The inhibition by quercetin and ganhuangenin on oxidatively modified low density lipoprotein

Oxidatively modified low-density lipoproteins (ox-LDL) have been strongly implicated in the pathogenesis of atherosclerosis. Both in vivo and in vitro experiments have shown that antioxidant treatment can attenuate oxidative damage from LDL. The aim of this study was to establish whether the ox-LDL induced by in vitro incubation can be inhibited by two well-known natural antioxidants, quercetin and ganhuangenin. In our study, oxidation was quantitatively assessed in the presence and absence of these antioxidants by measuring lipid oxidation products and lipid peroxide generation. When non-oxidized, native LDL was incubated in the presence of 20 mM Cu²⁺, LDL modifications were found to proceed in a time-dependent manner. Our results further showed both quercetin and ganhuangenin inhibited the oxidative modification of LDL, as evidenced by the reduced thiobarbituric acid reactive substances (TBARS), phosphatidylcholine hydroperoxides (PCOOH) production, and ox-LDL fluorescence intensity. Based on these data, we concluded that both quercetin and ganhuangenin have the ability to effectively suppress in vitro LDL oxidation, thereby providing additional evidence for their potential beneficial use as antiatherogenic agents. © 1998 John Wiley & Sons, Ltd.     

山柰酚和槲皮素对乳鼠心肌缺氧复氧及过氧化损伤的保护作用

目的:观察山柰酚和槲皮素对乳鼠心肌细胞缺氧复氧损伤的干预作用并探讨其作用机理。方法:取大鼠新生乳鼠心肌细胞做原代培养,MTT法检测细胞活力,确定药物作用安全范围;考察药物对心肌细胞缺氧复氧损伤模型LDH漏出的改变;复制心肌细胞过氧化氢损伤模型,观察药物对细胞活力及上清液中LDH含量的影响。结果:山柰酚和槲皮素125μg/ml以下对心肌细胞活力无明显影响。山柰酚或槲皮素100、50、25、12.5μg/ml均可以降低缺氧复氧损伤后心肌细胞的LDH漏出率(P<0.01或P<0.05),其中山柰酚100、50、25μg/ml浓度,槲皮素以50、25、12.5μg/ml浓度作用较佳。山柰酚、槲皮素对心肌细胞过氧化氢损伤均有显著的抑制作用,均呈浓度依赖性,并可显著降低过氧化氢损伤所致的LDH释放。结论:山柰酚和槲皮素具有显著的抗心肌细胞缺氧损伤的能力,与其抗氧化的药理作用有关。     

枫蓼肠胃康治疗急性胃肠炎的药效物质基础初探

目的 探讨枫蓼肠胃康治疗急性胃肠炎的药效物质基础.方法 对比观察枫蓼肠胃康和芦丁、槲皮素单体对正常小鼠腹腔毛细血管通透性及小肠推进作用的影响.结果 枫蓼肠胃康、芦丁和槲皮素单体均能抑制醋酸所致小鼠毛细血管通透性增加(P<0.05);枫蓼肠胃康和槲皮素单体亦能抑制小鼠小肠推进作用(P<0.05),而芦丁对小肠推进作用无明显影响.结论 芦丁、槲皮素单体是肠胃康治疗急性胃肠炎的有效成分之一.     

Antioxidant activity of flavonoids from Licania licaniaeflora

In our screening program for antioxidants with DPPH radical scavenging activity we tested several flavonoids isolated from the leaves of Licania licaniaeflora (Chrysobalanaceae family) and identified by spectroscopic evidence, particularly with 1H and 13C NMR. All the isolated compounds exhibited DPPH radical scavenging activity: quercetin derivatives showed the strongest action, while the flavanone 8-hydroxy-naringenin and kaempferol 3-O-alpha-rhamnoside had the lowest.     

