Antibacterial potential and mechanism of action of dithiocyano-methane as a bactericidal agent for farm disinfection

Novel design and development of Centella Asiatica extract - loaded poloxamer/ZnO nanocomposite wound closure material to improve anti-bacterial action and enhanced wound healing efficacy in diabetic foot ulcer

Diabetic wounds can occur as a prevalent complication among people diagnosed with diabetes, frequently resulting in the necessity for amputation. The cause and effect of diabetic foot ulcer is complex, involving multiple factors. In the present study, wound healing strategies utilizing nanomaterials have proven to be effective in battling bacterial infections and improve wound regeneration. Poloxamers (PLX) exhibit extensive potential as a viable option for the development of nanomedicines owing to their inherent characteristics of self-assembly and encapsulation. This study aims to design and develop a PLX/ZnO nanocomposite incorporated with Centella Asiatica extract (CAE) for the multi-functional action in the diabetic wound healing treatment. Subsequently physico-chemical characterizations, such as XRD, FTIR, and TEM observations, demonstrated that the ZnO were evenly distributed through the PLX framework. The developed nanocomposite was biocompatible with mouse fibroblast cell line (L929), and it had multiple beneficial characteristics, such as a rapid self-healing process and effective antibacterial action against G+ and G- bacterial pathogens. After being treated with the developed formulation, skin fibroblast cell line and HUVECs demonstrated a substantial increase in their in vitro cell proliferation ability, migration, and tube-forming abilities. The utilization of a CAE@PLX/ZnO nanoformulation presents a viable strategy and a distinctive, encouraging composite for diabetic wound healing treatment.

Synthetic Analogs of Antimicrobial Peptides from Limulus Inhibit the Growth of Listeria monocytogenes by Increasing Cell Membrane Permeability and Suppressing Virulence Genes

Listeria monocytogenes is a foodborne pathogen that can cause listeriosis in humans and animals. It is of significant concern to the food industry as it can grow at low temperatures. Aggravatingly, only some of the commonly used food preservatives can effectively inhibit the growth of LM. In this study, the effectiveness of synthetic analogs of antimicrobial peptides from Limulus in inhibiting the growth of LM was studied. As determined by the Kirby–Bauer disc diffusion method, the diameters of the inhibition zones produced by the synthetic antimicrobial peptides ranged from 8.24 mm to 8.86 mm, and the minimum inhibitory concentrations (MICs) of the peptides ranged from 40 μg/mL to 160 μg/mL. At their MICs, initially, the synthetic antimicrobial peptides exhibited bacteriostatic effects on LM. They permeabilized the cell membrane of the bacterium and suppressed virulence genes (the inlA, prfA, and hly genes) in the bacterium. However, the bacteriostatic effects were effective only for 1 h, after which the bacterium slowly became resistant to them. After 6 h, the bacterium resumed its growth. Although cells in treatment groups resumed their growth after 6 h, the growth of the cells was inhibited compared to the growth of cells in the control group. Further studies are necessary to reduce the resistance of LM to the antibacterial effects of the synthetic antimicrobial peptides.

Isolation, Identification and Antibacterial Mechanism of the Main Antibacterial Component from Pickled and Dried Mustard (Brassica juncea Coss. var. foliosa Bailey)

Our previous study showed that the ethyl acetate fraction (EAF) from an ethanolic extract of pickled and dried mustard (Brassica juncea Coss. var. foliosa Bailey) had significant antibacterial activity. Here, the EAF was further separated into seven sub-fractions by silica gel column chromatography. The antibacterial activities of the EAF and its sub-fractions against Staphylococcus aureus and Pseudomonas fluorescens were assessed using the agar diffusion method and double dilution method. Among the seven sub-fractions, the third sub-fraction (Fr 3) possessed the strongest antibacterial activity. The main component in Fr 3 was identified by GC-MS, UV-vis, FT-IR, HPLC, ¹H NMR and ¹³C NMR techniques, and was found to be succinic acid. The content of succinic acid in Fr 3 was determined as 88.68% (w/w) by HPLC. Finally, the antibacterial mechanism of succinic acid against the tested strains was explored by determining the intracellular component leakage, measuring the cell particle size and observing the cell morphology. The results showed that succinic acid could damage the cell membrane structure and intracellular structure to increase the leakage of cell components and reduce the cell particle size. Our results suggest that succinic acid could be used in food industry to control bacterial contamination by S. aureus and P. fluorescens.