Modulation of Neurotransmission by a Specified Oregano Extract Alters Brain Electrical Potentials Indicative of Antidepressant-Like and Neuroprotective Activities

Abstract

Different behavioral states are characterized by distinct patterns of global brain activity. Therefore, the biological effects of herbal extracts on brain functions can be assessed by analyzing the local field potentials, the so-called electropharmacogram analysis. Inspired by our recent findings that a specified oregano extract (OE) exhibited a triple-reuptake activity in vitro, this extract was tested in model of Tele-Stereo-electroencephalogram (EEG) to elucidate how OE affects the electrical brain activity in freely moving rats. Furthermore, discriminant analysis was performed to compare the electric brain activity of four standardized brain regions with those produced by several reference compounds, representing a whole variety of clinical indications. Oral intake of OE produced fast and robust dose and time dependent EEG alterations consisting of significant changes of spectral power in comparison to controls. Strongest effects were seen with respect to alpha1, alpha2 and beta1 waves representing an activation of serotonergic, dopaminergic and glutamatergic neurotransmission, respectively. Moreover, the discriminant analysis revealed that OE's pattern of activity locates in close vicinity to antidepressant and neuroprotective compound. The presented data support the hypothesis suggesting the use of OE as a neuroprotective dietary supplement to promote mood, motivation and mental wellbeing.

Food-derived serotonergic modulators: effects on mood and cognition

“…In the same study, the researchers used in vivo microdialysis in rats to confirm that extracellular 5-HT levels were indeed higher after a dose of the oregano extract, albeit more slightly compared with the antidepressant fluoxetine. Moreover, electroencephalogram measurements after acute oral supplementation in freely moving rats showed that this extract may exhibit antidepressant and neuroprotective activities ( 131 ) . Taken together, the results of these studies seem to justify further investigation into possible other dietary sources of monoamine reuptake inhibitors, as well as studies testing whether the beneficial behavioural effects of these plant extracts found in mice can be replicated in human subjects.…”