Hawaiian Yellow Vine
How Does Banisteriopsis caapi Work?
MAO Inhibitor
The beta-carbolines harmine, tetrahydroharmine, and harmaline are MAO-A inhibitors [6].
In the gut, they prevent MAO-A from breaking down N, N-Dimethyltryptamine (DMT), allowing it to travel to the brain and pass the blood-brain barrier [5].
Furthermore, this MAO-A inhibition stimulates dopamine release, which may help with Parkinson’s disease symptoms [9].
Tetrahydroharmine also inhibits serotonin reuptake, which helps the DMT in ayahuasca cause hallucinations [7, 4].
Serotonin reuptake inhibition may also have antidepressant effects [11].
Harmine, harmaline, epicatechin, and procyanidin B2 inhibit MAO-B [10, 6].
MOA-B inhibitors may improve Parkinson’s and Alzheimer’s diseases by reducing oxidative neurodegeneration in cells [12].
Serotonin and Dopamine Boost
In rat brain cells (rat striatal slices) harmaline and harmine from Banisteriopsis caapi increased dopamine release [9].
In rat fetuses, harmaline increased brain levels of serotonin and dopamine, but not norepinephrine [13].
Health Effects
1) Parkinson’s Disease
In a study of 30 people with newly diagnosed Parkinson’s disease, one dose of Banisteriopsis caapi improved motor function for all patients. The effects appeared after one hour and lasted for 3 more hours [14].
However, all Banisteriopsis caapi patients experienced adverse effects. They all experienced nausea/vomiting and abnormal, involuntary movements and tremors. Additionally, most of them also reported dizziness, diarrhea, and agitation, and one patient experienced confusion/hallucinations [14].
In rat brain cells, the harmaline and harmine from Banisteriopsis caapi stem extracts inhibited MAO-A. This suggests that these beta-carbolines may increase dopamine levels, which are lower in Parkinson’s disease [9].
Banisteriopsis caapi and other MAO-B inhibitors also fight motor symptoms and problems found in Parkinson’s disease based on animal studies [15, 12, 16].
In both human and animal cells, harmine and harmaline strongly inhibit human MAO-B enzymes while epicatechin and procyanidin B2 do so moderately [10].
However, in rat brain cells, beta-carbolines did not significantly inhibit MAO-B [9].
In mouse cells, harmaline and harmine reduced brain damage from various toxins (MPTP and MPP+) that cause Parkinson’s-like symptoms in humans and other primates. Based on this model, these beta-carbolines may slow down Parkinson’s progression by protecting the brain against oxidative cell damage [17].
Taken together, a small clinical trial and some animal and cell research cannot be considered conclusive evidence that Banisteriopsis caapi improves Parkinson’s disease. Larger, more robust clinical trials are needed to confirm these preliminary findings.
2) Depression and Anxiety
In 2 small trials on 12 people, a single dose of ayahuasca helped improve both depression and anxiety. In another trial on 9 people, it reduced panic and hopelessness but had no effects on state- or trait-anxiety [18, 19, 20].
Chemical analyses of Banisteriopsis caapi suggest that this plant may be responsible for some of the antidepressant and anti-anxiety effects of ayahuasca. The harmine and harmaline in Banisteriopsis caapi inhibit MAO-A, while tetrahydroharmine moderately inhibits serotonin reuptake. These two mechanisms may reduce depression [8, 11].
In mice, harmine from Banisteriopsis caapi had antidepressant effects [21].
In fish, exposure to infused ayahuasca reduced anxiety [22]
Furthermore, harmine stimulated the birth of brain cells (by increasing BDNF levels) and reduced depressive behavior in rats [23].
Harmaline, harmine, tetrahydroharmine, and harmol (a by-product of harmaline) caused adult nerve cell formation (neurogenesis) in mice [7].
Importantly, the birth of brain cells (neurogenesis) helped fight anxiety and depression in animal studies, This activity resembles antidepressant drugs that stimulate neurogenesis in the hippocampus and other regions of the brain [24, 7, 25, 26, 27].
The evidence to support the use of Banisteriopsis caapi for depression and anxiety comes from 3 small trials (which didn’t even test the plant alone but as part of ayahuasca) and some animal and cell-based research. Further clinical research is required to shed some light on this potential benefit.
Brain Enhancer and an Antioxidant
In mouse brains, harmine, tetrahydroharmine, harmaline, and harmol stimulated [7]:
Neurogenesis
Stem cell growth, migration, and production
According to a review of 2 animal cells and 9 animal studies, harmine increased BDNF and protected the brain. It decreased [28]:
Inflammation
Oxidative stress
Nerve cell damage and death due to overactivation of receptors (excitotoxicity)
Furthermore, it improved memory and learning in animals [28].
In cells, epicatechin and procyanidin from Banisteriopsis caapi acted as antioxidants [6].
In mice, beta-carbolines reduced brain damage caused by dopamine and the Parkinson’s-like toxins MPTP and MPP+ [17].