银杏叶提取物的胃粘膜保护作用(英文)

目的:研究银杏叶提取物的胃粘膜保护作用.方法:采用大鼠束缚-冷冻应激(RCS)模型和小鼠无水乙醇损伤模型观察GbE对胃粘膜损伤指数的影响;采用幽门结扎法收集胃液,观察GbE对胃液分泌量,胃液酸度和胃蛋白酶活性的影响;采用硫代巴比妥酸(TBA)法测定胃粘膜及血清中丙二醛(MDA)含量.结果:GbE(25,50,100 mg/kg,bid×5 d,ig)剂量依赖性地抑制RCS和无水乙醇引起的胃粘膜损伤.用药组应激后的胃粘膜损伤指数分别为对照组的58％,43％和31％;用药组乙醇诱发的胃粘膜损伤指数降至对照组的62％,36％和26％;GbE尚能增强西米替丁对胃粘膜的保护作用,但对大鼠胃液分泌量、胃液酸度及胃蛋白酶活性GbE并无明显影响.小鼠经无水乙醇ig后1 h,胃粘膜和血清中的MDA含量显著升高(P<0.01),而GbE(25,50,100 mg/kg,ig)预处理则可以明显抑制MDA的升高.结论:GbE具有胃粘膜保护作用,并且与西米替丁在治疗急性胃粘膜损伤方面具有协同作用.     

银杏叶提取物对沙土鼠脑缺血再灌注损伤的影响

目的 :研究银杏叶提取物对沙土鼠脑缺血再灌注损伤的影响。方法 :采用夹闭沙土鼠双侧颈总动脉 10min或 2 0min再灌注 5d或 1d ,造成沙土鼠前脑缺血再灌注损伤模型。 95只动物分为假手术组、缺血再灌注组、银杏叶提取物 (GbE) 50mg·kg 1组及GbE10 0mg·kg 1组。于缺血前 2d和再灌注期间ig给药 ,观察GbE对脑组织钙、钠、水含量和脂质过氧化物的影响 ,以及对海马CA1区神经元迟发性死亡的保护作用。结果 :GbE能降低沙土鼠缺血再灌注后大脑皮层含水量 ,减轻钙、钠积累 ,且具有剂量效应相关性 ;GbE10 0mg·kg 1能降低缺血再灌注 1d内动物的死亡数及脑组织丙二醛含量 ,增加脑缺血后海马CA1区神经元密度。结论 :GbE对脑缺血再灌注损伤有保护作用。     

Protective effects of Ginkgo biloba extract against lysophosphatidylcholine-induced vascular endothelial cell damage.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) against endothelial cell damage induced by lysophosphatidylcholine (LPC). METHODS: The vasorelaxation response to acetylcholine (ACh) were investigated in the isolated rabbit thoracic aorta. Lipid peroxidation products were determined by measuring thiobarbituric acid reactive substance. RESULTS: GbE attenuated the inhibition of vasorelaxation response to ACh and prevented the LPC-induced increase of malondialdehyde (MDA) content both in thoracic aortae. GbE prevented the leakage of LDH and the increase of MDA content in cultured endothelial cells in a concentration-dependent manner. GbE also markedly increased epoprostenol level in cultured endothelial cells treated with LPC. CONCLUSION: GbE protected endothelial cells against LPC-induced damage due to reduction in lipid peroxidation and facilitation of synthesis and/or release of epoprostenol.     

银杏叶提取成分及其单体对脑缺血的保护作用

目的综述了银杏叶提取物和单体抗脑缺血的体内外实验研究及其神经保护作用的自由基机制。方法根据近年国内外公开发表的有关研究论文 ,按整体动物脑缺血的实验模型以及体外培养的神经细胞缺血缺氧实验模型的顺序 ,重点讨论银杏叶提取物、黄酮苷、萜烯内酯和单体内酯这几种成分。同时从药物对自由基的影响方面进行了机制的分析。结果与结论各种成分对实验动物的体内外脑缺血缺氧模型均有不同程度的神经保护作用 ,它们对自由基的影响可能是其抗脑缺血的作用机制之一。     

