The structure-activity relationship of flavonoids as scavengers of peroxynitrite

Peroxynitrite is a cytotoxic intermediate produced by the reaction between a superoxide anion radical and nitric oxide. The scavenging activities of flavonoids on peroxynitrite were investigated to illustrate the structure-activity relationship. Peroxynitrite was scavenged by the presence of various flavonoids, whose structures seem to be closely related to the degree of scavenging. Of 31 compounds tested, the most active was quercetin, with an IC50 value of 0.93 microM. Others had IC50 values ranging from 0.96 to more than 10 microM. The scavenging activity was postulated to be governed by the position of the hydroxyl group. Ortho-hydroxyl structures increased the scavenging activity on peroxynitrite.     

苦参提取物体外抗菌实验研究

目的：探讨苦参总生物碱、总黄酮提取物及其混合物的体外抗菌效果。方法：采用液体二倍稀释法分析苦参总生物碱、苦参总黄酮提取物及其混合物对金黄色葡萄球菌、大肠埃希菌、福氏志贺菌、乙型副伤寒杆菌、铜绿假单胞菌、白色葡萄球菌、痢疾杆菌和柠檬色葡萄球菌的抗菌作用,并测定最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。结果：苦参总生物碱对以上菌株的MIC分别为：9.00、3.38、8.25、9.00、4.50、13.50、6.75、7.13mg.mL-1,MBC分别为：13.50、14.25、8.25、9.00、14.25、14.25、13.13、14.25mg.mL-1;苦参总黄酮对以上菌株的MIC分别为3.00、2.63、3.56、3.38、1.50、2.44、3.56、2.35mg.mL-1,MBC分别为14.25、12.75、7.13、13.50、13.50、12.75、12.75、13.13mg.mL-1;苦参总生物碱与总黄酮混合物对以上菌株的MIC分别为：2.25、2.07、3.28、3.94、1.22、2.44、2.07、1.97mg.mL-1,MBC分别为9.00、13.13、6.75、6.38、13.88、7.50、6.38、7.13mg.mL-1。结论：苦参总生物碱和总黄酮提取物对上述菌株存在体外抑菌和杀菌活性,混合物呈现一定协同作用。     

黄芪、苦参、皂角刺抗肝癌作用的比较研究

目的:比较黄芪、苦参、皂角刺抗肝癌作用。方法:在小鼠体内构建H 22肝癌细胞皮下移植瘤模型并进行评价;观察黄芪、苦参、皂角刺对H 22肝癌细胞荷瘤小鼠的作用;最后进行体外实验计算各组的抑瘤率。结果:体质量结果显示,与模型组相比,黄芪高剂量组体质量增高(P<0.05)。皮下移植瘤体积结果显示,与模型组相比,苦参高剂量组和皂刺高剂量组皮下移植瘤体积显著减小(P<0.01)。胸腺指数结果显示,与模型组相比,黄芪高剂量组显著增高(P<0.01)。肝脏指数显示,与模型组相比,苦参、皂角刺高剂量组均有降低(P<0.05)。脾脏、心脏、肺脏、双肾的脏器指数显示,组间无统计学差异。瘤重结果显示,与模型组相比,苦参和皂角刺高、中剂量组平均瘤重显著降低(P<0.01),低于阳性药组。体外实验抑制率结果显示各高剂量组抑瘤率,苦参为51.89%、皂刺为46.21%、黄芪为26.89%。结论:黄芪、苦参与皂角刺均具有抗肝癌作用,苦参和皂角刺抗癌作用强于黄芪;三药均可改善荷瘤小鼠的胸腺指数等免疫功能指标,其中黄芪提高机体免疫功能尤为显著,强于苦参和皂角刺。     

Antibacterial activity of sophoraflavanone G Isolated from the roots of Sophora flavescens against methicillin‐resistant Staphylococcus aureus

