槲皮素与金属元素配合物的制备及抗氧化活性研究

目的:合成槲皮素金属配合物并研究它们的抗氧化活性。方法:利用单因素实验设计制备槲皮素金属的配合物,采用分光光度法测定槲皮素及其金属配合物清除超氧自由基和羟基自由基的能力;用HPLC法测定清除DPPH自由基的能力。结果:槲皮素-Ca对超氧自由基、羟基自由基和DPPH自由基均表现出了较强的清除能力,槲皮素、槲皮素-Ca、槲皮素-Cu、槲皮素-Zn、槲皮素-Cr及Vc对超氧阴离子清除的IC50值分别为20.00×10-6mol/L,3.070×10-6mol/L,26.14×10-6mol/L,11.79×10-6mol/L,6.28×10-6mol/L和9.12×10-6mol/L;对羟自由基清除的IC50值分别为22.07×10-6mol/L,3.10×10-6mol/L,12.75×10-6mol/L,22.22×10-6mol/L,42.47×10-6mol/L和16.24×10-6mol/L;对DPPH自由基清除的IC50值分别为47.51×10-5mol/L,11.25×10-5mol/L,35.21×10-5mol/L,29.75×10-5mol/L,43.06×10-5mol/L和13.20×10-5mol/L。结论:槲皮素-Ca的清除能力最强,具有较好的开发前景。     

RP-HPLC法测定桉树蜜中木犀草素的含量

目的:建立RP-HPLC法测定桉树蜜中木犀草素含量的方法。方法:以Hpersil BDS C18(250×4.6 mm,5μm)为分析柱,甲醇:0.4%磷酸水溶液(45∶55)为流动相,流速为1.0 ml.min-1,检测波长为345 nm。结果:木犀草素的线性范围为5.1~255.0μg.ml-1,r=0.9999,平均回收率为100.39%。结论:该方法简便,准确,可用于桉树蜜中木犀草素的含量测定。     

独一味微丸中木犀草素含量的HPLC测定法

目的建立独一味微丸中木犀草素含量的测定方法.方法用高效液相色谱法测定了木犀草素含量,色谱柱:Diamonsil(钻石)C18柱(150 mm×4.6 mm,5 μm),流动相:甲醇-0.4%磷酸溶液(50:50),流速:1.0 ml/min,测定波长:350 nm.结果平均回收率99.8%(RSD=2.32%,n=5),线性关系r=0.999 9,重复性RSD=1.03%(n=5),精密度RSD=1.31%(n=5).结论方法稳定、可靠,可作为该制剂的质量控制方法.     

木犀草素对脑胶质瘤细胞氨肽酶N活性影响

目的探讨木犀草素对脑胶质瘤细胞氨肽酶N活性影响机制。方法本研究采用酶抑制动力学方法, 研究了木犀草素对氨肽酶N的抑制作用、抑制类型和抑制动力学常数, 并进行了脑胶质瘤U87细胞的凋亡生长抑制试验。结果木犀草素能够诱导了脑胶质瘤U87细胞的凋亡, 并呈现一定的剂量依赖性, 当浓度≥10 μmol时, 与阳性对照bestatin 相比差异有统计意义(P<0.05), 求得半细胞凋亡率IC₅₀为(61.23±2.13)μmol;此外木犀草素是一种可逆的竞争型氨肽酶N抑制剂, 半抑制率IC₅₀为(70.85± 2.05)μmol, 抑制常数Ki为(24.83± 0.14)μmol;失活动力学时间进程分析表明,木犀草素能快速与氨肽酶N发生作用并迅速降低酶的活性。结论木犀草素是一个竞争性的氨肽酶N抑制剂, 使氨肽酶N的活性降低, 对诱导了脑胶质瘤U87细胞的凋亡起到重要作用。     

