黄芩黄酮对H_2O_2导致的神经细胞损伤的保护作用

神经退行性病变与氧化应激密切相关。研究表明一些黄酮类化合物如银杏黄酮对神经细胞的氧化损伤具有良好的保护作用[1] 。前文[2 ] 发现 ,黄芩中的主要 4种黄酮———黄芩素、黄芩苷、汉黄芩素和汉黄芩苷能有效抑制脂质过氧化损伤 ,本文采用细胞培养的方法 ,探讨黄芩黄酮对Ｈ2 Ｏ2 导致的神经细胞损伤的保护作用。1　材料与方法1.1　 试剂　黄芩素 (Ｂａ)、黄芩苷 (Ｂａｉ)、汉黄芩素 (Ｗ )和汉黄芩苷 (Ｗｓ)为本实验室提取。胎牛血清、ＲＰＭＩ 16 40为Ｇｉｂｃｏ公司产品 ,ｐｏｌｙ Ｌ ｌｙｓｉｎｅ购自Ｓｉｇｍａ公司 ,ＬＤＨ测试盒购自…     

云南昭通产苦丁茶配糖体抗脂质过氧化研究

目的　观察云南昭通产苦丁茶总苷及 3种配糖体即阿克苷、紫茎女贞苷A和B对脂质过氧化的影响。方法　用Fe2 + 半胱氨酸反应系统产生超氧自由基激发大鼠肝微粒体脂质过氧化 ;Cu2 + 诱导人血浆低密度脂蛋白 (LDL)氧化修饰以及静脉注射四氧嘧啶引发小鼠自由基损伤。结果　 3种配糖体显著降低微粒体脂质过氧化产物MDA水平、延长LDL氧化修饰的延迟时间 (lagtime) ,总苷能显著降低小鼠血清及肝脏MDA升高水平。结论　苦丁茶总苷及 3种配糖体具有抗脂质过氧化作用。     

白藜芦醇苷对羟自由基所致大鼠脑线粒体氧化损伤的保护作用

目的　研究白藜芦醇苷对氧自由基所致大鼠脑线粒体损伤的保护作用 ,探讨白藜芦醇苷治疗心脑血管疾病的机制。方法　利用Fe2 + +VitC系统产生·OH ,诱导大鼠脑线粒体损伤 ;测定线粒体肿胀度、膜流动性、膜磷脂含量以显示线粒体膜功能 ,测定ATPase ,细胞色素C氧化酶活性以显示线粒体能量代谢能力 ,测定超氧化物歧化酶 (SOD)、丙二醛(MDA)以显示线粒体抗氧化能力。结果　·OH造成线粒体显著损伤 ,白藜芦醇苷 (终浓度 10 0、2 0 0、4 0 0mg·L-1)明显抑制膜磷脂降解、线粒体肿胀 ,增加膜流动性 ,改善线粒体能量代谢状态 ,增强抗氧化能力。结论　白藜芦醇苷对氧自由基所致大鼠脑线粒体损伤有明显保护作用 ,其机制与清除自由基、抑制脂质过氧化有关     

黄芩的生物化学及构效关系研究

黄芩为常用中药,用于治疗化脓性皮炎、腹泻、炎症和高血脂症,其主要有效成分为黄酮化合物。本文从五个方面研究了黄芩中黄酮类成分的生物学活性和构效关系。 1.对脂代谢的影响:黄芩中主要的黄酮成分黄芩甙、黄芩甙元、汉黄芩素等。黄芩甙对乙醇诱导的高血脂和脂解的离体脂肪细胞具有降低血中甘油三酯水平作用,黄芩甙元能提高血中高密度脂蛋白胆固醇水平。以上三种成分还可抑制以肾上腺素、去甲肾上腺素和多巴胺诱导的脂肪细胞的脂解作用,从而达到阻断的抑制动脉硬化的发生与发展。 2.对肝脏脂质过氧化的影响:在高等动物体内,脂质过氧化可损伤肝、肾和血管。黄     

