Neuroprotective effects of (-)-linalool against oxygen-glucose deprivation-induced neuronal injury

(-)-Linalool, a major component of many essential oils, is widely used in cosmetics and flavoring ingredients as well as in traditional medicines. Although various in vitro and in vivo studies have shown that (-)-linalool has anti-convulsant, anti-nociceptive, anti-inflammatory and anti-oxidative properties, its anti-ischemic/hypoxic effects have yet to be determined. This study assessed the neuroprotective effects of (-)-linalool against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cortical neuronal injury, an in vitro model of ischemic stroke. (-)-Linalool significantly attenuated OGD/R-evoked cortical neuronal injury/death, although it did not inhibit N-methyl-d-aspartate (NMDA)-induced excitotoxicity. (-)-Linalool significantly reduced intracellular oxidative stress during OGD/R-induced injury, as well as scavenging peroxyl radicals (Trolox equivalents or TE = 3.8). This anti-oxidant effect was found to correlate with the restoration of OGD/R-induced decreases in the activities of SOD and catalase. In addition, (-)-linalool inhibited microglial migration induced by monocyte-chemoattractant protein-1 (MCP-1), a chemokine released by OGD/R. These findings show that (-)-linalool has neuroprotective effects against OGD/R-induced neuronal injury, which may be due to its anti-oxidant and anti-inflammatory activities. Detailed examination of the anti-ischemic mechanisms of (-)-linalool may indicate strategies for the development of drugs to treat cerebral ischemic injury.