Solubilisation and binding characteristics of a recombinant beta(2)-adrenergic receptor expressed in the membrane of Escherichia coli for the multianalyte detection of beta-agonists and antagonists residues in food-producing animals

in Analytica Chimica Acta (2007), 589(2), 159-165

The number of substances with beta-agonistic activity, illegally introduced in meat production or in sports doping as anabolic or beta-blocking agents is increasing. Analytical methods suited for their ... [more ▼]

The number of substances with beta-agonistic activity, illegally introduced in meat production or in sports doping as anabolic or beta-blocking agents is increasing. Analytical methods suited for their multianalyte detection are thus necessary. In this perspective, receptor assays were developed. The research activities undertaken in this study describe the solubilisation of a recombinant human beta(2)-adrenergic receptor produced in the inner membrane of genetically modified Escherichia coli, using the detergent n-dodecyl-beta-D-maltoside. Its potential to detect the presence of beta-agonists or beta-blockers in biological samples was evaluated. The solubilised beta(2)-adrenergic receptor retained its binding affinity in a radio-receptor assay based on the competition for the binding to receptors between a ligand (beta-agonist or antagonist) and the radioligand [I-125]iodocyanopindolol. The IC50 values ranged from 5 +/- x 10(-8) M (clenbuterol) to 8 +/- 2 x 10(-6) M (isoxsuprine) for the beta-agonists tested and from 1.5 +/- 0.2 x 10(-10) M (carazolol) to 1.2 +/- 0.2 x 10(-5) M (metoprolol) for the beta-blockers tested. It was shown to have a lower limit of detection than a radio-receptor assay using the solubilised beta(2)-adrenoceptor expressed in a mammalian cell line. The solubilised recombinant human beta(2)-adrenoreceptor expressed in E. coli would be a useful tool to develop non radioactive multianalyte screening methods. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

Imazalil is an aryl hydrocarbon receptor (AhR) antagonist in AhR-dependent reporter human and rat hepatoma cells

in Toxicology Letters (2007), 172

Alteration of the estrogen hormone pathway in hepatic cells after exposure to polycyclic aromatic hydrocarbons

in Toxicology Letters (2007), 172

Endocrine disruptors in food: potential impact on human health

in Annales de Médecine Vétérinaire (2007), 151(1), 44-54

Several scientific studies revealed that substances with hormonal (or antihormonal) activity are widely distributed in the environment as well as in food, either as natural constituents (as phytoestrogens ... [more ▼]

Several scientific studies revealed that substances with hormonal (or antihormonal) activity are widely distributed in the environment as well as in food, either as natural constituents (as phytoestrogens), or as substances of anthropogenic origin (for example, Several observations concerning both the wild fauna and humans indicate that these products with hormonal activity are endocrine disruptors. Numerous ecotoxicological studies evidenced important disturbances of the fertility of the wild fauna in zones contaminated by pesticides. In humans, epidemiological studies revealed a significant increase of certain cancers (among others, that of the testicles) and a decrease of the male fertility. Substances with estrogenic activity are often considered, but other hormonal effects are more and more frequently discovered (i.e. anti-androgenic). Numerous worries appear concerning the long-term effects on human health linked to a chronic exposure to these substances by food ingestion. It is urgent to review, not only on the actual contamination of our food by endocrine disruptors (in terms of identification and quantification of every individual chemical), but also the potentially toxic activity of food containing a mixture of contaminants present at levels below their individual toxicity threshold. [less ▲]

Effects of polycyclic aromatic hydrocarbons on hepatic steroid metabolism

in Journal of Biotechnology (2007), 131(2, Suppl. S), 73

Development of a HPLC/UV-FLD method to detect the 15(+1) EU priority Polycyclic Aromatic Hydrocarbons (PAHs) in food supplements

in Book of abstracts - 3rd International Symposium on Recent Advances in Food Analysis (2007)

Strategy for DR-CALUX dioxin screening in feed under EC regulation

in Organohalogen Compounds (2006), 68

Dioxin analysis in feed: cell-based assay versus mass spectrometry method

in Accreditation and Quality Assurance (2006), 11(1-2), 38-43

In the determination of contaminants (dioxins, polychlorinated biphenyls, polyaromatic hydrocarbons), cell-based assays are useful methods for screening purposes: they are mainly characterized by high ... [more ▼]

In the determination of contaminants (dioxins, polychlorinated biphenyls, polyaromatic hydrocarbons), cell-based assays are useful methods for screening purposes: they are mainly characterized by high sample throughput and lower costs than the Mass Spectrometry (MS)-based methods. Although cell-based assays can be sensitive enough for the determination of dioxins and related substances in agreement with the presently tolerable limits in food and feed (Regulation No. 2375/2001/EC and Directive 2003/57/EC respectively), their lack of specificity make their use rather questionable in control laboratories. In this paper, we present and compare results obtained from the analysis of a limited number of feed samples by both gas chromatography-high resolution mass spectrometry (GC-HRMS) and cell-based assay (DR-CALUX: dioxin responsive-chemically activated luciferase gene expression) methods. The DR-CALUX screening led to less than 10% false non-compliant and no false compliant results. In addition, there is a good correlation between GC-HRMS and DR-CALUX data. However, these preliminary results have to be confirmed on a larger number of samples to demonstrate that total toxic equivalent (TEQ), including dioxins, furans and dioxin-like polychlorobiphenyls (PCBs) can be monitored in feed and food with a cell-based assay. [less ▲]

Development of a GC/MS method to detect the 15 (+1) EU priority PAHs in food samples

Poster (2006)

GCXGC-TOFMS, PTVLV-GC-MS/MS and DR-CALUX as screening and alternatives techniques to GC/HRMS for quantitative measurement of dioxins in food and feed.

Poster (2005, March)