色谱-串联质谱(LC-MS/MS)法测定血清同型半胱氨酸(Hcy)水平;免疫组化法观察MCP-1、iNOS、NF-κBp65的表达,HE染色观察主动脉组织形态学变化。结果模型组血清Hcy水平明显高于空白对照组(P<0.01)。模型组内皮细胞内NF-κBp65、iNOS及内皮下MCP-1呈较多棕黄色颗粒的表达,银杏叶组和叶酸组则呈较少棕黄色颗粒表达,空白对照组只有极少量棕黄色颗粒的表达。结论GBE可能通过减少HHcy主动脉内皮细胞NF-κBp65、iNOS及MCP-1表达,明显改善血管内皮功能,延缓HHcy动脉粥样硬化的进程。

超声-微波协同萃取银杏叶黄酮与内酯B的工艺研究

研究了超声-微波协同萃取银杏叶黄酮与内酯B的最佳工艺条件,以银杏叶黄酮与内酯B得率为考核指标,探讨料液比、提取温度、乙醇体积分数以及浸提时间等因素对银杏叶黄酮与内酯B得率的影响,并通过单因素及正交试验对其提取工艺条件进行了优化。结果表明,最优提取工艺条件为料液比1∶20(g∶m L),提取温度50℃,乙醇体积分数为70%和提取时间4 min。在此最佳条件下,银杏叶黄酮及内酯B的得率分别为2.25%和0.81%。

哮喘大鼠IKK/NF-kB信号通道及银杏叶提取物的调控作用

目的探讨IkB激酶mRNA(IKKβmRNA)、核转录因子(NF-kB)、IL-5与气道炎症的关系及银杏叶提取物(Egb)对支气管哮喘(简称哮喘)炎症影响的机制。方法36只SD雄性大鼠随机分为正常组(C组)、哮喘组(A组)、Egb治疗组(E组)。复制哮喘大鼠模型,光镜观察病理形态学改变；分类计数法检测支气管肺泡灌洗液(BALF)中的细胞计数；分别以原位杂交法和免疫组化检测肺组织IKKβmRNA和NF-kB p65蛋白活性；ELISA法检测血清及BALF中IL-5的浓度。结果A组IKKβmRNA及NF- kB p65表达量均显著高于C组(均为P＜0.01)；E组IKKβmRNA和NF-kB p65表达均显著低于A组(均为P＜0.01)；A组血清及BALF中的IL-5的浓度均显著高于C组；E组血清及BALF中的IL-5的浓度均显著低于A组(均为P＜0.01)；A组BLAF中的嗜酸细胞(EOS)显著高于C组(P＜0.01)；E组BLAF中的EOS显著低于A组(P＜0.01)。结论哮喘组肺组织IKKβmRNA,NF-kB p65表达显著增强,Egb能有效抑制哮喘大鼠肺组织IKKβmRNA表达及NF-kB p65的活性,提示Egb能抑制IKK/NF-kB信号通道的活性,从而减轻气道炎症。

银杏叶提取物、银杏黄酮和银杏内酯B对小鼠脑缺血／再灌注损伤的保护作用

目的比较银杏叶提取物及其主要成分银杏黄酮和银杏内酯B对小鼠脑缺血／再灌注损伤的保护作用。方法建立小鼠脑缺血／再灌注损伤模型，观察比较银杏叶提取物、银杏黄酮、银杏内酯B对小鼠存活时间、脑含水量及脑皮质组织中Na^＋-K^＋-ATP酶活性、丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性的影响。结果银杏叶提取物300mg·kg。能显著延长小鼠的存活时间，降低小鼠脑含水量，提高脑皮质组织中Na^＋-K^＋-ATP酶活性，抑制MDA含量增加和SOD活性降低（P〈0．01）。银杏内酯B和银杏黄酮亦有相似的作用，其中银杏内酯B对皮质Na^＋-K^＋-ATP酶活性的影响显著（P〈0．01），而银杏黄酮能显著降低皮质中MDA的含量（P〈0．01）。结论银杏叶提取物、银杏内酯和银杏黄酮对小鼠全脑缺血／再灌注损伤均具有保护作用，银杏内酯B较银杏黄酮有较好的抑制脑水肿、提高Na^＋-K^＋-ATP酶活性的作用，而银杏黄酮抗氧化作用较优于银杏内酯B。

