Efeito modulador do óleo essencial das folhas de Lippia alba: na atividade de antimicrobianos sobre biofilme de Salmonella typhi e Shigella dysenteriae e na inflamação induzida em camundongos

Abstract

The essential oil of the leaves of Lippia alba (Mill.) N.E. Brown (Verbenaceae) presents great pharmacological potential, as analgesic, antispasmodic and antimicrobial. The objective of this study was to evaluate the effect of Lippia alba (OELa I) essential oil on the antimicrobial activity of clinical use of Salmonella typhi and Shigella dysenteriae biofilms and inflammation. The Minimal Inhibitory Concentration of OELa I was determined by the microdilution method and by the effect of OELa I on the activity of antimicrobials for clinical use by the Checkboard method. The values obtained from CIMOELaI and ciprofloxacin were used to evaluate the exposure time in the cell pathway. The antibiofilm activity, an inhibition of biofilm formation was determined by the quantification of the biofilm mass and the eradication of the biofilm was by the counting of viable cells. The modulator effect of OELa I on carrageenan-induced peritonitis in mice was evaluated. OELa I presented as major component the geranial (34.2%), the mineral (25.9%) and the myrcene (12.5%). The concentrations of CIMOELaI for the strains under study were 1 mg / mL. OELa I positively modulated the action of ciprofoxacin, cefepime and ceftriaxone. After the first hour of treatment with CIMOELaI, the cell viability of the strains was reduced by 5 log10 CFU / ml and the OELa I-CIP association was able to inhibit growth during the first 6 hours tested. In the antibiofilm activity, CIMOELa I was able to reduce by 61.2% the biofilm mass of Salmonella typhi and 38.9% of Shigella dysenteriae. CIMOELa I was not able to eradicate the biofilm already formed, however, there was a reduction of microbial viability in the biofilm. The association 1/16 x CIMOELaI - 1/16 CIMCIP inhibited the formation of biofilm in 67.6 and 77.2% for Salmonella typhi and Shigella dysenteriae, respectively. In the evaluation of the anti-inflammatory effect, carrageenan 1% induced a significant increase (p <0.05) in the total number of leukocytes to the peritoneal cavity when compared to the vehicle group (PBS). Treatment of animals with a concentration of 10 and 30 mg / kg OELa I significantly reduced the migration of polymorphonuclear leukocytes into the peritoneal cavity (p <0.05). The hemolytic activity assay on erythrocytes revealed an EC50 = 0.058 mg/mL. OELaI has the potential for application as an antimicrobial and anti-inflammatory agent, since it interferes with biofilm formation and is able to reduce cell viability in preformed biofilm and can synergistically modulate antimicrobial activity and decrease neutrophil migration in inflammation.