The Efficacy of <i>Eucalyptus globulus</i> Essential Oil in the Management of Pain

Eucalyptus globulus (Myrtaceae family) is the only recognized medicinal species of the Eucalyptus genus, by Commission E, and its leaves are used to extract essential oil with minimum content of 60% 1,8-cineole content. Eucalyptus essential oil is traditionally used to treat rheumatoid arthritis, muscle joint pains, and inflammation. The purpose of this review is to evaluate the effectiveness of Eucalyptus globulus essential oil in the management of pain and inflammation. The analgesic and anti-inflammatory effects of eucalyptus essential oil were confirmed in some pharmacological and clinical studies of pain. Eucalyptus essential oil reduced the pain and inflammation, which is antagonized by naloxone, suggesting the participation of μ-opioid receptors in its analgesic effects. The analgesic effects of eucalyptus essential oil are related to its 1,8-cineole content as its main component, which inhibits the production or synthesis of pro-inflammatory cytokines, by attenuation of TREM pathway surface receptor (TREM-1) and MKP-1 phosphatase. Eucalyptus essential oil and 1,8-cineole are the activators of hTRPM8, the antagonist of hTRPA1, and the inhibitor of the P2X3 receptor, which reduces pain and inflammation. The role of other components in eucalyptus essential oil in pain is confirmed. Eucalyptus essential oil or 1,8-cineole can be used as an alternative treatment in topical pain preparation, but it is better to be evaluated in well-designed clinical trials of pain and inflammation.