Aldose reductase with quinolone antibiotics interaction: In vitro and in silico approach of its relationship with diabetic complications

Aldose reductase (AR, EC1.1.1.21), a member of the aldo-keto reductase family, is critically implicated in the pathogenesis of chronic complications associated with diabetes mellitus, including neuropathy, nephropathy, and retinopathy. Hyperglycemia-induced AR overactivity results in intracellular sorbitol accumulation, NADPH depletion, and oxidative stress. Consequently, AR is recognized as a key mediator of oxidative and inflammatory signaling pathways involved in diverse human pathologies such as cardiovascular diseases, inflammatory disorders, and cancer. This has sparked renewed interest in developing novel AR inhibitors (ARIs) with enhanced therapeutic profiles. In this study, we evaluated the inhibitory potential of five quinolone antibiotics-gatifloxacin, lomefloxacin, nalidixic acid, norfloxacin, and sparfloxacin-as ARIs relevant to various physiological and pathological conditions. Through comprehensive in vitro and in silico analyses, we explored these antibiotics' binding interactions and affinities within the AR active site. Our findings reveal that these quinolones moderately inhibit AR at micromolar concentrations, with inhibition constants (K_Is) ranging from 1.03 ± 0.13 μM to 4.12 ± 0.51 μM, compared to the reference drug epalrestat (K_I of 0.85 ± 0.06 μM). The combined in vitro and in silico results underscore significant interactions between these drugs and AR, suggesting their potential as therapeutic agents against the aforementioned pathological conditions. Furthermore, these insights will aid in optimizing clinical dosing regimens and mitigating unexpected drug-drug interactions when these antibiotics are co-administered with other treatments.