(CN) – Purple and pleasant, lavender has long been used by folk medicine to induce calmness. Now, a study published Tuesday in Frontiers in Behavioral Neuroscience offers new insight into how linalool, one of the relaxation-inducing components found in lavender, works.
Researchers in the physiology department at Kagoshima University in Japan found that linalool, a terpene alcohol naturally found in lavender, decreased anxiety levels in laboratory mice when simply inhaled and does not need to enter the bloodstream to work.
In addition to effectively decreasing anxiety in mice, linalool does not cause detrimental side effects associated with medications often prescribed to reduce anxiety.
Nearly one in five Americans exhibit symptoms of an anxiety disorder, but the side effects of some commonly prescribed medications can outweigh the benefits of taking them. Selective serotonin reuptake inhibitors like Paxil, Prozac and Zoloft can cause sexual dysfunction and serotonin syndrome. Benzodiazepines like Xanax and Valium can cause amnesia or sedation and are commonly abused.
So researchers wondered: “Lavender works its relaxing magic all around us: from garden borders to bath bombs to fabric softener. But why not in our hospitals and clinics? And what is the science behind the magic?”
In their work, researchers exposed lab-conditioned male mice to linalool scents and then gave them a common anxiety test: the light/dark box. In this test, mice are placed in a small, dark, safe area connected to a brightly lit area and researchers observe how willing mice are to explore this stressful new environment.
In addition to noting the anxiolytic effects of the linalool, researchers found that mice were able to navigate an elevated maze without trouble – indicating linalool didn’t impair motor functions. Mice injected with benzodiazepines exhibited signs of drunkenness.
Previously, scientists thought linalool entered the bloodstream through the lungs. But because mice that lacked the sense of smell were not affected by linalool in the lab, researchers have concluded neurons in the nose detect the linalool and relay the calming message to the nervous system.
“These results provide information about the potential central neuronal mechanisms underlying the odor-induced anxiolytic effects and the foundation for exploring clinical application of linalool odor in anxiety treatments,” the authors wrote.
In addition to studying linalool in female mice, co-author Dr. Hideki Kashiwadani said his team is also studying other odors which may provide alternatives for antidepressants.
While Kashiwadani cautions against “rough-and-ready conclusions” about marketing linalool for human consumption any time soon, he added, “At the same time, I believe that our research established a bridgehead to reach safer alternatives.”
Linalool may used to ease pre-surgery stress or as “a safe alternative for patients who have difficulties with oral or suppository administration of anxiolytics, such as infants or confused elders,” according to the study authors.
The research was funded by the Japan Society for the Promotion of Science.