The antioxidant effect of β-caryophyllene protects rat liver from carbon tetrachloride-induced fibrosis by inhibiting hepatic stellate cell activation.

Plant-based whole foods provide thousands of bioactive metabolites to the human diet that reduce the risk of developing chronic diseases. β-Caryophyllene (CAR) is a common constituent of the essential oil of numerous plants, vegetables, fruits and medicinal herbs, and has been used as a flavouring agent since the 1930 s. Here, we report the antioxidant activity of CAR, its protective effect on liver fibrosis and its inhibitory capacity on hepatic stellate cell (HSC) activation. CAR was tested for the inhibition of lipid peroxidation and as a free radical scavenger. CAR had higher inhibitory capacity on lipid peroxidation than probucol, α-humulene and α-tocopherol. Also, CAR showed high scavenging activities against hydroxyl radical and superoxide anion. The activity of 5-lipoxygenase, an enzyme that actively participates in fibrogenesis, was significantly inhibited by CAR. Carbon tetrachloride-treated rats received CAR at 2, 20 and 200 mg/kg. CAR significantly improved liver structure, and reduced fibrosis and the expression of Col1a1, Tgfb1 and Timp1 genes. Oxidative stress was used to establish a model of HSC activation with overproduction of extracellular matrix proteins. CAR (1 and 10 μm) increased cell viability and significantly reduced the expression of fibrotic marker genes. CAR, a sesquiterpene present in numerous plants and foods, is as a natural antioxidant that reduces carbon tetrachloride-mediated liver fibrosis and inhibits hepatic cell activation.

Mutations inducing divergent shifts of constitutive activity reveal different modes of binding among catecholamine analogues to the beta(2)-adrenergic receptor.

1. We compared the changes in binding energy generated by two mutations that shift in divergent directions the constitutive activity of the human beta(2) adrenergic receptor (beta(2)AR). 2. A constitutively activating mutant (CAM) and the double alanine replacement (AA mutant) of catechol-binding serines (S204A, S207A) in helix 5 were stably expressed in CHO cell lines, and used to measure the binding affinities of more than 40 adrenergic ligands. Moreover, the efficacy of the same group of compounds was determined as intrinsic activity for maximal adenylyl cyclase stimulation in wild-type beta(2)AR. 3. Although the two mutations had opposite effects on ligand affinity, the extents of change were in both cases largely correlated with the degree of ligand efficacy. This was particularly evident if the extra loss of binding energy due to hydrogen bond deletion in the AA mutant was taken into account. Thus the data demonstrate that there is an overall linkage between the configuration of the binding pocket and the intrinsic equilibrium between active and inactive receptor forms. 4. We also found that AA mutation-induced affinity changes for catecholamine congeners gradually lacking ethanolamine substituents were linearly correlated to the loss of affinity that such modifications of the ligand cause for wild-type receptor. This indicates that the strength of bonds between catechol ring and helix 5 is critically dependent on the rest of interactions of the beta-ethanolamine tail with other residues of the beta(2)-AR binding pocket.

Effets du cannabis oral et du dronabinol sur la capacité à conduire [Effects of oral cannabis and dronabinol on driving capacity]

