Major implications of single nucleotide polymorphisms in human carboxylesterase 1 on substrate bioavailability

The number of studies and reviews conducted for the Carboxylesterase gene is limited in comparison with other enzymes. Carboxylesterase (CES) gene or human carboxylesterases (hCES) is a multigene protein belonging to the α/β-hydrolase family. Over the last decade, two major carboxylesterases (CES1 and CES2), located at 16q13–q22.1 on human chromosome 16 have been extensively studied as important mediators in the metabolism of a wide range of substrates. hCES1 is the most widely expressed enzyme in humans, and it is found in the liver. In this review, details regarding CES1 substrates include both inducers (e.g. Rifampicin) and inhibitors (e.g. Enalapril, Diltiazem, Simvastatin) and different types of hCES1 polymorphisms (nsSNPs) such as rs2244613 and rs71647871. along with their effects on various CES1 substrates were documented. Few instances where the presence of nsSNPs exerted a positive influence on certain substrates which are hydrolyzed via hCES1, such as anti-platelets like Clopidogrel when co-administered with other medications such as angiotensin-converting enzyme (ACE) inhibitors were also recorded. Remdesivir, an ester prodrug is widely used for the treatment of COVID-19, being a CES substrate, it is a potent inhibitor of CES2 and is hydrolyzed via CES1. The details provided in this review could give a clear-cut idea or information that could be used for further studies regarding the safety and efficacy of CES1 substrate.