槲皮素药理作用研究进展

槲皮素是一种天然的黄酮类物质,具有抗肿瘤、抗氧化、抗感染、免疫抑制、心血管保护和血糖调节等多种药理作用。近年来,槲皮素因其生物活性强、药理作用广泛、副作用小而受到众多学者的关注。本文综述近10年槲皮素药理作用的研究进展,指出了目前存在的主要问题及今后研究的方向,以期对槲皮素的进一步研究有一定的指导作用。     

黄酮类成分黄芩素、槲皮素、丹参素钠对吸烟致细胞毒性和DNA损伤的保护作用

目的评价吸烟致细胞毒性和DNA损伤以及黄酮类成分黄芩素、槲皮素、丹参素钠的保护作用。方法以自动吸烟机按照FTC协议吸烟产生的主流烟雾在线染毒B-16细胞和人颊黏膜细胞两种真核细胞,通过MTT比色法和单细胞凝胶电泳法检测吸烟所致的细胞毒性和DNA损伤,并考察黄芩素、槲皮素、丹参素钠的保护作用。结果吸烟可致体外培养的B-16细胞活力明显下降,两种细胞的DNA明显损伤。随着烟气作用时间的延长,表征细胞内DNA损伤程度的彗星尾矩、Olive尾矩都有增加;1mmol／L槲皮素、黄芩素和丹参素均可明显缓解吸烟引起的细胞毒性和DNA损伤,对B-16细胞的活力提升50％左右,对人颊黏膜细胞的DNA保护效果超过60％。结论吸烟可致细胞毒性和细胞DNA损伤,但是黄酮类成分黄芩素、槲皮素、丹参素钠均对细胞和DNA具有保护作用。     

The antioxidant activity of Flavonoids Isolated from Corylus colurna

A natural mixture of flavonoids (F₄) was isolated from Corylus colurna leaves. In this study the antioxidant and the free radical scavenging activities of this mixture have been investigated. It was found that F₄ had a strong antioxidant activity comparable to that of quercetin and myricetin and higher than that of rutin. F₄ is a potent superoxide radical scavenger, more efficient than quercetin and myricetin or their mixture. F₄ is also a strong inhibitor of ischaemia/reperfusion-induced peroxidation in the brain and liver. In addition to these advantages F₄ had low toxicity and can be readily isolated. All these advantages make it an alternative to the more toxic synthetic antioxidants for the treatment of pathological conditions in which free radicals are involved.     

Effect of flavonoids on daunorubicin-induced toxicity in H9c2 Cardiomyoblasts

Daunorubicin (DNR) is one of the most important antitumor agents belonging to the anthracycline group. However, its use is seriously limited by the development of cardiac toxicity. The present study was designed to investigate the effects of quercetin, pycnogenol and naringenin on daunorubicin-induced cytoxicity in H9c2 cells. Protection of H9c2 cardiomyocyte cells was concentration/dose dependent for quercetin > naringenin > pycnogenol = trolox. Quercetin (10(-4)-10(-5) mol/L) after 24 h of co-incubation with DNR significantly increased the cardiomyocyte survival (p < 0.001 and p < 0.05, respectively). A protective effect of other compounds was observed only in the highest concentration/dose used (p < 0.01). After 48 h of incubation quercetin and naringenin significantly decreased daunorubicin-induced cell death at concentrations of 10(-4)-10(-5) mol/L (p < 0.001 and p < 0.01, respectively). The protective effect of pycnogenol and trolox was weaker but significant in the two highest concentrations/doses (p < 0.001 and p < 0.05, respectively). This study also investigated DNR-induced apoptosis and it was shown that both quercetin and naringenin inhibit apoptosis of H9c2 cardiomyocytes cells in vitro. The findings provide evidence that quercetin and naringenin may act as survival factors. The protective effect of flavonoids was compared with that of trolox, a known cardioprotective antioxidant. These results are consistent with the notion that the use of flavonoids may be beneficial in modulating or preventing the cardiotoxicity associated with DNR therapy.     

