Protective effects of ginkgo biloba leaves extract on peroxide-induced oxidative stress damage in PC12 cells

BACKGROUND： Extracts of ginkgo biloba leaves （EGB） and its metabolites have been reported to enhance brain function and nerve behavior. It has also been hypothesized that they can protect neurons from oxidative stress. OBJECTIVE： To investigate protective effects of EGB on peroxide （H2O2）-induced oxidative stress damage in PC12 cells. DESIGN： Observational contrast study. SETTING： Department ofPathophysiology, Guangdong Pharmacological College. MATERIALS： EGB was provided by Xi＇an Fujie Biotechnological Development Company; 1640 culture medium, methylthiazolyl tetrazolium （MTT）, trypsin and dimathyl sulfoxide （DMSO） by Sigma Company; PC12 cell strain by Cell Center of Medical College of Zhongshan University; calf serum by Hangzhou Sijiqing Bioengineering Company; lactate dehydrogenase （LDH） kit by Nanjing Jiancheng Bioengineering Research Institute. METHODS： The experiment was carried out in Department of Cell Biology of Guangdong Pharmacological College from June to December 2005. ①Cell culture： PC12 cells were cultured in 1640 medium containing 200 g/L fetal calf serum. The cells were diluted to 1 × 10^7 L^-1 and washed every two days. Those cells were used to experiment until they grew in logarithm on solid wall. ② Grouping and intervention： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates with the density of 200 μ L/hole and divided into three groups： normal control group （routinely adding media）, H2O2 group （treating with media and H2O2 for 20 hours） and EGB group （adding media, 100μmol/L EGB and 100 μmol/L H2O2）. ③ MTT assay： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates and divided into three groups with 8 holes for each group. Under sterile condition, cells were added with 5 g/L MTT （100μL） and cultured for 4 hours. And then, 200 μ L DMSO fluid was added and shaken for 30 minutes until blue crystal products formed were dissolved soundly ④ Experimental evaluation： Absorbance （A） at 630 nm was measured and LDH activity was measured at the same time. MAIN OUTCOME MEASURES： Results of MTT assay and LDH activity. RESULTS： ① Results of MTT assay： A value was lower in the H2O2 group than that in the normal control group （P 〈 0.01）, while A value was higher in the EGB group than that in the H2O2 group （P 〈 0.01）. ② LDH activity： LDH activity was higher in the H2O2 group than that in the normal control group （P 〈 0.01 ）, while LDH activity was lower in the EGB group than that in the H2O2 group （P 〈 0.01）. CONCLUSION： EGB can inhibit H2O2-induced oxidative stress damage in PC12 cells possibly by preventing damage to the cell membrane.

The Effects of Standardized Ginkgo Biloba Extracts (GBE) on Subjective Cognitive Decline (SCD) in Middle-Aged Adults: A Review

Subjective cognitive decline (SCD) is defined as the presence of self-reported cognitive complaints with unimpaired performance in neuropsychological cognitive tests. SCD has been identified as a precursor of mild cognitive impairment (MCI) and potentially represents the earliest clinical sign of Alzheimer’s disease (AD). Standardized extracts of Ginkgo biloba (GBE) are widely used as a treatment for cognitive impairment. Nonetheless, most of the available review articles focus on the effects of GBE in MCI and dementia but not in SCD and its specific cognitive effects. Thus, this review collects and discusses the available published clinical data for the effects of standardized GBE on the early stages of cognitive decline among an age group where SCD becomes a topic—the middle-aged adults. Randomized clinical trials (RCTs), systematic reviews and meta-analyses of standardized GBEs in cognitive decline subjects were searched using PubMed/MEDLINE, Science direct, Cochrane, and Google Scholar until January 2019. Data from relevant RCT were critically evaluated to determine the potential effects of GBE on SCD. The results showed that the number of available GBE studies on SCD is small. Eight studies were selected in which subjects reported memory impairment, in some cases with concerns (worries), and with an average age at onset SCD of 60 years. Six studies gave a proof of efficacy for GBE for the treatment of SCD in at least one cognitive parameter. One study is inconclusive, however, a post-hoc analysis demonstrates efficacy in preventing AD with intake >4 years. The most common GBE dosage used was 240 mg GBE/day over a minimum period of 8 weeks. Hence, there might be beneficial effects of GBE to prevent, improve or delay SCD in the generation of 50 years or older. However, larger, well-defined RCTs using SCD criteria are necessary to further substantiate this effect in SCD subjects.

