Associação de diclofenaco sódico e inibidores de síntese de estafiloxantina em Staphylococcus aureus

Abstract

The evolutionary pressure caused by the use of antibiotics has been a significant issue in the development of new drugs, especially in the context of bacterial resistance. Anti-virulence strategies, or treatments that target virulence without directly causing toxicity to the pathogen, have emerged as a promising alternative since they exert less evolutionary pressure. Consequently, staphyloxanthin (STX), a carotenoid pigment produced by Staphylococcus aureus, has become a promising target in drug development for treating S. aureus infections, given that it is produced by over 90% of clinical isolates of this bacterium. This study aims to evaluate the synergism between staphyloxanthin inhibitors and diclofenac sodium. To this end, phenotypic single-dose assays were conducted with 73 molecules with distinct scaffolds. The experimental results demonstrated that 10 molecules derived from furocoumarin, indazole, quinazoline, and phenyl-benzothiazole are potential STX inhibitors. Among these, the most potent compound was the benzothiazole derivative QHM 782 (IC50 11.67µM). Evaluating the combination with diclofenac sodium resulted in a synergistic effect on cell viability (FICI = 5), presenting a promising result for developing new combination therapies against S. aureus.