EGb761对NMB诱导的小鼠妊娠子宫平滑肌细胞中NF-κB活性和IL-6表达的影响

目的探讨银杏叶提取物EGb761对神经调节素B(Neuromedin B,NMB)诱导的分娩期小鼠子宫平滑肌细胞中NF-κB活性和IL-6表达的影响。方法应用原代培养的、NMB受体(Neuromedin B receptor,NMBR)表达阳性的分娩期小鼠子宫平滑肌细胞,联合NMBR和核因子κB(Nuclearfactor kappa B,NF-κB)p65的RNA干扰技术、real-time PCR和磷酸化ELISA等方法,确定EGb761对NMB诱导的小鼠子宫平滑肌细胞中NF-κB和IL-6表达的影响。结果高浓度的EGb761(100 mg.L-1)组,NF-κB p65DNA结合活性明显低于对照组及低浓度组(P<0.01),中、低浓度EGb组与对照组比较差异均无统计学意义。高浓度的EGb761预处理,可明显下调NMB诱导的子宫平滑肌细胞中NF-κB活性和IL-6的表达(P<0.01),且二者的变化呈正相关(r=0.892,P<0.01)。EGb761对NMB诱导的NF-κB活性和IL-6表达的调节作用可被NMBR及NF-κB基因沉默所阻断,且沉默两基因的阻断效率无差异。结论 EGb761可借助NMBR通路,抑制NF-κB活性和IL-6表达的上调,影响平滑肌细胞的活动。

EGb761对H_2O_2诱导的晶状体上皮细胞增殖的影响

目的:观察银杏叶提取物(EGb761)对过氧化氢(H2O2)诱导的晶状体上皮细胞增殖细胞核抗原(PCNA)表达的影响。方法:将离体培养的SD大鼠的晶状体上皮细胞分成3组:实验组用H2O2+EGb761处理,对照组用H2O2处理,空白对照组未做任何处理。用免疫组化的方法检测上皮细胞PCNA表达,分析实验组、对照组和空白对照组的表达情况。结果:PCNA阳性细胞率:实验组由于EGb761的抑制作用,在3h为15.3±4.0(%),对照组在H2O2诱导下,3h增加至34.2±5.9(%),空白对照组仅为9.9±2.3(%)。结论:H2O2作用早期可引起晶状体上皮细胞增殖,EGb761在H2O2作用早期能减少氧化应激引起的细胞增殖。

银杏叶提取物对重复＋GZ暴露高脂血症大鼠主动脉LOX-1及NF-κB表达的影响

目的观察银杏叶提取物、对重复正加速度(+G_z)暴露高脂血症大鼠主动脉凝集素样氧化低密度脂蛋白受体-1(oxidized low-density lipoprotein receptor-1,LOX-1)及核因子-κB(NF-κB)表达的影响。方法雄性SD大鼠50只随机分为5组,对照组、+Gz作用高脂模型组、银杏叶提取物低剂量干预组、银杏叶提取物中剂量干预组和银杏叶提取物高剂量干预组,每组10只。对照组给予普通饲料,模型组和药物干预组大鼠均给予高脂饲料喂养合并重复+Gz暴露处理,药物干预组大鼠每日灌胃给予各自剂量银杏叶提取物1次。实验持续8周后,检测各组大鼠血脂水平、氧化应激指标、炎症反应指标以及胸主动脉LOX-1、NF-κB表达。结果银杏叶提取物能降低重复+Gz暴露合并高脂饮食大鼠氧化型低密度脂蛋白水平,下调主动脉LOX-1表达,抑制NF-κB活化,减少促炎症因子的产生。结论银杏叶提取物可能通过下调主动脉LOX-1表达,抑制NF-κB活化,减轻炎症反应,进而减轻重复+Gz暴露合并高脂饮食导致的主动脉炎症损伤。