In this study, sophoraflavanone G obtained from Sophora flavescens was evaluated against 10 clinical isolates of methicillin‐resistant Staphylococcus aureus (MRSA), either alone or in combination with ampicillin or oxacillin, via checkerboard assay. At the end point of an optically clear well, the minimum inhibitory concentrations (MICs) ranged from 0.5 to 8 µg/ml for sophoraflavanone G, from 64 to 1024 µg/ml for ampicillin, and from 256 to 1024 µg/ml for oxacillin. The combination of sophoraflavanone G and ampicillin or oxacillin yielded a fractional inhibitory concentration index ranging from 0.188 to 0.375, thereby indicating a principally synergistic effect. The synergistic interaction was verified by time‐kill studies using sophoraflavanone G and/or antibiotics. Thirty minutes of treatment with sophoraflavanone G with ampicillin or oxacillin resulted in an increase in the rate of killing in units of CFU/ml to a greater degree than was observed with Sophoraflavanone G alone. These findings indicated that the application of the tested sophoraflavanone G alone or in combination with antibiotics might prove useful in the control and treatment of MRSA infections. Copyright © 2009 John Wiley & Sons, Ltd.     

红茶中多酚类物质的抗氧化机制及其构效关系

绿茶中主要多酚类物质为儿茶素。儿茶素抗氧化作用与机制已经较明确。茶黄素作为红茶中主要多酚类物质,是衡量红茶品质的重要指标,也是红茶中发挥生物学作用的主要物质。根据目前关于红茶中多酚类物质的研究报道,分析了茶黄素结构对抗氧化活性的影响,并阐明其发挥抗氧化作用的机制。     

Sedative and anticonvulsant activities of goodyerin,a flavonol glycoside from Goodyera schlechtendaliana

Goodyerin is a flavonol glycoside isolated from the whole plants of Goodyera schlechtendaliana which has been used as a substitute for the crude drug, Anoectochilus formosanus. The pharmacological properties of goodyerin were assayed for effects on spontaneous locomotor activity, on pentobarbital-induced hypnosis, and on anticonvulsant activity against picrotoxin-induced seizures in rodents. Goodyerin exhibited a significant and dose-dependent sedative and anticonvulsant effect.     

牛蒡根中黄酮苷类化学成分及其抗氧化活性构效关系的研究

目的研究牛蒡Arctium lappa根中的黄酮苷类化学成分及其抗氧化活性,分析构效关系。方法采用重结晶、硅胶柱色谱、RP18柱色谱、Sephadex LH-20柱色谱和PHPLC等多种分离手段,对黄酮苷类化合物进行分离纯化,通过现代波谱学方法(NMR、ESI-MS)鉴定其结构,并采用DPPH法、ABTS法和FRAP法对分离得到的化合物进行抗氧化活性测试。结果从牛蒡根55%乙醇提取物中分离得到8个黄酮苷类化合物,分别鉴定为柚皮素-7-芸香糖苷(1)、橙皮苷(2)、淫羊藿苷(3)、芒柄花苷(4)、异芒柄花苷(5)、新甘草苷(6)、新异甘草苷(7)、甘草苷(8);经3种不同方法测试,分析了这一类化合物的抗氧化活性构效关系。结论化合物3为首次从该植物中分离得到,其他化合物均为首次从该属植物中分离得到;化合物1和8显示出较强抗氧化活性;黄酮的B环上的3′-OH和4′-OCH3结构具有较高电子离域并且能形成氢键,很大程度提高了其结构的稳定性,增强了其抗氧化活性。     

KD-501, a standardized extract of Scrophularia buergeriana has both cognitive-enhancing and antioxidant activities in mice given scopolamine

Aim of the study

The cognitive-enhancing and antioxidant activities of KD-501, a standardized extract of the roots of Scrophularia buergeriana Miquel (Scrophulariceae) were investigated.

Materials and methods

KD-501 was orally administered to amnesic mice induced by scopolamine and we performed passive avoidance and the Morris water maze tests. To elucidate the mechanism of cognitive-enhancing activity, the effects of KD-501 on the activities of acetylcholinesterase and antioxidant enzymes within the cortex and hippocampus of mice were evaluated.

