HPLC法测定舒筋活血片的含量

目的:建立舒筋活血片中4-甲氧基水杨醛的HPLC测定方法。方法:Zorbax C_(18)柱(250mm×4.6mm,5μm);流动相为甲醇-水-磷酸(70:30:0.1);流速为1.0 ml·min~(-1);柱温25℃;检测波长为278nm。结果:4-甲氧基水杨醛在0.44～3.52μg范围内与峰面积有良好的线性关系(r=0.9999),平均回收率为104.2%,RSD=1.7%。结论:本法简便、灵敏、准确、重现性好,可用于舒筋活血片的质量控制。     

周围神经损伤后银杏叶提取物EGb761对感觉神经元的保护作用

目的　研究大鼠坐骨神经损伤后 ,银杏叶提取物 (EGb76 1)对感觉神经元的保护作用。方法　SD大鼠36只 ,分为EGb76 1组和生理盐水 (SAL)组。制作大鼠坐骨神经部分切除断端结扎模型 ,术后每天经腹腔分别注射EGb76 1(10 0mg·kg-1·d-1)和同体积的生理盐水直到取材。 2、4、6周处死大鼠取材L4、5脊神经节 ,酶组化染色观察乙酰胆碱酯酶 (AChE)及酸性磷酸酶 (ACP)的活性变化 ,冰冻切片硫槿染色计数神经节感觉神经元数目 ,电镜观察神经节感觉神经元超微结构的变化。结果　与对照组相比 ,治疗组乙酰胆碱脂酶、酸性磷酸酶活性、感觉神经元存活率及神经元超微结构有明显改善。结论　EGb76 1对周围神经损伤后的脊神经节感觉神经元损害有保护作用     

新鲜银杏叶经微波辅助提取后微观结构的变化

目的：研究微波辅助溶剂萃取对植物微观结构的破坏，并探讨微波辅助提取的机制。方法：以新鲜银杏叶片为原料，借助透射子显微镜，观察细胞结构。结果：在微波、溶剂或热的作用下，植物细胞的结构都会发生较为明显的变化，主要表现在有质壁分离现象，细胞器、淀粉粒等胞内物质被破坏。但微波辅助溶剂提取和传统的热提取都没有使细胞壁破裂。结论：微波的作用会导致银杏叶细胞结构的松散，但不足以使细胞壁破裂。     

Protective effects of Ginkgo biloba extract 761 against glutamate-induced neurotoxicity in cultured retinal neuron

Alarge part of neuronal death is the result of episodes of anoxia and ischaemia in the retina and other eye diseases, such as anterior ischemic optic neuropathy, glaucoma. The neuronal death is due to the accumulation of glutamate in the extracellular space. Glutamate is the primary excitatory neurotransmitter in the retina. However,excessive overactivation of glutamate receptors leads to excitotoxic neuronal cell death. Glutamate induces cell death by increasing the levels ofintracellular Ca^2 in neurons, thereby leading to generation of free radicals and activation proteases,     

Effects of Ginkgo leaf extract on function of dendritic cells and Th1/Th2 cytokines in patients with unstable angina pectoris

The instability of atherosclerosis plaqueis the pathological basis of unstable anginapectoris (UAP) ,andtheinflammatory reac-tion occurring in the plaque is one of themain mechanisms for the instability of theplaque(1). As antigen presenting cells withthe highest potential in the body,the den-dritic cells (DC) could be highly activatedinpatients with UAP(2),and might definitivelyaffect the cellular i mmune reaction duringinitiation of UAP.So , medicines having in-hibitory effect on DC whi…     

The beta subunit increases the ginkgolide B sensitivity of inhibitory glycine receptors

We investigated the effect of ginkgolide B (GB), a component of the extract from the leaves of the Ginkgo biloba tree, on recombinant glycine receptors (GlyRs) expressed in Xenopus oocytes by using voltage-clamp recording. GB (0.01-10 microM) inhibited glycine-induced currents of homo-oligomeric alpha1, alpha2 and alpha 3 GlyRs, with the highest potency being found at the alpha1 GlyR (IC(50) value=0.61+/-0.1 microM). Coexpression of the alpha subunits with the beta subunit resulted in a shift of the IC(50) value of GB to nanomolar values, indicating selectivity of GB for beta subunit containing GlyRs. We also analyzed the mechanism of GB inhibition and the effect of point mutations introduced into the alpha1 subunit. Our results are consistent with a channel blocking effect, since (i) GB inhibited glycine currents non-competitively, and (ii) a point mutation in the pore forming M2 domain reduced GB potency. In conclusion, GB is a potent blocker of beta subunit containing GlyR channels and hence can be used to discriminate homo- from hetero-oligomeric GlyRs. As hetero-oligomeric GlyRs are known to be synaptically localized, GB represents a channel blocker that may be employed to separate extrasynaptic from synaptic glycine currents.     

