ABSTRACT
This work describes the preparation, characterization and antimicrobial activity of four palladium(II) complexes, namely, [Pd(meg)(1,10-phen)] 1, [Pd(meg)(PPh3)2] 2, [Pd(og)(1,10-phen)] 3 and [Pd(og)(PPh3)2] 4, where meg = methyl gallate, og = octyl gallate, 1,10-phen = 1,10-phenanthroline and PPh3 = triphenylphosphine. As to the chemical structures, spectral and physicochemical studies of 1-4 indicated that methyl or octyl gallate coordinates a palladium(II) ion through two oxygen atoms upon deprotonation. A chelating bidentate phenanthroline or two triphenylphosphine molecules complete the coordination sphere of palladium(II) ion, depending on the complex. The metal complexes were tested against the Mycobacterium tuberculosis H37Rv strain and 2 exhibited high activity (MIC = 3.28 µg/mL). As to the tests with Campylobacter jejuni, complex 1 showed a significant effect in reducing bacterial population (greater than 7 log CFU) in planktonic forms, as well as in the biomass intensity (IBF: 0.87) when compared to peracetic acid (IBF: 1.11) at a concentration of 400 µg/mL. The effect provided by these complexes has specificity according to the target microorganism and represent a promising alternative for the control of microorganisms of public health importance.
Subject(s)
Campylobacter jejuni , Coordination Complexes , Mycobacterium tuberculosis , Palladium/pharmacology , Palladium/chemistry , Crystallography, X-Ray , Coordination Complexes/pharmacology , Coordination Complexes/chemistryABSTRACT
As a biologic reservoir of Mycobacterium tuberculosis (M. tb), one-quarter of the world population is infected with the well-known latent tuberculosis (LTBI). About 5-10% of LTBI patients will progress to active disease in the first years after primary infection and, despite using the recommended treatment, 20% can still reactivate the infection. A new LTBI treatment could minimize adverse effects and antibiotic resistance that can occur when the same drug is used to treat the latent and active disease. New hydrazones were evaluated, and they showed great inhibitory activity against intramacrophagic and non-replicating M. tb, commonly found at this stage of infection, in addition to bactericidal and narrow-spectrum activity. When tested against eukaryotic cells, the hydrazones showed great safety at different exposure times. In vitro, these compounds performed better than isoniazid and could be considered new candidates for LTBI treatment, which may promote greater engagement in its prescription and adherence.
ABSTRACT
Imbalances in gut microbiota composition occur in individuals with autism spectrum disorder (ASD). The administration of probiotics, prebiotics, and synbiotics is emerging as a potential and promising strategy for regulating the gut microbiota and improving ASD-related symptoms. We first investigated the survival of the probiotics Limosilactobacillus (L.) reuteri and Bifidobacterium (B.) longum alone, mixed and combined with a galacto-oligosaccharide (GOS) under simulated gastrointestinal conditions. Next, we evaluated the impact of probiotics (L. reuteri + B. longum), prebiotic (GOS), and synbiotic (L. reuteri + B. longum + GOS) on gut microbiota composition and metabolism of children with ASD using an in vitro fermentation model (SHIME®). The combination of L. reuteri, B. longum, and GOS showed elevated gastrointestinal resistance. The probiotic, prebiotic, and synbiotic treatments resulted in a positive modulation of the gut microbiota and metabolic activity of children with ASD. More specifically, the probiotic treatment increased the relative abundance of Lactobacillus, while the prebiotic treatment increased the relative abundance of Bifidobacterium and decreased the relative abundance of Lachnoclostridium. Changes in microbial metabolism were associated with increased short-chain fatty acid concentrations and reduced ammonium levels, particularly in the prebiotic and synbiotic treatments.
