10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 3 2014 (July- September) Usage of lessThan i greaterThan Allium sativum lessThan /i greaterThan L. bulb (Amaryllidaceae) against the pathogenesis of lessThan i greaterThan Pseudomonas aeruginosa lessThan /i greaterThan is an emphasized approach. However, biological response and safety of herbal extracts depend upon the processing methods and solvents used in preparation. In this study, various garlic bulb extracts (ethanol, ethyl acetate, methanol, acetone, chloroform, toluene, raw and heated) were prepared and examined for their quorum sensing inhibitory (QSI) potential in terms of reduction in quorum sensing signal molecules(QSSMs) production, biofilm formation and motility exhibited by lessThan i greaterThan P. aeruginosa lessThan /i greaterThan . Out of all these, toluene extract of garlic (TGE) in its sub-MIC showed highly significant reduction in production of QSSMs (80%), biofilm formation (5 folds, p lessThan 0.01) and three forms of motilities (p lessThan 0.05) as compared to lessThan i greaterThan P. aeruginosa lessThan /i greaterThan grown in the absence of any of the extracts. Further, phytochemical profiling of extracts indicated a maximum abundance of thiosulfinates (THS) in TGE and possibility of relevance of saponins in motility. ANITHA VADEKEETIL,SANJAY CHHIBBER AND KUSUM HARJAI Garlic extracts; Pseudomonas aeruginosa; quorum sensing inhibitory potential; thiosulfinates; phytochemicals. 873-884