ABSTRACT
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)-1ß, 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-1ß, 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.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Cyclohexenes/pharmacology , Cytokines/immunology , Macrophages/drug effects , Monoterpenes/pharmacology , Tea Tree Oil/pharmacology , Terpenes/pharmacology , Cyclohexane Monoterpenes , Humans , Lipopolysaccharides , Macrophages/immunology , Mitogen-Activated Protein Kinases/immunology , NF-kappa B/immunology , Signal Transduction , Toll-Like Receptor 2/immunology , Toll-Like Receptor 4/immunology , U937 CellsABSTRACT
O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil), de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialidades médicas, o TTO passou a ser empregado na área odontológica. Esta revisão de literatura foi realizada com o objetivo de discutir os ensaios já realizados com o TTO contra microrganismos relacionados à doença cárie, doença periodontal e problemas pulpares. O óleo de Melaleuca tem demonstrado boa ação antibacteriana in vitro contra microrganismos bucais, porém, pesquisas envolvendo o estudo do mecanismo de ação sobre as células microbianas ou estudos in vivo ainda são escassos e precisam ser realizados, já que esse produto pode ser útil na odontologia, seja na manutenção química da higiene ou prevenção de doenças bucais.
The interest in alternative medicines, especially those from natural extracts, has increased in recent decades. Melaleuca alternifolia is a shrub belonging to the genus Melaleuca, popularly known as "tea tree", the main product of which is its essential oil (TTO - tea tree oil), of great medicinal importance for its proven bactericidal and antifungal activity against several human pathogens. By virtue of its therapeutic activity in various medical specialties, TTO is now used in dentistry. This literature review was conducted in order to discuss the tests already carried out with TTO against microorganisms related to dental caries, periodontal disease and pulpal problems. Melaleuca oil has shown good in vitro antibacterial activity against oral microorganisms; however, research involving the study of its mechanism of action on the microbial cells or in vivo studies are still scarce and need to be done since this product may be useful in dentistry, either in the chemical maintenance of hygiene or in the prevention of oral diseases.
