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

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川东獐牙菜素A保护溶血性磷脂酰胆碱诱导的内皮细胞损伤

目的 观察川东獐牙菜素A对溶血性磷脂酰胆碱(LPC)诱导的血管内皮细胞损伤的保护。方法 ①检测Cu2+诱导的低密度脂蛋白(LDL)氧化和二苯代苦味肼基自由基(DPPH)反应。②在大鼠离体胸主动脉环,检测乙酰胆碱诱导的内皮依赖性舒张反应。③培养内皮细胞,测定培养液中乳酸脱氢酶(LDH)、丙二醛(MDA)、一氧化氮(NO)和非对称性二甲基精氨酸(ADMA)浓度及细胞内二甲精氨酸二甲胺水解酶(DDAH)活性。结果①川东獐牙菜素A能显著抑制Cu2+诱导的LDL氧化和清除DPPH。②川东獐牙菜素A(10或30μmol·L-1)能改善LPC(5 mg·L-1)所致血管内皮依赖性舒张功能损伤。⑧川东獐牙菜素A(1、3或10μmol·L-1)能抑制LPC(5 mg·L-1)诱导的培养液中LDH和MDA浓度的降低以及NO浓度的增加;川东獐牙菜素A(3或10 μmol·L-1)能显著抑制LPC诱导的ADMA水平升高;川东獐牙菜素A(10μmol·L-1)能显著增加DDAH活性。结论 川东獐牙菜素A对LPC所致的血管内皮细胞损伤有保护作用,其作用与增加DDAH活性和降低AD-MA浓度有关。     

Protective effects of D,L-carnitine against arrhythmias induced by lysophosphatidylcholine or reperfusion

Electrophysiological effects of lysophosphatidylcholine (50 or 100 microM) and D,L-carnitine (100 microM) were studied under control conditions and in response to simulated ischaemia and reperfusion using the superfused right ventricular free wall preparation from the guinea pig heart. Lysophosphatidylcholine, 100 microM, induced a significant depolarization of the maximum diastolic potential (MDP) in the epicardium, as well as the development of ventricular premature beats, salvos and ventricular tachycardia. Both coupled beats and abnormal automaticity were observed in lysophosphatidylcholine (100 microM)-treated preparations. Carnitine (100 microM) alone had no effect on preparations superfused with normal Tyrode solution. However, it delayed the time to onset and reduced the cumulative duration of lysophosphatidylcholine-induced arrhythmias (P less than 0.05). The incidence of lysophosphatidylcholine-induced abnormal automaticity and salvos was also significantly decreased in the presence of carnitine. Twenty minutes of simulated ischaemia caused depolarization of MDP as well as prolongation followed by block of transmural conduction. Lysophosphatidylcholine (100 microM) did not alter this response however, carnitine significantly reduced ischaemia-induced depolarization in the epicardium. All control preparations developed arrhythmic activity during 30 min of reperfusion. Carnitine accelerated recovery of MDP in the epicardium upon reperfusion, prolonged the time to onset of arrhythmic activity and reduced both its cumulative duration and incidence. In contrast, reperfusion in the presence of lysophosphatidylcholine (100 microM) significantly increased the incidence of arrhythmic activity. Carnitine exerted only minimal antiarrhythmic action when preparations were exposed to reperfusion in the presence of lysophosphatidylcholine. In conclusion, this study demonstrates that carnitine can modify various cellular mechanisms of arrhythmia induced by lysophosphatidylcholine or by reperfusion but is much less effective when lysophosphatidylcholine and reperfusion are combined.     

Protective effect of ginkgo biloba extract on endothelial cell against damage induced by oxidative stress

The viability of bovine aortic endothelial cells (BAECs) treated with 0.1 m H O was decreased by 39.8%, and 100 mg/l EGb761 increased the viability by 20.6%. Exposure BAECs to H O for 6 min resulted in a significant elevation in the intracellular free Ca. Pretreatment of BAECs with 10 mg/l and 100 mg/l EGb761 for 10 min showed a decrease in the intracellular free Ca, 4.5% and 20.6%, respectively. The apoptotic rate of BAECs measured by propidium iodide (PI) staining was (38.1 +/- 2%) after 18 h of treatment with H O. Pretreatment of BAECs with 100 mg/l EGb761 for 1 h reduced the apoptotic rate to 27 +/- 1%. In addition, there were about 5-7% of cells stained positive measured by TUNEL assay. When BAECs were exposed to 0.1 m H O for 18 h, the number of TUNEL-positive cells increased to 37-44%. When 10 mg/l EGb761 and 100 mg/l EGb761 were used, the TUNEL-positive cells decreased to 26.5 +/- 3.1% and 17.5 +/- 1.7%, respectively. Furthermore, EGb761 also inhibited caspase-3 activity induced by H O. It is concluded that EGb761 has protective effect on bovine vascular endothelial cells against damage induced by H O. Further studies are needed to clarify the mechanisms of action of EGb761.     