Two retrospective epidemiologic studies have shown that cannabis is the main psychoactive substance detected in the blood of drivers suspected of driving under the influence of psychotropic drugs. An oral administration double-blind crossover study was carried out with eight healthy male subjects, aged 22 to 30 years, all occasional cannabis smokers. Three treatments and one placebo were administered to all participants at a two week interval: 20 mg dronabinol, 16.5 mg D9-tétrahydrocannabinol (THC) and 45.7 mg THC as a cannabis milk decoction. Participants were asked to report the subjective drug effects and their willingness to drive under various circumstances on a visual analog scale. Clinical observations, a psychomotor test and a tracking test on a driving simulator were also carried out. Compared to cannabis smoking, THC, 11-OH-THC and THC-COOH blood concentrations remained low through the whole study (<13.1 ng THC/mL,<24.7 ng 11-OH-THC/mL and<99.9 ng THC-COOH/mL). Two subjects experienced deep anxiety symptoms suggesting that this unwanted side-effect may occur when driving under the influence of cannabis or when driving and smoking a joint. No clear association could be found between these adverse reactions and a susceptibility gene to propensity to anxiety and psychotic symptoms (genetic polymorphism of the catechol-O-methyltransferase). The questionnaires have shown that the willingness to drive was lower when the drivers were assigned an insignificant task and was higher when the mission was of crucial importance. The subjects were aware of the effects of cannabis and their performances on the road sign and tracking test were greatly impaired, especially after ingestion of the strongest dose. The Cannabis Influence Factor (CIF) which relies on the molar ratio of active and inactive cannabinoids in blood provided a good estimate of the fitness to drive.

Deviant trajectories of cortical maturation in 22q11.2 deletion syndrome (22q11DS): a cross-sectional and longitudinal study.

22q11.2 deletion syndrome (22q11DS) is associated with an increased susceptibility to develop schizophrenia. Despite a large body of literature documenting abnormal brain structure in 22q11DS, cerebral changes associated with brain maturation in 22q11DS remained largely unexplored. To map cortical maturation from childhood to adulthood in 22q11.2 deletion syndrome, we used cerebral MRI from 59 patients with 22q11DS, aged 6 to 40, and 80 typically developing controls; three year follow-up assessments were also available for 32 patients and 31 matched controls. Cross-sectional cortical thickness trajectories during childhood and adolescence were approximated in age bins. Repeated-measures were also conducted with the longitudinal data. Within the group of patients with 22q11DS, exploratory measures of cortical thickness differences related to COMT polymorphism, IQ, and schizophrenia were also conducted. We observed deviant trajectories of cortical thickness changes with age in patients with 22q11DS. In affected preadolescents, larger prefrontal thickness was observed compared to age-matched controls. Afterward, we observed greater cortical loss in 22q11DS with a convergence of cortical thickness values by the end of adolescence. No compelling evidence for an effect of COMT polymorphism on cortical maturation was observed. Within 22q11DS, significant differences in cortical thickness were related to cognitive level in children and adolescents, and to schizophrenia in adults. Deviant trajectories of cortical thickness from childhood to adulthood provide strong in vivo cues for a defect in the programmed synaptic elimination, which in turn may explain the susceptibility of patients with 22q11DS to develop psychosis.

Daytime sleepiness and the COMT val158met polymorphism in patients with Parkinson disease.

STUDY OBJECTIVE: A preliminary study by our group suggested an association between daytime sleepiness and the catechol-O-methyltransferase (COMT) val158met polymorphism (rs4680) in patients with Parkinson disease (PD). We sought to confirm this association in a large group of patients with PD. DESIGN: Genetic association study in patients with PD. SETTING: Movement disorder sections at 2 university hospitals. PARTICIPANTS: PD patients with and without episodes of suddenly falling asleep matched for antiparkinsonian medication, disease duration, sex, and age, who participated in a previous genetic study on dopamine-receptor polymorphisms. INTERVENTIONS: Not applicable. MEASUREMENTS AND RESULTS: In this study, 240 patients with PD (154 men; age 65.1 +/- 6.1 years; disease duration 9.4 +/- 6.0 years) were included. Seventy had the met-met (LL), 116 the met-val (LH), and 54 the val-val (HH) genotype. In the combined LL+LH group (featuring reduced COMT activity), the mean Epworth Sleepiness Scale (ESS) score was 9.0 +/- 5.9 versus 11.0 +/- 6.1 in the HH (high COMT activity) group (P = .047). Forty-seven percent of the LL and LH patients had sudden sleep onset compared with 61% of the HH patients (P = .07). Logistic regression, however, showed that both pathologic ESS scores (i.e., > 10) and sudden sleep onset were predicted by subjective disease severity (P < .001 each) but not by the COMT genotype. CONCLUSIONS: Our previous finding that the L-allele may be associated with daytime sleepiness could not be confirmed in the present study. Altogether, our data do not support a clinically relevant effect of the COMT genotype on daytime sleepiness in PD.