HPLC测定独一味中木犀草素的含量

目的:建立独一味中木犀草素含量测定的HPLC方法。方法:Diamonsil C18(5μm,250×4.6 i.d.mm,迪马公司);流动相:甲醇—水—磷酸(60∶40∶0.4);流速:1ml/min;温度:35℃;检测波长为350 nm。结果:木犀草素在100.12~800.96 ng范围内与峰面积呈良好线性关系,r=0.9999,独一味药材平均回收率为97.95%,RSD为0.97%。结论:HPLC测定独一味中木犀草素结果准确可靠、快速、灵敏、重现性好。     

木犀草素对宫颈癌细胞增殖、迁移及Ras-MAPK通路的影响

目的探讨木犀草素对宫颈癌细胞增殖、迁移及Ras-MAPK通路的影响。方法设宫颈癌细胞株Si Ha组、木犀草素低、中、高剂量组(木犀草素剂量分为1. 0、2. 0、4. 0μg/ml),以上各组每孔设6个平行样,培养72 h。培养结束后,检测各组Si Ha宫颈癌株细胞活力、细胞凋亡水平、细胞迁移能力、RAS、PERK1/2 RNA水平以及MMP-9、Cyc D1、VEGF蛋白水平。结果木犀草素低、中、高剂量组OD值、存活率、穿膜数、RAS、PERK1/2 RNA表达水平、MMP-9、Cyc D1、VEGF蛋白表达水平低于Si Ha组,凋亡率水平高于Si Ha组(P0. 01);木犀草素中、高剂量组OD值、存活率、穿膜数、RAS、PERK1/2RNA表达水平、MMP-9、Cyc D1、VEGF蛋白表达水平低于木犀草素低剂量组,凋亡率水平高于木犀草素低剂量组(P0. 01);木犀草素高剂量组OD值、存活率、穿膜数、RAS、PERK1/2 RNA表达水平、MMP-9、Cyc D1、VEGF蛋白表达水平低于犀草素中剂量组,凋亡率高于犀草素中剂量组,随着木犀草素剂量逐渐增加,各剂量组OD值、存活率、穿膜数、RAS、PERK1/2 RNA表达水平、MMP-9、Cyc D1、VEGF蛋白表达水平率明显降低,凋亡率水平明显增加,剂量—效应关系明显(P0. 01)。结论木犀草素能有效促进宫颈癌细胞凋亡,抑制宫颈癌细胞增殖迁移;其机制与木犀草素抑制Ras-MAPK信号通路中RAS、PERK1/2及其下游MMP-9、Cyc D1、VEGF的表达有关。     

木犀草素提高机体耐缺氧能力研究

目的 探索木犀草素的抗缺氧作用,为抗缺氧新药物的研制提供思路。方法 将40只昆明（KM）雄性小鼠分为4组,每组10只,连续灌胃（0.5%羧甲基纤维素钠溶液、25、50和100mg/kg木犀草素溶液）15d,进行常压密闭缺氧实验,记录小鼠存活时间（survivaltime,ST）、检测小鼠血清以及心、肝等组织的谷胱甘肽过氧化物酶(glutathioneperoxidase,GSH-Px)和总超氧化物歧化酶(total-superoxidedismutase,T-SOD)活力,总抗氧化能力(total antioxidant capacity, T-AOC),丙二醛(malondialdehyde, MDA)含量,观察木犀草素对常压缺氧小鼠的保护作用。结果 与对照组相比,木犀草素中、高剂量灌胃给预组小鼠在常压密闭缺氧条件下的常压缺氧密闭时间（the survival time, ST）、标准耐缺氧时间（standard hypoxia tolerance time,STT）和校准后的标准耐缺氧时间（adjusted standard hypoxia tolerance time,ASTT）...     

木犀草素对肝纤维化的防护作用及其机制

木犀草素是一种广泛存在于多种植物中的黄酮类化合物.现代研究证实,木犀草素存在多种药理作用,主要表现在抗菌、抗炎、抗氧化、免疫调解等.其对保护肝纤维化方面的作用也较突出,其主要机制可能与木犀草素能够抑制肝脏胶原表达合成和抑制肝星状细胞(hepatic stellate cells,HSC)的增殖、活化有关.结合国内外对木犀草素及肝纤维化的研究资料,笔者对木犀草素对肝纤维化的防护作用及其机制做进一步阐述和说明.     

