Clinical Use and Molecular Mechanisms of Action of Extract of Ginkgo biloba Leaves in Cardiovascular Diseases

Ginkgo biloba is one of the oldest living tree species that has been referred to as a living fossil. Extract from Ginkgo biloba leaves (GBE) is among the most commonly used herbal drugs and is popularized for its alleged tonic effect and possible curative and restorative properties. There is an increasing evidence of the potential role of GBE in treating cardiovascular diseases. We examined the history of GBE usage and reviewed the literature on its effects on the cardiovascular system. In the extensive studies involving cell cultures and animal models, GBE has been shown to exert its action through diverse mechanisms. GBE has been reported to have antioxidatant properties, to modify vasomotor function, to reduce adhesion of blood cells to endothelium, to inhibit activation of platelets and smooth muscle cells, to affect ion channels, and to alter signal transduction. In addition, relevant clinical trials with CBE are being carried out, particularly in the treatment of arterial and venous insufficiency and in the prevention of thrombosis. Finally, the controversial clinical findings and the possible adverse interactions between GBE and other drugs are discussed. This review underscores the potential benefits of Ginkgo biloba in cardiovascular diseases, highlights the gaps in our current research, and suggests the necessity for more rigorous systematic investigation of cardiovascular properties of CBE.     

白果内酯对脓毒症急性肺损伤大鼠TLR4/NFκB信号通路及Th1/Th2细胞的影响

【摘要】目的 探讨白果内酯（BB）对脓毒症致急性肺损伤（ALI）大鼠Toll样受体-4(TLR4)/核因子-κB(NF-κB)信号通路及辅助性T细胞1/2（Th1/Th2）的影响。方法 50只SD大鼠随机分为假手术组（Sham组）、模型组(ALI组)、BB低（2.5 mg/kg）剂量组、BB高（10 mg/kg）剂量组、地塞米松阳性对照组（0.45 mg/kg）,每组各10只,除Sham组外,其余各组采用盲肠结扎穿孔法复制脓毒症ALI模型,术后6 h各药物组经尾静脉注射相应剂量药物,Sham组、ALI组经尾静脉注射生理盐水,均3次/d,共3 d。末次给药1 h后处死大鼠,取肺组织,以苏木精-伊红染色（HE）检测各组大鼠肺组织病理变化;以酶联免疫吸附（ELISA）试剂盒检测大鼠肺组织氧化物酶(MPO)活性、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平;凝胶电泳迁移率转变分析（EMSA）法检测肺组织 NF-κB 活性;以蛋白免疫印迹法检测肺组织中TLR4通路蛋白表达;采用流式细胞仪(FACS）检测肺脏细胞中辅助性T细胞1/2(Th1/Th2)比值。结果 与Sham组相比,ALI组大鼠肺组织可见水肿、炎性细胞浸润等病理损伤,肺组织MPO、IL-6、TNF-α含量、TLR4蛋白表达、NF-κB活性均明显升高（P＜0.05）,Th1/Th2、TNF-α/IL-6均明显降低（P＜0.05）。与ALI组相比,BB低、高剂量组及地塞米松阳性组肺组织水肿、炎性细胞浸润等病理损伤减轻,肺组织MPO、IL-6、TNF-α含量、TLR4蛋白表达、NF-κB活性均明显降低（P＜0.05）,Th1/Th2、TNF-α/IL-6均明显升高（P＜0.05）。与BB低剂量组相比,BB高剂量组及地塞米松阳性组肺组织水肿、炎性细胞浸润等病理损伤减轻,MPO、IL-6、TNF-α含量、TLR4蛋白表达、NF-κB活性均明显降低（P＜0.05）,Th1/Th2、TNF-α/IL-6均明显升高（P＜0.05）。结论 BB可抑制TLR4/NF-κB信号通路活化,调节Th1/Th2平衡,减轻炎性介质释放,改善脓毒症ALI大鼠肺组织损伤。     

Ginkgolide A contributes to the potentiation of acetaminophen toxicity by Ginkgo biloba extract in primary cultures of rat hepatocytes

