Over the past few decades, complementary and alternative treatments have become increasingly popular worldwide. The purported therapeutic characteristics of natural products have come under increased scrutiny both in vitro and in vivo as part of efforts to legitimize their usage. One such product is tea tree oil (TTO), a volatile essential oil primarily obtained from the native Australian plant, Melaleuca alternifolia, which has diverse traditional and industrial applications such as topical preparations for the treatment of skin infections. Its anti-inflammatory-linked immunomodulatory actions have also been reported. This systematic review focuses on the anti-inflammatory effects of TTO and its main components that have shown strong immunomodulatory potential. An extensive literature search was performed electronically for data curation on worldwide accepted scientific databases, such as Web of Science, Google Scholar, PubMed, ScienceDirect, Scopus, and esteemed publishers such as Elsevier, Springer, Frontiers, and Taylor & Francis. Considering that the majority of pharmacological studies were conducted on crude oils only, the extracted data were critically analyzed to gain further insight into the prospects of TTO being used as a neuroprotective agent by drug formulation or dietary supplement. In addition, the active constituents contributing to the activity of TTO have not been well justified, and the core mechanisms need to be unveiled especially for anti-inflammatory and immunomodulatory effects leading to neuroprotection. Therefore, this review attempts to correlate the anti-inflammatory and immunomodulatory activity of TTO with its neuroprotective mechanisms.
Tea Tree Oil/therapeutic use* ; Melaleuca ; Neuroprotection ; Drug Repositioning ; Neuroinflammatory Diseases ; Australia ; Oils, Volatile ; Anti-Inflammatory Agents/pharmacology*

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.
Adult ; Aedes ; Biological Assay ; Brugia pahangi ; Elephantiasis, Filarial ; Flowers* ; Humans ; In Vitro Techniques ; Melaleuca* ; Methanol* ; Microscopy, Electron ; Polymerase Chain Reaction ; Wolbachia

BACKGROUND: Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF) are now considered as major health problems in the Philippines. N,N,-dietyl-3-toluamide (DEET) is recognized as the most effective against Aedes aegypti. However, the concern about its use have underscored the need to find a safer alternative repellent.
OBJECTIVES: This study aims to determine and compare the repellent activity of tea tree (Melaleuca alternifolia) oil against Aedes aegypti with 7% DEET using a double-blind controlled experimental trial
METHODOLOGY: Twenty healthy subjects were allocated systematically by alternate assignment into three treatment groups (Control vs. Tea Tree oil, control vs. 7 percent DEET, Tea Tree oil vs DEET). All subjects were exposed to Aedes aegypti for 5 minutes every hour for 8 hours and the number of mosquitoes biting/landing were recorded and compared for each treatment group
RESULTS: Fifty percent tea tree oil has a repellent activity against Aedes aegypti and its efficacy is comparable to 7% DEET. Both treatments were equally effective in repelling mosquitoes for 7 hours. No cutaneous reactions to both repellents were noted
CONCLUSION: The efficacy of tea tree oil is comparable to 7% DEET and is recommended as an alternative natural mosquito repellent.

Human ; Aedes ; Deet ; Dengue ; Healthy Volunteers ; Insect Repellents ; Melaleuca ; Severe Dengue ; Tea ; Tea Tree Oil ; Trees

Melaleuca alternifolia Cheel was acclimatized from Australia to grow in Vietnam. Samples were collected from various provinces, and the analysis of M. alternifolia Cheel was performed by means of gas chromatography-mass spectrometry to afford four different chemotypes with terpinene-4-ol (34.08-40.44%), terpinelene (39.47-60.34%), 1,8-cineole (71.23-77.54%) and terpinolene (34.89-38.30%) plus 1,8-cineole (30.84-35.26%) respectively as main components of the essential oil
Melaleuca ; chemistry ; Biochemistry