丙泊酚对自由基引起的大鼠脑皮质线粒体损伤的保护作用

目的：在大鼠脑皮质线粒体自由基损伤的体外实验中，观察丙泊酚的保护作用，为治疗脑缺血再灌注损伤提供实验依据。方法：采用抗坏血酸-Fe^2＋体系诱导产生氧自由基，对分离的大鼠脑线粒体进行体外损伤实验，与丙泊酚温育后测定线粒体膜流动性、肿胀度和丙二醛（MDA）含量的变化。结果：脂质过氧化可降低线粒体膜流动性、增加线粒体肿胀和MDA含量，30μmol／L的丙泊酚均可减轻上述损伤。结论：脂质过氧化使大鼠脑皮质线粒体结构和功能显著量损．丙泊酚对此有明显保护作用。     

6,7-二乙酰黄芩素对四氯化碳和D-氨基半乳糖所致的急性肝损伤的保护作用

目的:研究6,7-二乙酰黄芩素对四氯化碳(CCl4)和D-氨基半乳糖(D-GalN)所致急性肝损伤的保护作用。方法:分别用CCl4和D-GalN诱导化学性急性肝损伤模型,测定血清中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)水平;并用苏木素-伊红(HE)染色处理肝脏组织切片,光镜观察病理学改变;用试剂盒测定肝线粒体中AST,SOD和GSH-PX的活性及脂质过氧化产物MDA含量。结果:在CCl4和D-GalN诱导和的小鼠肝急性损伤模型中,6,7-二乙酰黄芩素给药(50,100 mg.kg-1,ig)明显降低血清ALT,AST水平;明显改善肝脏病理组织状况;6,7-二乙酰黄芩素给药(25,50,100 mg.kg-1,ig)明显降低CCl4诱导的肝急性损伤小鼠的肝线粒体中AST活性和MDA的含量,显著增加SOD和GSH-PX的活性。结论:6,7-二乙酰黄芩对CCl4和D-GalN诱导和的小鼠肝急性损伤均具有保护作用,该作用与其增加线粒体中抗氧化酶的酶的活性、降低脂质过氧化水平有关。     

一测多评法测定复方黄白胶囊中四种黄酮成分的含量

目的建立一测多评测定复方黄白胶囊中4种黄酮成分（黄芩苷、汉黄芩苷、黄芩素和汉黄芩素）的方法。方法采用斜率校正法,以黄芩苷作为内参物,计算汉黄芩苷、黄芩素和汉黄芩素与黄芩苷的相对校正因子;分别用一测多评法和外标法测定复方黄白胶囊中4种黄酮成分的含量。结果黄芩苷、汉黄芩苷、黄芩素及汉黄芩素的色谱保留时间分别为14．80、28．58、37．76及47．52。阴性对照在相应位置处未见色谱峰,样品色谱图中黄芩苷、汉黄芩苷、黄芩素及汉黄芩索色谱峰的纯度因子分别为998．8、995．2、989．6及988．5。汉黄芩苷、黄芩素及汉黄芩素与黄芩苷间的相对校正因子分别为1．396、1．808和2．010。复方黄白胶囊中4种黄酮成分采用校正因子计算的含量值与外标法实测值之间无明显差异。黄芩苷、汉黄芩苷、黄芩素及汉黄芩素的加样回收率平均值分别为99．5％、99．7％、100．5％、99．4％,相对标准偏差分别为1．3％、0．9％、1．6％及1．1％（n=6）。本研究表明一测多评法测定黄芩苷、汉黄芩苷、黄芩素及汉黄芩素方法专属性、精密度、稳定性、重复性和回收率均良好。结论一测多评法可用于复方黄白胶囊中4种黄酮成分的定量分析。     

硫酸酯化虎奶多糖的制备及其抗氧化作用研究

目的对虎奶多糖进行硫酸酯化修饰 ,并研究其抗氧化活性。方法用氯磺酸 吡啶法对虎奶多糖进行硫酸酯化修饰得到硫酸酯化虎奶多糖 (S HNP) ;以Fe2 + Vc为氧自由基生成系统 ,体外观察S HNP对·OH引起的大鼠肝线粒体脂质过氧化损伤的保护作用 ;用化学发光法研究化学模拟体系CuSO4 Phen Vc H2 O2 DNA中S HNP对DNA损伤的保护作用 ;连苯三酚自氧化法观察S HNP对O·- 2 的清除作用。结果S HNP能显著抑制·OH引起的线粒体脂质过氧化产物TBARS的生成、线粒体的肿胀及膜流动性的降低 ;对·OH导致的DNA损伤有一定保护作用 ;对O·-2 有直接清除作用。结论S HNP具有较强的抗氧化活性。     

