Binding of tigecycline to human serum albumin in the presence of (+)-catechin

Human serum albumin (HSA) is a protein with a major role in the transportation and deposition of many ligands present in the blood. Many papers in science field deal with the interaction between drugs and HSA because those mechanisms are very important for understanding the pharmacokinetics and pharmacodynamics of drug pathways. Further, food components (such as flavonoids) may influence drug-HSA binding. It is known that flavonoids are polyphenolic secondary plant metabolites, which are very common in fruits and vegetables. Catechins are one of such representatives widely distributed in various groceries (green tea, red wine, juices, etc.). One of the most studied catechins is (+)-catechin due to its high abundance in the human diet and relevant antioxidant activity. Here, the binding affinity of tigecycline (TGC), tetracycline antibiotic, to HSA in the presence of (+)-catechin has been investigated by fluorescence and UV–Vis absorption spectroscopy under simulated physiological conditions (pH 7.4), and using molecular docking simulations. The main objective of the study was to reveal the mechanism of interactions and evaluate the influence of (+)-catechin on TGC-HSA binding. The presented study contributes to improving the current knowledge about the pharmacology of TGC in presence of food contents.