Linalool is a monoterpene compound present in many plants. The enantiomer naturally occurring in essentiaI oils is (-)- linalool. Many reports have described the racemate form of this monoterpene and its effect on the brain neurotransmitters glutamic acid, -y-aminobutyric acid (GASA),acetylcholine and dopamine. Moreover, linalool has been reported to exhibit a local anaesthetic activity, related to its effects on the nicotinic receptor-ion channel, and to be effective against several bacteria and fungi. Spasmolytic effects and antioxidant properties have also been described. Studies recently performed by our research group have shown that (-)-linalool possesses anti-inflammatory, antinociceptive and antihyperalgesic activities in different animai models. These properties have been ascribed to the ability of (-)-linalool to stimulate the opioidergic, cholinergic M2 and dopaminergic D2 systems, as well as to its interaction with potassium ion (K+)-channels. In addition, the effects of (-)-linalool on pain responses are mediated, at least in part, by the activity of adenosine Al and A2Areceptors and by the reduction of nitric oxide (NO) production/release, probably through mechanisms involving opioidergic, cholinergic and/or glutamatergic systems. Even though many papers have dea!t with the biological activities of racemic linalool and (-)-linalool, the molecular mechanism of these compounds remains poorly understood.
(-)-Linaloolis a drug able to all€viate,in some degree, pain responsesmediatedby a wide range of neurotransmitter systems. Receptors modulated by this compound are expressed in both the peripheral and the centrai nervous system (CNS). Pain research is currently targeting a complex system of receptors, ion channels and their modulators in an effort to identify newer, safer methods for pain relief. Thus, (-)-linalool may constitute a valuable tool for the treatment of p<1in, hyperalgesia and inflammatory pain. Moreover, the unique properties of (-)-linalool, which displ<1Yasntimicrobial, anti- inflammatory, analgesic and antihyperalgesic activities, make it potentially very useful for the treatment of infective conditions, often accompanied by inflammation and pain.