title: Toxicity of bovicin HC5 against mammalian cell lines and the role of cholesterol in bacteriocin activity.
abstract: Bacteriocins are ribosomally synthesized antimicrobial peptides produced by Bacteria and some Archaea. The assessment of the toxic potential of antimicrobial peptides is important in order to apply these peptides on an industrial scale. The aim of the present study was to investigate the in vitro cytotoxic and haemolytic potential of bovicin HC5, as well as to determine whether cholesterol influences bacteriocin activity on model membranes. Nisin, for which the mechanism of action is well described, was used as a reference peptide in our assays. The viability of three distinct eukaryotic cell lines treated with bovicin HC5 or nisin was analysed by using the MTT assay and cellular morphological changes were determined by light microscopy. The haemolytic potential was evaluated by using the haemoglobin liberation assay and the role of cholesterol on bacteriocin activity was examined by using model membranes composed of DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) and DPoPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). The IC(50) of bovicin HC5 and nisin against Vero cells was 65.42 and 13.48 µM, respectively. When the MTT assay was performed with MCF-7 and HepG2 cells, the IC(50) obtained for bovicin HC5 was 279.39 and 289.30 µM, respectively, while for nisin these values were 105.46 and 112.25 µM. The haemolytic activity of bovicin HC5 against eukaryotic cells was always lower than that determined for nisin. The presence of cholesterol did not influence the activity of either bacteriocin on DOPC model membranes, but nisin showed reduced carboxyfluorescein leakage in DPoPC membranes containing cholesterol. In conclusion, bovicin HC5 only exerted cytotoxic effects at concentrations that were greater than the concentration needed for its biological activity, and the presence of cholesterol did not affect its interaction with model membranes.
authors.affiliation: Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Aline Dias
authors.initials: AD
authors.lastname: Paiva
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Michelle Dias
authors.initials: MD
authors.lastname: de Oliveira
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Sérgio Oliveira
authors.initials: SO
authors.lastname: de Paula
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Baracat-Pereira
authors.affiliation: Department Biochemistry of Membranes, Utrecht University, Utrecht, The Netherlands.
authors.forename: Eefjan
authors.initials: E
authors.lastname: Breukink
authors.affiliation: Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Hilário Cuquetto
authors.initials: HC
authors.lastname: Mantovani
mesh_terms: D000818:Animals; D001430:Bacteriocins / Q000737:chemistry / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism*; D005057:Eukaryotic Cells / Q000187:drug effects* / Q000378:metabolism*; D053878:Hemolytic Agents / Q000633:toxicity; D006801:Humans; D014709:Vero Cells
chemical_list: D001430:Bacteriocins; D053878:Hemolytic Agents; C514465:bovicin HC5, Streptococcus bovis HC5; D002784:Cholesterol