Protective effects of Astragalus polysaccharides against endothelial dysfunction in hypertrophic rats induced by isoproterenol

Astragalus polysaccharide (APS) is an important bioactive component extracted from Chinese herb Astragalus membranaceus. It has been widely used in treatment of cardiovascular diseases. We have previously reported that APS could inhibit isoproterenol-induced cardiac hypertrophy. The present study was designed to evaluate the protective effect of APS on vascular endothelia in cardiac hypertrophy rats induced by isoproterenol (ISO). ISO (10 mg × kg^− 1) was intraperitoneally injected once daily for 2 weeks to induce cardiac hypertrophy. APS (400 and 800 mg × kg^− 1) was intragastrically injected once daily along with ISO. The results showed that combination with APS significantly ameliorates the endothelial dysfunction while attenuates cardiac hypertrophy induced by ISO. We found that administration with APS could attenuate the increase in number of circulating endothelial cell (CEC). APS also decreases the superoxide anion generation and the protein expression of p65 and the levels of TNF-α and IL-6; while increases the cGMP levels, an activity marker for nitric oxide (NO) in aortas. In addition, APS improves the relaxation dysfunction in isolated aortic rings and increases the protein expression of IκBα and Cu/Zn-SOD in aortas. In conclusion, our results suggested that APS had a protective effect against endothelial dysfunction in hypertrophic rats induced by ISO. The underlining mechanisms may be contributed to the anti-inflammatory effects and the improvement of the imbalance between reactive oxygen species (ROS) and NO.     

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.     

Tempol对高原缺氧致小鼠脑组织损伤的保护作用

目的：研究Tempol对高原缺氧小鼠脑组织的保护作用及其机制。方法：将60只小鼠随机分为正常对照组、缺氧模型组、乙酰唑胺组和Tempol组,单次腹腔注射给药后,在模拟海拔8 000 m环境停留12 h,检测脑组织中H₂O₂、MDA、ATP酶和抗氧化酶的活性变化,蛋白印迹法检测HIF-1α、VEGF、Nrf2和HO-1蛋白的表达情况。结果：与正常对照组相比,缺氧模型组中H₂O₂和MDA含量显著增加,ATP酶和抗氧化酶活性显著减低,HIF-1α、VEGF、Nrf2和HO-1x蛋白表达增强。经Tempol预处理后能够显著降低高原缺氧小鼠脑组织中H₂O₂和MDA含量,提高抗氧化酶和ATP酶活性,降低HIF-1α和VEGF蛋白表达,显著提高Nrf2和HO-1蛋白的表达。结论： Tempol能够减轻高原缺氧脑组织损伤,作用机制可能与其能清除自由基,激活Nrf2/HO-1信号途径,提高抗氧化酶活性,降低机体氧化应激,改善能量代谢有关。     

6－苄胺基嘌呤对 D－半乳糖致小鼠脑组织氧化损伤的保护作用

目的：观察6－苄氨基嘌呤（6－BA）对小鼠脑组织氧化损伤的保护作用。方法小鼠随机分为4组,对照组、模型组和低、高2个剂量实验组（6－BA,20,40 mg? kg－1）,用D－半乳糖复制小鼠脑组织氧化损伤模型,连续给药6周。用分光光度法检测小鼠脑组织总超氧化物歧化酶（ T－SOD）、谷胱甘肽过氧化物酶（ GSH－Px）活力和丙二醛（ MDA）含量;HE染色观察形态结构,单细胞凝胶电泳观察DNA氧化损伤水平。结果与模型组相比,实验组小鼠的 T－SOD、GSH－Px活力显著提高,MDA含量显著降低;同时,6－BA明显改善D－半乳糖诱发的形态损伤和DNA损伤。结论6－BA对小鼠脑组织氧化损伤具有一定的保护作用。     

Protective effects of diltiazem against vascular endothelial cell injury induced by angiotensin‐II and hypoxia

