Due to their antimicrobial, immunomodulatory, antioxidant, and regenerative activities, culinary herbs have multiple medicinal uses, among which to prevent and treat oral diseases. The whole essential oils (EOs) have multiple advantages over purified components, such as a low probability to select for antimicrobial resistance, synergic effects of different components, and multi-pharmacological activities. In this study, we aimed to evaluate essential oils from Salvia officinalis (sage), Satureja hortensis (summer savory), and Anethum graveolens (dill) using an in vitro analysis of their antimicrobial activity against Gram-positive and Gram-negative bacterial strains isolated from the oral cavity of patients with periodontitis; the assays addressed both the planktonic and biofilm growth states and used culture-based approaches. Some of the tested EOs exhibited excellent bactericidal and antibiofilm activity, being active at concentrations as low as 0.08–1.36 mg/mL. Flow cytometry was used to investigate the potential mechanisms of their antibacterial activity and confirmed that the tested EOs act by permeabilizing the bacterial membrane and by inhibiting the activity of the efflux pumps. The immunomodulatory effect of the three EOs was determined by analyzing the gene expression profiles for pro- and anti-inflammatory cytokines of the THP-1 cells. The summer savory EO induced a clear proinflammatory effect, while the others did not significantly influence the cytokines profile of the tested cells. Taken together, our results indicate that summer savory EO and, to a lesser extent, sage and dill EOs could be used to inhibit bacteria involved in oral plaque formation and to reduce the expression of genes known to contribute to the inflammatory response using cell culture assessment.

The synthesis, structural characterization, cytotoxicity, and antimicrobial properties of four new complexes formed by employing acrylate anion and 2,2′-bipyridine are reported herein. X-ray crystallography revealed the trinuclear nature of [Mn3(2,2′-bipy)2(C3H3O2)6] (1), meanwhile complexes with general formula [M(2,2′-bipy)(C3H3O2)2(H2O)x]∙yH2O ((2) M: Ni, x = 1, y = 0; (3) M: Cu, x = 1, y = 0; (4) M: Zn, x = 0, y = 1; 2,2′-bipy: 2,2′-bipyridine; C3H3O2: acrylate anion) were shown to be mononuclear. The lowest minimum inhibitory concentration (MIC) of 128 μg mL−1 was recorded for all four tested complexes against Candida albicans, for complex (3) against Escherichia coli, and for complex (4) against Staphylocococcus aureus. Compounds (3) and (4) were also potent efflux pumps activity inhibitors (EPI), proving their potential for use in synergistic combinations with antibiotics. Complexes (1)–(4) revealed that they were not cytotoxic to HCT-8 cells. They also proved to interfere with the cellular cycle of tumour HCT-8 cells by increasing the number of cells found in the S and G2/M phases. Taken together, these results demonstrate the potential of zinc and copper complexes for use in the development of novel antimicrobial and anti-proliferative agents.

Three complexes, namely [Co(dmtp)2(OH2)4][CoCl4] (1), [Co(dmtp)2Cl2] (2) and [Co(dmtp)2(OH2)4]Cl2∙2H2O (3) (dmtp: 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine), were synthesized and characterized by spectral (IR, UV-Vis-NIR), and magnetic measurements at room temperature, as well as single crystal X-ray diffraction. Complex (1) crystallizes in monoclinic system (space group C2/c), complex (2) adopts an orthorhombic system (space group Pbca), and complex (3) crystallizes in triclinic system (space group P1¯). Various types of extended hydrogen bonds and π–π interactions provide a supramolecular architecture for all complexes. All species were evaluated for antimicrobial activity towards planktonic and biofilm-embedded microbial cells and influence on HEp-2 cell viability, cellular cycle and gene expression.

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Background: Early preliminary data on antibiotic resistance patterns available before starting the empiric therapy of urinary tract infections (UTIs) in patients with risk factors for acquiring antibiotic resistance could improve both clinical and epidemiological outcomes. The aim of the present study was two-fold: (i) to assess the antibiotic susceptibility of uropathogenic Escherichia coli isolates, exhibiting different antibiotic resistance phenotypes, directly in artificially contaminated urine samples using a flow cytometry (FC) based protocol; (ii) to optimize the protocol on urine samples deliberately contaminated with bacterial suspensions prepared from uropathogenic E. coli strains. Results: The results of the FC based antimicrobial susceptibility testing (AST) protocol were compared with the reference AST methods results (disk diffusion and broth microdilution) for establishing the sensitivity and specificity. The proposed FC protocol allowed the detection and quantification of uropathogenic E. coli strains susceptibility to nitrofurantoin, trimethoprim–sulfamethoxazole, ciprofloxacin, and ceftriaxone within 4 h after the inoculation of urine specimens. The early availability of preliminary antibiotic susceptibility results provided by direct analysis of clinical specimens could essentially contribute to a more targeted emergency therapy of UTIs in the anticipation of AST results obtained by reference methodology. Conclusions: This method will increase the therapeutic success rate and help to prevent the emergence and dissemination of drug resistant pathogens.