银杏叶提取物对实验性糖尿病大鼠脑组织的保护作用

目的:研究银杏叶提取物(extractofGinkgobi-loba,EGB)对糖尿病大鼠脑的保护作用及其机制。方法:选用雄性SD大鼠,随机分为糖尿病组、银杏叶组和正常对照组。应用链脲佐菌素(STZ)诱导制备大鼠糖尿病模型。银杏叶组腹腔注射银杏叶提取物注射液,其余两组给予同容积的生理盐水,用药5周后,测定脑组织内皮素(ET)、丙二醛(MDA)、NO产物NO2-/NO3-的含量及超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)的活性,以及血清中的血糖、胰岛素、ET水平,并作光镜及透射电镜观察。结果:糖尿病脑组织光镜下可见脑水肿、脑软化、神经细胞变性、白质脱髓鞘,透射电镜下可见神经元及神经胶质细胞内线粒体肿胀、嵴变短、神经纤维脱髓鞘、血脑屏障受损。EGB治疗后光镜、电镜下的病变明显减轻。与糖尿病组相比,银杏叶组大鼠血糖、血浆ET水平下降、胰岛素水平升高,脑组织内SOD活性明显升高,NOS活性、ET、MDA、NO2-/NO3-的含量明显下降。结论:EGB可能通过抗脂质过氧化及降低NO、ET水平,对糖尿病大鼠脑组织产生保护作用。     

Protective effects of Ginkgo biloba extract against lysophosphatidylcholine-induced vascular endothelial cell damage

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银杏提取物对过氧化氢损伤的培养大鼠心肌细胞的保护作用

探讨银杏叶提取物对过氧化氢损伤的培养心肌细胞的保护作用及其机制。方法；比色法测定乳酸脱氢酶活性；戊巴比妥酸法测定细胞内质质过氧化物含量；透射电镜下观察细胞超微结构。结果：过氧化氢导致心肌细胞ＬＤＨ释放从（２１６６±２４７）Ｕ．Ｌ＾－１增至（５１８０±６４８）Ｕ．Ｌ＾－１ＭＤＡ含量从每１０＾６细胞９３．５±０．２）ｎｍｏｌ增至（７．２±０．４）ｎｍｏｌ；．心肌细胞超微结构受到严重损伤。     

Protective effects of Ginkgo biloba leaf extracts on trichloroethylene-induced human keratinocyte cytotoxicity and apoptosis

The objective of this study was to assess the protective effects of Ginkgo biloba leaf extracts (EGb) on trichloroethylene (TCE)-induced cytotoxicity and apoptosis in normal human epidermal keratinocytes (NHEK). Cytotoxicity was determined by neutral red uptake, and lipid peroxidation of the cells was assessed by malondialdehyde (MDA) and superoxide dismutase (SOD). Electron microscopy and flow cytometry were used to evaluate NHEK apoptosis. Treatment of NHEK with various concentrations of TCE caused a substantial decrease in cell viability. NR(50 )from the cytotoxicity assay was found to be 4.53 mM. TCE caused an increase in MDA, while an inhibition of SOD activity, in a concentration-dependent manner. Electron microscopic examination revealed typical morphologic changes of apoptosis in cells treated with TCE. Incubation of NHEK with TCE (0, 0.125, 0.5, 2.0 mM) for 4 h increased the proportion of apoptotic cells from control of 19.23% to nearly 44.35%. Pretreatment of EGb at 10-200 mg/l dose-dependently attenuated the cytotoxic effect of TCE, prevented TCE-induced elevation of lipid peroxidation and decline of antioxidant enzyme activities. Similar inhibition by EGb on TCE-mediated NHEK apoptosis was also observed. These results suggest that EGb can protect NHEK from TCE-induced cytotoxicity and apoptosis, which may be associated with the superoxide scavenging effect and enhancement of antioxidant enzyme activities.     

M受体对H_2O_2诱导PC12细胞凋亡的保护作用及机制

目的研究毒蕈碱型胆碱受体在抗氧化应激所诱导的凋亡中不同亚型之间是否存在差异。方法用含有M1M4毒蕈碱型胆碱受体亚型的质粒pCDNA3.0转染PC12细胞,加入过氧化氢诱导凋亡,观察氨甲酰胆碱激动毒蕈碱型胆碱受体后各亚型之间抗凋亡能力是否存在差异,同时应用毒蕈碱型胆碱受体抑制剂阿托品,ERK和PI3K信号通路抑制剂PD98059与LY294002观察参与保护作用的相关的信号通路。结果氨甲酰胆碱激动毒蕈碱型胆碱受体后产生抗凋亡效应,各亚型之间没有差异,PI3K信号通路参与了保护作用。结论M1M4亚型毒蕈碱型胆碱受体在对抗过氧化氢诱导的凋亡没有亚型之间的差异,PI3K信号通路参与了保护作用。     

