Screening of anti-obesity agent from herbal mixtures

Globally, one in three of the World's adults are overweight and one in 10 is obese. By 2015, World Health Organization (WHO) estimates the number of chubby adults will balloon to 2.3 billion--Equal to the combined populations of China, Europe and the United States. The discovery of bioactive compounds from herbs is one possible way to control obesity and to prevent or reduce the risks of developing various obesity-related diseases. In this study, we screened anti-obesity agents such as methyl gallate from the herbal composition known as HemoHIM that actively inhibits lipid formation as evidenced by Oil Red O staining and triglyceride (TG) contents in 3T3-L1 adipocytes, suggesting their use as an anti-obesity agent. Furthermore, the amount of glycerol released from cells into the medium had increased by treatment of methyl gallate in a concentration-dependent manner. The present study suggests that a promising anti-obesity agent like methyl gallate might be of therapeutic interest for the treatment of obesity.     

Metal components analysis of metallothionein-III in the brain sections of metallothionein-I and metallothionein-II null mice exposed to mercury vapor with HPLC/ICP-MS

Mercury vapor is effectively absorbed via inhalation and easily passes through the blood–brain barrier; therefore, mercury poisoning with primarily central nervous system symptoms occurs. Metallothionein (MT) is a cysteine-rich metal-binding protein and plays a protective role in heavy-metal poisoning and it is associated with the metabolism of trace elements. Two MT isoforms, MT-I and MT-II, are expressed coordinately in all mammalian tissues, whereas MT-III is a brain-specific member of the MT family. MT-III binds zinc and copper physiologically and is seemed to have important neurophysiological and neuromodulatory functions. The MT functions and metal components of MTs in the brain after mercury vapor exposure are of much interest; however, until now they have not been fully examined. In this study, the influences of the lack of MT-I and MT-II on mercury accumulation in the brain and the changes of zinc and copper concentrations and metal components of MTs were examined after mercury vapor exposure by using MT-I, II null mice and 129/Sv (wild-type) mice as experimental animals. MT-I, II null mice and wild-type mice were exposed to mercury vapor or an air stream for 2 h and were killed 24 h later. The brain was dissected into the cerebral cortex, the cerebellum, and the hippocampus. The concentrations of mercury in each brain section were determined by cold vapor atomic absorption spectrometry. The concentrations of mercury, copper, and zinc in each brain section were determined by inductively coupled plasma mass spectrometry (ICP-MS). The mercury accumulated in brains after mercury vapor exposure for MT-I, II null mice and wild-type mice. The mercury levels of MT-I, II null mice in each brain section were significantly higher than those of wild-type mice after mercury vapor exposure. A significant change of zinc concentrations with the following mercury vapor exposure for MT-I, II null mice was observed only in the cerebellum analyzed by two-way analysis of variance. As for zinc, the copper concentrations only changed significantly in the cerebellum. Metal components of metal-binding proteins of soluble fractions in the brain sections were analyzed by size-exclusion high-performance liquid chromatography (HPLC) connected with ICP-MS. From the results of HPLC/ICP-MS analyses, it was concluded that the mercury components of MT-III and high molecular weight metal-binding proteins in the cerebellum of MT-I, II null mice were much higher than those of wild-type mice. It was suggested that MT-III is associated with the storage of mercury in conditions lacking MT-I, and MT-II. It was also suggested that the physiological role of MT-III and some kind of high molecular weight proteins might be impaired by exposure to mercury vapor and lack of MT-I and MT-II.     

Electroanalysis of dopamine at a gold electrode modified with N-acetylcysteine self-assembled monolayer

Voltammetric behavior of dopamine (DA) on a gold electrode modified with the self-assembled monolayer (SAM) of N-acetylcysteine has been investigated, and one pair of well-defined redox peaks of dopamine is obtained at the SAM modified gold electrode. The oxidation peak current increases linearly with the concentration of dopamine in the range of  mol l⁻¹. The detection limit is 8.0×10⁻⁷ mol l⁻¹. This method will be applicable to the determination of dopamine in injection of dopamine hydrochloride, and the good recovery of dopamine is obtained. Furthermore, The SAM modified gold electrode can resolve well the voltammetric responses of dopamine and ascorbic acid (AA), so it can also be applied to the determination of dopamine in the presence of ascorbic acid.     