银杏叶提取物对内毒素诱导巨噬细胞核因子-κB活化及炎性细胞因子表达的调节

探讨银杏叶提取物(EGb761)对内毒素(LPS)诱导RAW264.7细胞核因子-κB(NF-κB)活化及炎性细胞因子基因表达的调节,为银杏叶提取物的临床运用提供理论依据.分别用LPS或EGb761+LPS处理体外培养的小鼠巨噬细胞系RAW264.7细胞,采用蛋白质印迹分析检测细胞中NF-κB活性,用逆转录-聚合酶链反应(RT-PCR)和酶联免疫吸附法(ELISA)检测细胞中TNF-α、IL-1β、IL-6mRNA和蛋白的表达.研究结果表明LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量在刺激后2～12h明显高于正常对照组,而EGb761+LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量均显著低于LPS组.结果提示LPS可诱导RAW264.7细胞NF-κB活化,导致TNF-α、IL-1β、IL-6基因表达增强,而EGb761能抑制NF-κB活化而调节TNF-α、IL-1β、IL-6基因的表达.

银杏叶提取物联合复方甘草酸苷治疗HBV感染慢加急性肝功能衰竭疗效及对外周血NF-κB、TNF-α、LXA4和LPS的影响

目的观察银杏叶提取物联合复方甘草酸苷治疗HBV感染慢加急性肝功能衰竭(HBV-ACLF)的疗效及对外周血核因子-κB(NF-κB)、肿瘤坏死因子-α(TNF-α)、脂氧素A4(LXA4)和内毒素(LPS)的影响。方法将60例HBV-ACLF患者随机分为对照组和观察组,每组30例。2组均采取常规西医治疗(抗病毒+保肝+营养支持+血浆置换等),在常规治疗基础上对照组给予复方甘草酸苷注射液治疗,观察组在对照组治疗基础上给予银杏叶提取物注射液治疗,疗程2个月。观察2组治疗前后临床症状体征、肝功能、营养状态、凝血功能情况,记录MELD评分、Child-Pugh改良分级评分变化,检测2组治疗前后血浆NF-κB、TNF-α、LXA4和LPS水平,并记录2组临床结局。结果 2组治疗后恶心呕吐、腹胀、腹水、黄疸、乏力、食欲减退、尿少积分均显著降低(P均<0.05),且观察组上述积分均显著低于对照组(P均<0.05);2组治疗后TBil、AST、ALT、GGT、ALB、PA、Plt、PTA均显著改善(P均<0.05),观察组改善情况显著优于对照组(P均<0.05);2组治疗后MELD评分、Child-Pugh改良分级评分均显著降低(P均<0.05),且观察组上述评分均显著低于对照组(P均<0.05);2组治疗后血浆NF-κB、TNF-α、LPS水平显著降低而LXA4水平显著升高(P均<0.05),且观察组上述指标改善情况均优于对照组(P均<0.05);观察组不良结局发生率显著低于对照组(P均<0.05)。结论银杏叶提取物联合复方甘草酸苷能够显著改善HBV-ACLF患者的临床症状,促进肝功能、营养和凝血功能的恢复,并可减少并发症,其机制可能与调节血浆NF-κB、TNF-α、LXA4和LPS的水平有关。

Neuroprotective effects of Ginkgo biloba extract and GinkgoUde B against oxygen-glucose deprivation/reoxygenation and glucose injury in a new in vitro multicellular network model

