Natural MAO-B Inhibitors: Inhibiting the Degradation of Dopamine


Dopamine Neurotransmitter

Dopamine is a catecholamine monoamine neurotransmitter.

Dopamine controls the brains voltage or power.  The brains power determines the ability to:

  • Stay focused
  • Stay on task
  • Concentrate
  • Get a job done

A deficiency of dopamine results in not enough maintenance of brain voltage, which is generally manifested as the brain slowing down.

The Table below lists the physical symptoms and conditions and the corresponding voltage level:

Change in Voltage and Impact on Cognitive Abilities

Voltage Change 
20Superior energy and concentration
10Normal energy and concentration
9Fatigue, mild memory loss and cognitive deficit
8Insomnia, panic disorder
7Obesity, moderate obsessive-compulsive disorder, mild depression
6Moderate addiction,major depression
5Borderline personality disorder, chronic fatigue
4Chronic depression, violent behavior
3Attention deficit disorder
2Alzheimer’s disease
Source: Younger Brain, Sharper Mind, by Eric R. Braverman, MD

After age 45, the brain’s dopaminergic neurons age rapidly, causing a decline in dopamine levels of 13% per decade.  1  A drop in brain dopamine to 30% of the normal level leads to Parkinson’s, and a plummet to 10% results in death.

The following physical manifestations are apparent with a deficiency of dopamine:

  • Loss of mental intensity
  • More time and effort needed to complete a task
  • Less concentration (mind wandering)
  • Decision making is not as quick
  • Work intensity diminished

A comprehensive list of the physical manifestations of dopamine deficiency is listed in the Table below:

Dopamine Deficiency Physical Symptoms

Dopamine Deficiency 
Overall SymptomsPhysical Symptoms
Confusion/Loss of AttentionAddiction
Bone density loss
Difficulty acheiving orgasm
Disgestion problems
Excessive sleep
High blood pressure
Inability to lose weight
Involuntary movements
Joint pain
Kidney problems
Lack of quickness
Low sex drive
Parkinson’s disease
Poor blood sugar stability
Poor physical strength
Poor walking
Shuffling gait
Slow metabolism
Slow or rigid movements
Thyroid disorders
Wide-based gait
Source: Younger Brain, Sharper Mind,
by Eric R. Braverman, MD

Monoamine Oxidase (MAO)

Monoamine Oxidase (MAO) is a group of endogenous oxidase enzymes.  These enzymes are present inside neurons and other cells including those of the liver.



MAO breaks down (inactivates/oxidizes/metabolizes) essential monoamine neurotransmitters (this activity, when under control, is desirable to prevent the excessive accumulation of neurotransmitters, however excessive MAO production causes depletion of essential neurotransmitters):

  • MAO catalyzes the conversion of Adrenaline to Dihydroxymendalic Acid.
  • MAO catalyzes the conversion of Dopamine to Dihydroxyphenylacetic Acid.
  • MAO catalyzes the conversion of Norepinephrine to Dihydroxymendalic Acid.
  • MAO catalyzes the break down of Phenylethylamine to its metabolites.

Serotonin, melatonin, noradrenaline, and adrenaline are mainly broken down by MAO-A.

Phenethylamine and benzylamine are mainly broken down by MAO-B.

Both forms break down dopamine, tyramine, and tryptamine equally.

The levels of dopamine in the brain begin to diminish with age.  2  3   This depletion of dopamine is primarily due to an increase in MAO-B.

MAO Inhibitors

MAO Inhibitors act by inhibiting the activity of monoamine oxidase, thus preventing the breakdown of monoamine neurotransmitters and thereby increasing their availability. There are two isoforms of monoamine oxidase, MAO-A and MAO-B.

MAO-A inhibitors act as antidepressant and antianxiety agents, whereas MAO-B inhibitors are used alone or in combination to treat Alzheimer’s and Parkinson’s diseases.

Alzheimer’s disease and Parkinson’s disease are both associated with elevated levels of MAO-B in the brain.

Inhibition of MAO-B is considered desirable due to MAO-B causing the degradation of various neurotransmitters within the brain.

Natural MAO-B Inhibitors

Avena sativa L. (oats) has been traditionally used for centuries for its physical and psychological fortifying properties.


Avena sativa L

Potentially bioactive constituents of Avena sativa L. include:  4

  • avenanthramides
  • saponins
  • phytoalexin
  • vitexin
  • isovitexin 

The researched and studied benefits of Avena sativa L include:

  • Anti-depressant effects
  • Ability to cope with stress
  • Reduced anxiety  5
  • Anti-inflammatory properties  6
  • Relief of skin irritation  7

Neuravena® (EFLA®955, Frutarom, Switzerland) is an extract of a variety of Avena sativa L., wild green oat herb.

Recent studies suggest that supplementation with an oat extract from green oats, Neuravena®, can acutely improve mental function in humans.  8  9

In vitro bioassays of Neuravena® indicated inhibitory effects on monoamine oxidase B (MAO-B) and phosphodiesterase-4 (PDE4).  10

Two separate studies have demonstrated the neurological benefits of Neuravena®:

  • Taking 1600 mg of oat herb extract may acutely improve attention and concentration and the ability to maintain task focus in older adults with differing levels of cognitive status.  11
  • Wild green oat extract (WGOE) supplementation can improve vasodilator function in systemic and cerebral arteries, suggesting a potential role in the maintenance of cardiovascular health.  12

There are a number of pharmaceutical MAO-B inhibitors.  Pharmaceutical MAO-B inhibitors can be very effective yet are subject to some dangers. 

One such danger is the combination of pharmaceutical MAO-B inhibitors with tyramine rich foods.  Patients taking MAO Inhibitor’s generally need to change their diets to limit or avoid foods and beverages containing tyramine. If large amounts of tyramine are consumed, they may suffer hypertensive crisis, which can be fatal.  13

The other down-side with pharmaceutical MAO-B inhibitors is that there are a number of adverse side effects.  A list of such adverse side effects can be viewed at the following websites:

National Parkinson Foundation®

University of California, San Francisco

There are additional natural MAO-B inhibitors that have been researched and studied and are listed in the Table below:

Natural MAO-B Inhibitors

MAO-B Inhibitors  
Paeonol 3
Emodin (Japanese knotweed)4
Ginko Biloba5
Saint John’s Wort6
Green Tea9
Lycium chinense11
Uncaria rhynchophylla12
Banisteriopsis caapi (Ayahuasca)13
Hypericin (St. John’s Wort)17


Life Extension – Dopa-MindTM

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