Nitrogen-doped carbon nanotubes modified with gold nanoparticles for simultaneous analysis of N-acetylcysteine and acetaminophen

A novel film consisting of nitrogen-doped multi-walled carbon nanotubes modified with gold nanoparticles (further denoted as N-MWCNTs/AuNPs) was fabricated and applied for the simultaneous electrochemical analysis of N-acetylcysteine (NAC) and acetaminophen (AC) in phosphate buffer solution (PBS, pH 7.0). The fabricated film exhibits powerful response towards simultaneous analysis of NAC and AC followed by well-separated cyclic voltammetric waves (～440 mV). The oxidation peak currents of NAC and AC increase linearly with their concentrations in the ranges of 0.100–1.510 mM and 0.063–0.190 mM, respectively. The detection limits of N-MWCNTs/AuNPs towards NAC and AC were estimated to be 3.0 and 0.35 μM, respectively. The good catalytic activity, the high detection ability, and the great stability of N-MWCNTs/AuNPs verify that such composite materials are extremely promising for the construction of biosensors.     

Determination of ethacrynic acid in pharmaceutical formulations by difference ultraviolet spectrophotometry after derivatisation with N-acetylcysteine

A selective difference spectrophotometric procedure is described for the assay of ethacrynic acid (a diuretic drug) in pharmaceutical dosage forms. The method is based on the reaction of the drug with N-acetylcysteine at pH 7.4 and ambient temperature, affording thiol adducts having different spectral properties, and involves the measurement of the absorbance of the reaction mixture relative to an equimolar solution of unreacted ethacrynic acid. The absorbance at 270 nm (A(270)) and the absorbance difference, delta A=A(270-A(244), obtained from the difference spectrum, were found to be linearly correlated with the drug concentration. The proposed spectrophotometric procedure was applied successfully to the determination of ethacrynic acid in pharmaceutical formulations using a reversed-phase high-performance liquid chromatographic procedure as a reference method.     

A new flavone glucoside together with known ellagitannins and flavones with anti-diabetic and anti-obesity activities from the flowers of pomegranate (Punica granatum)

A new flavone glucoside tricetin 4′-O-β-glucopyranoside (1) and four known ellagitannins and flavones tricetin (2), luteolin (3), ellagic acid (4), and granatin B (5) were isolated from the flowers of Punica granatum L. (Lythraceae). Their structures were established by 1D and 2D NMR as well as mass spectrometry analyses. Among all tested compounds, tricetin (2) exhibited the strongest α-glucosidase inhibitory activity that was comparable to the anti-diabetic drug acarbose. Comparative structure-function analysis of tri-, tetra-, and pentahydroxy flavones [apigenin, luteolin (3), and tricetin (2), respectively] suggested that a greater number of hydroxyl groups on the flavone molecule enhanced its suppression of α-glucosidase, α-amylase, and lipase activities.     

高效液相色谱-串联质谱法同时测定血液中的15种减肥药物

建立了一种专属、灵敏的同时测定血液中咖啡因、盐酸西布曲明等15种减肥药的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经乙腈沉淀后,进入HPLC-MS/MS中分析检测。以甲醇和含0.1%(v/v)冰醋酸的20 mmol/L醋酸铵溶液作为流动相,采用梯度洗脱方式,以UltimateXB-C18为色谱柱进行HPLC分析;质谱分析采用电喷雾离子源,正负离子快速切换扫描,选择反应监测模式检测。15种减肥药的定量限在0.001～0.05 mg/L内,各种药物的灵敏度较高,各成分的线性相关系数均大于0.99,精密度均小于12.3%,回收率范围为77.3%～110.8%。研究了这15种药物的质谱特征。该方法灵敏、简便、快捷、专属性强,可用于动物实验样品中减肥药物的含量测定,并且对其他药品、食品中目标减肥药物的测定具有借鉴意义。     

Determination of N-acetylcysteine in human plasma by gas chromatography-mass spectrometry

An automatic mass spectrometric method for the quantitation of N-acetylcysteine (NAC) in human plasma has been developed. NAC was extracted from plasma with ethyl acetate and derivatized in two steps with 2-propanol and pentafluoropropionic anhydride. The volatile derivative obtained was ideal for gas chromatographic-mass spectrometric analysis. Data obtained by analysing the plasma of healthy volunteers to whom 600 mg of NAC had been orally given are reported.     

