title: Contribution of reactive oxygen species to (+)-catechin-mediated bacterial lethality.
abstract: The contribution of reactive oxygen species to (+)-catechin-mediated bacterial lethality was investigated. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) of (+)-catechin against E. coli, P. aeruginosa and S. aureus were investigated using 96-well microtitre plate. MIC and MBC of (+)-catechin against E. coli, P. aeruginosa and S. aureus are 600 and 700; 600 and 800; 600 and 800 μg/mL respectively. The optical densities and colony forming units of (+)-catechin-treated bacteria decreased. (+)-Catechin (4× MIC) significantly increased the superoxide anion content of E. coli, P. aeruginosa and S. aureus compared to DMSO. Superoxide dismutase and catalase in (+)-catechin treated E. coli, P. aeruginosa and S. aureus increased significantly. Conversely, level of reduced glutathione in (+)-catechin-treated E. coli, P. aeruginosa and S. aureus decreased significantly while glutathione disulfide increased significantly. Furthermore, malondialdehyde and fragmented DNA increased significantly following exposure to (+)-catechin. From the above findings, (+)-catechin enhanced the generation of reactive oxygen species (superoxide anion radical and hydroxyl radical) in E. coli, P. aeruginosa and S. aureus, possibly by autoxidation, Fenton chemistry and inhibiting electron transport chain resulting into lipid peroxidation and DNA fragmentation and consequentially bacterial cell death.
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria. Electronic address: ajiboyeyong@yahoo.com.
authors.forename: T O
authors.initials: TO
authors.lastname: Ajiboye
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: M
authors.initials: M
authors.lastname: Aliyu
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: I
authors.initials: I
authors.lastname: Isiaka
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: F Z
authors.initials: FZ
authors.lastname: Haliru
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: O B
authors.initials: OB
authors.lastname: Ibitoye
authors.affiliation: Department Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: J N
authors.initials: JN
authors.lastname: Uwazie
authors.affiliation: Department Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: H F
authors.initials: HF
authors.lastname: Muritala
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: S A
authors.initials: SA
authors.lastname: Bello
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: I I
authors.initials: II
authors.lastname: Yusuf
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: A O
authors.initials: AO
authors.lastname: Mohammed
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D062105:Molecular Docking Simulation; D018384:Oxidative Stress / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D015415:Biomarkers; D017382:Reactive Oxygen Species; D013481:Superoxides; D017665:Hydroxyl Radical; D002392:Catechin; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione
keywords: Antioxidant enzymes; Bacteria; Catechin; Electron transport chain complex; Fragmented DNA; Hydroxyl radical; Superoxide anion radical