Researchers found the flavonoid apigenin - found in parsley, thyme and other plants and herbs - triggered the formation of human brain cells and strengthened their connections.
Lead author Stevens Rehen, of the D'Or Institute for Research and Education (IDOR) and the Federal University of Rio de Janeiro (UFRJ), and colleagues publish their findings in the journal Advances in Regenerative Biology.
The team says their findings suggest apigenin - also found in red pepper, chamomile and many other plants and herbs - shows promise as a treatment for numerous neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease and schizophrenia.
Previous animal studies have shown that substances from the same flavonoid group as apigenin may benefit memory and learning, and other research has demonstrated that flavonoids have the potential to preserve and boost brain function.
For this latest study, Rehen and colleagues set out to gain a better understanding of how apigenin affects human brain cells, or neurons.
Apigenin transformed human stem cells into neurons in 25 days
The team applied apigenin to human stem cells - cells that have the ability to develop into different cell types - in a laboratory dish.
They found that after 25 days, these stem cells transformed into neurons - an effect the researchers say was not seen in the absence of apigenin.
The team found apigenin-treated neurons (right) developed stronger synapses than untreated neurons (left).
Image credit: Rehen et al.
What is more, the researchers found that the connections that developed between the newly formed neurons - known as synapses - were stronger and more sophisticated. "Strong connections between neurons are crucial for good brain function, memory consolidation and learning," notes Rehen.
Further investigation revealed that apigenin boosts neuron formation and connections by binding to estrogen receptors (ERs), which influences the development, progression, function and plasticity of the nervous system.
While studies have shown the hormone estrogen may delay development of Alzheimer's, schizophrenia, depression and Parkinson's, among other neurodegenerative conditions, Rehen and colleagues note the use of estrogen therapy is hampered by the risks of tumor growth and cardiovascular problems it poses.
However, the team says their findings suggest apigenin could offer a promising future treatment alternative for a number of neurodegenerative disorders.
"An alternative approach would be to mimic estrogenic-mediated positive effects by modulating specific ERs with other estrogenic compounds, such as some flavonoids classified as selective ER modulators (SERMs)," they explain.
In addition, Rehen says their study suggests the possibility of a simple brain-boosting strategy we can all adopt:
"[...] Flavonoids are present at high amounts in some foods and we can speculate that a diet rich in flavonoids may influence the formation of neurons and the way they communicate within the brain."
Last year, Medical News Today reported on a study suggesting some further benefits of plant-derived compounds; researchers discovered compounds present in herbs such as rosemary and oregano may help fight type 2 diabetes.