Metabolic inhibition of meloxicam by specific CYP2C9 inhibitors in Cunninghamella blakesleeana NCIM 687: in silico and in vitro studies

Abstract

Specific inhibitors of Cytochrome P4502C9 enzyme (CYP2C9) viz. clopidogrel, fenofibrate fluvoxamine and sertraline at concentration of 50, 100, 150 and 200 µM were employed to investigate the nature of enzyme involved in bioconversion of meloxicam to its main metabolite 5-OH methyl meloxicam by Cunninghamella blakesleeana. Virtual screening for interaction of specific CYP2C9 inhibitors with human CYP2C9 enzyme was performed by molecular docking using Auto dock vina 4.2 version. The in silico studies were further substantiated by in vitro studies, which indicated fenofibrate to be a potent inhibitor of CYP2C9 enzyme followed by sertraline, clopidogrel and fluvoxamine, respectively. Two-stage fermentation protocol was followed to study metabolism of meloxicam and its inhibition by different CYP2C9 inhibitors. Meloxicam metabolites were identified using HPLC, LC–MS analysis and based on previous reports, as 5-OH methyl meloxicam (M1), 5-carboxy meloxicam (M2) and an unidentified metabolite (M3). All the inhibitors tested in the study showed a clear concentration dependent inhibition of meloxicam metabolism. The results suggest that the enzymes involved in metabolism of meloxicam in C. blakesleeana are akin to mammalian metabolism. Hence, C. blakesleeana can be used as a model organism in studying drug interactions and also in predicting mammalian drug metabolism.

Liquid Chromatography-Tandem Mass Spectrometry Method for Detection and Quantification of Meloxicam and 5′-Carboxymeloxicam in Oral Fluid Samples

“…Meloxicam is highly metabolized, with cytochrome P4502C9 enzyme (CYP2C9) being the main enzyme responsible for the drug metabolism with a small contribution from cytochrome P4503A4 enzyme (CYP3A4). Almost 60% of the ingested dose is metabolized to its major metabolite, 5′-carboxymeloxicam, from an oxidation of liver cytochrome enzymes to an intermediate metabolite, 5′-hydroxymethylmeloxicam [ 6 , 7 , 8 , 9 , 10 , 11 ] ( Figure 1 ).…”

“…Meloxicam is highly metabolized, with cytochrome P4502C9 enzyme (CYP2C9) being the main enzyme responsible for the drug metabolism with a small contribution from cytochrome P4503A4 enzyme (CYP3A4). Almost 60% of the ingested dose is metabolized to its major metabolite, 5 -carboxymeloxicam, from an oxidation of liver cytochrome enzymes to an intermediate metabolite, 5 -hydroxymethylmeloxicam [6][7][8][9][10][11] (Figure 1). Recent studies have demonstrated that allelic variations in CYP2C9 are related to the increase in the adverse events induced by non-steroidal anti-inflammatory drugs (NSAIDs), including meloxicam.…”