Trigonella foenum-graceum (Seed) extract interferes with quorum sensing regulated traits and biofilm formation in the strains of pseudomonas aeruginosa and Aeromonas hydrophila

Abstract

Trigonella foenum-graecum L. (Fenugreek) is an important plant of the Leguminosae family known to have medicinal properties. However, fraction based antiquorumsensing and antibiofilm activities have not been reported fromthis plant. In the present study T. foenum-graecum seed extract was sequentially fractionated and sub-MICs were tested for above activities.Themethanol fraction of the extract demonstrated significant inhibition ofAHLregulated virulence factors: protease, LasB elastase, pyocyanin production, chitinase, EPS, and swarmingmotility in Pseudomonas aeruginosa PAO1 and PAF79. Further, QS dependent virulence factor in the aquatic pathogen Aeromonas hydrophilaWAF38 was also reduced. Application of T. foenum-graecum seed extract to PAO1, PAF79, andWAF38 decreased the biofilm forming abilities of the pathogens by significant levels. The extract also exhibited reduced AHL levels and subsequent downregulation of lasB gene. In vivo study showed an enhanced survival of PAO1-preinfected C. elegans after treatment with extract at 1mg/mL. Further, the major compound detected by GC-MS, caffeine, reduced the production of QS regulated virulence factors and biofilm at 200 μg/mL concentration indicating its role in the activity of the methanol extract. The results of the present study reveal the potential anti-QS and antibiofilm property of T. foenum-graceum extract and caffeine.