Molecular genetics and treatment of narcolepsy.

Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness and cataplexy. The hypocretin/orexin deficiency is likely to be the key to its pathophysiology in most of cases although the cause of human narcolepsy remains elusive. Acting on a specific genetic background, an autoimmune process targeting hypocretin neurons in response to yet unknown environmental factors is the most probable hypothesis in most cases of human narcolepsy with cataplexy. Although narcolepsy presents one of the tightest associations with a specific human leukocyte antigen (HLA) (DQB1*0602), there is strong evidence that non-HLA genes also confer susceptibility. In addition to a point mutation in the prepro-hypocretin gene discovered in an atypical case, a few polymorphisms in monoaminergic and immune-related genes have been reported associated with narcolepsy. The treatment of narcolepsy has evolved significantly over the last few years. Available treatments include stimulants for hypersomnia with the quite recent widespread use of modafinil, antidepressants for cataplexy, and gamma-hydroxybutyrate for both symptoms. Recent pilot open trials with intravenous immunoglobulins appear an effective treatment of cataplexy if applied at early stages of narcolepsy. Finally, the discovery of hypocretin deficiency might open up new treatment perspectives.

The clc element of Pseudomonas sp. strain B13, a genomic island with various catabolic properties.

Pseudomonas sp. strain B13 is a bacterium known to degrade chloroaromatic compounds. The properties to use 3- and 4-chlorocatechol are determined by a self-transferable DNA element, the clc element, which normally resides at two locations in the cell's chromosome. Here we report the complete nucleotide sequence of the clc element, demonstrating the unique catabolic properties while showing its relatedness to genomic islands and integrative and conjugative elements rather than to other known catabolic plasmids. As far as catabolic functions, the clc element harbored, in addition to the genes for chlorocatechol degradation, a complete functional operon for 2-aminophenol degradation and genes for a putative aromatic compound transport protein and for a multicomponent aromatic ring dioxygenase similar to anthranilate hydroxylase. The genes for catabolic functions were inducible under various conditions, suggesting a network of catabolic pathway induction. For about half of the open reading frames (ORFs) on the clc element, no clear functional prediction could be given, although some indications were found for functions that were similar to plasmid conjugation. The region in which these ORFs were situated displayed a high overall conservation of nucleotide sequence and gene order to genomic regions in other recently completed bacterial genomes or to other genomic islands. Most notably, except for two discrete regions, the clc element was almost 100% identical over the whole length to a chromosomal region in Burkholderia xenovorans LB400. This indicates the dynamic evolution of this type of element and the continued transition between elements with a more pathogenic character and those with catabolic properties.

Medroxyprogesterone abrogates the inhibitory effects of estradiol on vascular smooth muscle cells by preventing estradiol metabolism.

Sequential conversion of estradiol (E) to 2/4-hydroxyestradiols and 2-/4-methoxyestradiols (MEs) by CYP450s and catechol-O-methyltransferase, respectively, contributes to the inhibitory effects of E on smooth muscle cells (SMCs) via estrogen receptor-independent mechanisms. Because medroxyprogesterone (MPA) is a substrate for CYP450s, we hypothesized that MPA may abrogate the inhibitory effects of E by competing for CYP450s and inhibiting the formation of 2/4-hydroxyestradiols and MEs. To test this hypothesis, we investigated the effects of E on SMC number, DNA and collagen synthesis, and migration in the presence and absence of MPA. The inhibitory effects of E on cell number, DNA synthesis, collagen synthesis, and SMC migration were significantly abrogated by MPA. For example, E (0.1micromol/L) reduced cell number to 51+/-3.6% of control, and this inhibitory effect was attenuated to 87.5+/-2.9% by MPA (10 nmol/L). Treatment with MPA alone did not alter any SMC parameters, and the abrogatory effects of MPA were not blocked by RU486 (progesterone-receptor antagonist), nor did treatment of SMCs with MPA influence the expression of estrogen receptor-alpha or estrogen receptor-beta. In SMCs and microsomal preparations, MPA inhibited the sequential conversion of E to 2-2/4-hydroxyestradiol and 2-ME. Moreover, as compared with microsomes treated with E alone, 2-ME formation was inhibited when SMCs were incubated with microsomal extracts incubated with E plus MPA. Our findings suggest that the inhibitory actions of MPA on the metabolism of E to 2/4-hydroxyestradiols and MEs may negate the cardiovascular protective actions of estradiol in postmenopausal women receiving estradiol therapy combined with administration of MPA.

