国产与进口银杏叶片萜类内酯Beagle犬生物利用度的比较

目的比较国产与进口银杏叶片在Beagle犬体内的药动学参数和生物利用度。方法 Beagle犬分别ig国产与进口银杏叶片后,取血测定。采用LC-MS检测Beagle犬血浆中银杏叶片萜类内酯(银杏内酯A、银杏内酯B和白果内酯)的含量,绘制血药浓度-时间曲线,采用DAS软件计算药动学参数。结果 Beagle犬ig国产银杏叶片(80 mg/kg)后银杏内酯A、银杏内酯B和白果内酯的药-时曲线下面积(AUC0~t)分别为51.64、19.86和72.90 ng·h/m L,而ig进口银杏叶片(80 mg/kg)后三者的药-时曲线下面积(AUC0~t)分别为69.98、24.35和169.60 ng·h/m L。根据2种制剂中3种成分的含量,国产银杏叶片中银杏内酯A、银杏内酯B、白果内酯的相对生物利用度分别为37.77%、33.70%和95.98%。结论 Beagle犬ig国产银杏叶片后的萜类内酯生物利用度显著低于进口银杏叶片。     

银杏内酯A、B和白果内酯的分离与纯化

以银杏叶浸膏ＥＧｂ７６１为原料,通过预处理,制备色谱和重结晶过程,得到纯度达９８％以上的银杏内酯Ａ、Ｂ和白果内酯纯品。建立了一种较简单的分离和纯化银杏内酯Ａ、Ｂ和白果内酯的方法。     

高速逆流色谱法分离纯化银杏叶中白果内酯和银杏内酯A、B、C

目的从银杏叶中分离纯化白果内酯和银杏内酯A、B、C。方法银杏叶提取液经醋酸乙酯萃取、D-101大孔吸附树脂柱和Al2O3柱纯化后得到总内酯提取物,提取物再经两次高速逆流色谱分离制备4种内酯单体。结果25%乙醇热提取、醋酸乙酯萃取、D-101柱、pH4.0的Al2O3柱对总内酯的提纯最终使总内酯质量分数达到44.98%。经高速逆流色谱制备得到的白果内酯和银杏内酯A、B、C最高质量分数分别为98.3%、98.9%、98.8%、98.4%。结论本法简便快速、回收率高,为银杏叶中内酯单体的制备提供了一种新方法     

银杏叶提取物制剂中萜类内酯含量考察

 目的：对国内外20个厂家银杏叶提取物制剂中萜类内酯的含量进行考察，以对比国内外银杏叶制剂的质量状况。方法：采用高效液相示差折光检测法测定银杏叶提取物制剂中白果内酯及银杏内酯A，B，C的含量，回收率及精密度良好。结果：萜类内酯的含量参差不齐，所考察的国内绝大部分产品萜类内酯含量低，或白果内酯与银杏内酯比例失调。结论：为保证我国银杏叶制剂的质量与疗效，对我国银杏叶的提取与制剂工艺进行深入的规范化研究并严格统一质量标准已势在必行。     

Summative interaction between astaxanthin,Ginkgo biloba extract (EGb761) and vitamin C in Suppression of respiratory inflammation: a comparison with ibuprofen

In this study, combinations of Ginkgo biloba leaf extract (EGb761) plus the carotenoid antioxidant astaxanthin (ASX) and vitamin C were evaluated for a summative dose effect in the inhibition of asthma‐associated inflammation in asthmatic guinea‐pigs. Ovalbumin‐sensitized Hartley guinea‐pigs challenged with ovalbumin aerosol to induce asthma, were administered EGb761, ASX, vitamin C or ibuprofen. Following killing, bronchoalveolar lavage (BAL) fluid was evaluated for inflammatory cell infiltrates and lung tissue cyclic nucleotide content. Each parameter measured was significantly altered to a greater degree by drug combinations, than by each component acting independently. An optimal combination was identified that included astaxanthin (10 mg/kg), vitamin C (200 mg/kg) and EGb761 (10 mg/kg), resulting in counts of eosinophils and neutrophils each 1.6‐fold lower; macrophages 1.8‐fold lower, cAMP 1.4‐fold higher; and cGMP 2.04‐fold higher than levels in untreated, asthmatic animals (p < 0.05). In conclusion, EGb761, ASX and vitamin C are shown here to interact summatively to suppress inflammation with efficacy equal to or better than ibuprofen, a widely used non‐steroidal antiinflammatory drug (NSAID). Such combinations of non‐toxic phytochemicals constitute powerful tools for the prevention of onset of acute and chronic inflammatory disease if consumed regularly by healthy individuals; and may also augment the effectiveness of therapy for those with established illness. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluation of Ginkgo biloba extract as an activator of human glucocorticoid receptor