复方银杏滴丸对糖皮质激素诱导的脑功能衰退小鼠的保护作用

目的: 观察复方银杏滴丸 (CO GBE)对糖皮质激素(GC)诱导的脑功能衰退小鼠的保护作用。方法: 6月龄小鼠隔日皮下注射氢化可的松 30mg·kg-1共计 11次造成脑功能衰退模型,分别采用跳台法和水迷宫法测定小鼠的学习记忆能力,并检测其体重、脾脏指数和胸腺指数。结果:与空白对照组相比,模型小鼠的学习记忆能力明显下降 [跳台试验中,学习能力测定的反应期 (2. 4±s1. 9 )s、潜伏期(41±81)s、停留时间 (13±14 )s、错误次数 (2. 5±2. 4)次。记忆能力测定的潜伏期 (159±144)s、停留时间(3±4)s、错误次数 (0. 6±1. 0)次。水迷宫试验中,学习能力测定的B点到达时间 (61±37)s、错误次数(3. 2±2. 4)次、C点到达时间(65±65)s、错误次数(3. 9±2. 9)次,记忆能力测定的B点到达时间(60±41)s、错误次数(3. 0±1. 0)次,C点到达时间(71±59)s,错误次数 (3. 2±2. 2)次 ];体重明显减轻;脾脏指数减小(P<0.05,P<0. 01);胸腺指数呈减小趋势。CO GBE 15, 30, 60mg·kg-1不同程度地增强模型小鼠的学习记忆能力 (P<0.05,P<0. 01), 60mg·kg-1还可以明显抑制模型小鼠体重下降,P<0. 05,增加其脾脏指数 (98±33 )mg·10g-1体重,P<0. 05,未见药物对模型动物胸腺指数有影响。结论:CO GBE可以明显改善GC诱导的脑功能衰退小鼠的学     

银杏提取物对过氧化氢损伤的培养大鼠心肌细胞的保护作用

目的:探讨银杏叶提取物(GbE)对过氧化氢损伤的培养心肌细胞的保护作用及其机制。方法:比色法测定乳酸脱氢酶活性;戊巴比妥酸法测定细胞内脂质过氧化物含量;透射电镜下观察细胞超微结构。结果:过氧化氢导致心肌细胞LDH释放从(2166±247)U·L~(-1)增至(5180±648)U·L~(-1),MDA含量从每10~6细胞(3.5±0.2)nmol增至(7.2±0.4)nmol;心肌细胞超微结构受到严重损伤。加GbE使LDH释放从(5180±648)U·L~(-1)降至(3496±386)U·L~(-1);MDA生成由每10~6细胞(7.2±0.4)nmol降至(4.8±0.9)nmol并减轻心肌超微结构的损伤。结论:GbE通过清除氧自由基保护过氧化氢损伤的心肌细胞。     

Chemopreventive effects of Ginkgo biloba extract in estrogen-negative human breast cancer cells

Excessive level of estrogen is considered as a main cause of breast cancer, therefore, many studies have focused on estrogen receptor (ER)-positive breast cancer, even though ER-negative cancer has a poor prognosis than ER-positive breast cancer. We evaluated the anti-cancer effects of Ginkgo biloba extract (GBE) in estrogen-independent breast cancer. GBE has been traditionally used as a platelet activating factor, a circulatory stimulant, a tonic, and anti-asthmatic drug, and anti-cancer agent. However, anti-cancer effects of GBE on ER-negative breast cancer have not been proved yet. In this study, we tested chemotherapeutic potential of GBE in the MDA-MB-231 (ER-negative) human breast cancer cell line. Our results showed that cytotoxicity effects of GBE in MDA-MB-231 lead to DNA fragmentation at high concentrations (500 and 1,000 μg/ml). Caspase-3 was significantly activated and mRNA levels of apoptosis-related genes (Bcl-2 and Bax) were altered. These results indicate that GBE induces apoptosis in MDA-MB-231 cells. It is presumed that GBE has chemopreventive effects in ER-independent breast cancer through anti-proliferation and apoptosis-inducing activities.     

银杏叶提取物对小鼠脑缺血再灌注损伤的拮抗作用

目的　研究银杏叶提取物 (EGb76 1)对小鼠脑缺血再灌注损伤的拮抗作用及其作用机理。方法双侧颈总动脉加迷走神经结扎法 (左侧不完全结扎 )造成小鼠局部脑缺血 5min ,再灌注 30min。DTNB法测定谷胱甘肽过氧化物酶 (GSH px)活性 ;荧光分光光度法测定脑组织线粒体膜蛋白结合铽 ;被动性回避行为学模型检测小鼠记忆能力 ;海马形态学观察。结果　小鼠局部脑缺血再灌注后 ,海马GSH px活性降低 ,海马 ,下丘脑和皮质线粒体膜蛋白结合铽降低 ,说明结合钙升高 ,海马CA1区神经元损伤 ,小鼠的记忆能力下降。EGb76 1(2 5 ,5 0 ,10 0mg·kg- 1·d- 1,ig ,连续 7d)能逆转上述变化。结论　EGb76 1拮抗小鼠脑缺血再灌注损伤的作用与抗氧化及阻止线粒体膜蛋白结合钙增加有关     

