“The results suggest that these extracts have exciting possibilities for cognitive benefits in humans,” said Dr Susan Farr, Professor at St. Louis University School of Medicine, Division of Geriatrics, who was the corresponding author of the study.
“The reduction in oxidative stress markers in specific areas of the mouse brain indicates that these extracts are having effects at the cellular level in the brain, which could be a mechanism for the observed learning and memory improvements,” she added.
This latest study, published in Physiology and Behavior, adds to the growing cognitive benefits evidence of Kemin’s Neumentix ingredient. A human study on the ingredient was published last year in the FASEB Journal, which showed its potential to aid sleep. The ingredient was first launched two years ago at SupplySide West.
Senescence accelerated mouse (SAMP8) model and treatments
“The SAMP8 mouse model is an established animal model for studying age-related cognitive decline and oxidative damage to brain tissue,” said Dr Farr. “Previous research has shown the SAMP8 mice to be an excellent model for testing ingredients that could provide potential cognitive health solutions that translate to humans.”
The mice were divided into four groups for each of the three separate parts of the study. The first study looked at combinations of 60% carnosic acid in different ratios with a sunflower oil control group, the second study looked at rosemary extract containing 10% carnosic acid in different ratios with a sunflower oil control group, and the final study looked at spearmint extract containing 5% rosmarinic acid in different ratios with a control group (water).
Brain games
On the 90th day of treatment, the mice were tested in T-maze foot shock avoidance, object-place recognition, and lever press paradigms—tasks which, when performed by SAMP8 mice, can be translated to human hippocampal-dependent and procedural learning.
The T-maze foot shock avoidance test requires a mouse to learn to avoid a shock by moving from a start box to a clear escape box located at the end of one arm before the start of a shock, which occurs five seconds after a door opening and a buzzer.
Object-place recognition is a memory task where mice were observed studying an object. When the object is switched out with a new one, the observation time was noted down.
The final test, lever press for milk reinforcement, observed how quickly mice can learn to press a lever to get milk after food deprivation for 16 hours.
Results: Cognitive benefits in learning & memory
Researchers found that spearmint extract with 5% rosmarinic acid improved acquisition and retention in T-maze foot shock avoidance and object recognition.
In addition, rosemary extract containing 60% carnosic acid improved acquisition and retention in T-maze foot shock, object recognition and lever press; and rosemary extract with 10% carnosic acid improved retention in T-maze foot shock avoidance and lever press.
“Mice treated with all three extracts showed reduced brain tissue markers of oxidative stress,” the researchers said in a press release. “In the brain cortex, 4-hydroxynonenal was reduced after treatment with all three extracts compared to the vehicle treated SAMP8. Protein carbonyls were reduced in the hippocampus after administration of spearmint containing 5% rosmarinic acid and rosemary with 10% carnosic acid.”
Without the minty flavor
Kemin's ingredient contains spearmint from two clonal lines that have been developed for their content of rosmarinic acid, the key polyphenol bioactive. For versatility, the spearmint was also cultivated to not have the minty flavor.
Dr. John Greaves, VP of specialty crops at Kemin Industries told NutraIngredients-USA that the development of the two spearmint strains began over six years ago. The clonal lines are not genetically modified, he said. Instead, they were developed from publicly available seed sources by growing out a large enough population.
Source: Physiology & Behavior
Volume 165, Pages 328-338, doi:
"Effect of botanical extracts containing carnosic acid or rosmarinic acid on learning and memory in SAMP8 mice"
Authors: S.A. Farr, et al.