Ethnopharmacological relevance

Ginkgo biloba, which is one of the most frequently used herbal medicines, is commonly used in the management of several conditions, including memory impairment. Previously, it was reported to decrease the expression of peripheral benzodiazepine receptor and the biosynthesis of glucocorticoids, thereby regulating glucocorticoid levels. However, it is not known whether Ginkgo biloba extract regulates the function of the glucocorticoid receptor.

Aim of the study

We determined whether Ginkgo biloba extract and several of its chemical constituents affect the activity of human glucocorticoid receptor (hGR).

Materials and methods

A hGR-dependent reporter gene assay was conducted in HepG2 human hepatocellular carcinoma cells and hGR target gene expression assays were performed in primary cultures of human hepatocytes.

Results

Multiple lots and concentrations of the extract and several of its chemical constituents (ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, and bilobalide) did not increase hGR activity, as assessed by a cell-based luciferase reporter gene assay. The extract did not influence the expression of hGR target genes, including tyrosine aminotransferase (hTAT), constitutive androstane receptor (hCAR), or pregnane X receptor (hPXR), in primary cultures of human hepatocytes. Moreover, hGR antagonism by mifepristone (also known as RU486) did not attenuate the extent of induction of hCAR- and hPXR-regulated target genes CYP2B6 and CYP3A4 by Ginkgo biloba extract.

Conclusion

Ginkgo biloba extract, ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, and bilobalide are not activators of hGR. Furthermore, the extract does not influence the hGR-hCAR or the hGR-hPXR signaling pathway in primary cultures of human hepatocytes.     

含量测定和指纹图谱结合LC-MS技术整体评价银杏叶片的质量

建立银杏叶片合理质量控制的方法,评价市售不同厂家银杏叶片的质量.收集市售银杏叶片,采用HPLC对其进行总黄酮醇苷和萜类内酯含量测定,根据2010年版《中国药典》一部方法进行测定,2批银杏叶片总黄酮醇苷含量不合格,3批银杏叶片萜类内酯含量不合格;建立HPLC指纹图谱检测方法对其进行检测,不同厂家生产的16批银杏叶片HPLC指纹图谱标记出31个共有峰,与生成的对照指纹图谱相似度为0.763~0.989;采用LC-MS对指纹图谱色谱峰进行指认,鉴定出31个黄酮类成分.以总黄酮醇苷含量、萜类内酯含量和指纹图谱结合LC-MS技术整体评价银杏叶片的质量,为银杏叶片质量研究提供一些研究思路.     

HPLC-ELSD结合化学计量学研究银杏叶片中萜类内酯指纹图谱

目的：建立不同厂家银杏叶片中萜类内酯成分HPLC-ELSD指纹图谱。方法：色谱柱为Agi-lentExtend-C18（4．6mm×250mm,5μm）,流动相为正丙醇-四氢呋喃-水（1：15：84）,柱温为30℃,流速为1mL·min-1,蒸发光散射检测器检测;采用LC／Q-TOFMS对指纹图谱中的共有峰进行指认。并利用化学计量学方法,包括主成分分析（PCA）、相似度分析（SA）、聚类分析（HCA）,对色谱数据进行分析。结果：该方法精密度、稳定性、重复性良好。同时采用LC／Q-TOFMS方法指认了5个共有峰,分别为银杏内酯J（M）、银杏内酯C、银杏内酯A、银杏内酯B及白果内酯。并采用该方法测定了市售14批银杏叶片,结合PCA、SA及HCA生成了银杏叶片中萜类内酯对照指纹图谱,并根据质量差异将样品分为4大类。结论：本方法可用于银杏叶片中萜类内酯成分的质量评价。     

