Olive phenols efficiently inhibit the oxidation of serum albumin-bound linoleic acid and butyrylcholine esterase.

Background: Olive phenols are widely consumed in the Mediterranean diet and can be detected in human plasma. Here, the capacity of olive phenols and plasma metabolites to inhibit lipid and protein oxidations is investigated in two plasma models.

Methods: The accumulation of lipid oxidation products issued from the oxidation of linoleic acid bound to human serum albumin (HSA) by AAPH-derived peroxyl radicals is evaluated in the presence and absence of phenolic antioxidants.

Antioxidant phenylethanoid glycosides and a neolignan from Jacaranda caucana.

Extracts from several plants of the family Bignoniaceae from Panama were submitted to a rapid DPPH TLC test for the detection of radical-scavenging activity. The MeOH extract of the stems of Jacaranda caucana, a tree that grows from Costa Rica to Colombia, was selected due to its interesting activity and the lack of phytochemical studies on the polar extract. This extract was partitioned between ethyl acetate, butanol, and water.

Monoamine oxidase inhibition by Rhodiola rosea L. roots.

Aim Of The Study: Rhodiola rosea L. (Crassulaceae) is traditionally used in Eastern Europe and Asia to stimulate the nervous system, enhance physical and mental performance, treat fatigue, psychological stress and depression. In order to investigate the influence of Rhodiola rosea L.

Antioxidant C-glucosylxanthones from the leaves of Arrabidaea patellifera.

Chemical investigation of the methanol extract from the leaves of Arrabidaea patellifera, a Bignoniaceae from Panama, afforded mangiferin, isomangiferin, and six new derivatives (3'-O-p-hydroxybenzoylmangiferin, 3'-O-trans-coumaroylmangiferin, 6'-O-trans-coumaroylmangiferin, 3'-O-trans-cinnamoylmangiferin, 3'-O-trans-caffeoylmangiferin, and 3'-O-benzoylmangiferin). All these compounds had antioxidant and radical-scavenging activities, and four of them were relatively active in vitro against Plasmodium falciparum. The structures were determined by spectrometric and chemical methods, including 1D and 2D NMR experiments and MS analysis.

Structure-antioxidant activity relationships in a series of NO-donor phenols.

Recently we reported a new class of NO-donor phenols that could be of interest in the treatment of many forms of cardiovascular disease (CD). Their potencies as inhibitors of ferrous salt/ascorbate-induced peroxidation of membrane lipids of rat hepatocytes were assessed as pIC(50) values through the TBARS assay. In this work we aimed to find quantitative relationships between the antioxidant activity of these compounds and appropriate molecular descriptors.

In vitro screening assays to identify natural or synthetic acetylcholinesterase inhibitors: thin layer chromatography versus microplate methods.

Acetylcholinesterase inhibitors (AChEI) are currently still the best available pharmacotherapy for Alzheimer patients. Successful screening for new AChEI relies on effective and fast assays. Two colorimetric screening assays frequently used to search for new AChEI, namely a thin layer chromatography (TLC) assay with Fast Blue B salt as reagent and a 96-well plate assay based on Ellman's method, were compared.

Novel screening assay for antioxidant protection against peroxyl radical-induced loss of protein function.

Oxidative damage to proteins, implicated amongst other in the etiology and progression of Parkinson's disease (PD) and Alzheimer's disease (AD), results in the loss of specific biological protein function. A simple, sensitive, and cost-effective fluorimetric test to assess the antioxidant capacity of new chemical entities to protect proteins from loss of activity caused by reactive oxygen species (ROS) was developed using alkaline phosphatase (ALP) as model protein. Protein oxidation was induced by 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) and the decrease in catalytic activity of ALP to hydrolyze 4-methylumbelliferyl phosphate (4-MUP) to fluorescent 4-methylumbelliferone (4-MU) was monitored as a marker of protein degradation.

NO-donor melatonin derivatives: synthesis and in vitro pharmacological characterization.

Numerous studies document that melatonin possesses a broad-spectrum antioxidant activity. It traps a number of reactive oxygen species (ROS) such as hydroxyl and peroxyl radicals, singlet oxygen and hypochlorous acid. It also inhibits peroxynitrite-induced reactions.

Impact of species-dependent differences on screening, design, and development of MAO B inhibitors.

The impact of species-dependent differences between human and rat MAO B on inhibitor screening was evidenced for two classes of compounds, coumarin and 5H-indeno[1,2-c]pyridazin-5-one derivatives. All examined compounds have shown a greater inhibitor potency toward human MAO B than toward rat MAO B. Moreover, no correlation was found between human and rat pIC(50) values.