Results

Acute and prolonged oral administration of KD-501 significantly ameliorated scopolamine-induced amnesia in passive avoidance test. In the Morris water maze test, acute and prolonged administration of KD-501 improved the impairment of spatial memory induced by scopolamine indicated by the formation of reference and working memories. The activity of acetylcholinesterase was significantly inhibited by KD-501 within the cortex and hippocampus. Moreover, the reduced activities or contents of glutathione reductase, superoxide dismutase (SOD) and reduced GSH within the cortex and hippocampus caused by scopolamine were elevated by the treatment of KD-501.

Conclusions

Taken together, it could be postulated that KD-501 may exert its potent cognitive-enhancing activity through both anti-acetylcholinesterase and antioxidative actions.     

灯盏细辛中1个新咖啡酰酯类化合物的分离鉴定及抗肿瘤活性研究

目的 研究灯盏细辛Erigeron breviscapus的化学成分及其体外抗胶质母细胞瘤和结肠癌活性。方法 采用大孔树脂柱色谱、中压制备色谱、高压制备色谱等多种方法进行分离和纯化,利用1D-NMR、2D-NMR、HR-ESI-MS、UV、IR等波谱技术对分离得到的化合物进行结构鉴定,采用CCK-8法对新化合物的活性进行筛选。结果 从灯盏细辛80%甲醇提取物中分离得到4个化合物,分别鉴定为反式-4-咖啡酰氧基-3-羟基-6-咖啡酰氧甲基-7,8-二氧杂环[3.2.1]辛烷-1-羧酸（1）、异绿原酸A（2）、绿原酸（3）和新绿原酸（4）;其中化合物1对人胶质瘤U87细胞和人结肠癌HT29细胞的半数抑制浓度（half inhibitory concentration,IC₅₀）分别为（13.31±0.77）、（14.83±0.92）μmol/L。结论 化合物1为新化合物,命名为新飞蓬酯乙;化合物1对肿瘤细胞的增殖具有一定的抑制作用。     

Antihyperglycemic,hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis in experimental type 2 diabetic rats

Ethnopharmacological relevance

As a well-known traditional Chinese medicine the root bark of Aralia taibaiensis has multiple pharmacological activities, including relieving rheumatism, promoting blood circulation to arrest pain, inducing diuresis to reduce edema, and antidiabetic action. It has long been used as a folk medicine for the treatment of traumatic injury, rheumatic arthralgia, nephritis, edema, hepatitis and diabetes mellitus in China.

Aim of study

To evaluate the antihyperglycemic, hypolipidemic and antioxidant activities of total saponins extracted from Aralia taibaiensis (SAT) in experimental type 2 diabetic mellitus (T2DM) rats.

Materials and methods

Acute toxicity was studied in rats to determine the safe oral dose of SAT. Then, SAT was given orally to normal and streptozotocin–nicotinamide induced T2DM rats at 80, 160 and 320 mg/kg doses for a series of 28 days to determine the antihyperglycemic activity. Glibenclamide (600 μg/kg), a standard antidiabetic drug, was used as a positive control drug. At the end of treatment, biochemical parameters and antioxidant levels were measured to evaluate the hypolipidemic and antioxidant activities of SAT.

Results

Oral administration of SAT did not exhibit toxicity and death at a dose not more than 2000 mg/kg. SAT dose-dependently improved the symptoms of polydipsia, polyuria, polyphagia and weight loss in diabetic rats. Compared with diabetic control group, administration of 320 mg/kg SAT resulted in significant (P<0.05) fall in the levels of fasting blood glucose, glycosylated hemoglobin, creatinine, urea, alanine transarninase, aspartate aminotransferase, total cholesterol, triglycerides, low density lipoprotein cholesterol and malondialdehyde, but significant (P<0.05) increase in the levels of serum insulin, superoxide dismutase and reduced glutathione. However, SAT did not have any effect on the normal rats.

Conclusions

SAT had excellent antihyperglycemic, hypolipidemic and antioxidant activities in T2DM rats and might be a promising drug in the therapy of diabetes mellitus and its complications.