槲皮素及其衍生物防治肝损伤作用及机制的研究进展

槲皮素是一种多羟基黄酮类化合物,广泛存在于多种药用植物中,具有抗氧化、抗病毒、抗菌、抗炎和抗肿瘤等多种药理作用。分析了近10年国内外有关槲皮素及衍生物防治肝损伤方面的文献,发现其对各种急、慢性肝损伤均具有良好的防治作用,其作用机制主要涉及抗氧化、抗炎、调节脂质代谢、抗凋亡及自噬、抗病毒等。主要对槲皮素及其衍生物防治不同类型肝损伤的作用及机制进行综述,以期为槲皮素保肝作用的深入研究提供较为全面的文献信息支持。     

STUDY ON INVOLVEMENT OF L-ARG-NO IN THE PROTECTIVE ACTION OF ELECTROACUPUNCTURE ON CEREBRAL ISCHEMIC INJURY IN THE RAT

In the present study, the involvement of L-arginine(L-Arg) NO on he protective action of electroacupuncture(EA) on cerebral ischemic injury was observed in acute ischemia-reperfusion(IR)rat model by taking regional cerebral blood flow(r-CBF), cerebral water content(CWC), and blood nitric oxide(NO) contents as indexes. Results showed that 1) EA could cause r-CBF and serum NO content to increase and CWC to lower, suggesting an protective action of EA on IR cerebral injury; 2) intravenous injection of L-Arg also had an protective effect on cerebral IR cerebral injury, while L-NNA had no this effect; and 3) pre-treatment with L-Arg might strengthen the effect of EA further, while pretreatment with L-NNA could weaken its effect. It indicates that L-Arg-NO may be involved in the effect of EA in protecting the brain from ischemic injury.     

榭皮素对GSNO诱导损伤的内皮细胞的保护作用及其机制研究

目的：考察榭皮素（Quercetin）对S-亚硝基化谷胱甘肽（GSNO）诱导损伤的内皮细胞的保护作用,探讨其保护机制。方法：内皮细胞（EA．hy926）预先给予不同浓度榭皮素,之后给予GSNO损伤,建立模型。采用：噻唑兰染色（MTT法）检测细胞存活率测定,之后通过对超氧化物歧化酶（SOD）,丙二醛（MDA）,谷胱甘肽过氧化物酶（GSH—PX）,活性氧（ROS）,Caspase-3等指标测定进行分析。结果：榭皮素可明显提高内皮细胞内SOD,GSH—Px的活性,抑制MDA的产生,降低ROS的活性,减少细胞凋亡率,具有统计学差异（P〈0．05）。结论：榭皮素对GSNO诱导损伤的细胞具有保护作用,其机制可能与榭皮素可提高细胞内抗氧化酶活性有关。     

延髓内阿片肽对电针抗心肌缺血效应的影响

目的探讨延髓头端腹外侧区(rVLM)内阿片肽在"双固一通"针法电针抗家兔心肌缺血损伤中的作用。方法在"双固一通"针法对家兔急性心肌缺血保护作用的基础上,进一步观察rVLM内微量注射纳洛酮后电针对急性心肌缺血家兔心电图及心肌细胞跨膜电位的影响。结果rVLM内微量注射纳洛酮对正常家兔心肌电活动无明显影响,"双固一通"针法电针对缺血心肌电活动有一定保护作用,能显著改善心肌缺血时心电图和心肌跨膜电位的变化(P<0.05),该作用可被纳洛酮减弱(P<0.05),但不具有完全阻断作用。结论"双固一通"针法对急性心肌缺血电活动具有改善作用,其作用与rVLM内源性阿片肽系统的介导有关。     

Quercetin allievates oxidative stress in streptozotocin-induced diabetic rats

Diabetes mellitus is found in almost all populations and is emerging as a growing problem in developing countries. A large number of studies are in progress to fi nd natural sources, which are effective in reducing the intensity of diabetes. Quercetin, a constituent present in fruits and vegetables, was studied in two different doses (50 and 80 mg/kg body weight) for 45 days to assess its effect on streptozotocin induced diabetes. The blood glucose level was elevated in diabetic rats. Circulatory lipid peroxidation, vitamin C, vitamin E and enzymic antioxidants such as superoxide dismutase and catalase were analyzed. Alterations in the antioxidant defense were observed in diabetic animals compared to normal. Oral administration of quercetin to diabetic rats resulted in a decrease in the levels of blood glucose, plasma thiobarbituric acid reactive substances and hydroperoxides. Quercetin also resulted in the activities of superoxide dismutase, catalase coming to near normal, along with the levels of vitamin C and vitamin E. Quercetin at lower doses was found to be more effective. These result indicate that quercetin ameliorated the diabetes-induced changes in oxidative stress.     

