Abstract

The aim of the study was to PEGylate the antibiotic enrofloxacin, investigate its antimicrobial activity in vitro, and test the effect of intramuscular administration to Wistar rats on the functional state and structure of the liver. PEGylation of enrofloxacin was carried out using polyethylene glycol (nanopolymer PEG-400). To study the antimicrobial activity of PEGylated enrofloxacin and enrofloxacin, the minimum inhibitory concentrations (MIC) were determined using the strain from microbial culture collection: Escherichia coli ATCC 11105 and Staphylococcus aureus ATCC 6538P. It was found that the MIC of enrofloxacin against E. coli was 0.86 μM/l and the MIC of the PEGylated enrofloxacin 0.44 μM/l. The MIC of enrofloxacin and PEGylated enrofloxacin against S. aureus were 0.86 μM/l. Four groups of rats (control and three experimental) were formed to study the hepatotoxicity of the enrofloxacin in traditional and PEGylated forms. The animals of the control group were injected intramuscularly with saline in a volume of 0.03 ml. Rats of the first experimental group were injected intramuscularly with enrofloxacin (2.7 mg/kg), the second group with PEG-400 (1.5 mg/kg), and the third group with PEGylated enrofloxacin (2.7 mg/kg). Biochemical studies of blood serum and histological analysis of the liver indicated that the PEGylated enrofloxacin had lower hepatotoxicity than traditional enrofloxacin. The liver morphology of the rats injected with PEGylated enrofloxacin was unchanged and identical to the control group at the end of the experiment.

Key words: PEGylated antibiotic enrofloxacin, antimicrobial activity, hepatotoxicity