Abstract. It has been previously reported that Toll-like receptor 4 (TLR4)/NF-κB signaling mediates early inflammation during myocardial ischemia and reperfusion. It has additionally been suggested that resveratrol produces cardioprotective and anti-inflammatory effects. The aim of the present study was to investigate whether resveratrol could modulate TLR4/NF-κB signaling, reduce neutrophil accumulation and TNF-α induction in an ischemia/reperfusion injured rat heart model. Rats were randomly exposed to a sham operation, myocardial ischemia and reperfusion (MI/R), MI/R + resveratrol or MI/R + resveratrol + L-NAME. The data showed that following MI/R, the expression of myocardial TLR4 and NF-κB increased significantly in the area of induced ischemia. As compared with MI/R, resveratrol significantly attenuated the expression of TLR4 and NF-κB and reduced the levels of myeloperoxidase, serum and myocardial TNF-α production, myocardial infarct size and myocardial apoptosis induced by MI/R. All the effects of resveratrol were abolished upon application of L-NAME, a nitric oxide (NO) synthase inhibitor. These data provide evidence that resveratrol inhibits TLR4/NF-κB signaling in the rat heart subjected to MI/R, and the anti-inflammatory effect of resveratrol is associated with NO production.
Objectives
Contezolid acefosamil is a novel O-acyl phosphoramidate prodrug of contezolid. In the current study, we aimed to systemically evaluate the efficacy of contezolid acefosamil against infections caused by multiple Gram-positive pathogens, and compare the efficacy of the prodrug by oral and intravenous administrations.
Methods
The in vivo pharmacodynamic efficacy of contezolid acefosamil was evaluated in mouse models of systemic (with five S. aureus, three S. pneumoniae and two S. pyogenes bacterial isolates) and thigh (with two S. aureus isolates) infections using linezolid as the reference agent.
Results
In both models, contezolid acefosamil administrated either orally or intravenously, demonstrated high antibacterial efficacy similar to linezolid, and the antibacterial efficacy of oral and intravenous contezolid acefosamil were comparable.
Conclusions
The high aqueous solubility and great efficacy of contezolid acefosamil support its clinical development as an injectable and oral antibiotic suitable for serious Gram-positive infections.
As a major public health problem, the prevalence of Acinetobacter baumannii (A. baumannii) infections in hospitals due to the pathogen’s multiple-antibiotic resistance has attracted extensive attention. We previously reported a series of 1,3-diamino-7H-pyrrolo[3,2-f]quinazoline (PQZ) compounds, which were designed by targeting Escherichia coli dihydrofolate reductase (ecDHFR), and exhibited potent antibacterial activities. In the current study, based on our molecular-modeling study, it was proposed that PQZ compounds may function as potent A. baumannii DHFR (abDHFR)-inhibitors as well, which inspired us to consider their anti-A. baumannii abilities. We further found that three PQZ compounds, OYYF-171, -172, and -175, showed significant antibacterial activities against A. baumannii, including multidrug-resistant (MDR) strains, which are significantly stronger than the typical DHFR-inhibitor, trimethoprim (TMP), and superior to, or comparable to, the other tested antibacterial agents belonging to β-lactam, aminoglycoside, and quinolone. The significant synergistic effect between the representative compound OYYF-171 and the dihydropteroate synthase (DHPS)-inhibitor sulfamethoxazole (SMZ) was observed in both the microdilution-checkerboard assay and time-killing assay, which indicated that using SMZ in combination with PQZ compounds could help to reduce the required dosage and forestall resistance. Our study shows that PQZ is a promising scaffold for the further development of folate-metabolism inhibitors against MDR A. baumannii.
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