Nitrooleic acid inhibits macrophage activation induced by lipopolysaccharide from Prevotella intermedia

The hypothesis of the present study was that nitro-fatty acids (NO2-FAs) would suppress flammation associated with periodontal disease. To test this hypothesis, we investigated the influence of nitrooleic acid, a prototypical NO2-FA, on the inflammatory response of murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen associated the etiology of different types of periodontal diseases. LPS was prepared from intermedia cells by using phenol-water protocol. Culture supernatants were assayed for tric oxide (NO), interleukin-1 beta (IL-1 beta), and IL-6. Real-time polymerase chain reaction and im-munoblotting analyses were performed to quantify messenger RNA and protein expression, respectively. The secreted embryonic alkaline phosphatase reporter assay was performed to measure NF -KB activation. The transcription factor assay kit was used to measure DNA binding of NF -KB subunits. Findings obtained from the present study revealed that nitrooleic acid suppresses the generation and messenger RNA expression of inducible NO synthase-derived NO, IL-1 beta, and IL-6 in RAW264.7 cells activated with P . intermedia LPS and promotes macrophage polarization toward anti-inflammatory M2 phenotype. We also found that trooleic acid exerts its effect via heme oxygenase-1 induction and suppression of NF -signaling. The inhibition of NO and proinflammatory cytokine production by nitrooleic acid was independent from PPAR- gamma , JNK, p38, and STAT1/3. Nitrooleic acid may represent a novel class of agent as a host modulator which has therapeutic benefit in periodontal disease, though more work is needed to confirm this.(c) 2022 Elsevier Inc. All rights reserved.