Ginkgo biloba Extract EGb 761® Improves Central Vestibular Vertigo in Patients Undergoing Vestibular Exercises: A Randomised Placebo-Controlled Trial

Background: Ginkgo biloba extract EGb 761® is widely used to treat various types of vertigo. Aims: An exploratory trial was conducted to evaluate the efficacy of EGb 761® in addition to vestibular exercises in central vestibular vertigo caused by vertebro-basilar ischaemia. Subjects and Methods: In this randomised, placebo-controlled, double-blind trial, 40 patients were enrolled in the vertigo clinic of a neurological university hospital and treated with daily doses of 240 mg EGb 761® or placebo for a period of 180 days. All patients regularly performed vestibular exercises in addition. Efficacy was assessed using: a visual analogue scale for the patients to rate the overall intensity of vertigo;a numeric scale for physician-rated change;a vertigo score based on intensity, duration, and frequency of vertigo;and electronystagmography. Results: Until day 180, the mean patient-rated intensity of vertigo decreased by 46% during EGb 761® treatment and by 19% with placebo (p ® group compared to the placebo group. Nystagmus or other eye movement disorders were present only in small subgroups of patients without sufficient statistical power to detect differences between treatment groups. Conclusions: EGb 761® alleviated vertigo caused by ischaemic lesions in the brainstem or cerebellum in patients undergoing vestibular exercises.

A ginkgo biloba extract promotes proliferation of endogenous neural stem cells in vascular dementia rats

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.

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.

银杏叶浸膏(EGB)浸取溶剂与浸取工艺的改进

目的 :改进银杏叶浸膏 (EGB)浸取溶剂与提取工艺 ,以提高有效成分的含量与得率。方法 :通过分析几种典型的黄酮甙与内酯在常用溶剂中的溶解度 ,在乙醇 水体系中 ,加入 10 %对内酯有较高溶解度的溶剂 ,形成新的溶剂体系EPW。针对黄酮甙中的酚羟基易被氧化而使黄酮含量降低的特点 ,采用氮气保护提取工艺以避免提取过程中黄酮被氧化。结果 :采用EPW为溶剂并用氮气保护提取 ,可使EGB得率提高 4 2 % ,黄酮含量提高 2 2 % ,内酯含量提高 3 3 %。结论

银杏叶提取物EGb761对MPP^+诱导的人脑神经瘤母细胞SH-SY5Y细胞损伤的影响

目的观察银杏叶提取物EGb761对人脑神经瘤母细胞SH-SY5Y细胞损伤的影响,探讨其作用机制。方法采用细胞培养方法,建立SH-SY5Y细胞1-甲基-4-苯基吡啶离子(MPP^+)损伤帕金森病体外模型。实验分为对照组、模型组和中药低、中、高剂量组,各给药组给予相应剂量药物。MTT法测定细胞存活率,Annexin V凋亡检测试剂盒和流式细胞仪测定细胞凋亡率;倒置显微镜观察细胞形态;硝酸还原法检测SH-SY5Y细胞一氧化氮(NO)的含量。结果与对照组比较,模型组SH-SY5Y细胞存活率降低、细胞凋亡率增加和NO含量升高(P<0.05);与模型组比较,中药中、高剂量组SH-SY5Y细胞存活率增加、细胞凋亡率降低,NO含量降低(P<0.05)。结论银杏叶提取物EGb761可以通过抑制细胞内NO自由基的含量对MPP^+诱导的SH-SY5Y细胞损伤起到保护作用。

