Antibacterial effect of isoeugenol against Pseudomonas aeruginosa

Abatsract Pseudomonas aeruginosa is an important nosocomial pathogen and its clinical importance is mainly related to nosocomial infections. Increased rates of bacterial resistance in recent years has led WHO to publish a global priority list to guide research and discovery of new antibiotics, where P. aeruginosa is among the group of bacteria for which there is a critical level of priority for new drugs to be discovered. In this context, isoeugenol appears as an interesting alternative and the objective of this study was to investigate its action against P. aeruginosa. Isoeugenol presented significant antibacterial activity, with minimum inhibitory concentration (MIC) of 64µg/mL and minimum bactericidal concentration (MBC) of 128µg/mL, and was considered bactericidal against this species. Molecular docking revealed interactions that suggest that isoeugenol may bind to the enzyme Penicillin-Binding Protein 3 and interfere with the bacterial cell wall synthesis process. This study reinforces the antibacterial potential of this compound and emphasizes that more studies are needed in order to better investigate its mechanism of antibacterial action.

4-Carvomenthenol, a monoterpene of essential oils, and its underlying effects on anti-inflammatory activity and immediate hypersensitivity reaction

Abstract The monoterpene 4-carvomenthenol (Carvo) is found in essential oils of plant. Here, we evaluate the Carvo oral pretreatment in acute inflammatory experimental models and in silico molecular docking. Mice pretreated with Carvo were challenged and submitted to the protocols: paw edema, peritonitis, scratching behavior and anaphylactic shock reaction. Besides, we used histamine H1 receptor, cyclooxygenases (COX-1 and COX-2) and phospholipase A2, as targets for molecular docking analysis. Carvo inhibited the carrageenan-induced paw edema and decreased the peritoneal influx of polymorphonuclear cells on carrageenan-challenged mice without interfering with the mononuclear cell influx. Moreover, Carvo diminished the histamine, PGE2 and compound 48/80 induced paw edematogenic effect. The monoterpene also diminished the mice scratching behavior and, surprisingly, avoided the animal death caused by compound 48/80 in 30 min. Through the docking analysis, Carvo showed favorable binding energy to the histamine H1 receptor. This study demonstrates that Carvo attenuated the allergic inflammatory process, decreasing edema, cell migration, activation of mast cells and the histamine release, probably due to interaction of Carvo with the histamine H1 receptor, ameliorating the itching and the anaphylactic shock reaction. Therefore, the results of this study indicate that Carvo has anti-inflammatory properties by reducing the histamine effects.