Development of an in vitro rat intestine segmental perfusion model to investigate permeability and predict oral fraction absorbed.

Purpose: The aims of the study are to develop and evaluate an in vitro rat intestine segmental perfusion model for the prediction of the oral fraction absorbed of compounds and to assess the ability of the model to study intestinal metabolism.

Methods: The system consisted of a perfusion cell with a rat intestinal segment and three perfusion circulations (donor, receiver, and rinsing circulation). Lucifer yellow (LY) was applied as internal standard together with test compounds in the donor circulation.

Human recombinant monoamine oxidase B as reliable and efficient enzyme source for inhibitor screening.

Interest in inhibitors of monoamine oxidase type B (MAO B) has grown in recent years, due to their therapeutic potential in aging-related neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. This study is devoted to the use of human recombinant MAO B obtained from a Baculovirus expression system (Supersomes MAO B, BD Gentest, MA, USA) as reliable and efficient enzyme source for MAO B inhibitor screening. Comparison of inhibition potencies (pIC50 values) determined with human cloned and human platelet MAO B for the two series of MAO B inhibitors, coumarin and 5H-indeno[1,2-c]pyridazin-5-one derivatives, showed that the difference between pIC50 values obtained with the two enzyme sources was not significant (P>0.

Gd-BOPTA transport into rat hepatocytes: pharmacokinetic analysis of dynamic magnetic resonance images using a hollow-fiber bioreactor.

Rationale And Objectives: To investigate the transport of the hepatobiliary magnetic resonance (MR) imaging contrast agent Gd-BOPTA into rat hepatocytes.

Materials And Methods: In a MR-compatible hollow-fiber bioreactor containing hepatocytes, MR signal intensity was measured over time during the perfusion of Gd-BOPTA. For comparison, the perfusion of an extracellular contrast agent (Gd-DTPA) was also studied.

Liposome/water lipophilicity: methods, information content, and pharmaceutical applications.

This review discusses liposome/water lipophilicity in terms of the structure of liposomes, experimental methods, and information content. In a first part, the structural properties of the hydrophobic core and polar surface of liposomes are examined in the light of potential interactions with solute molecules. Particular emphasis is placed on the physicochemical properties of polar headgroups of lipids in liposomes.

Hollow fiber bioreactor: new development for the study of contrast agent transport into hepatocytes by magnetic resonance imaging.

The aim of our study was to develop a magnetic resonance (MR)-compatible in vitro model containing freshly isolated rat hepatocytes to study the transport of hepatobiliary contrast agents (CA) by MR imaging (MRI). We set up a perfusion system including a perfusion circuit, a heating device, an oxygenator, and a hollow fiber bioreactor (HFB). The role of the porosity and surface of the hollow fiber (HF) as well as the perfusate flow rate applied on the diffusion of CAs and O2 was determined.

Hepatocyte hollow-fibre bioreactors: design, set-up, validation and applications.

Hepatocytes carry out many vital biological functions, such as synthetic and catabolic reactions, detoxification and excretion. Due to their ability to restore a tissue-like environment, hollow-fibre bioreactors (HFBs) show great potential among the different systems used to culture hepatocytes. Several designs of HFBs have been proposed in which hepatocytes or hepatocyte-derived cell lines can be cultured in suspensions or on a solid support.

Quantitative structure-permeation relationships for solute transport across silicone membranes.

Purpose: The purpose of this work was to assess the molecular properties that influence solute permeation across siliconemembranes and to compare the results with transport across human skin.

Methods: The permeability coefficients (log Kp) of a series of model solutes across silicone membranes were determined from the analysis of simple transport experiments using a pseudosteady-state mathematical model of the diffusion process. Subsequently, structure permeation relationships were constructed and examined, focusing in particular on the difference between solute octanol/water and 1,2 dichloroethane/water partition coefficients (deltalog P(oct-dce)), which re ported upon H-bond donor activity, and the computationally derived molecular hydrogen-bonding potential.

Molecular factors influencing retention on immobilized artifical membranes (IAM) compared to partitioning in liposomes and n-octanol.

Purpose: To assess the effect of molecular factors influencing retention on immobilized artificial membrane (IAM) high-performance liquid chromatography columns compared to liposomal partitioning and traditional n-octanol/water partition coefficients.

Methods: IAM capacity factors were measured at pH 7.0 on an IAM.