Related Experiment Video
Updated: May 5, 2026
Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
Published on: May 31, 2018
DHA suppresses Prevotella intermedia lipopolysaccharide-induced production of proinflammatory mediators in murine
Eun-Young Choi1, Ji-Young Jin1, Jeom-Il Choi2
1Department of Biological Science, College of Medical and Life Sciences, Silla University, 140 Baegyang-daero, 700beon-gil, Sasang-gu, Busan 617-736, Korea.
Abstract:
Several reports have indicated that dietary intake of DHA is associated with lower prevalence of periodontitis. In the present study, we investigated the effect of DHA on the production of proinflammatory mediators in murine macrophage-like RAW264.7 cells stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen implicated in inflammatory periodontal disease, and its mechanisms of action. LPS was isolated from lyophilised P. intermedia ATCC 25,611 cells using the standard hot-phenol-water protocol. Culture supernatants were collected and assayed for NO, IL-1β and IL-6. Real-time PCR analysis was carried out to detect the expression of inducible NO synthase (iNOS), IL-1β, IL-6 and haeme oxygenase-1 (HO-1) mRNA. Immunoblot analysis was carried out to quantify the expression of iNOS and HO-1 protein and concentrations of signalling proteins. DNA-binding activities of NF-κB subunits were determined using an ELISA-based assay kit. DHA significantly attenuated the production of NO, IL-1β and IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW264.7 cells. DHA induced the expression of HO-1 in cells treated with P. intermedia LPS. Selective inhibition of HO-1 activity by tin protoporphyrin IX significantly mitigated the inhibitory effects of DHA on LPS-induced NO production. DHA significantly attenuated the phosphorylation of c-Jun N-terminal kinase induced by LPS. In addition, DHA suppressed the transcriptional activity of NF-κB by regulating the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and inhibited the phosphorylation of signal transducer and activator of transcription 1. Further in vivo studies are needed to better evaluate the potential of DHA in humans as a therapeutic agent to treat periodontal disease.
Insights
Docosahexaenoic acid (DHA) reduces inflammatory mediators linked to periodontal disease. DHA works by inducing heme oxygenase-1 and inhibiting key inflammatory pathways in cells.
Area of Science:
- Biomedical Science
- Immunology
- Nutritional Science
Background:
- Dietary intake of docosahexaenoic acid (DHA) is linked to reduced periodontitis prevalence.
- Prevotella intermedia lipopolysaccharide (LPS) is implicated in inflammatory periodontal disease.
Purpose of the Study:
- Investigate DHA's effect on pro-inflammatory mediator production in LPS-stimulated murine macrophage-like RAW264.7 cells.
- Elucidate the mechanisms underlying DHA's anti-inflammatory actions.
Main Methods:
- Cells were stimulated with LPS from Prevotella intermedia.
- Assayed nitric oxide (NO), IL-1β, and IL-6 production.
- Quantified gene and protein expression of iNOS, HO-1, and signaling proteins using Real-time PCR and immunoblot analysis.
- Assessed NF-κB DNA-binding activity and STAT1 phosphorylation.
Main Results:
- DHA significantly reduced NO, IL-1β, and IL-6 production at both transcriptional and translational levels.
- DHA induced heme oxygenase-1 (HO-1) expression, and HO-1 inhibition partially reversed DHA's effect on NO production.
- DHA attenuated c-Jun N-terminal kinase phosphorylation and suppressed NF-κB transcriptional activity.
- DHA inhibited STAT1 phosphorylation.
Conclusions:
- DHA demonstrates anti-inflammatory effects against Prevotella intermedia LPS in macrophages.
- DHA's mechanism involves HO-1 induction and modulation of NF-κB and STAT1 signaling pathways.
- Further in vivo studies are warranted to explore DHA's therapeutic potential for periodontal disease in humans.
