title: Enantioselective inhibition of Cytochrome P450-mediated drug metabolism by a novel antithrombotic agent, S002-333: Major effect on CYP2B6.
abstract: A significant number of new chemical entities (NCEs) fail in drug discovery due to inhibition of Cytochrome P450 (CYP) enzymes. Therefore, to avert costly drug failure at the clinical phase it becomes indispensable to evaluate the CYP inhibition profile of NCEs early in drug discovery. In light of these concerns, we envisioned to investigate the inhibitory effects of S002-333 [2-(4-methoxy-benzenesulfonyl)-2,3,4,9-tetrahydro-1H-b-carboxylic acid amide], a novel and potent antithrombotic agent, on nine major CYP enzymes (CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4) of human liver microsomes (HLM). S002-333 exists as racemic mixture of S004-1032 (R-isomer) and S007-1558 (S-isomer), consequently, we further examined the enantioselective differences of S002-333 in the inhibition of human CYP enzymes. Of the CYP enzymes tested, CYP2B6-catalyzed bupropion 6-hydroxylation was inhibited by S002-333 (IC50 ∼ 9.25 ± 2.46 μM) in a stereoselective manner with (S)-isomer showing potent inhibition (IC50 ∼ 5.28 ± 1.25 μM) in contrast to (R)-isomer which showed negligible inhibition on CYP2B6 activity (IC50 > 50 μM). S002-333 and its (S)-isomer inhibited CYP2B6 activity in a non-competitive fashion with estimated Ki values of 10.1 ± 3.4 μM and 5.09 ± 1.05 μM, respectively. No shift in the IC50 value was observed for S002-333 and its isomers when preincubated for 30 min in the presence of NADPH suggesting that neither S002-333 nor its enantiomers are time-dependent inhibitors. Thus, the present findings signified that S002-333 is a potent stereoselective inhibitor of CYP2B6, whereas, inhibition for other CYPs was substantially negligible. These in vitro findings would be useful in deciding the development of S002-333 as a single-enantiomer or as a racemic mixture.
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226032, Uttar Pradesh, India; Academy of Scientific and Innovative Research, New Delhi 110001, India.
authors.forename: Manisha
authors.initials: M
authors.lastname: Bhateria
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226032, Uttar Pradesh, India; Academy of Scientific and Innovative Research, New Delhi 110001, India.
authors.forename: Rachumallu
authors.initials: R
authors.lastname: Ramakrishna
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226032, Uttar Pradesh, India; Academy of Scientific and Innovative Research, New Delhi 110001, India.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Puttrevu
authors.affiliation: Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226032, Uttar Pradesh, India.
authors.forename: Anil K
authors.initials: AK
authors.lastname: Saxena
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226032, Uttar Pradesh, India; Academy of Scientific and Innovative Research, New Delhi 110001, India. Electronic address: rabi_bhatta@cdri.res.in.
authors.forename: Rabi Sankar
authors.initials: RS
authors.lastname: Bhatta
mesh_terms: D002243:Carbolines / Q000737:chemistry / Q000378:metabolism*; D065702:Cytochrome P-450 CYP2B6 / Q000378:metabolism*; D065686:Cytochrome P-450 CYP2B6 Inhibitors / Q000737:chemistry / Q000378:metabolism*; D065607:Cytochrome P-450 Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D013237:Stereoisomerism; D013449:Sulfonamides / Q000737:chemistry / Q000378:metabolism*
chemical_list: C000592767:2-(4'-methoxybenzenesulfonyl)-2,3,4,9-tetrahydro-1H-pyrido(3,4-b)indole-3-carboxylic acid amide; D002243:Carbolines; D065686:Cytochrome P-450 CYP2B6 Inhibitors; D065607:Cytochrome P-450 Enzyme Inhibitors; D005343:Fibrinolytic Agents; D020033:Protein Isoforms; D013449:Sulfonamides; D003577:Cytochrome P-450 Enzyme System; D065702:Cytochrome P-450 CYP2B6
keywords: Antithrombotic drugs; CYP2B6 inhibition; Drug-drug interaction; IC(50) shift; S002-333; Stereoselectivity