Monoamine reuptake inhibition and mood-enhancing potential of a specified oregano extract

Abstract

A healthy, balanced diet is essential for both physical and mental well-being. Such a diet must include an adequate intake of micronutrients, essential fatty acids, amino acids and antioxidants. The monoamine neurotransmitters, serotonin, dopamine and noradrenaline, are derived from dietary amino acids and are involved in the modulation of mood, anxiety, cognition, sleep regulation and appetite. The capacity of nutritional interventions to elevate brain monoamine concentrations and, as a consequence, with the potential for mood enhancement, has not been extensively evaluated. The present study investigated an extract from oregano leaves, with a specified range of active constituents, identified via an unbiased, high-throughput screening programme. The oregano extract was demonstrated to inhibit the reuptake and degradation of the monoamine neurotransmitters in a dose-dependent manner, and microdialysis experiments in rats revealed an elevation of extracellular serotonin levels in the brain. Furthermore, following administration of oregano extract, behavioural responses were observed in mice that parallel the beneficial effects exhibited by monoamine-enhancing compounds when used in human subjects. In conclusion, these data show that an extract prepared from leaves of oregano, a major constituent of the Mediterranean diet, is brain-active, with moderate triple reuptake inhibitory activity, and exhibits positive behavioural effects in animal models. We postulate that such an extract may be effective in enhancing mental well-being in humans.

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

“…The major constituents of OE are carvacrol (CAS no. 499-75-2) and thymoquinone (CAS no: 490-91-5) as reported previously [4].…”

“…Moreover, imipramine and paroxetine, two drugs with antidepressant action are also located in relatively close vicinity to each other. We show here that oral application of OE, a constituent of the Mediterranean diet (please see [4] for details) leads to biological effects mainly originating from the transient activation of dopaminergic, serotonergic and glutamatergic neurotransmission and provide the evidence that OE has neuroprotective and antidepressant-like moodimproving properties.…”

“…The preparation of OE (oréVida™) by a specified twostep supercritical CO 2 extraction was described elsewhere [4]. In brief, dried leaves of oregano were mechanically milled and extracted twice with carbon dioxide under super critical conditions and the specifications were analyzed by gas chromatography/mass spectrometry [4].…”

“…In brief, dried leaves of oregano were mechanically milled and extracted twice with carbon dioxide under super critical conditions and the specifications were analyzed by gas chromatography/mass spectrometry [4]. The major constituents of OE are carvacrol (CAS no.…”

“…A reduction of serotonin and dopamine levels in the brain affects mood and mental wellbeing evidenced by waning motivation and increased anxiety [2,3]. Nutritional compounds may be valuable to improve mood and motivation in humans without the risk of side effects [4]. They exert their cellular action by interacting with biochemically defined targets on the cell membranes modulating the functions of receptors, enzymes, ion channels, and transporters.…”