title: Immunomodulatory activity of Melaleuca alternifolia concentrate (MAC): inhibition of LPS-induced NF-κB activation and cytokine production in myeloid cell lines.
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.
authors: School of Medical Sciences and Griffith Health Research Institute, Griffith University, Gold Coast campus, Southport, Queensland 4222, Australia.
authors: Pauline
authors: P
authors: Low
authors: School of Medical Sciences and Griffith Health Research Institute, Griffith University, Gold Coast campus, Southport, Queensland 4222, Australia.
authors: Amanda M
authors: AM
authors: Clark
authors: National Defense Medical Center, Taipei, Taiwan.
authors: Tz-Chong
authors: TC
authors: Chou
authors: National Defense Medical Center, Taipei, Taiwan.
authors: Tsu-Chung
authors: TC
authors: Chang
authors: School of Medical Sciences and Griffith Health Research Institute, Griffith University, Gold Coast campus, Southport, Queensland 4222, Australia; 98 Alive Pty Ltd., PO Box 82, Underwood, QLD 4119, Australia.
authors: Maxwell
authors: M
authors: Reynolds
authors: School of Medical Sciences and Griffith Health Research Institute, Griffith University, Gold Coast campus, Southport, Queensland 4222, Australia. Electronic address: s.ralph@griffith.edu.au.
authors: Stephen J
authors: SJ
authors: Ralph
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007155:Immunologic Factors / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D031650:Melaleuca / Q000737:chemistry*; D051379:Mice; D022423:Myeloid Cells / Q000187:drug effects* / Q000276:immunology; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000235:genetics; D020947:Tea Tree Oil / Q000737:chemistry*
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020947:Tea Tree Oil
keywords: Cytokines; Immunomodulation; Melaleuca alternifolia concentrate (MAC); Myeloid cells; NF-κB