银杏叶提取物EGb761对TNF-α诱导HeLa细胞凋亡的影响

目的 初步研究银杏叶提取物EGb761对重组人肿瘤坏死因子- α(rhTNF- α)诱导HeLa细胞凋亡的影响。方法 采用MTT法观察EGb761对HeLa细胞生长的影响;细胞凋亡实验分5组,即空白对照组,rhTNF -α对照组(10 0 μg/L ) ,EGb761低浓度组[rhTNF- α(10 0 μg/L) +EGb761(10mg/L) ] ,EGb761中浓度组[rhTNF -α(10 0 μg/L ) +EGb761(2 0mg/L ) ] ,EGb761高浓度组[rhTNF -α(10 0 μg/L) +EGb761(4 0mg/L) ] ,采用流式细胞术和Hoechst3 3 2 5 8荧光染色检测凋亡。结果 EGb761在5 .0～80 .0mg/L终浓度范围内对HeLa细胞生长无明显影响;流式细胞术测定各组亚倍体细胞峰积分百分率(% )为:空白对照组(5 .3 5±2 .2 ) ,rhTNF- α对照组(3 7.8±6.1) ,EGb761低浓度组(19.2±3 .4) ,EGb761中浓度组(16.5±5 .7)和EGb761高浓度组(11.3±3 .9) ;荧光染色检测各组凋亡百分率(% ) :对照组(4 .2 3±2 .0 )、rhTNF α对照组(2 7.8±4.3 )、EGb761低浓度组(14 .9±3 .4)、EGb761中浓度组(12 .1±3 .7)和EGb761高浓度组(9.61±2 .3 ) ;结果显示,EGb761在10～40mg/L终浓度范围内对rhTNF α诱导的HeLa细胞凋亡均有显著的抑制作用(P <0 .0 1) ,且呈剂量依赖关系。结论 EGb761能有效抑制rhTNF- α诱导的HeLa细胞凋亡。

银杏叶提取物EGb-761对乳腺癌肺转移型小鼠体内实体瘤的影响

目的:探讨银杏叶提取物EGb-761对乳腺癌肺转移型小鼠体内实体瘤的影响。方法:选取雌性BALB/c小鼠,使用小鼠乳腺癌4T1细胞系建立高转移性的肿瘤小鼠模型,随机分为五组,即正常组、模型组、EGb-761组[高剂量组(200 mg/kg)、中剂量组(100 mg/kg)、低剂量组(50 mg/kg)]。观察并测量各组小鼠原位灶实体瘤体积和小鼠体质量;观察并计算各组小鼠肺部转移灶结节数、转移率;采用RT-PCR法检测各组小鼠特异性标志物角蛋白-19(CK-19)mRNA表达。结果:随着EGb-761剂量的增加,小鼠原位灶实体瘤体积越来越小,而小鼠体质量越来越重(P<0.05);随着EGb-761剂量的增加,肺部结节数随之减少(P<0.05),肺部转移率随之降低(P<0.05);随着EGb-761剂量的增加,肺组织CK-19 mRNA表达量越低(P<0.05)。结论:银杏叶提取物(EGb-761)对乳腺癌肺转移型小鼠体内的实体瘤生长有抑制作用。

丁苯酞联合银杏叶提取物对急性缺血性脑卒中患者血流动力学及血清神经营养因子的影响分析

目的:探讨丁苯酞联合银杏叶提取物对急性缺血性脑卒中(AIS)患者血流动力学及血清神经营养因子的影响。方法:选取2020年1月~2022年4月期间某院收治的147例AIS患者作为研究对象,采用随机数字表法分为银杏叶组、丁苯酞组、联合组,每组49例。3组患者均给予阿司匹林肠溶片等常规治疗,银杏叶组在常规治疗基础上加用银杏叶提取物注射液,丁苯酞组在常规治疗基础上加用丁苯酞氯化钠注射液,联合组在银杏叶组基础上加用丁苯酞氯化钠注射液。比较3组患者美国国立卫生研究院卒中量表(NIHSS)、巴塞尔指数(BI)、卒中患者专用生活质量量表(SS-QOL)评分、血流动力学指标(平均血流速度、动态阻力、外周阻力)、血清神经营养因子[胶质细胞源性神经营养因子(GDNF)、脑源性神经营养因子(BDNF)]、血清胶质纤维酸性蛋白(GFAP)、同型半胱氨酸(Hcy)、超敏C反应蛋白(hs-CRP)水平、临床疗效和不良反应发生情况。结果:治疗后,3组患者NIHSS评分均降低(P<0.05),且联合组更低(P<0.05);BI、SS-QOL评分均升高(P<0.05),且联合组更高(P<0.05);外周阻力、动态阻力均降低(P<0.05),且联合组更低(P<0.05);平均血流速度均升高(P<0.05),且联合组更高(P<0.05);血清GDNF、BDNF水平均升高(P<0.05),且联合组更高(P<0.05);血清GFAP、Hcy和hs-CRP水平均降低(P<0.05),且联合组更低(P<0.05);联合组患者临床治疗总有效率高于银杏叶组和丁苯酞组(χ^(2)=6.019,P=0.049);3组患者不良反应总发生率比较无统计学差异(χ^(2)=0.632,P=0.729)。结论:丁苯酞联合银杏叶提取物可有效恢复AIS患者的神经功能,提高生活质量,改善脑部血流动力学与血清神经营养因子水平,临床疗效较好,且不会增加不良反应发生率。

