1. Immunomodulatory activity of Melaleuca alternifolia concentrate (MAC): Inhibition of LPS-induced NF-κB activation and cytokine production in myeloid cell lines
- Author
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Maxwell John Reynolds, Tz-Chong Chou, Amanda M. Clark, Tsu-Chung Chang, Stephen John Ralph, and Pauline Low
- Subjects
Lipopolysaccharides ,Myeloid ,Lipopolysaccharide ,Cell Survival ,medicine.medical_treatment ,Blotting, Western ,Immunology ,Cell Culture Techniques ,Gene Expression ,Biology ,Mice ,chemistry.chemical_compound ,Tea Tree Oil ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Immunologic Factors ,Immunology and Allergy ,Myeloid Cells ,Pharmacology ,Macrophages ,NF-kappa B ,NF-κB ,Melaleuca ,In vitro ,Cell biology ,Cytokine ,medicine.anatomical_structure ,Mechanism of action ,chemistry ,Biochemistry ,Cell culture ,Cytokines ,Tumor necrosis factor alpha ,medicine.symptom - Abstract
Melaleuca alternifolia concentrate (MAC) is a mixture predominantly composed of monoterpenoids and sesquiterpenes, refined from the essential oil of the tea tree by removing up to 99% of the more toxic, hydrophobic monoterpenes. MAC was examined here for its immunomodulatory effects on the human THP1 and murine RAW264.7 myeloid leukemic cell lines as models for macrophage-like cells. Firstly, MAC levels were determined that did not affect either the survival or proliferation of these cell lines in vitro. Next, the levels of lipopolysaccharide (LPS)-induced production of cytokines (IL-6, TNFα, IL-10, GM-CSF, IFNγ and IL-3) were examined from the myeloid cell lines using multiplex assays. Many of the LPS-inducible cytokines produced by either cell lines could be significantly inhibited by MAC. Closer examination of the mechanism of action of MAC showed that it inhibited the LPS-induced activation of IκB phosphorylation and nuclear factor (NF)-κB signalling and translocation, inhibiting iNOS protein expression and NO production. These results demonstrate that MAC exerts its immunomodulatory effects by inhibiting NF-κB signalling activation and levels of cytokine production by macrophage-like cell lines.
- Published
- 2015
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