title: Redox and respiratory chain related alterations in the lophirones B and C-mediated bacterial lethality.
abstract: The influence of chalcone dimers, lophirones B and C on redox status and respiratory chain activity of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was investigated. Minimum inhibitory concentrations (MIC) of lophirones B and C against E. coli, P. aeruginosa and S. aureus are 200-; 100-; 200- and 150-μg/mL respectively. Similarly, the minimum bactericidal concentrations (MBC) of lophirones B and C are 250; 200; 300 and 200-μg/mL respectively. The optical densities and colony forming units of lophirones B and C-treated bacteria decreased in time-dependent manner. Superoxide anion content of E. coli, P. aeruginosa and S. aureus exposed to lophirones B and C (4× MIC) increased significantly. Superoxide dismutase and catalase in the chalcone dimers-treated bacteria increased significantly. Conversely, reduced glutathione in lophirones B and C-treated bacteria decrease significantly with corresponding increase in glutathione disulfide. Furthermore, malondialdehyde and fragmented DNA increased significantly following exposure to the chalcone dimers. The respiratory complex I and II decreased significantly in the chalcone dimers-treated bacteria. From the findings, lophirones B and C altered intracellular redox status via enhanced oxidant generation possibly by autoxidation, Fenton chemistry and inhibiting electron transport chain resulting to lipid peroxidation and DNA fragmentation and consequentially bacterial cell death.
authors: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria. Electronic address: ajiboyeyong@yahoo.com.
authors: T O
authors: TO
authors: Ajiboye
authors: Antioxidants, Redox Biology and Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah University, Ilorin, Nigeria.
authors: F Z
authors: FZ
authors: Haliru
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002374:Catalase / Q000032:analysis; D047188:Chalcones / Q000494:pharmacology*; D015169:Colony Count, Microbial; D053938:DNA Fragmentation; D004579:Electron Transport / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D019803:Glutathione Disulfide / Q000032:analysis; D008315:Malondialdehyde / Q000032:analysis; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010084:Oxidation-Reduction; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013053:Spectrophotometry; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013482:Superoxide Dismutase / Q000032:analysis; D013481:Superoxides / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D047188:Chalcones; C000613963:lophirone B; C000613964:lophirone C; D013481:Superoxides; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase; D019803:Glutathione Disulfide
keywords: Antioxidant enzymes; Bacteria; Chalcone; Electron transport chain complex; Fragmented DNA; Hydroxyl radical; Superoxide anion radical