In Vitro Analysis of AKR1D1 Interactions with Clopidogrel: Effects on Enzyme Activity and Gene Expression

Clopidogrel, a P2Y12 receptor antagonist, is widely used to prevent cardiovascular events, but significant variability in its efficacy persists among patients. AKR1D1, involved in bile acid synthesis and regulation of CYP enzymes, may contribute to this variability. This study aims to investigate whether clopidogrel and its inactive metabolite, 2-oxoclopidogrel, interact with AKR1D1 at the enzymatic or transcriptional level. Enzymatic activity assays demonstrated that neither clopidogrel nor 2-oxoclopidogrel acts as a substrate or inhibitor of AKR1D1. Expression studies in HepG2 cells further revealed no significant changes in AKR1D1 mRNA levels following treatment with these compounds. These findings indicate that clopidogrel does not directly influence AKR1D1's metabolic functions, including bile acid synthesis, steroid hormone clearance, or the production of 5β-reduced steroids, which regulate CYP enzyme expression. From a physiological perspective, the absence of interaction minimizes the risk of adverse effects on CYP-mediated drug metabolism, nutrient absorption, lipid digestion, and the absorption of lipophilic drugs. Future research should explore AKR1D1's broader substrate specificity, particularly focusing on non-steroidal compounds, and investigate the clinical implications of AKR1D1 polymorphisms in clopidogrel-treated patients to enhance personalized therapeutic strategies.