The effect of tigecycline on the binding of fluoroquinolones to human serum albumin

Abstract

The co-administration of several drugs in multidrug therapy may alter the binding of each drug to human serum albumin (HSA) and, thus, their pharmacology effect. Therefore, in this study, the interaction mechanism between HSA and two fluoroquinolones (FQs), sparfloxacin (SPF) and levofloxacin (LVF), was investigated using fluorescence and absorption methods in the absence and presence of the competing drugtigecycline (TGC). The UV-Vis and fluorescence spectroscopy results showed that the fluorescence quenching of HSA was a result of the formation of the HSA-SPF and HSA-LVF complexes. The fluorescence quenching of HSA-TGC revealed that tigecycline can regulate the binding sites, binding mode and binding affinity of fl uoroquinolones. The binding constants (KA) and binding sites (n) of the interaction systems were calculated. The results confirmed that the KA values of the HSA-FQ system decreased in the presence of TGC, indicating that TGC can affect the binding ability of FQ for HSA. This interaction may increase the free plasma concentration of unbound FQ and enhance their pharmacology effect.

Istovremena primena nekoliko lekova, u multilek terapiji, može izmeniti njihovo vezivanje za humani serumski albumin (HSA) i njihov farmakološki efekat. Zbog toga, u ovom radu je proučavan mehanizam interakcije između HSA i dva fluorohinolona (FQs): sparfloksacina (SPF) i levofloksacina (LVF) fluorescentnim i apsorpcionim metodama u odsustvu i prisustvu konkurentskog leka - tigeciklina (TGC). Rezultati UV-Vis i fluorescentne spektroskopije su pokazali da je gašenje fluorescencije u HSA rezultat formiranja HSA-SPF i HSA-LVF kompleksa. Gašenje fluoroscencije u HSA-TGC je pokazalo da tigeciklin može regulisati mesta vezivanja, način vezivanja i afinitet vezivanja fluorohinolona. Konstante vezivanja (KA) i broj vezujućih mesta (n) za interakcije u sistemu su izračunate. Rezultati su potvrdili da su vrednosti KA u HSA-FQ sistemu, smanjene u prisustvu TGC, a to ukazuje da TGC može da utiče na sposobnost vezivanja FQ za HSA. Ova interakcija može povećati slobodnu koncentraciju u plazmi nevezanog FQ i poboljšati njegov farmakološki efekat.