Propolis from a Morocco-native plant found to improve cognitive function in male rats experiencing chronic mild stress

Chronic stress can have adverse effects on both the minds and bodies of affected individuals. Past studies suggest that particularly stressful life events can also impact people's cognitive abilities, for instance, producing changes in their memory and sometimes increasing the risk of experiencing mental health disorders.

Some studies have linked stress during adolescence and puberty to higher levels of stress at the adult age, as well as memory deficits . Identifying effective strategies to mitigate stress could thus contribute to promoting the health and well-being of individuals worldwide.

Researchers at Ibn Tofail University in Morocco have been exploring the potential of phytotherapy remedies for reducing mild stress and boosting cognitive performance. Their most recent paper, published in Neuroscience and Behavioral Physiology , shows that a concentrated propolis derived from the resin of a cactus-like plant native to Morocco improved cognitive function in male rats exhibiting chronic mild stress.

"Prepuberty and adolescence criticality could be associated with disease development and brain and memory dysfunctions in adult age," wrote Imane Kherrab, Miloud Chakit and their colleagues in their paper. "The study aimed to assess the effects of unpredictable chronic mild stress (UCMS) during prepuberty and adolescence and the propolis supplementation on cognitive functions in adult male rats."

Propolis is a resinous material that bees produce when collecting resin from plants. As part of their study, Kherrab, Chakit and their colleagues specifically explored the effects of propolis deriving from Euphorbia resinifera, a plant primarily found in Morocco that produces a resin with some known medicinal properties.

Active components of the propolis that bees produced from this plant were extracted using a type of alcohol known as methanol. The researchers then tested the effects of this methanolic extract on male adult rats.

Firstly, they divided 18 rats into 3 experimental groups : a non-stressed control group, a stressed group that did not receive the extract, and the experimental group. The 6 rats in the first group were not exposed to any stressors, while the rats in the second and third groups were exposed to 2 stressors per day for a period of 6 weeks.

After their six-week exposure to stress, the rats in the third group received the methanolic extract of propolis from the Morocco-native plant. A total of 200mg per kg of this extract was administered to the rats orally every day, for a period of 2 weeks.

"Memory was assessed by using an object recognition test and a Y-maze test; three-chamber sociability was used to assess social behaviors," wrote the researchers. "Histological analyses of hippocampal and prefrontal cortex were performed. Chronic stress induced long-term memory loss and negative impact on working memory and social behavior deterioration at adulthood, histological analysis [showed] that UCMS caused damages in hippocampal and prefrontal cortex."

Overall, the researchers found that the administered propolis improved the memory of stressed rats, protecting the integrity of neurons in the CA1 and CA3 regions of the hippocampus. In addition, rats that received the supplement after being exposed to stress were found to interact more with rats they were unacquainted with when placed in the same environment compared to rats that had not received the propolis extract.

This recent study hints at the possibility that propolis derived from Euphorbia resinifera may enhance memory performance and promote greater socialization in rats and potentially humans, a hypothesis that could be further tested in future studies. Additional studies with larger samples and on other animals could help to validate the reported effects of this specific propolis extract.

More information: Imane Kherrab et al, Methanolic extract of Euphorbia resinifera propolis improves cognitive functions in adult male rats with chronic unpredictable mild stress, Neuroscience and Behavioral Physiology (2024). DOI: 10.1007/s11055-024-01659-x

© 2024 Science X Network