title: Involvement of oxidative stress in protocatechuic acid-mediated bacterial lethality.
abstract: The involvement of oxidative stress in protocatechuic acid-mediated bacterial lethality was investigated. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) of protocatechuic acid against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus are 600 and 700 μg/ml, 600 and 800 μg/ml, and 600 and 800 μg/ml, respectively. The optical densities and colony-forming units of protocatechuic acid-treated bacteria decreased in time-dependent manner. Protocatechuic acid (4× MIC) significantly increased the superoxide anion content of E. coli, P. aeruginosa, and S. aureus compared to dimethyl sulfoxide (DMSO). Superoxide dismutase, catalase, and NAD+/NADH in protocatechuic acid-treated E. coli, P. aeruginosa, and S. aureus increased significantly when compared to DMSO. Conversely, level of reduced glutathione decreased in protocatechuic acid-treated E. coli, P. aeruginosa, and S. aureus, while glutathione disulfide increased when compared to DMSO. Furthermore, malondialdehyde and fragmented DNA increased significantly following exposure to protocatechuic acid. Protocatechuic acid inhibited the activity of complexes I and II. From the above findings, protocatechuic acid 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 in 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.
authors.forename: Taofeek O
authors.identifier: 0000-0003-2392-169X
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: Ramat S
authors.initials: RS
authors.lastname: Habibu
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Kabiru
authors.initials: K
authors.lastname: Saidu
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Fatimah Z
authors.initials: FZ
authors.lastname: Haliru
authors.affiliation: Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: Hikmat O
authors.initials: HO
authors.lastname: Ajiboye
authors.affiliation: Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: Najeeb O
authors.initials: NO
authors.lastname: Aliyu
authors.affiliation: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Oluwayemisi B
authors.initials: OB
authors.lastname: Ibitoye
authors.affiliation: Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: Judith N
authors.initials: JN
authors.lastname: Uwazie
authors.affiliation: Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.
authors.forename: Hamdalat F
authors.initials: HF
authors.lastname: Muritala
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Sharafa A
authors.initials: SA
authors.lastname: Bello
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Idris I
authors.initials: II
authors.lastname: Yusuf
authors.affiliation: Microbiology Unit, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors.forename: Aisha O
authors.initials: AO
authors.lastname: Mohammed
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D015169:Colony Count, Microbial; D004579:Electron Transport; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D062385:Hydroxybenzoates / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D018384:Oxidative Stress; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000633:toxicity; D013053:Spectrophotometry; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D062385:Hydroxybenzoates; D017382:Reactive Oxygen Species; C009091:protocatechuic acid
keywords: Antioxidant enzymes; bacteria; electron transport chain complex; fragmented DNA, hydroxyl radical, NAD+/NADH; protocatechuic acid, superoxide anion radical