Oxidative Stress and Antimicrobial Activity of Chromium(III) and Ruthenium(II) Complexes onStaphylococcus aureusandEscherichia coli

Abstract

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. The main aim of this work was to establish the potential of the synthetic α-diimine chromium(III) and ruthenium(II) complexes (where the α-diimine ligands are bpy = 2,2-bipyridine, phen = 1,10-phenanthroline, and dppz = dipyrido[3,2-a:2′,3′-c]-phenazine) like [Cr(phen)3]3+, [Cr(phen)2(dppz)]3+, [Ru(phen)3]2+, and [Ru(bpy)3]2+ as antibacterial agents by generating oxidative stress. The [Cr(phen)3]3+ and [Cr(phen)2(dppz)]3+ complexes showed activity against Gram positive and Gram negative bacteria with minimum inhibitory concentrations (MICs) ranging from 0.125 μg/mL to 1 μg/mL, while [Ru(phen)3]2+ and [Ru(bpy)3]2+ do not exhibit antimicrobial activity against the two bacterial genera studied at the concentration range used. When ciprofloxacin was combined with [Cr(phen)3]3+ for the inhibition of Staphylococcus aureus and Escherichia coli, an important synergistic effect was observed, FIC 0.066 for S. aureus and FIC 0.064 for E. coli. The work described here shows that chromium(III) complexes are bactericidal for S. aureus and E. coli. Our results indicate that α-diimine chromium(III) complexes may be interesting to open new paths for metallodrug chemotherapy against different bacterial genera since some of these complexes have been found to exhibit remarkable antibacterial activities.

Investigations on the ZnO- and Cr-doped ZnO powders

“…An earlier study has shown the importance of Cr doping in metal oxide nanoparticles in the antibacterial activity [39]. In the present study, though Cr-doped ZnO showed the synergetic effect on the antibacterial activity, however, the reports on chromium oxide alone showed independent antibacterial action in different bacterial strains [40,41]. It seems that the explanation of a detailed mechanism of the activities of the undoped and metal-iondoped ZnO is still under debate.…”

Antimicrobial Effect of Asiatic Acid Against Clostridium difficile Is Associated With Disruption of Membrane Permeability

“…MIC A+B is the MIC of compound A in the combination with compound B and vice versa for MIC B+A , whereas MIC A or MIC B are the MIC of the compound alone. The combination effect is defined as synergy when FIC ≤ 0.5, additive when 0.5 < FIC ≤ 1.0, no interaction when 1.0 < FIC ≤ 4.0, and antagonism when FIC > 4.0 ( Páez et al, 2013 ).…”

Synthesis, Characterization and Antibacterial Studies of (3,3-Dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid-Cr (III) Complex

“…Osella and co-workers [8] inserted a ferrocenyl group into the side chain of the chloroquine, and it has been reported that the resulting compound ferroquine was much safer and more effective in mice, as well as non-mutagenic. Páez and co-workers [9] synthesized complexes of α-diimine chromium (III), and the results showed that they exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria. The study also showed that the chromium (III) complexes of α-diimine when combined with ciprofloxacin, an important synergistic effect was observed for the inhibition of Staphylococcus aureus and Escherichia coli.…”