银杏叶提取物与盐酸倍他司汀联合治疗低频下降型突发性耳聋的有效性及安全性分析

目的观察银杏叶提取物与盐酸倍他司汀联合治疗低频下降型突发性耳聋的有效性及安全性。方法选取2022年2月—2024年2月九江市第一人民医院收治的100例低频下降型突发性耳聋患者为研究对象,按随机数字表法分为对照组和联合用药组,每组50例。对照组患者予盐酸倍他司汀注射液,联合用药组患者在对照组基础上予银杏叶提取物注射液。2组治疗时间均为10 d。比较2组治疗前、治疗10 d后不同频率(250、500、1000 Hz)纯音听阈、血液流变学指标[血小板黏附率(PAR)、血浆黏度(PV)和全血黏度(WBV)]、血管内皮功能指标[超氧化物歧化酶(SOD)、一氧化氮(NO)],并发症。结果治疗10 d后,2组250、500、1000 Hz下纯音听阈低于治疗前,且联合用药组低于对照组(P<0.01);2组PAR、PV、WBV低于治疗前,且联合用药组低于对照组(P<0.01);2组血清SOD水平高于治疗前,NO水平低于治疗前,且联合用药组高/低于对照组(P<0.01)。对照组与联合用药组并发症总发生率比较,差异无统计学意义(10.00%vs.8.00%,P=1.000)。结论银杏叶提取物与盐酸倍他司汀联合治疗低频下降型突发性耳聋患者的疗效确切,能有效改善患者不同频率纯音听阈及血液流变学,提高血管内皮功能,且安全性较高。

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。

银杏叶提取物注射液联合盐酸倍他司汀治疗脑动脉供血不足性眩晕患者的效果

目的:观察银杏叶提取物注射液联合盐酸倍他司汀治疗脑动脉供血不足性眩晕患者的效果。方法:选取2021年6月至2022年12月该院收治的68例脑动脉供血不足性眩晕患者进行前瞻性研究,按随机数字表法将其分为对照组和研究组各34例。对照组采用注射用盐酸倍他司汀治疗,观察组在对照组基础上联合银杏叶提取物注射液治疗。比较两组临床疗效,治疗前后眩晕程度[眩晕残障程度评定量表(DHI)]评分、血流动力学指标[左侧椎动脉(LVA)、右侧椎动脉(RVA)、基底动脉(BA)血流速度]水平,以及不良反应发生率。结果:研究组治疗总有效率为88.24%(30/34),高于对照组的55.88%(19/34),差异有统计学意义(P<0.05);治疗后,两组躯体、情绪、功能等DHI评分均低于治疗前,且研究组低于对照组,差异有统计学意义(P<0.05);两组LVA、RVA、BA血流速度均高于治疗前,且研究组高于对照组,差异有统计学意义(P<0.05);两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:银杏叶提取物注射液联合盐酸倍他司汀治疗脑动脉供血不足性眩晕患者可提高治疗总有效率和血流动力学指标水平,降低DHI评分,其效果优于单纯盐酸倍他司汀治疗。

超声法提取银杏叶黄酮的研究

研究了银杏叶黄酮的超声提取法,并与连续热回流中的索氏提取作了比较研究。实验表明:超声提取法优于索氏提取法。超声提取法的最佳操作条作为:超声波频率40KHZ, 处理时间10min,静置时间12h。