To provide pharmacological data for future clinical studies, this study investigated the protective effects of diltiazem on vascular endothelial cell (VEC) injury induced by angiotensin‐II (AngII), hypoxia, and a combination of both treatments. The concentration of intracellular free calcium and the mitochondrial membrane potential in VEC were assessed as indicators of cell injury. An in vivo hypoxic animal model was used to test the protective effect of diltiazem on vascular endothelial tissues. Our study showed that AngII and hypoxia decreased the mitochondrial membrane potential in VEC, which was significantly inhibited by diltiazem. Diltiazem protected against VEC injury induced by the increased concentration of intracellular free calcium, which was associated with AngII and hypoxia. Diltiazem reduced the apoptosis of rat VEC under a sustained hypoxic condition. In addition, it reduced AngII and endothelin I levels in rat vascular endothelial tissues. Our study confirmed that AngII and hypoxia induced VEC injury by regulating the levels of mitochondrial membrane potential and intracellular free calcium. Diltiazem, a calcium channel blocker, protected VEC from AngII‐ and hypoxia‐induced injury.     

Protective effects of cariporide on endothelial dysfunction induced by high glucose

Aim: To explore the effects of cariporide, a selective sodium-hydrogen antiporter inhibitor, on endothelial dysfunction induced by high glucose. Methods: Acetylcholine (ACh)-induced endothelium-dependent relaxation (EDR), sodium nitroprusside (SNP)-induced endothelium-independent relaxation and biochemical parameters including malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO) were measured in rat isolated aorta. Results: A 6-h incubation of aortic rings with high glucose (44 mmol/L) resulted in a significant inhibition of EDR, but had no effects on endothelium-independent relaxation. After the 6-h incubation of aortic rings in the co-presence of cariporide (0.01, 0.1, and 1μmol/L) with high glucose, cariporide prevented the inhibition of EDR caused by high glucose in concentration-dependent manners. Similarly, high glucose decreased SOD activity and contents of NO, and increased MDA concentration in aortic tissue. Cariporide (1 μmol/L) significantly resisted the decrease of NO content and SOD activity, and elevation of MDA concentration caused by high glucose in aortic tissues. Mannitol (44 mmol/L) or cariporide (1μmol/L) alone had no effect on EDR, endothelium-independent relaxation and biochemical parameters. Conclusion: Cariporide significantly prevented endothelial dysfunction induced by high glucose. The mechanisms of endothelial dysfunction induced by high glucose may involve the activation of sodium-hydrogen antiporter and the generation of oxygen-free radicals, but it is not related to the change of osmolarity.     

Protective effects of lactoferrin against intestinal mucosal damage induced by lipopolysaccharide in human intestinal Caco-2 cells

Indirect evidence suggests that lactoferrin (Lf), a major iron-binding protein in human milk, induces enterocyte growth and proliferation, depending on its concentration and affects the function and permeability of the intestinal mucosa. The bacterial endotoxin (lipopolysaccharide, LPS) is known to cause mucosal hyperpermeability in vivo. However, protective effects of Lf against LPS-mediated intestinal mucosal damage and barrier function in epithelial cells are not yet fully clarified. The aim of this study was to investigate whether Lf can reduce the cellular injury and alter epithelial hyperpermeability caused by LPS in human intestinal Caco-2 cells. When cell viability was measured by a WST-1 assay (tetrazolium salt-based assay), the protective effects against LPS-induced damage to Caco-2 cells were observed at doses of 800 and 1000 microg/ml Lf. The barrier function of Caco-2 monolayer tight junctions was assessed by measuring transepithelial electrical resistance (TEER) and permeability of FITC-labeled dextran 4000 (FD-4). The treatment of Caco-2 cells with Lf at doses of 400 and 1000 microg/ml significantly increased TEER as compared to treatment with LPS alone for 2 h (p<0.05). Further, at doses of 400 and 1000 microg/ml, Lf inhibited the enhancement of LPS-mediated permeability in Caco-2 cell monolayer. The results of this study suggest that Lf may have protective effects against LPS-mediated intestinal mucosal damage and impairment of barrier function in intestinal epithelial cells.     

