Mandarin fruit essential oil inhibit Pseudomonas virulence factors

CONSTANZA LUCIARDI; CARTAGENA E; ARENA MARIO EDUARDO

International Journal of Pharmaceutical Sciences and Research

society of pharmaceutical sciences and research

Año: 2014

Antipathogenic compounds don´t kill bacteria or stop their growth. They rather control bacterial virulence factors like biofilm formation or elastase activity, and prevent the development of resistant strains. P. aeruginosa employs Quorum sensing (QS) to coordinate the communal behavior. QS consists in the regulation and coordinated expression of genes in response to cell density. The bacterial virulence factors have been shown to specifically involve the recognition of and response to self-generated secreted small molecules called autoinducers. Gram negative bacteria produce N-acylhomoserine lactones (AHL) as quorum signal molecules.The main objective of this work was to study the interruption of QS, or bacterial cell-to-cell communication by antipathogenic natural products from mandarin fruits. Mandarin oil is extracted from Citrus reticulata of the Rutaceae family, like all citrus oils.Essential oil and terpenes were obtained from regional industry while, bacterial strains came from ATCC collection, and from clinical isolates. The techniques used were: Crystal violet to measure biofilm formation, MTT assay to determine metabolic activity, Congo Red Test to measure elastolytic activity and Miller to quantify the AHL production.The higher biofilm inhibition was displayed by 4 mg/ml of terpenes against both strains P. aeruginosa: ATCC 27853 (88%), and clinical isolated (92%), in concordances, they with the higher viability inhibition (21% and 61%, respectively). The other sample study, essential oil of mandarin, produce lower inhibitions against both strains (2-19%).Both mandarin natural products exerted important inhibitory effects against elastase activity even at lower concentrations assayed, 0.1 mg/ml, against both strains (from 80 to 88%), and this action is correlated with the lower AHL formation (inhibition between 30 to 50%).The use of local production of essential oil to inhibit P. aeruginosa virulence is a key strategy to employ this product to prevent food contamination by pathogenic bacteria.