title: Guarea kunthiana Bark Extract Enhances the Antimicrobial Activities of Human and Bovine Neutrophils.
abstract: Guarea kunthiana is used in folk remedies for the treatment of several diseases including microbial infections. The mechanism behind this phenomenon still needs to be elucidated. Here, we investigated the effect of G. kunthiana bark extract on antimicrobial functions of human and bovine neutrophils as the first line of defense against infections. For this aim, neutrophils were isolated from either human or bovine blood and treated with G. kunthiana bark extract. The antimicrobial activity of the neutrophils against Staphylococcus (S.) aureus and Escherichia (E.) coli was tested in a bacterial survival assay and a fluorescence-based phagocytosis assay. Furthermore, the formation of neutrophil extracellular traps (NETs) was visualized by immunofluorescence microscopy. We show that neutrophils treated with G. kunthiana extract distinctly increased phagocytosis of S. aureus or E. coli. Interestingly, we demonstrate that G. kunthiana bark extract induces the formation of NETs in both cell types. This effect was abolished when treating the cells with diphenyleniodonium chloride (DPI) pointing to a direct implication of the NADPH oxidase-dependent formation of reactive oxygen species in this process. In summary, our data strongly suggest that G. kunthiana bark extract boosts the antimicrobial activities of neutrophils as the first line of defense against invading pathogens.
authors.forename: Natalja
authors.initials: N
authors.lastname: Jerjomiceva
authors.forename: Hisham
authors.initials: H
authors.lastname: Seri
authors.forename: Ragheda
authors.initials: R
authors.lastname: Yaseen
authors.forename: Nicole
authors.initials: N
authors.lastname: de Buhr
authors.forename: William N
authors.initials: WN
authors.lastname: Setzer
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Naim
authors.forename: Maren
authors.initials: M
authors.lastname: von Köckritz-Blickwede
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004926:Escherichia coli / Q000502:physiology; D006801:Humans; D029582:Meliaceae / Q000737:chemistry*; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology* / Q000382:microbiology; D010587:Phagocytosis / Q000187:drug effects; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000502:physiology
chemical_list: D010936:Plant Extracts