Gold nanoparticles synthesized with Poria cocos modulates the anti-obesity parameters in high-fat diet and streptozotocin induced obese diabetes rat model

Obesity is a foremost health issue that affects about 1.6 million people out of which 400 million worldwide. Epidemiological evidences prove obesity is the primary cause for various metabolic ailments e.g. diabetes. Poria cocos possess extensive biological actions, for instance, antioxidant, anti-inflammatory, antitumor, immunomodulatory actions. The primary limitation of all phytomedicine was their poor bioavailability hence in this investigation, we bio-fabricated the gold nanoparticles from Poria cocos aqueous extract and inspected their potency to treat obesity. Obese rat model were produced via fed the young female rats with high fat food for 8 weeks regimen. Further to confirm the potency of Poria cocos gold nanoparticles against obesity induced metabolic disorders we treated obese rats with low dose streptozotocin in the conclusion of the investigational time. The synthesis of Poria cocos gold-nanoparticles was evidenced via the UV-Spectroscopic study and characterized with SEM, TEM and EDAX studies. The anti-obesity actions of Poria cocos gold-nanoparticles were investigated by estimating the glucose profile, kidney markers, lipid profile, inflammatory cytokines, adipocyte markers, antioxidants in the Poria cocos gold nanoparticles treated obese rats. To confirm the Poria cocos gold nanoparticles role on inhibiting the obesity induced metabolic disorders we analyzed the histopathological changes in cardiac tissues. Our physical characterization confirms the synthesized Poria cocos gold nanoparticles assure the distinctions of influential nanoparticles to be utilized for the treatment. The results from biochemical and histopathological analysis confirms Poria cocos gold nanoparticles is a persuasive antidiabetic, anti-inflammatory, antioxidant, anti-obesity drug. Overall our results authentically confirm Poria cocos gold nanoparticles is a potent anti-obesity drug and it also protects from obesity induced metabolic disorders.     

Association of polyacrylic acids with metronidazole

Intermolecular interactions in mixtures of dilute solutions of poly acids with 1-(β-hydroxyethyl)-2-methyl-5-nitroimidazole were studied by viscometry, potentiometry, and IR spectroscopy. The rheological behavior of dilute aqueous solutions of polyacrylic and polymethacrylic acids and of metronidazole at a total concentration of the components of 0.1 wt % was examined. The composition dependences of the specific viscosity show positive deviations from the additivity with a maximum at approximately 50% relative content of the poly acid. In these mixtures, polyelectrolytic complexes stabilized by hydrogen bonds are formed. The strength of the associates increases with an increase in the temperature to 40°C. Hydrophobic groups in macromolecules of the poly acid play a significant role in stabilization of the complexes. In aqueous solutions metronidazole interacts with acrylic, methacrylic, and hydrochloric acids, and in the solid state it forms linear hydrogen-bonded associates.     

Association of (Ca + Mg)-ATPase activity with ATP-dependent Ca uptake in vesicles prepared from human erythrocytes.

Ghost membranes prepared from human erythrocytes exhibit 2 distinct (Ca + Mg)-ATPase1 activities (Quist and Roufogalis, Arch Biochem Biophys 168:240, 1975). (Ca + Mg)-ATPase activity dependent on a water soluble protein fraction is selectively lost from ghost membranes during preparation of vesicles under low ionic strength, slightly alkaline conditions. In this study, the Ca2+ dependence of the remaining membrane bound (Ca + Mg)-ATPase activity and ATP-dependent Ca uptake in vesicles were compared. The Ca2+ activation curves for (Ca + Mg)-ATPase activity and Ca uptake into vesicles were parallel over a Ca2+ range of 0.3-330 micrometer, and both curves have 2 apparent KA values for Ca2+ of 0.45 and 100 micrometer. Addition of a concentrated soluble protein fraction containing predominantly spectrin to the vesicles increased (Ca + Mg)-ATPase activity over twofold but did not affect the rate of Ca uptake. These findings suggest that the (Ca + Mg)-ATPase activity remaining in vesicles after extraction of the water soluble proteins is associated with the Ca pump whereas (Ca + Mg)-ATPase activity dependent on the soluble protein fraction is associated with some other function.     

Quantification of N-acetylcysteine in pharmaceuticals using cobalt phthalocyanine modified graphite electrodes

Flow injection analysis (FIA) with amperometric detection was employed for the quantification of N-acetylcysteine (NAC) in pharmaceutical formulations, utilizing an ordinary pyrolytic graphite (OPG) electrode modified with cobalt phthalocyanine (CoPc). Cyclic voltammetry was used in preliminary studies to establish the best conditions for NAC analysis. In FIA-amperometric experiments the OPG-CoPc electrode exhibited sharp and reproducible current peaks over a wide linear working range (5.0 × 10⁻⁵-1.0 × 10⁻³ mol L⁻¹) in 0.1 mol L⁻¹ NaOH solution. High sensitivity (130 mA mol⁻¹ cm²) and a low detection limit (9.0 × 10⁻⁷ mol L⁻¹) were achieved using the sensor. The repeatability (R.S.D.%) for 13 successive flow injections of a solution containing 5.0 × 10⁻⁴ mol L⁻¹ NAC was 1.1%. The new procedure was applied in analyses of commercial pharmaceutical products and the results were in excellent agreement with those obtained using the official titrimetric method. The proposed amperometric method is highly suitable for quality control analyses of NAC in pharmaceuticals since it is rapid, precise and requires much less work than the recommended titrimetric method.     