Detection of siderophores in endophytic bacteria Methylobacterium spp. associated with Xylella fastidiosa subsp. pauca

The objective of this work was to study the production of siderophores by endophytic bacteria Methylobacterium spp., which occupy the same ecological niche as Xylella fastidiosa subsp. pauca (Xfp) in citrus plants. The siderophore production of Methylobacterium strains was tested according to chromeazurol agar assay test (CAS), Csáky test (hydroxamate-type) and Arnow test (catechol-type). In addition, the ability of Xfp to use siderophores, in vitro, produced by endophytic bacteria as source of iron, was evaluated. All 37 strains of Methylobacterium spp. tested were CAS-positive for siderophore production. Methylobacterium spp. produced hydroxamate-type, but not catechol-type siderophores. In vitro growth of Xfp was stimulated by the presence of supernatant siderophores of endophytic Methylobacterium mesophilicum.

Functional diversity of bacterial genes associated with aromatic hydrocarbon degradation in anthropogenic dark earth of Amazonia

The objective of this work was to evaluate the catabolic gene diversity for the bacterial degradation of aromatic hydrocarbons in anthropogenic dark earth of Amazonia (ADE) and their biochar (BC). Functional diversity analyses in ADE soils can provide information on how adaptive microorganisms may influence the fertility of soils and what is their involvement in biogeochemical cycles. For this, clone libraries containing the gene encoding for the alpha subunit of aromatic ring-hydroxylating dioxygenases (α-ARHD bacterial gene) were constructed, totaling 800 clones. These libraries were prepared from samples of an ADE soil under two different land uses, located at the Caldeirão Experimental Station - secondary forest (SF) and agriculture (AG) -, and the biochar (SF_BC and AG_BC, respectively). Heterogeneity estimates indicated greater diversity in BC libraries; and Venn diagrams showed more unique operational protein clusters (OPC) in the SF_BC library than the ADE soil, which indicates that specific metabolic processes may occur in biochar. Phylogenetic analysis showed unidentified dioxygenases in ADE soils. Libraries containing functional gene encoding for the alpha subunit of the aromatic ring-hydroxylating dioxygenases (ARHD) gene from biochar show higher diversity indices than those of ADE under secondary forest and agriculture.

Surface functionalization of alumina ceramic foams with organic ligands.

Different anchoring groups have been studied with the aim of covalently binding organic linkers to the surface of alumina ceramic foams. The results suggested that a higher degree of functionalization was achieved with a pyrogallol derivative - as compared to its catechol analogue - based on the XPS analysis of the ceramic surface. The conjugation of organic ligands to the surface of these alumina materials was corroborated by DNP-MAS NMR measurements.