木犀草素-Cr（Ⅲ）配合物对α-葡萄糖苷酶抑制作用的研究

目的：合成木犀草素-Cr（Ⅲ）,考察木犀草素及木犀草素-Cr（Ⅲ）对α-葡萄糖苷酶的抑制作用,确定抑制类型。方法：在无水乙醇中,用木犀草素与醋酸铬搅拌合成木犀草素-Cr（Ⅲ）配合物;用IR、UV、TG—DTA结合元素分析对结构进行表征,考察在不同的pH值和温度的条件下a一葡萄糖苷酶的酶活力,测定两者对α-葡萄糖苷酶的抑制作用,并采用双倒数作图法研究其动力学特性。结果：合成的木犀草素-Cr（Ⅲ）配合物的分子组成为：C15H9O6Cr（COOCH3）2（H2O）2·2H2O;酶的最适作用pH值为5．0,温度为55℃;木犀草素及其配合物对α-葡萄糖苷酶抑制作用的IC50值分别为1．496mmol／L、0．2320mmol／L,抑制类型为竞争型α-葡萄糖苷酶抑制剂。结论：木犀草素与Cr^3＋结合后,增强了对α-葡萄糖苷酶的抑制作用,为木犀草素-Cr（Ⅲ）的进一步研究打下了良好的基础。     

三七多糖抗氧化活性研究

目的:探讨三七多糖的体外抗氧化活性。方法:三七粗多糖经Sevage法纯化后用苯酚—硫酸法测定其含量,并采用还原/抗氧化能力、清除DPPH自由基、OH自由基和ABTS+自由基能力考察三七多糖的抗氧化能力。结果:三七多糖含量为80.49 mg/g;与对照品BHA和茶多酚相比较,还原/抗氧化能力和清除DPPH自由基能力(FRAP=11586.3μmol/g、IC50=0.055 mg/ml)都比茶多酚(FRAP=6507.5μmol/g、IC50=0.143mg/ml)强,但都比BHA(FRAP=1536.5μmol/g、IC50=0.030 mg/ml)弱;清除羟基自由基能力比BHA(IC50=0.028 mg/ml)及茶多酚(IC50=0.002 mg/m L)都强;清除ABTS+自由基能力(IC50=0.018 mg/ml)比BHA(IC50=0.175 mg/ml)强,但比茶多酚(IC50=0.002 mg/ml)弱。结论:三七多糖具有较强的抗氧化能力,为其生物活性的深入研究提供了参考依据。     

Effect of synergic dietary calcium enrichment and induced ferropenic anemia on antioxidant enzymes activity in rats

Objective

The aim of this study was to examine the synergism of dietary calcium enrichment (added to goat's or cow's milk) and induced nutritional ferropenic anemia on oxidative status.

Methods

Control rats and rats with induced nutritional ferropenic anemia were fed for 14 d with diets containing normal (5000 mg/kg) or double (10 000 mg/kg) the recommended calcium content. Thiobarbituric acid-reactive substances in plasma were measured, as were the activities of the antioxidant enzyme catalase, copper/zinc superoxide dismutase, and glutathione peroxidase in erythrocyte cytosol.

Results

Dietary calcium enrichment did not affect oxidative stress as assessed by thiobarbituric acid-reactive substances; however, it significantly upregulated the activities of some antioxidant enzymes examined in the erythrocyte cytosol. In particular, adding calcium to standard or milk-based diets significantly increased glutathione peroxidase activity in control and anemic rats and copper/zinc superoxide dismutase activity in control rats.

Conclusion

The increased activities of glutathione peroxidase and copper/zinc superoxide dismutase induced by dietary calcium enrichment suggest that calcium supplementation may protect against oxidative stress even in nutritionally induced ferropenic anemia.     