银杏叶提取物及制剂萜类内酯薄层色谱荧光扫描定量测定研究

建立了采用优化条件展开的薄层色谱进行热化学衍生荧光,原位薄层定量,同板同时测定银杏内酯A,B,C及白果内酯,最低检出限分别为0.12～0.35μg。灵敏度分别为0.25～0.5μg,较HPLC示差折光检测器提高约10倍,分析时效比提高6倍以上,精密度同板RSD2%～3%,异板RSD2.3%～3.7%,回收率95.3%～98.8%。     

银杏叶提取物及银杏内酯B对体外培养大鼠神经元损伤的保护作用比较

目的:经预处理给药模式观察了银杏叶提取物(extract ofGinkgo biloba,EGb761)及其单体银杏内酯B(ginkgol-ide B,GB)对神经元损伤的影响,以探讨EGb761及GB在抗兴奋毒性神经损害中的应用价值与实施途径。方法:原代培养新生Sprague-Dawley(SD)大鼠的海马神经元,建立谷氨酸诱导的兴奋毒性模型。采用台盼蓝染色、凋亡神经元测定及乳酸脱氢酶(LDH)测定的方法观察不同剂量EGb761,GB的神经保护作用,并与NMDA(N-甲基-D-天门冬氨酸盐)受体非竞争性拮抗剂MK801的神经保护作用相比较。结果:EGb761,GB在不同剂量下均能不同程度的提高细胞存活率,降低凋亡率,减少LDH泄露,且在一定范围内保护作用呈剂量依赖的方式。EGb761,GB分别在100 mg.L-1,100μmol.L-1的剂量下有最佳的保护效果,但均弱于MK-801(10μmol.L-1),GB最佳剂量下保护效果优于EGb761。结论EGb761,GB对谷氨酸兴奋毒性损害有保护作用。在预处理给药模式的最佳剂量下,GB的保护效果优于EGb761,将其用于高危人群的预防干预可能有更大价值。     

银杏叶提取物对星形胶质细胞诱导型一氧化氮合酶基因表达的调控

 目的研究银杏叶提取物(EGh761)对星形胶质细胞合成一氧化氮(NO)的作用以及对共培养的小脑颗粒神经元的作用。方法以脂多糖(LPS)和IFN-γ诱导体外培养的大鼠星形胶质细胞表达诱导型一氧化氮合酶(iNOS),产生NO作为病理条件下胶质细胞过度活化的实验模型,应用逆转录基因扩增技术和蛋白质印迹技术检测EGb761对星形胶质细胞中iNOS基因表达的影响,并探讨这一调控作用的分子机制。结果EGb761能明显降低星形胶质细胞中iNOS mRNA和蛋白质的表达、减少NO 的生成、防止活化的胶质细胞损伤共培养神经元,抑制IκB-α的降解和阻止p65/RelA进入细胞核,提示EGb761对iNOS基因表达的抑制作用依赖于NF-κB信号通路。结论EGb761可能对与胶质细胞过度活化有关的神经系统疾病具有治疗、预防的作用。     

不同树龄银杏叶在不同季节中总黄酮和总内酯的含量变化

目的：确定银杏叶最适宜采收季节。方法：采用HPLC法（二级管阵列检测器DAD和蒸发光散射检测器ELSD）分别测定银杏叶中总黄酮和总内酯的含量。结果：不同树龄,不同季节的银杏叶总黄酮、总内酯含量不同,结论：银杏叶的总黄酮、总内酯以二、三年生的为高,总黄酮在5月份,总内酯在9月份含量为高。     

Effect of Ginkgo Biloba Extract on Lipopolysaccharide‐induced Anhedonic Depressive‐like Behavior in Male Rats