自身酶解法测定黄芩药材中黄芩素和汉黄芩素的含量

目的 探讨一种黄芩药材中黄酮苷元类成分黄芩素和汉黄芩素定量测定方法.方法 通过黄芩自身所含的酶在适宜温度条件下将黄芩药材中的黄芩苷、汉黄芩苷等黄酮苷类成分酶解成黄芩素和汉黄芩素等黄酮苷元,再利用高效液相色谱法进行含量测定.结果 黄芩素酶解完全,色谱峰分离良好,且同一流动相下可同时测定黄芩素和汉黄芩素的含量.黄芩素的平均回收率为96.45%,RSD为1.34%(n=9);汉黄芩素的平均回收率为97.86%,RSD为1.89%(n=9).结论 所用测定方法简便、准确,为黄芩素和汉黄芩素的充分提取、分离提供了真实的基础含量数据.     

野山杏果肉总有机酸体外抑制脂质过氧化活性研究

目的探讨野山杏果肉总有机酸(TOAWA)体外抑制脂质过氧化活性的作用。方法以维生素C为阳性对照,采用硫代巴比妥酸法,观察不同质量浓度的TOAWA对卵黄脂蛋白过不饱和脂肪酸(PUFA)过氧化体系中脂质过氧化活性以及小鼠肝脏自发性脂质过氧化及CCl4、Fe2+-维生素C和H2O2诱导的脂质过氧化活性的抑制作用。结果 TOAWA能够明显抑制PUFA过氧化体系中的脂质过氧化活性,可减轻小鼠肝脏自发性脂质过氧化及CCl4、Fe2+-维生素C和H2O2诱导的肝脏脂质过氧化程度,除了对PUFA过氧化体系中的脂质过氧化抑制作用与剂量无关外,其他抑制脂质过氧化活性均呈明显的剂量依赖性。结论野山杏总有机酸具有较强的抑制体外脂质过氧化活性的作用。     

Effects of flavonoids extracted from Scutellaria baicalensis Georgi on hemin-nitrite-H2O2 induced liver injury

Hemin-nitrite-H2O2 system may play a role in liver oxidative injury in some pathological events. In this paper, the effects of the three active components of the root of Scutellaria baicalensis Georgi, i.e. baicalin, baicalein and wogonin, on hemin-nitrite-H2O2 induced liver injury were studied in liver homogenate, liver microsome and human hepatoblastoma cell line HepG2 cells. It was found that hemin-nitrite-H2O2 could induce liver homogenate protein nitration, lipid peroxidation and liver microsome protein oxidation; it also caused a decrease of HepG2 cells viability. Baicalein, baicalin and wogonin could inhibit protein nitration and lipid peroxidation in liver homogenate as well as in HepG2 cells in a dose-dependent manner, the inhibition order was baicalein>baicalin>wogonin. These three flavonoids also inhibited the oxidation of protein in liver microsome, the decrease of cell viability and the content of GSH in HepG2 cells, among which baicalin represented the most inhibitory effect. Besides, hemin-H2O2 induced cell injury could be augmented with the existence of nitrite, indicating protein nitration involved in hemin-nitrite-H2O2 induced liver injury. These results demonstrated hemin-nitrite-H2O2 could induce liver injury through oxidizing or nitrating different biomolecules. Baicalein, baicalin and wogonin could inhibit hemin-nitrite-H2O2 induced liver injury in dose-dependent manners by inhibiting oxidation and nitration.     

Protective effects of flavonoids in the roots of Scutellaria baicalensis Georgi against hydrogen peroxide-induced oxidative stress in HS-SY5Y cells.

Oxidative stress plays an important role in the pathological process of neurodegenerative diseases. The effects of four major flavonoids present in Scutellaria baicalensis Georgi on hydrogen peroxide-induced neuronal cell damage are studied in this paper. When human neuroblastoma SH-SY5Y cells were incubated in Hanks' solution with the addition of 400 microM hydrogen peroxide for 2 h, the viability of cells was decreased remarkably, while the cell lipid peroxidation and the percentage of lactose dehydrogenase released into the culture medium was significantly increased. Addition of 10 microM of baicalein and baicalin significantly attenuated the cellular injury induced by hydrogen peroxide, while the effect of wogonin was marginal and wogonoside showed no effect at the tested concentration. In a separate experiment, 10 microM of baicalein and baicalin also antagonized the intracellular free-calcium concentration ([Ca2+]i) increase caused by 1 mM hydrogen peroxide. The effects of baicalein in both experiments were similar to those of quercetin, a well-studied antioxidant flavonoid. These results demonstrated the protective effects of flavonoids originating from Scutellaria baicalensis Georgi on the oxidative injury of neuronal cells.     

