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Medicinal Plants from Indian Subcontinent Decrease Quorum Sensing Dependent Virulence in Pseudomonas aeruginosa
Author(s) -
Vattem Dhiraj,
Huerta Veronica,
Mihalik Kevin,
Crixell Sylvia
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.700.23
Subject(s) - pyocyanin , quorum sensing , pseudomonas aeruginosa , virulence , chromobacterium violaceum , microbiology and biotechnology , elastase , biology , pathogen , protease , human pathogen , antimicrobial , bacteria , chemistry , enzyme , biochemistry , gene , genetics
Pseudomonas aeruginosa (PAO1), an opportunistic pathogen in immune compromised patients is under the regulation of the LasR‐RhlR system for quorum sensing (QS) mediated development of virulence. Medicinal plants from Indian subcontinent used in traditional medicine are well known for their antimicrobial effects on a variety of human pathogens. However, few studies have investigated its QS related antivirulent activities. Our objective was to screen for the QS inhibitory properties of 16 high quality ayurvedic medicinal plants derived from Indian sub‐continent, understand their mechanism of action and investigate their effect on the expression of QS regulated virulence factors in PAO1. QS inhibition of sub‐lethal concentrations (SLC) of plant extracts was measured in violacein producing Chromobacterium violaceum bioassay model. Effect of these extracts on PAO1 virulent factors pyocyanin, elastase, and total protease were quantified by standard protocols. Results indicated that all extracts reduced violacein production significantly. The results from modified screening assay suggested the primary mechanism of QSI was a combination of (1) reduction in AI formation and (2) inhibition of AI activity. The extracts reduced pyocyanin synthesis, inhibited the activity of elastase and other proteolytic enzymes.