Terpinen-4-ol and alpha-terpineol (tea tree oil components) inhibit the production of IL-1β, IL-6 and IL-10 on human macrophages

• Published in: Inflammation research Vol. 63; no. 9; pp. 769 - 778
• Main Authors: Nogueira, M. N. M., Aquino, S. G., Rossa Junior, C., Spolidorio, D. M. P.
• Format: Journal Article
• Language: English
• Published: Basel Springer Basel 01.09.2014
• Subjects: Allergology; Anti-Inflammatory Agents - pharmacology; Biomedical and Life Sciences; Biomedicine; Cyclohexenes - pharmacology; Cytokines - immunology; Dermatology; Humans; Immunology; Lipopolysaccharides; Macrophages - drug effects; Macrophages - immunology; Melaleuca; Melaleuca alternifolia; Mitogen-Activated Protein Kinases - immunology; Monoterpenes - pharmacology; Neurology; NF-kappa B - immunology; Original Research Paper; Pharmacology/Toxicology; Rheumatology; Signal Transduction; Tea Tree Oil - pharmacology; Terpenes - pharmacology; Toll-Like Receptor 2 - immunology; Toll-Like Receptor 4 - immunology; U937 Cells; Inflammation; Cytokines; Macrophages; Tea tree oil
• ISSN: 1023-3830; 1420-908X
• DOI: 10.1007/s00011-014-0749-x

Objective Tea tree oil (TTO) is an essential oil with anti-inflammatory properties, steam distilled from the plant Melaleuca alternifolia . We investigated the immunomodulatory properties of TTO and its components (terpinen-4-ol and alpha-terpineol) using lipopolysaccharide (LPS)-stimulated macrophages. Methods The ability of TTO, terpinen-4-ol and alpha-terpineol to modulate the macrophage response to bacterial LPS stimulation was assessed by ELISA for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-10 cytokine production and by western blotting for the activation of nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling, which are associated with the expression of pro-inflammatory cytokines. We used a human monocytic cell line (U937) differentiated into macrophages. Results LPS induced the production of all cytokines, and TTO and its components significantly reduced the production of IL-1β, IL-6 and IL-10. The production of TNF-α was not affected by either TTO or its major components. The modulation of cytokine production was not mediated by changes in NF-κB or p38 MAPK activation. Conclusion TTO, terpinen-4-ol and alpha-terpineol can suppress the production of inflammatory mediators in LPS-stimulated human macrophages; this inhibition was mediated by interfering with the NF-kB, p38 or ERK MAPK pathways.