Inhibition of nitric oxide/cyclic GMP-mediated relaxation by purified flavonoids, baicalin and baicalein, in rat aortic rings

The dried roots of Scutellaria baicalensis Georgi (Huangqin) are widely used in traditional Chinese medicine. We purified two flavonoids, baicalin and baicalein from S. baicalensis Georgi and examined their effects on isolated rat aortic rings. Baicalin (3-50 microM) inhibited endothelium/nitric oxide (NO)-dependent relaxation induced by acetylcholine (Ach) or cyclopiazonic acid (CPA). Baicalein at 50 microM abolished Ach-induced relaxation and markedly reduced CPA-induced relaxation. Treatment with 1mM L-arginine partially but significantly reversed the effects of baicalin (50 microM) or baicalein (50 microM) on Ach-induced relaxation. In endothelium-denuded rings, treatment with baicalin, baicalein or methylene blue partially inhibited relaxations induced by the NO donors, sodium nitroprusside (SNP) and hydroxylamine. Both flavonoids markedly reduced the increase in cyclic GMP levels stimulated by Ach in endothelium-intact rings and by SNP in endothelium-denuded rings. In contrast, exposure of endothelium-denuded rings to baicalin or baicalein did not affect relaxations induced by pinacidil or NS 1619, putative K+ channel activators. Neither flavonoids affected agonist-induced increase in the endothelial [Ca2+]i. Our results indicate that baicalin and baicalein attenuated NO-mediated aortic relaxation and cyclic GMP increases, likely through inhibition of NO-dependent guanylate cyclase activity.     

HPLC测定12种中药制剂中黄芩甙含量

本文用ＨＰＬＣ方法测定了１２种中药制剂中黄芩甙含量，所建立的色谱方法使１２种中药制剂及生药中黄芩甙与其它成分均达较好的分离。本文还对生药中黄芩甙的提取条件进行了考察，结果表明以４５％甲醇超声提取方法较佳。该法简便、快速、精密度好。适合制剂生产中多批量样品的质量控制。     

黄芩中黄酮类成分在组织损伤中抗氧化作用的研究进展

对黄芩中黄酮类成分抗氧化药理作用的研究进展进行综述,为开发中药抗氧化新药提供理论依据。研究表明,黄芩在脑损伤、神经细胞损伤、心肌损伤、肝损伤等疾病中具有抗氧化作用。黄苓有望开发成为安全有效的中药抗氧化新药,但对其体内抗氧化作用机制的研究需要进一步深入。     

Biological properties of baicalein in cardiovascular system

The dried roots of Scutellaria baicalensis (S. baicalensis) Georgi (common name: Huangqin in China) have been widely employed for many centuries in traditional Chinese herbal medicine as popular antibacterial and antiviral agents. They are effective against staphylococci, cholera, dysentery, pneumococci and influenza virus. Baicalein, one of the major flavonoids contained in the dried roots, possesses a multitude of pharmacological activities. The glycoside of baicalein, baicalin is a potent anti-inflammatory and anti-tumor agent. This review describes the biological properties of baicalein (Table 1), which are associated with the prevention and treatment of cardiovascular diseases. Baicalein is a potent free radical scavenger and xanthine oxidase inhibitor, thus improving endothelial function and conferring cardiovascular protective actions against oxidative stress-induced cell injury. Baicalein lowers blood pressure in renin-dependent hypertension and the in vivo hypotensive effect may be partly attributed to its inhibition of lipoxygenase, resulting in reduced biosynthesis and release of arachidonic acid-derived vasoconstrictor products. On the other hand, baicalein enhances vasoconstricting sensitivity to receptor-dependent agonists such as noradrenaline, phenylephrine, serotonin, U46619 and vasopressin in isolated rat arteries. The in vitro effect is likely caused by inhibition of an endothelial nitric oxide-dependent mechanism. The anti-thrombotic, anti-proliferative and anti-mitogenic effects of the roots of S. baicalensis and baicalein are also reported. Baicalein inhibits thrombin-induced production of plasminogen activator inhibitor-1, and interleukin-1beta- and tumor necrosis factor-alpha-induced adhesion molecule expression in cultured human umbilical vein endothelial cells. The pharmacological findings have highlighted the therapeutic potentials of using plant-derived baicalein and its analogs for the treatment of arteriosclerosis and hypertension.     