The present cell culture study investigated the effect of Ginkgo biloba extract pretreatment on acetaminophen toxicity and assessed the role of ginkgolide A and cytochrome P450 3A (CYP3A) in hepatocytes isolated from adult male Long-Evans rats provided ad libitum with a standard diet. Acetaminophen (7.5-25 mM for 24 h) conferred hepatocyte toxicity, as determined by the lactate dehydrogenase (LDH) assay. G. biloba extract alone increased LDH leakage in hepatocytes at concentrations > or =75 mug/ml and > or =750 mug/ml after a 72 h and 24 h treatment period, respectively. G. biloba extract (25 or 50 mug/ml once every 24 h for 72 h) potentiated LDH leakage by acetaminophen (10 mM for 24 h; added at 48 h after initiation of extract pretreatment). The effect was confirmed by a decrease in [(14)C]-leucine incorporation. At the level present in a modulating concentration (50 mug/ml) of the extract, ginkgolide A (0.55 mug/ml), which increased CYP3A23 mRNA levels and CYP3A-mediated enzyme activity, accounted for part but not all of the potentiating effect of the extract on acetaminophen toxicity. This occurred as a result of CYP3A induction by ginkgolide A because triacetyloleandomycin (TAO), a specific inhibitor of CYP3A catalytic activity, completely blocked the effect of ginkgolide A. Ginkgolide B, ginkgolide C, ginkgolide J, quercetin, kaempferol, isorhamnetin, and isorhamnetin-3-O-rutinoside did not alter the extent of LDH leakage by acetaminophen. In summary, G. biloba pretreatment potentiated acetaminophen toxicity in cultured rat hepatocytes and ginkgolide A contributed to this novel effect of the extract by inducing CYP3A.     

Analysis of ginkgolides and bilobalide in food products using LC-APCI-MS

A method was developed for the extraction and quantification of five marker compounds characteristic of Ginkgo biloba. Five ginkgo terpene trilactones: bilobalide and ginkgolides A, B, C, and J, were selected as marker compounds for this study. Initial studies produced a simple methanol extraction method for determination of gingko markers in solid dietary supplements. Five dietary supplements were analyzed and the results were later compared to the concentrations detected in the analysis of beverages. Beverage samples were prepared by extracting the ginkgo terpene trilactones using an optimized solid phase extraction (SPE) method. The extracts were analyzed using LC–atmospheric pressure chemical ionization (APCI)–MS in the negative ionization mode. The limits of detection of the extraction method ranged from 6.8 to 3.2 ng mL⁻¹. Using the optimized method, 14 drinks and 3 tea products were analyzed. Concentrations of total marker compounds in drinks ranged between 1685 and 21.4 ng mL⁻¹ with individual ginkgo terpene trilactones being detected at ppb concentrations. Analysis of brewed tea products presented much higher total marker compound concentrations ranging from 8.12 and 16.6 μg mL⁻¹. Analytical results reproducibility data, and recovery of the SPE method are presented.     

白果内酯调控LEF1-AS1/miR-23b-3p分子轴缓解肺炎链球菌诱导的肺泡上皮细胞损伤

目的探讨白果内酯对肺炎链球菌诱导的肺泡上皮细胞损伤的保护作用及其对lncRNA LEF1-AS1/miR-23b-3p分子轴的调控作用。方法用肺炎链球菌诱导肺泡上皮细胞建立细胞损伤模型(感染组);分别转染si-NC、si-LEF1-AS1后,用肺炎链球菌感染细胞(感染+si-NC组和感染+si-LEF1-AS1组);pcDNA、pcDNA-LEF1-AS1分别转染至肺泡上皮细胞后用白果内酯与肺炎链球菌共同处理细胞(感染+白果内酯+pcDNA组和感染+白果内酯+pcDNA-LEF1-AS1组)。ELISA法检测TNF-α、IL-1β、IL-6的水平;流式细胞术检测细胞凋亡率;q RT-PCR法检测LEF1-AS1、miR-23b-3p的表达量;双荧光素酶报告基因实验检测LEF1-AS1与miR-23b-3p的靶向关系;Western blot检测Bcl-2、Bax蛋白表达量。结果白果内酯能够降低肺炎链球菌诱导的肺泡上皮细胞中TNF-α、IL-1β、IL-6的水平和LEF1-AS1的表达量(P<0.05),并可降低凋亡率和Bax蛋白水平(P<0.05),还可促进miR-23b-...     