依达拉奉对过氧化氢致血管内皮细胞氧化损伤的保护作用

目的探讨依达拉奉对过氧化氢(H2O2)致内皮细胞氧化损伤的影响。方法体外培养人脐静脉内皮细胞(HUVEC),采用H2O2作为外源性自由基生成系统,模拟血管内皮细胞氧化应激损伤模型,观察不同剂量依达拉奉对H2O2所致内皮细胞的影响。通过检测各组丙二醛(MDA)的含量反应细胞的损伤程度,检测超氧化物歧化酶(SOD)的活性及总抗氧化能力(T-AOC)反应细胞的抗氧化能力。结果依达拉奉各浓度组均明显降低MDA的含量,提高SOD的活性及总T-AOC,上述作用随药物浓度增加呈增强趋势。结论依达拉奉能降低内皮细胞的氧化损伤程度,提高内皮细胞抗氧化能力。     

卡托普利对糖基化终产物损伤大鼠血管内皮功能的保护作用

目的研究卡托普利对外源性制备的糖基化终末产物损伤大鼠离体胸主动脉环内皮依赖性舒张功能的影响及其机制。方法按文献方法制备糖基化终末产物,采用外源性糖基化终末产物（AGE-BSA）孵育大鼠离体胸主动脉环90 min诱导血管内皮功能的损伤,并观察卡托普利、超氧化物歧化酶和L-精氨酸对糖基化终末产物所致的血管内皮依赖性舒张反应损伤的影响。结果外源性糖基化终末产物孵育大鼠离体胸主动脉环90 min,明显抑制乙酰胆碱诱导的内皮依赖性血管舒张反应（endothelium-dependent relaxation,EDR）。但对硝普钠诱导的内皮非依赖性血管舒张反应没有影响。卡托普利（3、10和30μmol.L^-1）与AGE-BSA共同孵育血管环90 min,浓度依赖性地改善AGE-BSA对血管内皮依赖性舒张反应的损害。依那普利拉、氧自由基清除剂超氧化物歧化酶（superoxidedismutase,SOD,200 U.mL^-1）也可改善AGE-BSA对内皮依赖性血管舒张反应的损害,而L-精氨酸（L-argi-nine,L-Arg,3 mmol.L^-1）却没有明显的保护作用。结论卡托普利对AGE-BSA所引起的血管内皮依赖性舒张反应的损害具有明显的保护作用,该作用可能与其抗氧化作用有关,同时可能是部分巯基依赖性的。     

Protective effects of 4-nerolidylcatechol against genotoxicity induced by cyclophosphamide.

In the present work we evaluated both the mutagenicity and antimutagenicity of the Pothomorphe umbellata root extract (PUE) and its isolated active principle, the 4-nerolidylcatechol (4-NC), in bone marrow cells of mice using the micronucleus test. Swiss male mice were orally treated for 4 days with PUE (200, 100 or 50mg/kg/day) or 4-NC (50, 25 or 12.5mg/kg/day) prior to exposition with a single dose (200mg/kg) of cyclophosphamide (CP), 24h after the end of the treatment. The results demonstrated that the PUE and 4-NC did not have any mutagenic effect on mouse bone marrow cells; quite the opposite, there was a protective effect against genotoxicity induced by cyclophosphamide. Taken together, under the conditions tested herein, mice treated with PUE and 4-NC showed, in a dose-dependent manner, protective effect against CP-induced genotoxicity. Due to their ability to prevent chromosomal damage, with apparent low toxicity and cost, PUE or pure 4-NC are likely to open a field of interest concerning their possible use in clinical applications.     

槲皮素对肝细胞氧化应激损伤的保护作用

摘要： 目的 探讨槲皮素对氧化应激 Chang liver 细胞损伤的保护作用及其作用的分子机制。方法 培养 Chang liver 细胞, 将细胞随机分为正常对照组、 H2O2组及槲皮素低、 中、 高剂量组。MTT 法检测肝细胞的存活率; 流式 细胞术检测细胞凋亡率。2′,7′-二氯荧光素乙二酯(DCFH-DA)细胞内活性氧 （ROS） 荧光染色后, 荧光显微镜观察照 相及流式细胞仪检测细胞内活性氧水平。试剂盒测定细胞中超氧化物歧化酶（SOD）、 过氧化氢酶（CAT）、 谷胱甘肽 过氧化物酶 （GSH-Px） 活性及细胞中丙二醛 （MDA） 的含量。采用 Western blot 法检测 Nrf2 蛋白的表达。结果 H2O2 组较正常对照组细胞存活率、 SOD、 GSH-Px、 CAT 活性降低 (P < 0.05), 凋亡率、 平均荧光强度（MFI）及 MDA 升高 (P < 0.05)。不同剂量槲皮素组细胞存活率及细胞内 SOD、 GSH-Px、 CAT 活性高于 H2O2组(P < 0.05), MDA、 凋亡率、 MFI 水平低于 H2O2组(P < 0.05)。槲皮素低、 中及高剂量组 Nrf2 蛋白均高于 H2O2组(P < 0.05)。结论 槲皮素对氧化 应激肝细胞损伤具有保护作用, 其机制可能与激活 Nrf2-ARE 通路, 进而增强下游抗氧化基因的表达有关。     