Study on the antioxidant activity of tea flowers (Camellia sinensis)

Major chemical compounds in different extracts from tea flowers (Camellia sinensis) were analyzed. Distilled water or 70% ethanol extracts were then fractionated with chloroform, ethyl acetate and n-butanol, respectively. Each extract fraction was tested its scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl free radicals. The results showed that ethyl acetate fraction of ethanol-extract of tea flower (EEA) exhibited the highest quenching activity to hydroxyl radicals (SC50 11.6 mug/ml), followed by ethanol-extract (EE) of tea flower (SC50 19.7 microg/ml). Same tea flower extract showed big different scavenging activities on different free radicals. EEA quenched 80% of hydroxyl radicals generated by Fenton's reaction, however, only 40% of DPPH radical was scavenged in the Fe (II)-H2O2 -luminol system. The contents of flavones, polyphenols and catechins in EE and EEA fractions were higher than those in other fractions. We suggest that the stronger scavenging abilities to free radicals might be due to polyphenols, EGCG, ECG and flavones. However, the water extracts of tea flower and their fractions showed lower antioxidant activity for their inhibitory effect on hydroxyl radicals and DPPH radicals.     

玉米黄质的调脂作用及抗高脂诱发氧化损伤的动物实验研究

目的：探讨玉米黄质对脂质代谢的调节作用,并观察其对高脂诱发的主动脉及肝组织脂质过氧化损伤的影响。方法：采用高脂喂饲模型,将40只实验动物鹌鹑随机分为4组：对照组、高脂模型组、玉米黄质低、高两剂量组,分别给予普通饲料（对照组）和高脂饲料（高脂模型组、玉米黄质低、高两剂量组）喂养;喂养同时,玉米黄质低、高两剂量组再分别以306、0 mg/kg剂量玉米黄质标准给予灌胃。实验结束时取空腹血,测定血清总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）及丙二醛含量、血清超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）及诱导型一氧化氮合酶（iNOS）活性;检测各组动物肝脏组织中总胆固醇（TC）、甘油三酯（TG）含量及超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、诱导型一氧化氮合酶（iNOS）活性、丙二醛（MDA）及还原型谷胱甘肽（GSH）含量;并采用HE染色观察主动脉血管病理变化。结果：与高脂模型组相比,玉米黄质组血清甘油三酯、总胆固醇、低密度脂蛋白胆固醇含量明显降低,而血清高密度脂蛋白胆固醇含量明显增高;肝脏总甘油三酯及总胆固醇的合成也受到强烈抑制;玉米黄质组血清和肝组织中超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性明显提高,而诱导型一氧化氮合酶活性下降、丙二醛含量减少;肝组织中还原型谷胱甘肽含量明显上升。结论：玉米黄质具有良好的降脂功效,并对高脂诱发的血管及肝组织过氧化损伤有明显的抑制作用;高剂量玉米黄质改善效果更理想。     

Studies on the antioxidant activity of milk caseins

The antioxidant properties of milk casein subunits (alpha-casein, beta-casein and kappa-casein) were evaluated in liposomal models. All the subunits of casein are able to inhibit Fe-induced peroxidation of arachidonic acid inserted into multilamellar liposomes of dipalmitoylphosphatidylcholine (0.2 mM and 0.8 mM, respectively). The peroxidation was monitored as thiobarbituric acid reactive substances, and the strongest inhibitory effect occurred when 500 micrograms of alpha-casein were added to 0.5 ml of liposomal suspension. At this concentration, peroxidation was completely inhibited in our experimental conditions (incubation for 2 h at room temperature, with a mixture of ferrous sulfate and ascorbate, 50 and 500 microM final concentration, respectively). The mechanisms of antioxidant action are complex, but the strongest effect is achieved by modifying the Fe2+/Fe3+ equilibrium; in fact, caseins seem to favour the autoxidation of iron, and thus inhibit lipid peroxidation.     