银杏叶提取物速释滴丸的研制

目的 :研究银杏叶提取物速释滴丸的处方和滴制工艺。方法 :分别以银杏总黄酮溶出百分量和丸重差异为评价指标 ,采用正交试验进行处方和工艺优化。结果 :优化结果表明 ,滴丸平均T50 为 3.6 2min ,平均丸重差异为2 .80 %。结论 :所研制的银杏叶提取物速释滴丸能明显提高有效成分的溶出速率 。

银杏叶提取物对柑橘青霉病菌的抑菌效果

研究银杏叶乙醇提取物(EGb)对储藏期柑橘青霉病菌的抑菌作用。采用95%乙醇提取银杏叶,用针刺伤柑橘后以青霉病菌菌液和EGb处理柑橘进行药效试验,测试EGb对柑橘青霉病菌的抑菌效果。结果表明,EGb对储藏期柑橘青霉病菌具有较强的抑菌作用,且随着EGb浓度的增大抑菌作用增强,随着储藏时间的延长,EGb的抑菌作用降低。

响应曲面法优化酶法提取银杏叶总黄酮

本文研究了酶法提取银杏叶总黄酮的工艺。在单因子试验结果的基础上,采用响应曲面法(responsesur-facemethodology,RSM)研究了酶浓度、pH值、酶解温度和酶解时间对银杏叶总黄酮提取得率的影响。结果表明,纤维素酶具有较好的酶解能力,当酶浓度为100U/ml,酶解时间为116min,温度为40℃,pH4.5时,总黄酮得率达到2.63%,相对单一醇提法得率提高了约30%。

银杏酮酯促进大鼠坐骨神经再生的实验研究

目的评价银杏酮酯(EGb50)对大鼠坐骨神经损伤后神经再生的影响。方法建立大鼠坐骨神经损伤模型,将雄性SD大鼠48只随机分为损伤对照组和银杏酮酯组。分别于术后2、4、6、8周用电生理学、组织学和功能测定评估坐骨神经再生和功能恢复情况。结果术后坐骨神经功能指数(SFI)、运动神经传导速度(MNCV)、小腿三头肌肌张力、小腿三头肌肌湿重的恢复率及有髓神经纤维通过率在各时间点上银杏酮酯组均优于对照组(P<0.01)。结论银杏酮酯可以促进损伤神经的再生,明显提高神经肌肉功能的恢复。

银杏叶黄色素提取及稳定性研究

为充分利用银杏资源,增加其经济附加值及为寻找新的天然食品着色剂提供依据,从提取剂选择、液料比、提取温度、时间等条件对银杏叶黄色素的提取工艺及色素的耐光、热、pH的稳定性进行研究。结果表明,该色素的石油醚溶液在可见区445nm处有最大吸收;适宜的提取工艺条件为:以乙酸乙酯对石油醚的体积分数为70%的混合溶剂、液料比25:1(mL/g)、提取温度40℃、提取时间30min,以此方法提取4次较为彻底;经初步纯化的得率为3.0%,色价20.49。稳定性研究结果表明,银杏叶黄色素对光不稳定,宜避光保存;该色素在60℃以下加热1h降解率较小,但在70℃加热1h降解率较大;该色素在弱酸和弱碱条件下较稳定。

银杏叶提取物改善反复脑缺血再灌注小鼠血液流变学的作用

目的 :研究银杏叶提取物 (EGB)改善反复脑缺血再灌注小鼠血液流变学的作用。方法 :采用反复脑缺血再灌注模型鼠 ,应用毛细管微量热沉法和毛细管微量法分别检测血纤维蛋白原 (Fib)含量和红细胞压积 (HCT)数值 ,并将结果输入全自动血液流变仪得出血浆粘度 ( ηp)、血液粘度 ( ηb)、血液还原粘度 ( ηh)、血细胞聚集系数 (VAL)、血栓形成系数 (TEL)及微循环滞留时间 (MST)。结果 :EGB 2 5～ 1 0 0mg/kg均可不同程度地降低Fib、HCT ,降低 ηb、ηp、ηh ,缩小VAL及TEL ,缩短MST。 结论 :EGB可明显降低反复脑缺血再灌注小鼠的血液粘度、促进血液循环 。