绞股蓝总皂甙对氧化修饰低密度脂蛋白损伤小牛主动脉内皮细胞的防治作用

目的 :探讨绞股蓝总皂甙 (GYP)对氧化修饰低密度脂蛋白 (oxidativelymodifiedlowdensitylipopro tein ,oxLDL)损伤小牛主动脉内皮细胞的防治作用及可能机制。方法 :在体外培养的小牛主动脉内皮细胞 (bovineaorticendothelialcell ,BAEC )中加入oxLDL(终浓度为 0 .1gpr·L- 1)及GYP低、中、高剂量组 (5 .0 ,10 .0 ,2 0 .0mg·L- 1) ,培养 2 4h后 ,采用细胞毒试验、丙二醛 (MDA)测定及细胞计数等方法 ,分别对其贴壁细胞及培养液进行检测。结果 :①细胞毒试验发现 ,oxLDL对BAEC的生长增殖有明显的抑制作用 (2 0 .6 3% ) ,GYP组 (10 .0 ,2 0 .0mg·L- 1)为9.14 %和 6 .5 6 % (P <0 .0 1) ;②加oxLDL组和GYP组BAEC粘附的HL6 0细胞数明显多于对照组 (P <0 .0 1) ;③MDA检测发现oxLDL促进BAEC脂质过氧化物生成 ,并高于GYP组和对照组 (P <0 .0 1)。结论 :绞股蓝总皂甙具有对氧化修饰低密度脂蛋白损伤小牛主动脉内皮细胞的防治作用。     

高良姜素对H_2O_2诱导A375细胞氧化损伤的保护作用

目的探讨高良姜素对人A375黑素瘤细胞氧化损伤的保护作用。方法以700μmol·L-1的H2O2处理人A375黑素瘤细胞,建立氧化损伤模型,并以1,5和10μg·mL-1的高良姜素拮抗其作用。用倒置显微镜观察细胞形态;采用MTT比色法检测细胞存活率;并检测各组细胞上清液中丙二醛(MDA)、总抗氧化能力(T-AOC)、过氧化氢酶(CAT)、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)。结果高良姜素能明显改善H2O2损伤后的A375细胞形态,显著提高人A375黑素瘤细胞的存活率。与模型组相比,高良姜素给药后均能提高A375细胞T-AOC、CAT、SOD和GSH-Px活力(P<0.05),而MDA和NOS明显降低(P<0.05)。结论高良姜素对H2O2诱导的A375细胞氧化损伤具有保护作用。     

环孢素A改善异丙肾上腺素所致心肌损害和纤维化可能由抑制内皮素通路所介导

目的:研究环孢素A(Cyclosporine A,CsA)对异丙肾上腺素(isoproterenol,Iso)诱导心肌损害和纤维化的改善,探讨内皮素通路在其过程中的作用。方法:SD大鼠给予Iso(2 mg·kg-1·d-1,s.c.)10 d,建立大鼠心肌损害和纤维化病变。CsA治疗组预先给予CsA(25 mg/kg,s.c.)一次。结果:Iso损害心肌,引起心功能下降,使左室心肌中羟脯氨酸(hydroxyproline,Hyp)含量增高,内皮素-1(ET-1)及受体(ETAR)、结缔组织生长因子(CT-GF)和基质金属蛋白酶-9(MMP-9)mRNA和蛋白表达上调。CsA明显改善心功能,降低Hyp含量,减轻升高的mRNA和蛋白表达。结论:CsA改善Iso引起的大鼠心功能损害和纤维化,与抑制内皮素通路相关。     

羟乙基葛根素对脑星形胶质细胞氧化性损伤的保护作用

目的研究羟乙基葛根素对大鼠脑星形胶质细胞氧化性损伤的保护作用。方法取第4代培养的星形胶质细胞，以比色法测定细胞培养液中乳酸脱氢酶(LDH)活性，流式细胞术测定细胞凋亡率，［³H］-谷氨酸摄取法测定细胞摄取功能，比色法测定细胞内超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量。结果羟乙基葛根素可明显降低过氧化氢(H₂O₂)损伤所致的星形胶质细胞LDH的释放、降低细胞凋亡率、增加谷氨酸摄取率、使细胞内MDA含量减少而SOD活性增加。结论羟乙基葛根素可改善星形胶质细胞的神经营养功能、抑制星形胶质细胞凋亡，其机制可能与其抗氧化作用有关。