基于分子反向对接方法的槲皮素抗肿瘤机制研究

目的:确定槲皮素抗肿瘤作用的靶标和分子机制。方法:采用Autodock Vina软件,把槲皮素与91个抗肿瘤的靶蛋白进行对接。利用Ligplot软件对槲皮素与靶蛋白的作用模式进行了分析。结果:槲皮素与多个抗肿瘤靶标具有较好的亲和性,其中与槲皮素结合能在-9.0 kcal·mol-1以下的有8个。结论:槲皮素可以通过抑制基质金属蛋白酶-8、二氢乳氢酸脱氢酶、二氢叶酸还原酶和胸苷酸合成酶以及几种蛋白激酶的活性,发挥抗肿瘤作用。     

黄酮醇类化合物对心肌细胞凋亡过程caspase-3、Bcl-2、Bax蛋白表达影响

 目的研究槲皮素、杨梅素、桑色素和芦丁对大鼠心肌细胞凋亡的保护作用。方法体外培养Wistar乳鼠心肌细胞,建立心肌细胞凋亡模型;随机分组:正常组,损伤组和用药组。用药组分别加入30μmol·L^-1的4种黄酮醇类化合物,孵育1h后,除正常组之外,加入H₂O₂诱导细胞凋亡。加入不同浓度的药物后,采用MTT法观察细胞存活情况,来进行药物有效浓度的筛选。采用TUNEL、流式细胞仪法检测心肌细胞凋亡情况,免疫组化法检测caspase-3蛋白、Bcl-2、Bax蛋白的表达情况。结果MTT结果显示,4种黄酮醇类在5和30μmol·L^-1时对细胞没有毒性。4种黄酮醇类化合物与损伤组比较,槲皮素、杨梅素、桑色素的心肌细胞凋亡率降低、Bcl-2/Bax比值增大、抑制caspase-3蛋白的活化。结论槲皮素、杨梅素和桑色素对心肌细胞凋亡有保护作用,可以通过抑制caspase-3蛋白的活化、上调Bcl-2蛋白的表达或是降低Bax的表达来发挥作用,槲皮素表现出较强的抗凋亡活性。     

黄芪注射液对实验性心肌缺血的保护作用

采用实验性急性心肌缺血模型 ,观察黄芪注射液的抗心肌缺血作用。结果发现 iv.黄芪注射液 4g/kg,ip2 g/kg能分别对抗垂体后叶素和异丙肾上腺素所致家兔和大鼠急性心肌缺血 ,改变缺血心肌的心电图。结论 :黄芪注射液对动物心肌缺血有保护作用。     

芹菜素对同型半胱氨酸诱导的人脐静脉内皮细胞氧化损伤的保护作用

目的:探讨芹菜素(Apigenin)对同型半胱氨酸氧化损伤的人脐静脉内皮细胞的保护作用。方法:体外培养内皮细胞,将细胞分为7组,即空白对照组(control)、溶剂对照组(DMSO)、Hcy氧化损伤组(Hcy)、氧化损伤加入槲皮素对照组(quercetin+Hcy)、氧化损伤加入芹菜素低、中、高浓度组(Apigenin-L+Hcy、Apigenin-M+Hcy、Apigenin-H+Hcy)。将5mmol/L Hcy作用于加入槲皮素及不同浓度芹菜素预培养6h的内皮细胞,继续培养24h,以细胞毒四唑盐(MTT)比色试验,乳酸脱氢酶(LDH)、谷胱甘肽过氧化酶(GSH-px)、丙二醛(MDA)、活性氧,NADPH酶活性、流式细胞凋亡率为检测指标。结果:芹菜素呈剂量依赖性降低同型半胱氨酸对内皮细胞活力的影响,降低MDA、LDH量,增加培养液中GSH-px活性,并显著减少活性氧、NADPH酶活性和细胞凋亡数量,各指标差异有显著性(P0.01)。结论:芹菜素可保护和修复同型半胱氨酸诱导的内皮细胞的损伤,其作用可能与抗氧化、抑制内皮细胞凋亡有关。     