Evaluation of the anti-inflammatory effect of baicalein on dextran sulfate sodium-induced colitis in mice

The anti-inflammatory effect of three flavonoids from the root of Scutellaria baicalensis (baicalein, baicalin and wogonin) was evaluated in a murine model of acute experimental colitis induced by dextran sulfate sodium (DSS). Baicalein, but not baicalin or wogonin, given orally at 20 mg/kg for ten days, ameliorates all the considered inflammatory symptoms of the induced colitis, such as body weight loss, blood haemoglobin content, rectal bleeding and other histological and biochemical parameters. The effect of baicalein was similar to that of sulfasalazine, the reference drug given at 50 mg/kg.     

黄芩中金属元素与总黄酮的含量测定

目的:测定黄芩中金属元素与总黄酮的含量,研究黄芩中微量元素的作用及其与治疗脑血管疾病的关系。方法:用原子吸收分光光度法测定黄芩中宏量元素钠、钙、镁、钾和微量元素铁、锰、铜、锌的含量,并采用醇提法提取黄芩中总黄酮,用紫外分光光度法测定总黄酮的含量。结果:黄芩中含有丰富的金属元素和黄酮类化合物。结论:本测定结果为临床合理应用黄芩清除自由基、预防和治疗脑血管疾病提供了科学依据,也为大力开发、利用黄芩提供了数据。     

Protective effects of baicalin on oxygen/glucose deprivation- and NMDA-induced injuries in rat hippocampal slices

Baicalin is a flavonoid derivative from Scutellaria baicalensis Georgi with various pharmacological effects. Recently, the neuroprotective effect of baicalin was reported. To confirm this effect and explore the possible mechanism, we have investigated the protective effect of baicalin on ischaemiclike or excitotoxic injury and the activation of protein kinase C alpha (PKC(alpha)) in rat hippocampal slices. In-vitro ischaemic-like injury was induced by oxygen/glucose deprivation (OGD) and the excitotoxic injury by N-methyl-D-aspartate (NMDA). The viability and swelling of the slices were detected by triphenyltetrazolium chloride (TTC) staining and image analysis of light transmittance (LT), respectively. The translocation of PKC(alpha) was measured by immunoblotting. Baicalin was added during both injuries. Baicalin (0.1, 1, and 10 micromol L(-1)) concentration-dependently inhibited OGD-induced viability reduction and acute neuron swelling, and inhibited the increased portion of PKC(alpha) present in the membrane fraction over the total PKC(alpha). Baicalin ameliorated NMDA-induced viability reduction (not LT elevation) and inhibited the NMDA-increased membrane portion of PKC(alpha) at 1 micromol L(-1). We concluded that baicalin had a protective effect on ischaemic-like or excitotoxic injury in rat hippocampal slices, which might have been partly related to inhibition of PKC(alpha) translocation.     

Different effects of baicalein, baicalin and wogonin on mitochondrial function, glutathione content and cell cycle progression in human hepatoma cell lines

The effects of the flavonoids from Scutellaria baicalensis Georgi (baicalein, baicalin and wogonin) in cultured human hepatoma cells (Hep G2, Hep 3B and SK-Hep1) were compared by MTT assay and flow cytometry. All three flavonoids dose-dependently decreased the cell viabilities accompanying the collapse of mitochondrial membrane potential and the depletion of glutathione content. However, the influence of baicalein, baicalin or wogonin on cell cycle progression was different. All three flavonoids resulted in prominent increase of G2/M population in Hep G2 cells, whereas an accumulation of sub G1 (hypoploid) peak in Hep 3B cells was observed. In SK-Hep1 cells, baicalein and baicalin resulted in dramatic boost in hypoploid peak, but wogonin made mainly in G1 phase accumulation. These data, together with the previous findings in other hepatoma cell lines, suggest that baicalein, baicalin and wogonin might be effective candidates for inducing apoptosis or inhibiting proliferation in various human hepatoma cell lines.