Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2005-11-28
pubmed:abstractText
Many adverse drug reactions are caused by the cytochrome P450 (CYP) dependent activation of drugs into reactive metabolites. In order to reduce attrition due to metabolism-mediated toxicity and to improve safety of drug candidates, we developed two in vitro cell-based assays by combining an activating system (human CYP3A4) with target cells (HepG2 cells): in the first method we incubated microsomes containing cDNA-expressed CYP3A4 together with HepG2 cells; in the second approach HepG2 cells were transiently transfected with CYP3A4. In both assay systems, CYP3A4 catalyzed metabolism was found to be comparable to the high levels reported in hepatocytes. Both assay systems were used to study ten CYP3A4 substrates known for their potential to form metabolites that exhibit higher toxicity than the parent compounds. Several endpoints of toxicity were evaluated, and the measurement of MTT reduction and intracellular ATP levels were selected to assess cell viability. Results demonstrated that both assay systems are capable to metabolize the test compounds leading to increased toxicity, compared to their respective control systems. The co-incubation with the CYP3A4 inhibitor ketoconazole confirmed that the formation of reactive metabolites was CYP3A4 dependent. To further validate the functionality of the two assay systems, they were also used as a "detoxification system" using selected compounds that can be metabolized by CYP3A4 to metabolites less toxic than their parent compounds. These results show that both assay systems can be used to screen for metabolic activation, or de-activation, which may be useful as a rapid and relatively inexpensive in vitro assay for the prediction of CYP3A4 metabolism-mediated toxicity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Albendazole, http://linkedlifedata.com/resource/pubmed/chemical/Amitriptyline, http://linkedlifedata.com/resource/pubmed/chemical/Buthionine Sulfoximine, http://linkedlifedata.com/resource/pubmed/chemical/CYP3A protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CYP3A4 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Carbamazepine, http://linkedlifedata.com/resource/pubmed/chemical/Chromans, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP3A, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System, http://linkedlifedata.com/resource/pubmed/chemical/Dapsone, http://linkedlifedata.com/resource/pubmed/chemical/Flutamide, http://linkedlifedata.com/resource/pubmed/chemical/Glutathione, http://linkedlifedata.com/resource/pubmed/chemical/Isoniazid, http://linkedlifedata.com/resource/pubmed/chemical/Ochratoxins, http://linkedlifedata.com/resource/pubmed/chemical/Piperazines, http://linkedlifedata.com/resource/pubmed/chemical/Quinidine, http://linkedlifedata.com/resource/pubmed/chemical/Tamoxifen, http://linkedlifedata.com/resource/pubmed/chemical/Tetrazolium Salts, http://linkedlifedata.com/resource/pubmed/chemical/Thiazoles, http://linkedlifedata.com/resource/pubmed/chemical/Thiazolidinediones, http://linkedlifedata.com/resource/pubmed/chemical/Triazolam, http://linkedlifedata.com/resource/pubmed/chemical/Xenobiotics, http://linkedlifedata.com/resource/pubmed/chemical/ochratoxin A, http://linkedlifedata.com/resource/pubmed/chemical/thiazolyl blue, http://linkedlifedata.com/resource/pubmed/chemical/troglitazone, http://linkedlifedata.com/resource/pubmed/chemical/ziprasidone
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0300-483X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
216
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
154-67
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16169652-Adenosine Triphosphate, pubmed-meshheading:16169652-Albendazole, pubmed-meshheading:16169652-Amitriptyline, pubmed-meshheading:16169652-Animals, pubmed-meshheading:16169652-Buthionine Sulfoximine, pubmed-meshheading:16169652-Carbamazepine, pubmed-meshheading:16169652-Cell Culture Techniques, pubmed-meshheading:16169652-Cell Line, Tumor, pubmed-meshheading:16169652-Cell Survival, pubmed-meshheading:16169652-Chromans, pubmed-meshheading:16169652-Coculture Techniques, pubmed-meshheading:16169652-Cytochrome P-450 CYP3A, pubmed-meshheading:16169652-Cytochrome P-450 Enzyme System, pubmed-meshheading:16169652-Dapsone, pubmed-meshheading:16169652-Enzyme Activation, pubmed-meshheading:16169652-Flutamide, pubmed-meshheading:16169652-Glutathione, pubmed-meshheading:16169652-Humans, pubmed-meshheading:16169652-Isoniazid, pubmed-meshheading:16169652-Microsomes, pubmed-meshheading:16169652-Ochratoxins, pubmed-meshheading:16169652-Piperazines, pubmed-meshheading:16169652-Quinidine, pubmed-meshheading:16169652-Substrate Specificity, pubmed-meshheading:16169652-Tamoxifen, pubmed-meshheading:16169652-Tetrazolium Salts, pubmed-meshheading:16169652-Thiazoles, pubmed-meshheading:16169652-Thiazolidinediones, pubmed-meshheading:16169652-Toxicity Tests, pubmed-meshheading:16169652-Triazolam, pubmed-meshheading:16169652-Xenobiotics
pubmed:year
2005
pubmed:articleTitle
An in vitro approach to detect metabolite toxicity due to CYP3A4-dependent bioactivation of xenobiotics.
pubmed:affiliation
Department of Pre-Clinical Development, Nerviano Medical Sciences S.r.l., V.le Pasteur, 10, 20014, Nerviano, MI, Italy. luisella.vignati@nervianoms.com
pubmed:publicationType
Journal Article