Probing the potential toxicity of trimetazidine by characterizing its interaction with human serum albumin.

The small molecular drugs pharmacodynamics and pharmacokinetics could be affected by human serum albumin (HSA) transport, so we studied the interaction between HSA and the widely used anti-ischemic agent, trimetazidine (TMZ), using different approaches. As shown by synchronous fluorescence spectroscopy, the interaction affects the microenvironment confirmation around tyrosine residues. The site-competitive experiments showed that TMZ had an affinity toward subdomain III A (site II) of HSA. The enthalpy and entropy changes (ΔH and ΔS), which were 37.75 and 0.197 K J mol^-1, respectively, showed that the predominant intermolecular interactions are hydrophobic forces. According to FTIR research, the interaction between HSA and TMZ caused polypeptide carbonyl-hydrogen bonds to rearrange. The HSA esterase enzyme activity was decreased with TMZ. Docking analysis confirmed the site-competitive experiments and thermodynamic results. This study demonstrated that TMZ interacted with HSA, and the structure and function of HSA were influenced by TMZ. This study could aid in understanding the pharmacokinetics of TMZ and provide basic data for safe use.