Effects of Linalool on [3H] MK801 and [3H] Muscimol Binding in Mouse Cortical Membranes

Abstract Linalool is a monoterpene compound reported to be a major component of essential oils of several aromatic species. Several linalool‐producing species are used in traditional medical systems for sedative purposes, including the interruption and prevention of seizures. Previous studies in mice revealed that linalool modulates glutamatergic (competitive antagonism of L ‐[ 3 H]glutamate binding, delayed intraperitoneal NMDA‐induced convulsions and blockade of intracerebroventricular Quin‐induced convulsions) and GABAergic transmission (protection against pentylenetetrazol and picrotoxin‐induced convulsions). To further clarify the anticonvulsive mechanisms of linalool, we studied the effects of linalool on binding of [ 3 H]MK801 (NMDA antagonist) and [ 3 H]muscimol (GABA A agonist) to mouse cortical membranes. Linalool showed a dose dependent non‐competitive inhibition of [ 3 H]MK801 binding (IC 50 = 2.97 m M ) but no effect on [ 3 H]muscimol binding. The data suggest that the anticonvulsant mode of action of linalool includes a direct interaction with the NMDA receptor complex. The data do not, however, support a direct interaction of linalool with GABA A receptors, although changes in GABA‐mediated neuronal inhibition or effects on GABA release and uptake cannot be ruled out.