In Vitro Metabolism and Drug-Drug Interaction Potential of UTL-5g, a Novel Chemo- and Radioprotective Agent

Abstract

N-(2,4-dichlorophenyl)-5-methyl-1,2-oxazole-3-carboxamide (UTL-5g), a potential chemo-and radioprotective agent, acts as a prodrug requiring bioactivation to the active metabolite 5-methylisoxazole-3-carboxylic acid (ISOX). UTL-5g hydrolysis to ISOX and 2,4-dichloroaniline (DCA) has been identified in porcine and rabbit liver esterases. The purpose of this study was to provide insights on the metabolism and drug interaction potential of UTL-5g in humans. The kinetics of UTL-5g hydrolysis was determined in human liver microsomes (HLM) and recombinant human carboxylesterases (hCE1b and hCE2). The potential of UTL-5g and its metabolites for competitive inhibition and time-dependent inhibition of microsomal cytochrome P450 (P450) was examined in HLM. UTL-5g hydrolysis to ISOX and DCA in HLM were NADPH-independent, with a maximum rate of reaction (V max ) of 11.1 nmol/min per mg and substrate affinity (K m ) of 41.6 mM. Both hCE1b and hCE2 effectively catalyzed UTL-5g hydrolysis, but hCE2 exhibited ∼30-fold higher catalytic efficiency (V max /K m ) than hCE1b. UTL-5g and DCA competitively inhibited microsomal CYP1A2, CYP2B6, and CYP2C19 (IC 50 values <50 mM), and exhibited time-dependent inhibition of microsomal CYP1A2 with the inactivation efficiency (k inact /K I ) of 0.68 and 0.51 minute, respectively. ISOX did not inhibit or inactivate any tested microsomal P450. In conclusion, hCE1b and hCE2 play a key role in the bioactivation of UTL-5g. Factors influencing carboxylesterase activities may have a significant impact on the pharmacological and therapeutic effects of UTL-5g. UTL-5g has the potential to inhibit P450-mediated metabolism through competitive inhibition or time-dependent inhibition. Caution is particularly needed for potential drug interactions involving competitive inhibition or timedependent inhibition of CYP1A2 in the future clinical development of UTL-5g.

The Active Metabolite of UTL-5g, 5-Methylisoxazole-3-Carboxylic Acid, is Anti-Inflammatory and Reduces Doxorubicin-Induced Cardiac Toxicity

“…Overall, this is the first time that Isox is reported to show significant protective effect in reducing the acute cardiac toxicity induced by DOX; it is at least partially due to the antiinflammatory effect, which could be partially due to the modulation of TNF-α [1]. Therefore, it is of great importance to continue the development of Isox as a potential cardioprotective agent.…”

“…UTL-5g (Fig. 1) is a small-molecule TNF-α modulator known to be anti-inflammatory and is more effective than leflunomide in a carrageenaninduced edema animal model [1]. In addition, UTL-5g is chemoprotective and radioprotective in vivo and the modulation of TNF-α by UTL-5g plays an important role in its protective effects [2].…”

In vitro effect of Withania somnifera, AYUSH-64, and remdesivir on the activity of CYP-450 enzymes: Implications for possible herb−drug interactions in the management of COVID-19

“…The solutions were centrifuged at 10,000 rpm for 30 min, and the supernatant collected was used for further analysis. The concentration of positive controls ranged from 0.0005 to 5.00 µM, 1.00 to 0.01 µM, and 5.00 to 0.0005 µM for ketoconazole (CYP3A4) ( Patil et al, 2014 ), rosiglitazone (CYP2C8) ( Wu et al, 2014 ), and quinidine (CYP2D6) ( Kerry et al, 1994 ), respectively. The concentration of case–control small-molecule remdesivir was prepared in a range of 1–1,000 ng/ml ( Humeniuk et al, 2020 ).…”

AZD1775 MS Supplementary Materials from Quantitative and Mechanistic Understanding of AZD1775 Penetration across Human Blood–Brain Barrier in Glioblastoma Patients Using an IVIVE–PBPK Modeling Approach

“…In vitro Metabolism. In vitro metabolic kinetic parameters of AZD1775 were examined by incubating varying concentrations of AZD1775 (0.5 to 60 μM) with pooled human liver or intestine microsomes (0.4 mg/mL) at 37℃ for 30 min, as described previously with modifications (1,2). The kinetic profile of AZD1775 disappearance velocity versus initial drug concentrations was fitted to the Michaelis-Menton equation using the nonlinear regression analysis with Sigma Plot 12.0 (Systat Software, Inc., San Jose, CA).…”