白果内酯在鱼藤酮处理的PC12细胞中抑制α-共核蛋白蛋白寡聚体形成的实验研究

目的研究白果内酯对鱼藤酮诱导的帕金森病细胞模型是否具有保护作用,对α-共核蛋白（α-synuclein）的表达及聚集是否有影响。方法使用鱼藤酮对嗜铬细胞瘤株PCl2细胞进行处理,建立叶synuclein蛋白高表达的帕金森病细胞模型,白果内酯进行干预,采用四甲基偶氮唑盐法（MTT法）检测细胞活性,流式细胞术检测细胞凋亡,Western blotting法检测α-synuclein蛋白的表达。数据以均数±标准差（面±5）表示,应用SPSS16．0统计软件,多组间比较采用单因素方差分析,两组间独立样本的比较采用LSD—t检验,P〈0．05认为差异有统计学意义。结果1．6μmoL／L鱼藤酮组细胞活性显著低于对照组（t=17．422,P〈0．01）,细胞凋亡率和α--synuclein蛋白量高于对照组（t=9．141,t=8．392;P均〈0．01）;10μmol／L及50／μmol／L白果内酯组细胞活性均高于鱼藤酮组（t=4．257,t=6．501;P均〈0．01）,且高剂量者细胞活性更优（t=2．933,P=0．043）;10μmol／L及50μmoL／L白果内酯组细胞凋亡率较鱼藤酮组低（t=4．482,t=4．488,P均〈0．01）,α-synuclein蛋白的表达量低于鱼藤酮组（t=8．349,t：9．028,P均〈0．01）,但两剂量间二者均无统计学差异（￡=0．831,P=0．45;t=2．178,P=0．095）;实验中所显影的α-synuclein蛋白分子量在57kD左右。结论白果内酯对鱼藤酮诱导的PCI2细胞损伤有保护作用,该保护作用可能通过抑制仅,synuclein蛋白寡聚物的形成来实现。     

HPLC-ELSD法测定银杏叶分散片中萜内酯的含量

目的建立银杏叶分散片中萜内酯的含量测定方法。方法采用蒸发光散射检测器,以ODS柱（150mm×4．6mm）为色谱柱,以正丙醇-四氢呋喃-水（1：15：84）为流动相。结果白果内酯在7．848～39．24μg、银杏内酯A在3．8～19．0μg、银杏内酯B在7．08-35．40μg、银杏内酯C在3．768～18．840μg范围内进样量的对数与峰面积的对数线性关系较好,平均回收率依次分别为98．39％（RSD=0．31％）、98．41％（RSD=0．20％）、97．07％（RSD=0．48％）、98．39％（RSD=1．61％）。结论本法准确,重现性好,适用于银杏叶分散片中萜内酯的含量测定。     

白果内酯对大鼠心肌抗氧化机制的初步研究

目的 研究白果内酯的心肌的保护作用。方法 于2018年3月~12月选取30只健康SD大鼠,随机分为标准组、盐水组、白果内酯高、中、低剂量组,各6只。高、中、低剂量组大鼠分别以不同药物剂量灌胃,盐水组给生理盐水2 ml,标准组不做任何处理,连续给药1周后,取大鼠心肌组织,制作匀浆,测定各组心肌组织中超氧化物歧化酶（SOD）、丙二醛（MDA）、肌酸激酶（CK）、乳酸脱氢酶（LDH）的含量。结果 盐水组与标准组SOD、MDA、CK、LDH含量比较,差异无统计学意义（P＞0.05）;低剂量组SOD与标准组无统计学差异,中、高剂量组SOD高于标准组;高、中、低剂量组MDA低于标准组,CK和LDH均高于标准组,差异有统计学意义（P＜0.05）。结论 白果内酯可以增强心肌组织抗氧化作用,避免细胞膜的破坏,抑制有害物质释放入血,最终达到心肌保护的目的。     

高效液相色谱法测定银杏叶胶囊中银杏内酯的含量

目的：应用HPLC-ELSD法测定银杏叶胶囊中银杏内酯A、B、C及白果内酯的含量。方法：采用C18色谱柱（Kromasil,4.6×250mm,5μm）,以甲醇-水为流动相梯度洗脱,ELSD雾化温度为50℃,载气N2流速为1.2L/Min。结果：测得银杏内酯A、B、C及白果内酯分别在2.18μg-16.35μg、2.10μg-15.60μg、0.59μg-8.85μg、0.73μg-9.90μg线性关系良好;银杏内酯A、B、C及白果内酯的平均回收率分别为97.28%、97.68%、98.34%、99.52%。结论：该方法简单、准确可靠,分离效果好;本方法可用于银杏叶胶囊的质量评价。     

白果内酯激活 Nrf2/HO-1 通路抑制星形胶质细胞的氧化应激缓解 CPZ 诱导的髓鞘脱失

目的:探讨白果内酯(BB)是否可以减轻星形胶质细胞的氧化应激反应抑制髓鞘脱失及其可能的机制。方法:体内采用双环己酮草酰二腙(CPZ)脱髓鞘C57BL/6小鼠模型,从第4周末开始,BB治疗组腹腔注射BB 2周。体外采用脂多糖(LPS)刺激原代星形胶质细胞24 h的炎症模型。结果:BB在体内抑制CPZ诱导的氧化应激反应,促进Nrf2和HO-1的表达,抑制髓鞘脱失。BB在体外抑制星形胶质细胞氧化应激反应,并可促进星形胶质细胞Nrf2/HO-1蛋白表达。结论:BB可能通过Nrf2/HO-1信号通路,抑制星形胶质细胞氧化应激,缓解髓鞘脱失。