Gout is the most prevalent form of inflammatory arthritis worldwide and is characterized by chronic hyperuricemia, leading to the deposition of uric acid crystals in joints and tissues (Zhang et al., 2023). The primary objective in gout management is to lower serum uric acid levels to a predefined target, which can be achieved using various urate-lowering drugs, including xanthine oxidase inhibitors (XOIs), uricosurics, and uricases (Bernal et al., 2016). XOIs mainly include allopurinol, febuxostat, and topiroxostat (Piani et al., 2023), while uricosurics primarily consist of benzbromarone, lesinurad, and probenecid (Hosny et al., 2019). The chemical structures and classification of antigout drugs were shown in Fig. 1.

Gout is frequently accompanied by various comorbidities, including chronic kidney disease (CKD), cardiovascular disease (CVD), and metabolic syndrome (Dehlin et al., 2020). XOIs have been found to have a protective effect against the development of IgA nephropathy (Inoue et al., 2018) and exhibit the potential to ameliorate insulin resistance and reverse the upregulation of glucose and urate transporters in the kidneys (Ng et al., 2021). Among uricosuric drugs, benzbromarone has been associated with a lower incidence of stroke (Niu et al., 2022) and diabetes (Niu et al., 2018) in gout patients and may also reduce cardiovascular risk and mortality (Kang et al., 2021). Lesinurad, a novel selective uric acid reabsorption inhibitor, has been approved for the treatment of hyperuricemia associated with gout in combination with XOIs (Presa et al., 2019; Shen et al., 2017). Probenecid, a Panx1 hemichannel blocker, has been demonstrated to exhibit essential neuroprotective, antiepileptic, and anti-inflammatory properties, contributing to the reduction of neuroinflammation (Garcia-Rodriguez et al., 2023). Drug interactions may lead to undesirable side effects. Alterations in drug-metabolizing enzymes, especially inhibitions, are recognized as prevalent contributors. Therefore, it is imperative to understand and clarify the inhibitory effects of antigout drugs on drug-metabolizing enzymes for planning safe and effective combination therapies.

As important phase I metabolizing enzymes, human carboxylesterases (CESs) efficiently catalyse the hydrolysis of numerous therapeutic drugs. This pathway plays a vital role in both prodrug activation and the primary pathway of drug elimination (Chen et al., 2018). Human CESs consist of two isoforms, CES1 and CES2. As the most abundant drug-metabolizing enzyme in human livers, CES1 plays a crucial role in the metabolism of a wide range of drugs (especially ester-prodrugs), environmental pollutants, and endogenous compounds (Her and Zhu, 2020). CES1 prefers to hydrolyze ester substrates containing a bulky acyl group and a small alcoholic group, such as clopidogrel, cocaine, enalapril, imidapril, oseltamivir, and meperidine (Bencharit et al., 2003; Dominguez et al., 2014; Zhu and Markowitz, 2009). In contrast, CES2 exhibits a preference for hydrolyzing esters with a relatively small acyl group and a large alcohol group, such as irinotecan, capecitabine, flutamide, procaine, and molnupiravir (Shen et al., 2022; Zou et al., 2018). The inhibition of CES1 and CES2 by clinical drugs might result in significant drug-drug interactions (DDIs). For example, antidiabetic, antihyperlipidemic drugs and angiotensin-converting enzyme inhibitors have been demonstrated to have the potential to induce DDIs by inhibiting CES1 and CES2 (Fukami et al., 2010; Thomsen et al., 2014).

The objective of this study was to investigate the inhibitory effect of antigout drugs (allopurinol, febuxostat, topiroxostat, benzbromarone, lesinurad and probenecid) on human CES1 and CES2. Inhibition kinetics experiments and molecular docking analyses were conducted to elucidate the kinetics properties and mechanistic correlations between antigout drugs and CESs. In vitro-in vivo extrapolation (IVIVE) was employed to predict the in vivo inhibitory magnitude of antigout drugs against CESs.