Determination of N-acetylcysteine via its effect on the aggregation of gold nanoparticles

The effect of thiol compounds on the kinetics of the aggregation of gold nanoparticles in the presence of the cationic surfactant cetyltrimethyl ammonium bromide has been studied. It was applied to the determination of N-acetylcysteine using the stopped-flow mixing technique along with light scattering detection. The signal obtained was measured after about 5?s, and gave the analytical information for a calibration graph in the concentration range from 2.9 to 60???mol?L^?1 of N-acetylcysteine, and a detection limit of 0.87???mol?L^?1. The effect of other thiols on the system is also described. The relative standard deviation ranges between 0.6% and 3.5%. The method was applied to the determination of N-acetylcysteine in several pharmaceutical samples with recoveries that range from 97.7% to 101.1%.

Association, partition, and surface activity in biphasic systems displaying relaxation oscillations

Several biphasic systems giving rise to periodical Marangoni instability have been analyzed from the point of view of the physicochemical properties of the involved compounds. In each case, the compound at the origin of the oscillatory behavior has been identified: the reactant cetyltrimethylammonium bromide (CTAB) for the CTAB/picric acid (PH) system and the product of reaction dodecyl sulfate tetraalkylammonium (TAADS) for the sodium dodecyl sulfate/tetraalkylammonium bromide (SDS/TAAB) system. The properties of the latter system have been varied progressively by increasing the chain length of the tetraalkylammonium ion. Oscillations were observed whichever the direction of transfer (from water to dichloromethane and from dichloromethane to water). The comparison of the dynamic interfacial tension, recorded during transfer, to equilibrium measurements shows that the instability is favored when partition is highly in favor of the organic phase. The main criteria for the appearance of the instability are a high surface activity and a low interfacial adsorption.     

Fabrication of a nanostructure-based electrochemical sensor for simultaneous determination of N-acetylcysteine and acetaminophen

A carbon-paste electrode modified with 2,7-bis(ferrocenyl ethyl)fluoren-9-one (2,7-BF) and carbon nanotubes (CNTs) was used for the sensitive and selective voltammetric determination of N-acetylcysteine (NAC). The mediated oxidation of NAC at the modified electrode was investigated by cyclic voltammetry (CV). Also, the values of catalytic rate constant (k), and diffusion coefficient (D) for NAC were calculated. Differential pulse voltammetry (DPV) of NAC at the modified electrode exhibited two linear dynamic ranges with a detection limit (3σ) of 52.0 nmol L⁻¹. DPV was used for simultaneous determination of NAC and acetaminophen (AC) at the modified electrode, and quantitation of NAC and AC in some real samples by the standard addition method.     

Association of Molybdenum Ionic Species with Alumina Surface

The adsorption isotherms at 25, 45, and 65 degrees C of molybdenum solutions of concentration ranges between 10(-3) and 3x10(-2) M(Mo) (pH 4-5) on different alumina samples are investigated. The analysis is conducted using a modified Frumkin isotherm which takes a more realistic account of the lateral interaction between adsorbed species and considers that the adsorption takes place on the most basic OH groups on the surface of alumina. The results are discussed in view of the difference in solutions speciation, and the changes in the pH of the remaining supernatant solutions. The solution temperature, PZC of the used aluminas, the configuration of the basic OH groups on their surface, and the pore structure have been shown to intervene effectively. Copyright 2000 Academic Press.     

聚氧乙烯辛基酚醚与β-环糊精的缔合作用

用聚氧乙烯辛基酚醚(OP)作荧光探针研究了OP和β-环糊精(β-CD)的相互作用.结果表明,OP分子的正辛基基团和苯基基团被包络在β-CD空腔内;用1-溴代萘(BN)分子作磷光探针进一步考察了OP与β-CD分子的缔合方式及对BN分子所产生的空间效应,OP分子的正辛基以绕曲的方式位于β-CD空腔中,因空间效应使β-CD空腔进一步包络BN的能力下降.     

游离胆红素与固体碳酸钙的相互作用

应用红外光谱的方法研究了溶液中游离胆红素与固体碳酸钙的相互作用,探讨了色素型胆结石的形成机理.研究结果表明,溶液中游离的胆红素可以与固体碳酸钙作用,游离胆红素通过与固体碳酸钙表面的钙作用生成难溶性的胆红素钙络合物.牛磺胆酸钠、胆酸钠和脱氧胆酸钠的加入能阻止游离胆红素与碳酸钙的作用,其中加入牛磺胆酸钠后,游离胆红素几乎不与碳酸钙作用.