Genetic Factors in the Regulation of Striatal and Extrastriatal Dopamine D2 Receptor Expression

Positron emission tomography (PET) studies on healthy individuals have revealed a marked interindividual variability in striatal dopamine D2 receptor density that can be partly accounted for by genetic factors. The examination of the extrastriatal lowdensity D2 receptor populations has been impeded by the lack of suitable tracers. However, the quantification of these D2 receptor populations is now feasible with recently developed PET radioligands. The objective of this thesis was to study brain neurobiological correlates of common functional genetic variants residing in candidate genes relevant for D2 receptor functioning. For this purpose, healthy subjects were studied with PET imaging using [₁₁C]raclopride and [₁₁C]FLB457 as radioligands. The candidate genes examined in this work were the human D2 receptor gene (DRD2) and the catechol-Omethyltransferase gene (COMT). The region-specific genotypic influences were explored by comparing D2 receptor binding properties in the striatum, the cortex and the thalamus. As an additional study objective, the relationship between cortical D2 receptor density and a cognitive phenotype i.e. verbal memory and learning was assessed. The main finding of this study was that DRD2 C957T genotype altered markedly D2 receptor density in the cortex and the thalamus whereas in the striatum the C957T genotype affected D2 receptor affinity, but not density. Furthermore, the A1 allele of the DRD2-related TaqIA polymorphism showed increased cortical and thalamic D2 receptor density, but had the opposite effect on striatal D2 receptor density. The DRD2 –141C Ins/Del or the COMT Val158Met genotypes did not change D2 receptor binding properties. Finally, unlike previously reported, cortical D2 receptor density did not show any significant correlation with verbal memory function. The results of this study suggest that the C957T and the TaqIA genotypes have region-specific neurobiological correlates in brain dopamine D2 receptor availability in vivo. The biological mechanisms underlying these findings are unclear, but they may be related to the region-specific regulation of dopamine neurotranssion, gene/receptor expression and epigenesis. These findings contribute to the understanding of the genetic regulation of dopamine and D2 receptor-related brain functions in vivo in man. In addition, the results provide potentially useful endophenotypes for genetic research on psychiatric and neurological disorders.

Materiais à base de óxido de ferro para oxidação de compostos presentes no efluente da despolpa do café

Materials based on pure iron oxide and impregnated with niobia (Nb2O5) were prepared. Their catalytic activities were tested on the oxidation of compounds present in the wastewater from the processing of coffee berries. Particularly caffeine and catechol were tested. The oxidation reactions were carried out with the following systems (i) UV/H2O2, (ii) photo-Fenton and (iii) heterogeneous Fenton. All materials were characterized with X-ray diffraction, Mössbauer and infrared spectroscopy. Iron was mainly in the forms of goethite and maghemite. The oxidation kinetics were monitored by UV-vis and the oxidation products were monitored by mass spectrometry. The photo-Fenton reaction presented highest oxidation efficiency, removing 98% of all caffeine and catechol contents.

Degradação de benzeno, tolueno e xilenos em águas contaminadas por gasolina, utilizando-se processos foto-Fenton

In this work the potentiality of photo-Fenton processes were investigated toward the degradation of aromatic hydrocarbons (BTXs) from water contaminated with gasoline. The main results demonstrated that BTXs can be quickly degraded by photo-Fenton process assisted by solar or artificial UV-A radiation, degradation that leads to generation of characteristic phenolic transient species (ie. phenol, hydroquinone and catechol). In the treatment of contaminated water by photo-Fenton processes assisted by solar light, complete BTXs removal was observed in reaction times of about 5 min. Mineralization of about 90% was also observed by applying a multiple H2O2 addition system.

Evaluation of antiradical assays used in determining the antioxidant capacity of pure compounds and plant extracts

The efficiency of the chemiluminescence luminol method and colorimetric DPPH and ABTS methods in evaluating the antiradical capacity of pure compounds and plant extracts with antioxidant potential is compared. In case of pure compounds, the values of parameter 'n' (number of radicals quenched per molecule of antiradical) for ascorbic acid, p-hydroquinone, catechol, quercetin, and rutin are similar when measured by colorimetric assays; however, considerably lower values of n are obtained with the luminol assay. The antiradical activity of extracts from male and female individuals of Baccharis burchelli and Baccharis crispa were determined by the luminol assay and expressed using the new Trolox® percentage (%Trolox®) parameter.