The study, published in the journal Nutrients, is the first to report that GSE inhibits γ-aminobutyric acid transaminase (GABA-T), a key enzyme related to mood.
“This novel finding is particularly significant because GABA-T inhibition can lead to increased levels of GABA, a major inhibitory neurotransmitter in the central nervous system that is implicated in a variety of behaviors, including low mood, anxiety, stress regulation and memory enhancement,” the researchers from Turkey, Spain, Pakistan, the United Kingdom and Italy wrote.
They noted that this may add a new dimension to what is currently known about GSE's beneficial antioxidant effects, pointing to its potential as a supplement for mental health.
The experiments also showed that GSE inhibits monoamine oxidase A (MAO-A), an enzyme that breaks down serotonin and norepinephrine. This could potentially lead to higher levels of these neurotransmitters, which are crucial for mood regulation and cognitive function.
The researchers hypothesize that these beneficial effects may be due to the enzymes' interactions with oligomeric proanthocyanidin complexes (OPCs) in GSE.
“Unlike conventional treatments for low mood and cognitive decline, which often come with adverse side effects and a risk of tolerance, GSEe offers a natural and well-tolerated alternative,” they wrote. “Its multifaceted mechanisms of action, including neurotransmitter modulation, cognitive enhancement, neuroprotection, a high total phenolic content and minimal cytotoxicity, make it a promising candidate for further clinical investigation.”
Expanding GSE evidence
The new study expands the evidence for GSE’s beneficial polyphenols and OPCs.
Previous research shows that Enovita has positive effects on blood pressure, perceived stress and mild hypertension and that its bioactives exert potent antioxidant and anti-inflammatory effects in the brain. Additionally, GSE polyphenols and flavanols can support proteostasis, which maintains the balance of protein in cells.
Dysfunction in proteostasis is a hallmark of neurodegenerative disorders such as Alzheimer's and Parkinson's disease.
Study details
The researchers analyzed the effects of Enovita standardized food-grade GSE provided by botanical ingredients supplier Indena SpA on human neuroblastoma cell lines.
Indena produces Enovita by upcycling recovered grape seeds from white wine production and using water for extraction, resulting in product high in OPCs.
The results of the in vitro experiments showed GSE's inhibitory effects on GABA-T, acetylcholinesterase (AChE) and MAO-A and moderate binding affinity to the GABA-A receptor. GSE also exhibited robust antioxidant activity in all the tests.
“Overall, the promising results from these in vitro studies provide a strong foundation for the continued exploration and development of GSEe as a viable natural supplement for enhancing mental health and cognitive function,” the researchers wrote.
They called for clinical trials to validate their findings and establish optimal dosing for achieving desired outcomes in humans.
Source: Nutrients 2024, 16(20), 3459
doi: 10.3390/nu16203459
“In vitro mechanistic studies of a standardized sustainable grape seed extract for potential application as a mood-modulating and cognition-enhancing supplement.”
Authors: G. Hazbal-Celikok et al.