Antimicrobial properties of tea tree oil

Phytomedicine such as tea tree (melaleuca) oil have become increasingly popular in recent decades. This essential oil has been used for almost 100 years in Australia but is now available worldwide both as neat oil and as an active component in an array of products. The primary uses of tea tree oil have historically capitalized on the antiseptic, antifungal, antiviral and anti-inflammatory actions of the oil. Reports of activity in the field of antibacterial Tea tree oil research are widely conflicting, probably owing to interand intra-assay variation in susceptibility testing. However, several high-quality investigations have examined the relationship between component structure and antibacterial activity and these are in close agreement. The mechanism of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and alpha terpineol, against Staphylococcus aureus were investigated. In addition, numerous research groups have sought to elucidate the antibacterial mechanisms of action of selected components of tea tree oil. These compounds represent novel leads, and future studies may allow the development of a pharmacologically acceptable antimicrobial agent or class of agents. This review summarizes recent developments in our understanding of the antimicrobial activity of the oil. Specific mechanisms of antibacterial activity are reviewed, and the toxicity of the oil is briefly discussed.