The peripheral administration of lipopolysaccharide (LPS) induces depressive‐like behavior. Anhedonia is a core symptom of depression, defined as a loss of the capacity to experience pleasure. The present study used the sucrose preference test to investigate the influence of Ginkgo biloba extract (EGb 761) on LPS‐induced anhedonia in male rats. The animals were randomly divided into four groups: (I) vehicle + saline, (II) vehicle + LPS, (III) EGb 761 + saline, and (IV) EGb 761 + LPS. Saline or LPS (100 µg/kg) was administered intraperitoneally 2 h before the sucrose preference test. Sucrose consumption was recorded 2, 4, 6, 13, and 24 h after 100 µg/kg of LPS or saline injection in the dark phase of the light/dark cycle. Dopamine and serotonin levels in the nucleus accumbens were measured. Our results indicated that the vehicle + LPS group exhibited a significant decrease in sucrose intake compared with the vehicle + saline group. The EGb 761 + LPS group showed more sucrose and food consumption than the vehicle + LPS group. Additionally, compared with the EGb 761 + LPS group, the vehicle + LPS group had less dopamine levels in the nucleus accumbens. Treatment with EGb 761 had no effect on water intake. Our results suggest that EGb 761 may be useful for reducing anhedonic depressive‐like behavior. Copyright © 2015 John Wiley & Sons, Ltd.     

Effects of Ginkgo Biloba Extract EGb‐761 on Neuropathic Pain in Mice: Involvement of Opioid System

Neuropathic pain is considered as one of the most difficult types of pain to manage with conventional analgesics. EGb‐761 is extracted from leaves of Ginkgo biloba and has analgesia and anti‐inflammatory properties. This study aimed to examine the effect of EGb‐761 on chronic constriction injury (CCI)‐induced neuropathic pain behaviors, including thermal hyperalgesia and mechanical allodynia, and to explore the possible mechanisms underlying this action. To this end, CCI mice were intraperitoneally injected with EGb‐761 (10, 20, 40, and 80 mg/kg), and thermal hyperalgesia, mechanical allodynia, cytokines, and mu‐opioid receptor expression were measured. Results showed that EGb‐761 attenuated thermal hyperalgesia and mechanical allodynia dose‐dependently and the best delivery time window was from day 7 to day 14 after CCI. Additionally, EGb‐761 treatment significantly decreased pro‐inflammatory cytokines and enhanced mu opioid receptor (MOR) expression in the sciatic nerve. Moreover, the opioid antagonist naloxone prevented the effect of EGb‐761 on thermal hyperalgesia and mechanical allodynia but did not influence the effect of EGb‐761 on inflammatory cytokines. In conclusion, this study suggests that the potential of EGb‐761 as a new analgesic for neuropathic pain treatment, and opioid system may be involved in the EGb‐761‐induced attenuation of thermal hyperalgesia and mechanical allodynia. Copyright © 2016 John Wiley & Sons, Ltd.     

银杏叶制剂中银杏酚酸研究进展

银杏叶具有很高药用价值,银杏叶提取物(GBE)中的黄酮醇苷与萜类内酯分别具有抗氧化、抗血小板聚集及改善记忆、增强免疫等药理作用。但银杏叶中含有的银杏酸(GA)有强致敏性及细胞毒性,即使在制剂中微量残留也能引起严重的不良反应。为减少银杏类制剂用药安全隐患,该研究从GA的化学结构,不良反应与毒性及发生机制,GA脱除与减毒等进行综述,期望为提高银杏叶制剂的安全性研究提供新思路。     

f_2相似因子法评价银杏酮酯缓释微丸大类成分总黄酮和各类成分的体外释放相关性研究

目的引入f_2相似因子法对银杏酮酯(GBE)缓释微丸的大类成分总黄酮和各类成分(包括黄酮类和萜内酯类)的释放曲线进行分析,以能较全面地评价其体外释放。方法运用紫外分光光度法、高效液相-质谱联用(HPLC-MS)测定GBE缓释微丸中大类成分(总黄酮)和各类成分(槲皮苷、异鼠李素、芦丁、槲皮素、银杏内酯A、银杏内酯B、银杏内酯C、白果内酯)的体外释放率,并进行f_2相似因子计算;采用扫描电镜法观察微丸释药前后的微观结构,结合方程拟合分别对微丸中总黄酮和各类成分的释药机制解析,以验证f_2相似因子法的可靠性。结果优化工艺的GBE微丸黄酮类和内酯类的各成分与大类成分总黄酮的f_2均大于50,说明大类成分总黄酮与各类成分体外释放曲线具有较好的相关性。释药机制解析进一步验证了该结果的可靠性。结论 f_2相似因子法可运用于多组分中药缓释制剂大类成分和各类成分的体外释放评价。     

