Screening and Evaluation of Invasive Weeds against Pseudomonas aeruginosa (Mtcc 3541) for Quorum Sensing Interference and its Free Radical Scavenging

Four invasive plants from the family of Amaranthaceae were challenged against Pseudomonas aeruginosa (MTCC 3541) for quorum sensing interference. Gomphrena serrata (seed), Digera muricata (flower) and Alternanthera paronychioides (leaf) showed elevated anti swarming activity 61.14%, 73.60% and 68.99% respectively when compared with control. All the concentrations of plant extracts used do not inhibit the growth but the quorum sensing. Significant scavenging activity of free radicals was observed with seed and flower extracts is above 97% of Alternanthera paronychioides and Digeria muricata flower showed 97% of scavenging free radicals. Biofilm (70.92%), pyocyanin (79.08%) and Las A (76.26%) production was inhibited to the significant level by Alternanthera paronychioides leaf, flower and leaf respectively. From the results analysed it is the property of plant compound to interfere quorum sensing but not the single part of the plant contribute all the phenomenon of quorum sensing inhibition but the whole plant may do the activity on further research.