title: Plectasin has antibacterial activity and no affect on cell viability or IL-8 production.
abstract: Animals and plants express endogenous peptide antibiotics called defensins. Defensins show broad-spectrum antimicrobial activity, even against bacteria that have resistance to conventional antibiotics, which has made them viable candidates for new antibiotics. However, human defensins have failed to reach the market because of their cytotoxic effects and non-antimicrobial bioactivities. Plectasin is a defensin that has shown promise but has not had its potentially negative effects clarified. To address this issue, we examined plectasin's cytotoxicity in human cells using an AlamarBlue reduction assay, its interleukin (IL)-8-inducing capacity using real-time PCR and ELISA, and measured its MIC against bacteria. We confirmed that plectasin has specific antibacterial activity against Streptococcus pneumoniae. Plectasin showed no cytotoxicity to A549 cells, normal human bronchial epithelial cells, or lung fibroblasts, and it did not induce IL-8 transcription or production in A549 cells. Our results suggest that plectasin could be an inoffensive alternative antibiotic for clinical application.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Hara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mukae
authors.forename: Noriho
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishimoto
authors.forename: Misato
authors.initials: M
authors.lastname: Amenomori
authors.forename: Hanako
authors.initials: H
authors.lastname: Fujita
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishimatsu
authors.forename: Katsunori
authors.initials: K
authors.lastname: Yanagihara
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D023082:Defensins / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis; D008826:Microbial Sensitivity Tests; D010455:Peptides / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D013296:Streptococcus pneumoniae / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D023082:Defensins; D016209:Interleukin-8; D010455:Peptides; D012333:RNA, Messenger; C504857:plectasin