Citral modulates human monocyte responses to Staphylococcus aureus infection

• Published in: Scientific reports Vol. 11; no. 1; p. 22029
• Main Authors: Oliveira, Hellen Braga Martins, das Neves Selis, Nathan, Brito, Thamara Louisy Santos, Sampaio, Beatriz Almeida, de Souza Bittencourt, Rafaela, Oliveira, Caline Novais Teixeira, Júnior, Manoel Neres Santos, Almeida, Carolline Florentino, Almeida, Palloma Porto, Campos, Guilherme Barreto, Amorim, Aline Teixeira, Timenetsky, Jorge, Romano, Carla Cristina, Uetanabaro, Ana Paula Trovatti, Yatsuda, Regiane, Marques, Lucas Miranda
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-11-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/22; 631/326/421; Acyclic Monoterpenes - pharmacology; Adult; Anti-inflammatory agents; Antibiotics; Brazil; CD14 antigen; CD28 antigen; CD80 antigen; CD86 antigen; Cell surface; Cells, Cultured; Child; Citral; Cytokines; Gram-positive bacteria; Histocompatibility antigen HLA; Humanities and Social Sciences; Humans; Immune system; Immunologic Factors - pharmacology; Inflammation; Inflammation - complications; Inflammation - drug therapy; Inflammation - immunology; Inoculation; Interleukin 10; Interleukin 12; Interleukin 23; Interleukin 6; Leukocyte migration; Leukocytes (mononuclear); Male; Monocytes; Monocytes - drug effects; Monocytes - immunology; multidisciplinary; NF-κB protein; Peripheral blood mononuclear cells; Science; Science (multidisciplinary); Staphylococcal Infections - complications; Staphylococcal Infections - drug therapy; Staphylococcal Infections - immunology; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - immunology; Staphylococcus infections; Statistical analysis; Surface markers; Virulence; Young Adult; γ-Interferon; Brazil
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-01536-4

Staphylococcus aureus
is a Gram-positive bacterium that is considered an important human pathogen. Due to its virulence and ability to acquire mechanisms of resistance to antibiotics, the clinical severity of
S. aureus
infection is driven by inflammatory responses to the bacteria. Thus, the present study aimed to investigate the modulating role of citral in inflammation caused by
S. aureus
infection. For this, we used an isolate obtained from a nasal swab sample of a healthy child attending a day-care centre in Vitória da Conquista, Bahia, Brazil. The role of citral in modulating immunological factors against
S. aureus
infection was evaluated by isolating and cultivating human peripheral blood mononuclear cells. The monocytes were treated with 4%, 2%, and 1% citral before and after inoculation with
S. aureus
. The cells were analysed by immunophenotyping of monocyte cell surface molecules (CD54, CD282, CD80, HLA-DR, and CD86) and cytokine dosage (IL-1β, IL-6, IL-10, IL-12p70, IL-23, IFN-γ, TGF-β, and TNF-α), and evaluated for the expression of 84 genes related to innate and adaptive immune system responses. GraphPad Prism software and variables with
P
values < 0.05, were used for statistical analysis. Our data demonstrated citral’s action on the expression of surface markers involved in recognition, presentation, and migration, such as CD14, CD54, and CD80, in global negative regulation of inflammation with inhibitory effects on NF-κB, JNK/p38, and IFN pathways. Consequently, IL-1β, IL-6, IL-12p70, IL-23, IFN-γ, and TNF-α cytokine expression was reduced in groups treated with citral and groups treated with citral at 4%, 2%, and 1% and infected, and levels of anti-inflammatory cytokines such as IL-10 were increased. Furthermore, citral could be used as a supporting anti-inflammatory agent against infections caused by
S. aureus
. There are no data correlating citral,
S. aureus
, and the markers analysed here; thus, our study addresses this gap in the literature.