Written by Greg Arnold, DC, CSCS. This study demonstrated that Salvia lavandulaefolia essential oil extract inhibits human acetylcholinesterase as evidenced by significant improvements in cognitive function tests, improved alertness and decreased fatigue in participating test subjects.
Use of essential oils for health promotion has increasingly gained traction over the past several years. Perhaps the most high-profile essential oil is eucalyptus, which the Centers for Disease Control approved as an insect repellant to replace DEET-containing modern repellents. 1 Fortunately, other essential oils are also gaining attention for many health-related issues.
Extract leaves of edible members of the sage family have been used for millennia to improve cognitive function and slow down cognitive decline. In addition to their well-tolerated active components called terpenoids, these extracts also have antioxidant, anti-inflammatory and estrogenic properties which support healthy brain function. 2
This study consisted of an in vitro investigation of the cholinesterase inhibitory properties of a potent Salvia lavandulaefolia (LS) essential oil and a double-blind, placebo-controlled, balanced crossover study. 3 The latter assessed the effects of a single dose of essential oil on cognitive performance and mood in 36 healthy participants. Young adults (10 male, 26 female) aged 19-28 years, received capsules containing either 50 µL of the essential oil or placebo (olive oil) on separate occasions, 7 days apart. Before each supplementation and then 1 hour and 4 hours after supplementation, each subject completed several computerized tests to measure cognitive function and memory. Included was the Cognitive Demand Battery (CDB), a series of cognitively demanding tasks designed to assess the treatment impact on speed, accuracy and mental fatigue while continuously performing these tasks.
In vitro tests demonstrated that LS essential oil that was found to consist almost exclusively of monoterpenoids. It was shown to be a potent inhibitor of human acetylcholinesterase (AChE) and was 10 times more active than previously assessed SL extracts. 4
Assessment of the crossover study showed a statistically significant improvement in performance of secondary memory and attention tasks at the one hour post-dose session, and reduced mental fatigue and increased alertness at the four-hour post-dose session in the sage group compared to the placebo group. Specifically,
- A significant improvement in reaction time for the one-hour post -dose group (p < 0.01)
- A significant improvement in word recall for the one-hour (p< 0.05) and four-hours (p<0.01) post-dose groups
- A significant improvement in word recognition task (p<0.01) and picture recognition task (p<0.01) compared to the placebo group.
- Participants in the sage group showed significantly reduced mental fatigue and increased alertness in the cognitive demand battery of tests at the 4-hour post dose compared to placebo group.(p<0.01 and p<0.05) for all tests.
When suggesting how sage extract helped elicit these benefits to cognitive function, they pointed to research showing sage to decrease activity of an enzyme called acetylcholinesterase (AChE) which breaks down a nerve chemical (“neurotransmitter”) called acetylcholine. 2,5 By inhibiting acetylcholinesterase activity and helping maintain acetylcholine levels between nerve cells, nerve function can improve.
The researchers add, “These results extend previous observations of improved cognitive performance and mood following AChE inhibitory sage extracts” and that “the ability of sage extract to beneficially modulate cholinergic function and cognitive performance deserves further attention.”
Source: Kennedy, David O., Fiona L. Dodd, Bernadette C. Robertson, Edward J. Okello, Jonathon L. Reay, Andrew B. Scholey, and Crystal F. Haskell. “Monoterpenoid extract of sage (Salvia lavandulaefolia) with cholinesterase inhibiting properties improves cognitive performance and mood in healthy adults.” Journal of Psychopharmacology 25, no. 8 (2011): 1088-1100.
© The Author(s) 2011
Posted October 26, 2017.
References:
- CDC. Insect Repellents Help Prevent Malaria and Other Diseases Spread by Mosquitoes. 2015.
- Kennedy DO, Scholey AB. The psychopharmacology of European herbs with cognition-enhancing properties. Current pharmaceutical design. 2006;12(35):4613-4623.
- Kennedy DO, Dodd FL, Robertson BC, et al. Monoterpenoid extract of sage (Salvia lavandulaefolia) with cholinesterase inhibiting properties improves cognitive performance and mood in healthy adults. Journal of Psychopharmacology. 2011;25(8):1088-1100.
- Savelev SU, Okello EJ, Perry EK. Butyryl‐and acetyl‐cholinesterase inhibitory activities in essential oils of Salvia species and their constituents. Phytotherapy Research. 2004;18(4):315-324.
- Scholey AB, Tildesley NT, Ballard CG, et al. An extract of Salvia (sage) with anticholinesterase properties improves memory and attention in healthy older volunteers. Psychopharmacology. 2008;198(1):127-139.
