title: Lagerstroemia speciosa fruit extract modulates quorum sensing-controlled virulence factor production and biofilm formation in Pseudomonas aeruginosa.
abstract: Lagerstroemia speciosa (Lythraceae) is a south-east Asian tree more commonly known as 'Jarul'. Research on health benefits suggests that the L. speciosa plant contains phytomolecules that may have antioxidant, anti-diabetic and anti-obesity properties. However, antimicrobial activities have not been reported for this plant. The ability of L. speciosa fruit extract (LSFE) to antagonize cell-to-cell communication, expression of virulence genes and factors, and biofilm formation was evaluated in Pseudomonas aeruginosa strain PAO1. Our results suggested that LSFE caused downregulation of quorum sensing (QS)-related genes (las and rhl) and their respective signalling molecules, N-acylhomoserine lactones, without affecting the growth of P. aeruginosa PAO1. Significant inhibition of virulence factors: LasA protease, LasB elastase, and pyoverdin production, was also recorded. Application of LSFE to P. aeruginosa PAO1 biofilms increased bacterial susceptibility to tobramycin. These data suggest a possible role for quorum-quenching mechanisms unrelated to static or cidal effects, and also suggest that L. speciosa could serve as a cost-effective source in the development of new QS-based antibacterial drugs.
authors: Department of Pharmacology, Toxicology and Therapeutics, School of Medicine, The University of Kansas Medical Center, The University of Kansas, Kansas City, 66160 KS, USA.
authors: Brahma N
authors: BN
authors: Singh
authors: Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi-211 005, India.
authors: H B
authors: HB
authors: Singh
authors: Department of Botany, Faculty of Sciences, Banaras Hindu University, Varanasi-211 005, India.
authors: Akanksha
authors: A
authors: Singh
authors: DNA Research Chair, Department of Zoology, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia.
authors: Braj R
authors: BR
authors: Singh
authors: CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow-226001, India.
authors: Aradhana
authors: A
authors: Mishra
authors: CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow-226001, India.
authors: C S
authors: CS
authors: Nautiyal
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects*; D005638:Fruit / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D031563:Lagerstroemia / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D053038:Quorum Sensing / Q000187:drug effects*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D010936:Plant Extracts; D037521:Virulence Factors; C088386:homoserine lactone; D015107:4-Butyrolactone