title: Antimicrobial properties of Kalanchoe blossfeldiana: a focus on drug resistance with particular reference to quorum sensing-mediated bacterial biofilm formation.
abstract: OBJECTIVE
  This study attempts to investigate the antimicrobial properties of Kalanchoe blossfeldiana with a particular reference to quorum sensing (QS)-mediated biofilm formation.
  
  
  METHODS
  The methanol extract of K. blossfeldiana leaves (MEKB) was evaluated for antimicrobial properties including QS-controlled production of biofilm (including virulence factor, motility and lactone formation) in Pseudomonas aeruginosa. Methanol extract of K. blossfeldiana was also evaluated for anti-cytokine (tumour necrosis factor-alpha, interleukin-6 and interleukin-1 beta) properties in peripheral blood mononuclear cells (PBMC).
  
  
  RESULTS
  Methanol extract of K. blossfeldiana exhibited antimicrobial effect on clinical isolates, as well as standard reference strains. Pseudomonas aeruginosa exposed to MEKB (subminimum inhibitory concentration (MIC)) displayed reduced biofilm formation, whereas supra-MIC produced destruction of preformed biofilms. Methanol extract of K. blossfeldiana reduced the secretion of virulence factors (protease and pyoverdin) along with generation of acyl homoserine lactone (AHL). Confocal laser scanning microscopy images indicate reduction of biofilm thickness. The extract also reduced cytokine formation in lipopolysaccharide-stimulated PBMC.
  
  
  CONCLUSIONS
  Kalanchoe blossfeldiana was found to interfere with AHL production, which in turn may be responsible for downregulating QS-mediated production of biofilm and virulence. This first report on the antibiofilm and anticytokine properties of this plant may open up new vistas for future exploration of this plant for combating biofilm-related resistant infections.
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.|Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Ratul
authors.initials: R
authors.lastname: Sarkar
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Chaitali
authors.initials: C
authors.lastname: Mondal
authors.affiliation: TCG Life Sciences Ltd, Kolkata, West Bengal, India.
authors.forename: Rammohan
authors.initials: R
authors.lastname: Bera
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Sumon
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: TCG Life Sciences Ltd, Kolkata, West Bengal, India.
authors.forename: Rajib
authors.initials: R
authors.lastname: Barik
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Paramita
authors.initials: P
authors.lastname: Roy
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Alekh
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Kirendra K
authors.initials: KK
authors.lastname: Yadav
authors.affiliation: Department of Environmental Studies, School of Environmental Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Jayanta
authors.initials: J
authors.lastname: Choudhury
authors.affiliation: Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Chaudhary
authors.affiliation: Calcutta Institute of Pharmaceutical Technology, Uluberia, West Bengal, India.
authors.forename: Samir K
authors.initials: SK
authors.lastname: Samanta
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.|Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Sanmoy
authors.initials: S
authors.lastname: Karmakar
authors.affiliation: Microbiology and Immunology Department, B.K. Roy Research Center, Peerless Hospital, Kolkata, West Bengal, India.
authors.forename: Satadal
authors.initials: S
authors.lastname: Das
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.|Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Pulok K
authors.initials: PK
authors.lastname: Mukherjee
authors.affiliation: Department of Environmental Studies, School of Environmental Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Joydeep
authors.initials: J
authors.lastname: Mukherjee
authors.affiliation: Division of Pharmacology, Jadavpur University, Kolkata, West Bengal, India.|Department of Pharmaceutical Technology, School of Natural Product Studies, Jadavpur University, Kolkata, West Bengal, India.
authors.forename: Tuhinadri
authors.initials: T
authors.lastname: Sen
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002478:Cells, Cultured; D004351:Drug Resistance / Q000187:drug effects*; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D031962:Kalanchoe / Q000737:chemistry*; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D053038:Quorum Sensing / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha
keywords: Kalanchoe blossfeldiana; acyl homoserine lactone; anticytokine; biofilm; quorum sensing