Search results for "metabolite"
showing 10 items of 551 documents
Metabolomics of Human Amniotic Fluid and Maternal Plasma during Normal Pregnancy
2016
Metabolic profiles of amniotic fluid and maternal blood are sources of valuable information about fetus development and can be potentially useful in diagnosis of pregnancy disorders. In this study, we applied 1H NMR-based metabolic profiling to track metabolic changes occurring in amniotic fluid (AF) and plasma (PL) of healthy mothers over the course of pregnancy. AF and PL samples were collected in the 2nd (T2) and 3rd (T3) trimester, prolonged pregnancy (PP) until time of delivery (TD). A multivariate data analysis of both biofluids reviled a metabolic switch-like transition between 2nd and 3rd trimester, which was followed by metabolic stabilization throughout the rest of pregnancy proba…
Fluorescence-Based Screening of Cytochrome P450 Activities in Intact Cells
2013
Fluorimetric methods to assess cytochrome P450 (P450) activities that do not require metabolite separation have been developed. These methods make use of non- or low-fluorescent P450 substrates that produce highly fluorescent metabolites in aqueous solutions. The assays are based on the direct incubation of intact cells in culture with appropriate fluorogenic probe substrates, followed by fluorimetric quantification of the product formed and released into incubation medium. We describe a battery of fluorescence assays for rapid measurement of the activity of nine P450s involved in drug metabolism. For each individual P450 activity the probe showing the best properties (highest metabolic rat…
Chemoecological study of the invasive alga Caulerpa taxifolia var. distichophylla from the Sicilian coast
2022
Marine invasive species and their bioactive metabolites have become critical ecological issues in the Mediterranean Sea. In particular, the highly invasive green algae Caulerpa taxifolia and Caulerpa cylindracea are known to contain the bioactive sesquiterpene caulerpenyne (1) and the bisindolic alkaloid caulerpin (2), potentially acting as chemical stressors for native species. The recent spread of a variety of C. taxifolia, Caulerpa taxifolia var. distichophylla, also raises urgent questions about its chemical composition. Indeed, the only chemical data available for this alga are limited to the seasonal variations of caulerpenyne (1) in samples collected in the Eastern Mediterranean. In …
A metabolomics cell-based approach for anticipating and investigating drug-induced liver injury
2016
AbstractIn preclinical stages of drug development, anticipating potential adverse drug effects such as toxicity is an important issue for both saving resources and preventing public health risks. Current in vitro cytotoxicity tests are restricted by their predictive potential and their ability to provide mechanistic information. This study aimed to develop a metabolomic mass spectrometry-based approach for the detection and classification of drug-induced hepatotoxicity. To this end, the metabolite profiles of human derived hepatic cells (i.e., HepG2) exposed to different well-known hepatotoxic compounds acting through different mechanisms (i.e., oxidative stress, steatosis, phospholipidosis…
SUBSTRATE-ELICITED DISSOCIATION OF THE ISOSAFROLE METABOLITE-CYTOCHROME P-450 COMPLEX AND THE CONSEQUENTIAL REACTIVATION OF MONOOXYGENATION
1977
ABSTRACT The present study was initiated to determine whether the substrate-elicited dissociation of the isosafrole metabolite-cytochrome P-450 complex resulted in increased monooxygenase activity. It was found that the substrates p -nitroanisole and ethoxycoumarin would elicit dissociation, furthermore this dissociation was accompanied by increased dealkylation of the substrates. Benzo(a)pyrene was found not to effect the dissociation of the complex, while biphenyl, which undergoes a similar hydroxylation, was effective.
Isolation and identification of intermediates from biodegradation of low chlorinated biphenyls (Delor-103).
2004
Abstract Microorganism Pseudomonas species P2 metabolizes polychlorinated biphenyls (PCBs) and biphenyl, producing the whole spectrum of intermediates, among them coloured intermediates, which are suitable for the monitoring of PCBs degradation by optical sensors. Knowledge of chemical structures and conditions of development of colour metabolites is necessary for application of optical analytical methods. The main goal of this work was the isolation and identification of intermediates from the biodegradation of the mixture of low chlorinated biphenyls (Delor-103), which is based on the solid phase extraction (SPE) of the whole mixture using LiChrolut EN cartridges, then silylation of the e…
Pharmacokinetics of acute and sub-chronic aripiprazole in P-glycoprotein deficient mice
2010
Abstract Background P-glycoprotein (P-gp), an efflux transporter localized in the blood–brain barrier, limits the access of multiple xenobiotics to the central nervous system (CNS). For the new antipsychotic aripiprazole and its active metabolite dehydroaripiprazole differences in disposition in blood and brain were investigated after acute and sub-chronic administration in a P-gp knockout mouse model. Methods Serum and brain concentrations of both drugs were measured at several time points 1–24 h after i.p. injection of 10 mg/kg aripiprazole and after 11 days of sub-chronic administration in several tissues. Moreover, the expression of P-gp was determined by Western blot analysis after sub…
Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian c…
2014
This study focuses on the differences in total phenolic content and its seasonal variations in two temperate brown algae, Cystoseira amentacea (C. Agardh) Bory and Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux, inhabiting respectively the infralittoral fringe and the upper infralittoral zone. Phenolic compounds are secondary metabolites, found in almost all brown algal orders, that function as defense against grazers, epiphytes and UV radiation. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Results showed significant differences in total phenol content between D. polypodioides and C. amentacea with higher values observed in the first…
Difference in Ki67 and thymidylate synthase expression in primary tumour compared with metastatic nodes in breast cancer patients.
2005
Breast cancer is a heterogeneous disease, so therapeutic predictive biological markers need to be identified. To date an accurate evaluation of predictive markers is mainly done at the primary site; however, the main goal of adjuvant therapy for breast cancer is the control of micrometastases. The aim of this study is to assess as therapeutic and/or prognostic marker, the proliferation status of primary tumors and involved nodes as measured by Ki67 and thymidylate synthase (TS) expression, in 30 breast cancer node positive patients. TS is the main target of 5-fluorouracil (5-FU) activity, and its overexpression is one of the mechanisms of 5-FU drug resistance; however, in some studies its a…
A systematic review and combined analysis of therapeutic drug monitoring studies for longacting risperidone
2017
Introduction: This systematic review of therapeutic drug monitoring (TDM) identifies three long-acting injectable (LAI) risperidone formulations. Areas covered: Limited data is available on two formulations (RBP-7000 and in Situ Microparticle), but 20 TDM articles on the microsphere formulation were found. Risperidone TDM includes the serum concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone, used for calculating: 1) the risperidone/9-hydroxyrisperidone (R/9-OH-R) ratio (a measure of CYP2D6; values >1 are indicative of a CYP2D6 poor metabolizer) and 2) the total risperidone concentration-to-dose (C/D) ratio (a measure of risperidone clearance with a normal value…