Anti-Inflammatory and Active Biological Properties of the Plant-Derived Bioactive Compounds Luteolin and Luteolin 7-Glucoside

Flavonoids are interesting molecules synthetized by plants. They can be found abundantly in seeds and fruits, determining the color, flavor, and other organoleptic characteristics, as well as contributing to important nutritional aspects. Beyond these characteristics, due to their biochemical properties and characteristics, they can be considered bioactive compounds. Several interesting studies have demonstrated their biological activity in different cellular and physiological processes in high-order organisms including humans. The flavonoid molecular structure confers the capability of reacting with and neutralizing reactive oxygen species (ROS), behaving as scavengers in all processes generating this class of molecules, such as UV irradiation, a process widely present in plant physiology. Importantly, the recent scientific literature has demonstrated that flavonoids, in human physiology, are active compounds acting not only as scavengers but also with the important role of counteracting the inflammation process. Among the wide variety of flavonoid molecules, significant results have been shown by investigating the role of the flavones luteolin and luteolin-7-O-glucoside (LUT-7G). For these compounds, experimental results demonstrated an interesting anti-inflammatory action, both in vitro and in vivo, in the interaction with JAK/STAT3, NF-κB, and other pathways described in this review. We also describe the effects in metabolic pathways connected with inflammation, such as cellular glycolysis, diabetes, lipid peroxidation, and effects in cancer cells. Moreover, the inhibition of inflammatory pathway in endothelial tissue, as well as the NLRP3 inflammasome assembly, demonstrates a key role in the progression of such phenomena. Since these micronutrient molecules can be obtained from food, their biochemical properties open new perspectives with respect to the long-term health status of healthy individuals, as well as their use as a coadjutant treatment in specific diseases.     

Tin(IV) complexes of pyrrolidinedithiocarbamate: synthesis, characterisation and antifungal activity

The reaction of ammonium pyrrolidinedithiocarbamate, [NH4{S2CN(CH2)4}], with SnCl2, [Sn(C6H5)2Cl2], [Sn(C6H5)3Cl], [Sn(C4H9)2Cl2] and [Sn(C6H11)3Cl] produced in good yield the compounds [Sn{S2CN(CH2)4}2Cl2] (1), [Sn{S2CN(CH2)4}2Ph2] (2), [Sn{S2CN(CH2)4}Ph3] (3), [Sn{S2CN(CH2)4}2 n-Bu2] (4) and [Sn{S2CN(CH2)4}Cy3] (5). The complexes were characterised by infrared, multinuclear NMR (1H, 13C{1H} and 119Sn{1H}) and 119Sn M?ssbauer spectroscopies. In addition, the crystal structure of 4 was determined by X-ray crystallography. The in vitro antifungal activity of the tin(IV) complexes as well of the ligand was performed on human pathogenic fungi, Candida albicans, in concentrations of 0.025; 0.050; 0.100; 0.200; 0.400; 0.800; 1.600 and 3.200 mM. The microorganism presented resistance to the dithiocarbamate ligand and all tin(IV) complexes tested were actives. The highest activity was found for compounds 1 and 4.     

原花青素的致突变性及抗氧化性实验研究

目的：原花青素的致突变性和抗氧化性研究。方法用Ames试验、小鼠微核试验和小鼠精子畸形试验研究原花青素的致突变性。按老龄小鼠血中丙二醛（ MDA）值分为5组（每组10只）,设空白对照组、溶剂对照组、41.67、83.33及250.0 mg/kg体重3个剂量组,观察给药后鼠血中超氧化物歧化酶（ SOD）、谷胱甘肽过氧化物酶（ GSH-Px）、丙二醛（ MDA）水平的变化。结果 Ames试验、小鼠骨髓细胞微核试验和小鼠精子畸形试验结果均为阴性。与空白对照组和溶剂对照组比较,83.33、250.0 mg/kg组老龄小鼠实验后红细胞MDA含量明显降低,250.0 mg/kg组全血GSH-PX活力明显增高（ P〈0.05）。结论在本实验条件下,原花青素未显示有致突变性;原花青素对老龄小鼠具有抗氧化功能。