100例IgA肾病临床与病理分析

目的：回顾性地总结我科20多年来所积累的IgA肾病资料，包括各年龄组的发病率、临床、病理特点及其相关性。方法：100例IgA肾病按照年龄分成3组，根据各年龄组的临床及其组织学特点进行分析。结果：少儿组复发性内眼血尿发生率最高为47．2％，慢性肾损害为4．6％。青壮年组恶性高血压的发生率为3．8％，也称为恶性IgA肾病。老年组肾病综合征和急性肾功能衰竭的发生率高于上述两组。结论：随着肾活检的广泛开展，少儿和老年的IgA肾病的发生率也增加，尤其是少儿，必须加强对他们的随访。老年人疑为IgA肾病者，必须及时肾活检。青壮年IgA肾病仍然占大部分比例。     

New bioactive polyphenols from Theobroma grandiflorum ("cupuaçu")

Activity-guided fractionation of Theobroma grandiflorum ("cupua?u") seeds resulted in the identification of two new sulfated flavonoid glycosides, theograndins I (1) and II (2). In addition, nine known flavonoid antioxidants, (+)-catechin, (-)-epicatechin, isoscutellarein 8-O-beta-d-glucuronide, hypolaetin 8-O-beta-d-glucuronide, quercetin 3-O-beta-d-glucuronide, quercetin 3-O-beta-d-glucuronide 6' '-methyl ester, quercetin, kaempferol, and isoscutellarein 8-O-beta-d-glucuronide 6' '-methyl ester, were identified. Theograndin II (2) displayed antioxidant activity (IC(50) = 120.2 microM) in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay, as well as weak cytotoxicity in the HCT-116 and SW-480 human colon cancer cell lines with IC(50) values of 143 and 125 microM, respectively. While 1 was less active as an antioxidant than 2, the known compounds were more potent in the DPPH assay (IC(50) range 39.7-89.7 microM).     

蒙古族药芯芭治疗2型糖尿病的网络药理学研究

该文采用网络药理学方法探讨蒙古族药芯芭治疗2型糖尿病潜在的活性成分和作用机制。根据文献收集汇总建立蒙古族药芯芭成分数据库,结合活性成分筛选、靶点预测技术及生物信息学手段,获取与降糖效应相关的重要活性成分和关键靶点来预测作用机制。分子对接预测主要活性成分与关键靶点结合活性,体外实验验证活性成分的降糖作用机制。该文共收集芯芭中含有177个化学成分,确认90个化学成分结构,34个化学成分存在有效靶点,显著影响过氧化物酶体增殖物激活受体信号代谢通路等脂肪酸代谢、调节蛋白激酶活性和胰岛素反应等61条生物过程,关键靶点为Akt1和TNFα。预测降糖活性成分主要为槲皮素、木犀草素和梓醇,分子对接预测关键靶点Akt1与木犀草素、槲皮素和梓醇有较强的结合活性;TNFα与木犀草素有较强的结合活性,与槲皮素和梓醇有一定的结合活性。体外细胞模型验证梓醇具有降糖药效,上调p-Akt(Ser473)/Akt,PPARα,PPARδ水平,降低FABP4蛋白水平,调节糖脂代谢改善肝胰岛素抵抗。网络药理学方法预测蒙古族药芯芭降糖多成分、多通路、多靶点的作用机制,为芯芭降糖研究提供科学视野和提示研究方向。