Search results for "metabolite"
showing 10 items of 551 documents
Toxicological implications of enzymatic control of reactive metabolites.
1990
Many foreign compounds are transformed into reactive metabolites, which may produce genotoxic effects by chemically altering critical biomolecules. Reactive metabolites are under the control of activating, inactivating and precursor sequestering enzymes. Such enzymes are under the long-term control of induction and repression, as well as the short-term control of post-translational modification and low molecular weight activators or inhibitors. In addition, the efficiency of these enzyme systems in preventing reactive metabolite-mediated toxicity is directed by their subcellular compartmentalization and isoenzymic multiplicity. Extrapolation from toxicological test systems to the human req…
The metabolism of mono-(2-ethylhexyl) phthalate (MEHP) and liver peroxisome proliferation in the hamster.
1988
This study has investigated the in vivo metabolism of mono-(2-ethylhexyl) phthalate (MEHP), the initial metabolite of di-(2-ethylhexyl) phthalate in mammals, and the hepatic peroxisome proliferation induced by this compound following multiple oral administration to hamsters. Hamsters received [14C]-MEHP, by gavage, at doses of 50 and 500 mg/kg body wt on each of three consecutive days. Urine was collected every 24 hours and metabolite profiles were determined using capillary gas-chromatography. Multiple high doses of MEHP (500 mg/kg) induced a change in the relative proportions of metabolites produced. As previously reported for the rat, metabolites derived from sequential ω-following by β…
Glycolysis/gluconeogenesis- and tricarboxylic acid cycle–related metabolites, Mediterranean diet, and type 2 diabetes
2020
Background: Glycolysis/gluconeogenesis and tricarboxylic acid (TCA) cycle metabolites have been associated with type 2 diabetes (T2D). However, the associations of these metabolites with T2D incidence and the potential effect of dietary interventions remain unclear. Objectives: We aimed to evaluate the association of baseline and 1-y changes in glycolysis/gluconeogenesis and TCA cycle metabolites with insulin resistance and T2D incidence, and the potential modifying effect of Mediterranean diet (MedDiet) interventions. Methods: We included 251 incident T2D cases and 638 noncases in a nested case-cohort study within the PREDIMED Study during median follow-up of 3.8 y. Participants were alloc…
The Gut Microbial Metabolite Trimethylamine-N-Oxide Is Present in Human Cerebrospinal Fluid
2017
Trimethylamine-N-oxide (TMAO) is a small organic molecule, derived from the intestinal and hepatic metabolism of dietary choline and carnitine. Although the involvement of TMAO in the framework of many chronic diseases has been recently described, no evidence on its putative role in the central nervous system has been provided. The aim of this study was to evaluate whether TMAO is present at detectable levels in human cerebrospinal fluid (CSF). CSF was collected for diagnostic purposes from 58 subjects by lumbar puncture and TMAO was quantified by using liquid chromatography coupled with multiple-reaction monitoring mass spectrometry. The molecule was detected in all samples, at concentrati…
Dairy consumption, plasma metabolites, and risk of type 2 diabetes.
2021
Background Epidemiologic studies have reported a modest inverse association between dairy consumption and the risk of type 2 diabetes (T2D). Whether plasma metabolite profiles associated with dairy consumption reflect this relationship remains unknown. Objectives We aimed to identify the plasma metabolites associated with total and specific dairy consumption, and to evaluate the association between the identified multi-metabolite profiles and T2D. Methods The discovery population included 1833 participants from the Prevencion con Dieta Mediterranea (PREDIMED) trial. The confirmatory cohorts included 1522 PREDIMED participants at year 1 of the trial and 4932 participants from the Nurses' Hea…
Plasma metabolites predict both insulin resistance and incident type 2 diabetes: a metabolomics approach within the Prevención con Dieta Mediterránea…
2019
Background Insulin resistance is a complex metabolic disorder and is often associated with type 2 diabetes (T2D). Objectives The aim of this study was to test whether baseline metabolites can additionally improve the prediction of insulin resistance beyond classical risk factors. Furthermore, we examined whether a multimetabolite model predicting insulin resistance in nondiabetics can also predict incident T2D. Methods We used a case-cohort study nested within the Prevencion con Dieta Mediterranea (PREDIMED) trial in subsets of 700, 500, and 256 participants without T2D at baseline and 1 and 3 y. Fasting plasma metabolites were semiquantitatively profiled with liquid chromatography-tandem m…
Immunometabolism Modulation in Therapy.
2021
The study of cancer biology should be based around a comprehensive vision of the entire tumor ecosystem, considering the functional, bioenergetic and metabolic state of tumor cells and those of their microenvironment, and placing particular importance on immune system cells. Enhanced understanding of the molecular bases that give rise to alterations of pathways related to tumor development can open up new therapeutic intervention opportunities, such as metabolic regulation applied to immunotherapy. This review outlines the role of various oncometabolites and immunometabolites, such as TCA intermediates, in shaping pro/anti-inflammatory activity of immune cells such as MDSCs, T lymphocytes, …
HIV infection results in metabolic alterations in the gut microbiota different from those induced by other diseases.
2016
Imbalances in gut bacteria have been associated with multiple diseases. However, whether there are disease-specific changes in gut microbial metabolism remains unknown. Here, we demonstrate that human immunodeficiency virus (HIV) infection (n=33) changes, at quantifiable levels, the metabolism of gut bacteria. These changes are different than those observed in patients with the auto-immune disease systemic lupus erythaematosus (n=18), and Clostridium difficile-associated diarrhoea (n=6). Using healthy controls as a baseline (n=16), we demonstrate that a trend in the nature and directionality of the metabolic changes exists according to the type of the disease. The impact on the gut microbia…
Sex-dependent metabolism of nevirapine in rats: impact on plasma levels, pharmacokinetics and interaction with nortriptyline.
2017
Abstract Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) widely used in the treatment of human immunodeficiency virus type 1 (HIV-1) and is the first-choice NNRTI during pregnancy. NVP shows a sex dimorphic profile in humans with sex differences in bioavailability, biotransformation and toxicity. In this study, sex differences in NVP metabolism and inhibition of NVP metabolism by the antidepressant nortriptyline (NT) were evaluated using rats as experimental animals. NVP was administered orally to male and female rats and sex differences in plasma levels and pharmacokinetic parameters were analysed. NVP plasma levels were higher in female compared with male rats…
Discovery of phloeophagus beetles as a source of pseudomonas strains that produce potentially new bioactive substances and description of pseudomonas…
2018
15 páginas, 6 tablas, 2 figuras. -- First publication is due to Frontiers Media