Acute ischemic stroke （AIS）, as the third leading cause of death worldwide, is characterized by its high incidence, mortality rate, high incurred disability rate, and frequent reoccurrence. The neuroprotective effects of Ginkgo biloba extract （GBE） against several cerebral diseases have been reported in previous studies, but the underlying mechanisms of action are still unclear. Using a novel in vitro rat cortical capillary endothelial cell- astrocyte-neuron network model, we investigated the neuroprotective effects of GBE and one of its important constituents, Ginkgolide B （GB）, against oxygenglucose deprivation/reoxygenation and glucose （OGD/R） injury. In this model, rat cortical capillary endothelial cells, astrocytes, and neurons were cocultured so that they could be synchronously observed in the same system. Pretreatment with GBE or GB increased the neuron cell viability, ameliorated cell injury, and inhibited the cell apoptotic rate through Bax and Bcl-2 expression regulation after OGD/R injury. Furthermore, GBE or GB pretreatment enhanced the transendothelial electrical resistance of capillary endothelial monolayers, reduced the endothelial permeability coefficients for sodium fluorescein （Na-F）, and increased the expression levels of tight junction proteins, namely, ZO-1 and occludin, in endothelial cells. Results demonstrated the preventive effects of GBE on neuronal cell death and enhancement of the function of brain capillary endothelial monolayers after OGD/R injury in vitro; thus, GBE could be used as an effective neuroprotective agent for AIS/reperfusion, with GB as one of its significant constituents.

银杏叶提取物对肺纤维化模型大鼠TGF-β_(1)、MMP-9及NF-κB表达的影响

[目的]探讨银杏叶提取物对肺纤维化模型大鼠转化生长因子β_(1)(TGF-β_(1))、基质金属蛋白酶9(MMP-9)、核转录因子-κB(NF-κB)表达和肺组织病理变化的影响。[方法]选取72只雄性SD大鼠,按随机数字表法分为正常对照组、肺纤维化模型组、吡非尼酮组、银杏叶提取物高剂量组、银杏叶提取物中剂量组、银杏叶提取物低剂量组,每组各12只。采用气管滴注博来霉素进行肺纤维化造模,于造模后29 d取标本,HE染色和Masson染色法评估肺组织肺泡炎症和纤维化程度,酶联免疫法(ELISA法)测定血清中TGF-β_(1)含量,免疫组化法检测MMP-9、NF-κB表达水平。[结果]肺纤维化模型组肺泡结构紊乱,肺泡壁增厚变形,管腔狭窄,胶原纤维明显增厚;吡非尼酮组及银杏叶提取物组肺泡结构破坏较少,胶原纤维沉积较为缓慢,银杏叶提取物组肺泡炎症积分及纤维化程度均低于肺纤维化模型组,TGF-β_(1)、MMP-9和NF-κB表达水平均低于肺纤维化模型组(P<0.05)。[结论]银杏叶提取物可缓解肺纤维化大鼠的肺泡炎症和纤维化程度,机制可能与其抑制肺组织中TGF-β_(1)、MMP-9与NF-κB表达水平有关。

Ginkgo biloba extracts attenuate lipopolysaccharide-induced inflammatory responses in acute lung injury by inhibiting the COX-2 and NF-κB pathways

In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide（LPS）-induced acute lung injury （ALl）. ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract （12 and 24 mg.kg^-1） and dexamethasone （2 mg.kg^-1）, as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid （BALF） were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase （SOD） and myelop- eroxidase （MPO） activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1/3, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H＆E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg.kg ^-1 markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation.

银杏叶提取物对高糖环境下系膜细胞血小板源性生长因子-B表达的影响

目的:观察银杏叶提取物对高糖培养条件下系膜细胞外基质产生及血小板源性生长因子-B(PDGFB)表达的影响。方法:体外培养人肾小球系膜细胞,分为对照组(葡萄糖终浓度为5.5 mmol/L)、高糖组(葡萄糖终浓度为30 mmol/L)、银杏叶提取物干预组(12.5 mg/L、25 mg/L、50 mg/L、100 mg/L),采用实时定量PCR检测系膜细胞PDGF-B m RNA的表达、Western blot检测系膜细胞PDGF-B蛋白表达、ELISA检测上清液Ⅳ型胶原(ColⅣ)、纤维连接蛋白(Fn)含量。结果:高糖组刺激24 h后,细胞上清液中Fn、ColⅣ含量、系膜细胞PDGF-B m RNA及蛋白的表达均高于对照组(P<0.05);银杏叶提取物干预组(25 mg/L、50 mg/L、100 mg/L)作用24 h后,细胞上清液Fn、ColⅣ含量均低于高糖组,系膜细胞PDGF-B m RNA及蛋白的表达均低于高糖组(P<0.05);且银杏叶提取物浓度越高,该作用越明显。结论:银杏叶提取物可以呈浓度依赖性抑制系膜细胞PDGF-B的合成,从而达到减少细胞外基质聚集、保护肾脏的作用。

