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

• Published in: British journal of nutrition Vol. 105; no. 8; pp. 1150 - 1163
• Main Authors: Mechan, Annis O., Fowler, Ann, Seifert, Nicole, Rieger, Henry, Wöhrle, Tina, Etheve, Stéphane, Wyss, Adrian, Schüler, Göde, Colletto, Biagio, Kilpert, Claus, Aston, James, Elliott, J. Martin, Goralczyk, Regina, Mohajeri, M. Hasan
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.04.2011; CABI Pub
• Subjects: Amino acids; analysis; Animal behavior; Animal models; Animals; Anti-Anxiety Agents; Anti-Anxiety Agents - chemistry; Anti-Anxiety Agents - metabolism; Anti-Anxiety Agents - therapeutic use; Antidepressive Agents; Antidepressive Agents - chemistry; Antidepressive Agents - metabolism; Antidepressive Agents - therapeutic use; antioxidants; anxiety; Anxiety - prevention & control; appetite; Behavior, Animal; Benzoquinones; Benzoquinones - analysis; Benzoquinones - pharmacology; Biogenic Monoamines; Biogenic Monoamines - physiology; Biological and medical sciences; blood; brain; Brain - metabolism; chemistry; cognition; Depression; Depression - prevention & control; Diet; Dietary Supplements; Dietary Supplements - analysis; dopamine; Drug Discovery; Drug Discovery - methods; essential fatty acids; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; genetics; HEK293 Cells; Herbs; Humans; leaves; Male; Mediterranean diet; metabolism; methods; Mice; microdialysis; Micronutrients; Molecular Nutrition; Monoamine Oxidase Inhibitors; Monoamine Oxidase Inhibitors - chemistry; Monoamine Oxidase Inhibitors - metabolism; Monoamine Oxidase Inhibitors - therapeutic use; Monoterpenes; Monoterpenes - analysis; Monoterpenes - blood; Monoterpenes - pharmacology; Neurotransmitter Uptake Inhibitors; Neurotransmitter Uptake Inhibitors - chemistry; Neurotransmitter Uptake Inhibitors - metabolism; Neurotransmitter Uptake Inhibitors - pharmacology; Neurotransmitter Uptake Inhibitors - therapeutic use; Neurotransmitters; norepinephrine; nutritional intervention; oregano; Origanum; Origanum - chemistry; pharmacology; physiology; Plant Extracts; Plant Extracts - chemistry; Plant Extracts - metabolism; Plant Extracts - therapeutic use; Plant Leaves; Plant Leaves - chemistry; prevention & control; Random Allocation; Rats; Rodents; screening; serotonin; Serotonin Plasma Membrane Transport Proteins; Serotonin Plasma Membrane Transport Proteins - genetics; Serotonin Plasma Membrane Transport Proteins - metabolism; sleep; therapeutic use; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Well being; Oregano extract; In vivo microdialysis; Monoamine reuptake inhibition; Mood-enhancing potential; Monoamine; Oregano; Extract; In vivo; Vertebrata; Mood; Mammalia; Microdialysis; Inhibition
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114510004940

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.