Protective Effect and Potential Mechanism of Ginkgo biloba Extract EGb 761 on STZ‐induced Neuropathic Pain in Rats

Diabetes induced neuropathic pain is recognized as one of the most difficult types of pain to treat with conventional analgaesics. EGb 761 is a standardized extract of Ginkgo biloba that has analgaesic and antiinflammatory properties and modulatory effects on key pain‐related molecules. We examined the effect of EGb 761 on streptozotocin (STZ)‐induced neuropathic pain behaviours and assessed its mechanism of action. Streptozotocin (20 mg/kg i.p for 5 days) was administered to induce experimental diabetes. Pain hypersensitivity to radiant heat was measured using the Dynamic Plantar Aesthesiometer to test the pain threshold. Diabetic rats exhibited mechanical allodynia and thermal hyperanalgaesia after the third week of STZ injection and concomitantly increased thiobarbituric acid reactive substance and nitric oxide concentration. The antioxidant enzymes level of superoxide dismutase and catalase was markedly reduced in STZ‐diabetic rats (p < 0.05). Systemic administration of EGb 761 (25, 50 and 100 mg/kg), starting after the third week following STZ injection, dose‐dependently reversed STZ‐induced thermal hyperanalgaesia and mechanical allodynia. Moreover, it reduced oxidonitrosative stress and concomitantly restored the level of antioxidant enzymes (p < 0.05) as compared with untreated diabetic rats. These results suggest that EGb 761 attenuated STZ‐induced neuropathic pain behaviours by inhibiting oxidative and nitrosative stress and may constitute a new approach for treatment of painful diabetic neuropathy. Copyright © 2012 John Wiley & Sons, Ltd.     

The effects of Ginkgo biloba on metabolic syndrome: A review

The Ginkgo biloba (G. biloba), commonly known as ginkgo, brings considerable benefit to common medicine, including weight loss effects, as well as antidiabetic, antihypertensive, and antilipidemic properties that could be effective in the treatment of Metabolic syndrome (MetS ) associated with increased risk of cardiovascular disease events. Major compounds of G. biloba are terpene lactones (bilobalide and ginkgolides A, B, and C) and flavone glycosides (isorhamnetin, quercetin, and kaempferol). We evaluated the most relevant original articles to indicate the effects of G. biloba on different components of MetS, including obesity, high blood pressure, dyslipidemia, and hyperglycemia. Several electronic databases (Scopus, PubMed, Web of Science and Google Scholar) were searched and the articles that included Ginkgo's effect on one or more of the criteria for MetS were selected. This review indicated that G. biloba might be efficient in the improvement of MetS; however, more studies especially clinical trials are needed to evaluate safety and efficacy of G. biloba.     

LC-MS/MS快速测定不同采摘时间银杏叶中银杏内酯和白果内酯的含量

 目的建立银杏叶中银杏内酯和白果内酯的高效液相电喷雾二级质谱(LC-MS/MS)定量分析方法,并对不同采摘时间银杏叶中银杏内酯和白果内酯含量进行测定。方法银杏叶样品以甲醇-水(1:9)提取,并用乙酸乙酯萃取,采用Phenomenex ODS柱分离,流动相为甲醇-水(60:40),流速0.7 mL·min^-1。电离方式为电喷雾正离子,采用多反应检测模式(MRM),捡测离子分别为m/z 409.4→345.3(银杏内酯A)、m/z 425.3→361.3(银杏内酯B)、m/z 441.4→325.3(银杏内酯C)和m/z 327.4→309.3(白果内酯)。结果分析过程仅需8.5 min,且无杂质干扰,4种成分回收率为91.79%～101.48%银杏内酯A,B和白果内酯含量分别在7月18日、8月19日和7月5日采摘的样品达到最高。结论方法快速、准确、选择性好,适合银杏内酯和白果内酯的定量分析,七月份叶子中内酯含量最高,为最佳采摘时间。