银杏叶提取物联合多奈哌齐对阿尔茨海默病模型大鼠的协同作用及其机制

目的探讨银杏叶提取物(EGb 761)联合多奈哌齐对阿尔茨海默病(AD)模型大鼠的协同作用及其机制。方法取雄性SD大鼠72只,随机分为正常组(等体积生理盐水)、假手术组(等体积生理盐水)、模型组(等体积生理盐水)、多奈哌齐组(25 mg/kg)、EGb 761组(50 mg/kg)和联合组(多奈哌齐25 mg/kg+EGb 76150 mg/kg),各12只。腹膜内注射水合氯醛300 mg/kg麻醉,将聚集的Aβ25-35(10μL)以1μL/min的速率注入大鼠双侧海马,以复制AD大鼠模型。建模成功后,各组大鼠均灌胃相应药物或生理盐水,每天1次,共2个疗程(每个疗程10 d,间隔3 d)。采用Morris水迷宫实验评估大鼠的认知和记忆能力;采用TUNEL染色法,观察大鼠海马神经细胞凋亡情况,并计算凋亡指数;采用酶联免疫吸附法检测大鼠血清乙酰胆碱酯酶(AChE)、丙二醛(MDA)、超氧化物歧化酶(SOD)水平;采用Western blot法检测大鼠海马组织中核因子(NF)-κB通路相关蛋白p-IKKα,p-IκBα,p-NF-κB表达水平。结果与模型组比较,各给药组大鼠Morris水迷宫实验第6天逃避潜伏期均大幅缩短,第7天各给药组大鼠在象限Ⅰ中穿越平台的次数及耗时百分比均显著增加;各给药组大鼠海马神经细胞阳性数量均显著减少,凋亡指数均显著降低(P<0.05);各给药组大鼠AChE和MDA水平均显著降低,SOD水平显著升高(P<0.05);各给药组大鼠NF-κB通路相关蛋白p-IKKα,p-IκBα,p-NF-κB的表达水平均显著升高(P<0.05);且联合组上述指标变化均更显著(P<0.05)。结论EGb 761联合多奈哌齐可协同改善AD模型大鼠的记忆能力,其机制可能与减少海马神经细胞NF-κB通路激活后的细胞凋亡有关。

银杏叶提取物对糖尿病肾病的防治作用与机制研究

目的:观察银杏叶提取物(GBE)对糖尿病肾病大鼠核转录因子κB(NFκB)活性、肿瘤坏死因子α(TNFα)和白细胞介素6(IL 6)水平的影响,探讨其对糖尿病肾病的防治作用及其机制。方法:22只W istar大鼠分为正常对照组(A组),糖尿病无干预组(B组),GBE干预组(C组)。以一次性腹腔注射链脲佐菌素60 m g/kg制备糖尿病大鼠模型。12周后取肾组织进行病理学观察,以电泳迁移率变动分析法检测肾组织NFκB活性,放射免疫法测定血清TNFα和IL 6水平。结果:B、C组大鼠饲养过程中各死亡2只,存活大鼠空腹血糖>13.9 mm o l/L,模型制作成功。B组肾小球基底膜厚度、肾小球内细胞数和单个核细胞数显著多于A组,C组显著少于B组而多于A组(P均<0.05)。与A组比较,B组肾组织NFκB活性、TNFα和IL 6水平均显著升高,C组也有升高但明显低于B组(P均<0.05)。TNFα、IL 6水平与NFκB活性呈正相关(r1=0.83,r2=0.78;P均<0.05)。结论:银杏叶提取物可以通过抑制肾组织中NFκB的活化、减轻过度的炎症反应而延缓糖尿病肾病的发生、发展。