Identification of three competitive inhibitors for membrane-associated, Mg2+-dependent and neutral 60 kDa sphingomyelinase activity

Methanol extracts of domestic plants of Korea were evaluated as a potential inhibitor of neutral pH optimum and membrane-associated 60 kDa sphingomyelinase (N-SMase) activity. In this study, we partially purified N-SMase from bovine brain membranes using ammonium sulfate. It was purified approximately 163-fold by the sequential use of DE52, Butyl-Toyopearl, DEAE-Cellulose, and Phenyl-5PW column chromatographies. The purified N-SMase activity was assayed in the presence of the plant extracts of three hundreds species. Based on the in vitro assay, three plant extracts significantly inhibited the N-SMase activity in a time- and concentration-dependent manner. To further examine the inhibitory pattern, a Dixon plot was constructed for each of the plant extracts. The extracts of Abies nephrolepis, Acer tegmentosum, and Ginkgo biloba revealed a competitive inhibition with the inhibition constant (Ki) of 11.9 microg/ mL, 9.4 microg/mL, and 12.9 microg/mL, respectively. These extracts also inhibited in a dose-dependent manner the production of ceramide induced by serum deprivation in human neuroblastoma cell line SH-SY5Y.     

Ginkgo biloba prevents mobile phone-induced oxidative stress in rat brain

Background: The widespread use of mobile phones (MP) in recent years has raised the research activities in many countries to determine the consequences of exposure to the low-intensity electromagnetic radiation (EMR) of mobile phones. Since several experimental studies suggest a role of reactive oxygen species (ROS) in EMR-induced oxidative damage in tissues, in this study, we investigated the effect of Ginkgo biloba (Gb) on MP-induced oxidative damage in brain tissue of rats. Methods: Rats (EMR+) were exposed to 900 MHz EMR from MP for 7 days (1 h/day). In the EMR+Gb groups, rats were exposed to EMR and pretreated with Gb. Control and Gb-administrated groups were produced by turning off the mobile phone while the animals were in the same exposure conditions. Subsequently, oxidative stress markers and pathological changes in brain tissue were examined for each groups. Results: Oxidative damage was evident by the: (i) increase in malondialdehyde (MDA) and nitric oxide (NO) levels in brain tissue, (ii) decrease in brain superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and (iii) increase in brain xanthine oxidase (XO) and adenosine deaminase (ADA) activities. These alterations were prevented by Gb treatment. Furthermore, Gb prevented the MP-induced cellular injury in brain tissue histopathologically. Conclusion: Reactive oxygen species may play a role in the mechanism that has been proposed to explain the biological side effects of MP, and Gb prevents the MP-induced oxidative stress to preserve antioxidant enzymes activity in brain tissue.     

银杏叶提取物金纳多对心内直视手术期间心肌损伤标志物的影响

目的 探讨银杏叶提取物金纳多对心内直视手术期间心肌损伤标志物的影响。方法 40例先天性心脏病单纯房间隔缺损或室间隔缺损修补术患者,按随机数字表法随机分为银杏组和对照组,每组20例。两组均采用4℃St Thomas＇停搏液主动脉根部灌注,银杏组在此基础上加入银杏叶提取物金纳多（0．5mg／kg）;两组均于心脏完全停跳后开始心内手术。手术前、术后即刻、术后6、12、24、48h取中心静脉血,采用免疫比浊法测定血清C-反应蛋白（CRP）,采用ELISA法检测肌酸激酶同功酶（CK-MB）、肌钙蛋白T（cTnT）和肌钙蛋白Ⅰ（cTnI）浓度的变化。结果术前两组间CRP、CK-MB、cTnT、cTnI浓度比较,差异无显著性（P〉0．05）,两组患者血清CRP、CK-MB、cTnT、cTnI浓度在术后即刻显著升高（P〈0．05）,对照组于术后12h达峰值,术后48h降至术前水平,同一时点比较,银杏组明显低于对照组（P〈0．05,P〈0．01）。结论 银杏叶提取物金纳多应用于心内直视手术中可显著降低心肌损伤标志物升高程度,促进术后心功能恢复,具有良好的心肌保护效果。