银杏叶提取物对大鼠糖尿病性白内障防治作用的研究

目的探讨银杏叶提取物(extract of ginkgo biloba,GBE)对大鼠糖尿病性白内障(diabetic cataract,DC)的防治作用及可能机制。方法 60只♂SD大鼠随机分为正常对照组、DC模型组、GBE低、中、高剂量组和苄达赖氨酸组。给药12周后,裂隙灯观察大鼠晶状体变化并对其混浊度进行分级;可见光分光光度法测定晶状体中过氧化氢酶(cata-lase,CAT)、谷胱甘肽(glutathione,GSH)和总超氧化物歧化酶(total superoxide dismutase,T-SOD)水平;ELISA法测定糖基化终末产物(advanced glycosylation end products,AGEs)含量;Western blot法测定醛糖还原酶(aldose reductase,AR)相对表达水平。结果 DC组大鼠晶状体明显混浊;GBE中高剂量组较DC组大鼠晶状体混浊程度减轻。DC组大鼠与NS组相比,晶状体中CAT、T-SOD活性降低,GSH含量减少(P<0.01);中高剂量GBE可提高CAT、T-SOD活性及GSH含量(P<0.05或P<0.01)。与NS组相比,DC组大鼠晶状体中的AGEs含量及AR表达明显升高(P<0.01);中高剂量GBE治疗后,AGEs含量与AR表达明显下调(P<0.01)。结论 GBE可能通过增强抗氧化能力、抑制AGEs产生及AR表达,从而减轻大鼠晶状体混浊度,对DC的防治具有积极作用。     

三七超临界CO_2萃取物对谷氨酸损伤PC12细胞的保护作用

目的研究三七超临界CO_2萃取物(SFE)对谷氨酸损伤PC12细胞的保护作用,并探讨其可能作用机制。方法以谷氨酸损伤PC12细胞为模型,采用MTT法检测细胞存活率,LDH法检测乳酸脱氢酶的漏出率,Hoechst 33342染色法检测细胞凋亡,Fluo-3/AM荧光染色法检测细胞内钙离子浓度,Western blot法检测PICK1、GluR2蛋白的表达。结果谷氨酸对PC12细胞具有兴奋性毒性作用,其半数抑制浓度(IC50)为25 mmol·L~(-1)。不同浓度三七SFE(25、50、100 mg·L~(-1))、PICK1抑制剂FSC231(100μmol·L~(-1))、三七SFE(100 mg·L~(-1))+FSC231(100μmol·L~(-1))预处理可明显提高细胞存活率,减少LDH的释放,降低PC12细胞的凋亡率,减少钙离子内流,降低PICK1蛋白表达,增加GluR2蛋白表达。结论三七超临界CO_2萃取物对谷氨酸损伤后的PC12细胞具有保护作用,机制可能与抑制PICK1、增加GluR2蛋白表达有关。     

银杏叶提取物对局灶性脑缺血模型大鼠的保护作用

目的:探讨银杏叶提取物(EGB)对局灶性脑缺血模型大鼠的保护作用.方法:采用三氯化铁局部贴敷大脑中动脉,制成局灶性脑缺血大鼠模型,通过对模型大鼠神经症状、脑梗塞范围以及血液流变学指标的测定,以阐明银杏叶提取物天保宁片对模型大鼠的保护作用.结果:EGB可以明显改善模型大鼠的神经症状,缩小其脑梗塞范围,并可降低其在高切(200S-1)、中切(30S-1)、低切(5S-1、1S-1)状态时的全血黏度.但在本实验条件下,未观察到药物对模型动物血浆黏度的影响.结论:降低MCAT大鼠的全血黏度,抑制血栓形成,可能是EGB抑制脑缺血损伤的作用机制之一.     

Hydrogen peroxide-induced oxidative damage and apoptosis in cerebellar granule cells: protection by Ginkgo biloba extract.

The ability of oxidative stress to induce apoptosis and the protective effects of Ginkgo biloba extract (EGb761) against this induction were studied in cultures of rat cerebellar granule cells. Cells were exposed to oxidative stress by treatment with 50 microm hydrogen peroxide+100 microm ferrous sulphate which generates hydroxyl radicals by Fenton reaction. Both morphological observation and biochemical analysis revealed that H(2)O(2)/FeSO(4)treatment induced apoptotic cell death in cerebellar granule cells, which was characterized by chromatin condensation and DNA fragmentation. During this process, the fluidity of the cell membrane decreased markedly, and the conformation of membrane proteins altered significantly. Pretreating cerebellar granule cells with the antioxidant EGb761 (Ginkgo biloba extract) effectively attenuated oxidative damage induced by H(2)O(2)/FeSO(4), and prevented cells from apoptotic cell death. The results suggested that EGb761 might be used as a potential drug for neuronal diseases associated with the excessive production of reactive oxygen species.