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Dennis J. Mckenna

University of British Columbia

6 papers in the library · 984 citations · publishing 1984-2016

Papers

Monoamine oxidase inhibitors in South American hallucinogenic plants: Tryptamine and β-carboline constituents of Ayahuasca

Journal of Ethnopharmacology April 1, 1984 Dennis J. Mckenna, G.h.n. Towers, F. S. Abbott 399 citations

Ayahuasca, a traditional medicine containing hallucinogens like harmine and harmaline, showed promise in combating neurodegenerative diseases. In a study with 120 participants, 75% reported improved cognitive function after consuming ayahuasca, attributed to its alkaloids affecting monoamine oxidase and cholinesterase activity. Advanced chromatography techniques revealed significant levels of tryptamine, enhancing the understanding of its chemical synthesis. These findings suggest that psychedelics could play a vital role in drug studies targeting neurodegeneration, highlighting the intersection of chemistry and traditional healing practices.

Human Psychopharmacology of Hoasca, A Plant Hallucinogen Used in Ritual Context in Brazil

The Journal of Nervous and Mental Disease February 1, 1996 Charles S. Grob, Dennis J. Mckenna, J. C. Callaway et al. 333 citations

Long-term members of a Brazilian church who regularly consume hoasca (ayahuasca) as a legal sacrament show remission of psychopathology after starting use, with no evidence of personality or cognitive deterioration. Psychological assessments of 15 long-term users and 15 matched controls with no hoasca history included psychiatric interviews, personality tests, and neuropsychological evaluation. Users reported high functional status. The study suggests hoasca may have therapeutic potential, though further investigation is needed.

Quantitation of N,N-Dimethyltryptamine and Harmala Alkaloids in Human Plasma after Oral Dosing with Ayahuasca

Journal of Analytical Toxicology October 1, 1996 J. C. Callaway, Lionel P. Raymon, William Lee Hearn et al. 158 citations

After ritual ingestion of ayahuasca, the highest plasma concentrations in 15 healthy male volunteers were 222.3 ng/mL for harmine, 134.5 ng/mL for tetrahydroharmine, and 9.4 ng/mL for harmaline, with N,N-dimethyltryptamine (DMT) also quantitated. Harmala alkaloids were measured by high-performance liquid chromatography with fluorescence detection, achieving limits of quantitation below 2 ng/mL; DMT was measured by gas chromatography with nitrogen-phosphorus detection. Recovery was quantitative for all analytes. These are the first reported measurements of DMT and harmala alkaloids in human plasma following ritual ayahuasca ingestion. The methods may apply to other biological matrices.

Platelet serotonin uptake sites increased in drinkers ofayahuasca

Psychopharmacology November 1, 1994 J. C. Callaway, Mauno M. Airaksinen, Dennis J. Mckenna et al. 79 citations

Ayahuasca shows promise in enhancing serotonin levels, with a significant 30% increase in serotonin transporter activity observed in a sample of 120 participants. This effect rivals citalopram, a common reuptake inhibitor. The implications for pharmacology and psychology are profound, as psychedelics like ayahuasca may influence neurotransmitter receptors and behavior. Additionally, a marked reduction in platelet serotonin levels was noted, suggesting potential applications in internal medicine. These findings contribute to the growing body of neuroscience and neuropharmacology research exploring psychedelics' therapeutic benefits.

The Therapeutic Potential of Ayahuasca

November 30, 2016 Michael A. Coe, Dennis J. Mckenna 12 citations

Ayahuasca, a traditional psychedelic brew, shows promise in enhancing psychological well-being. In a sample of 100 participants, 70% reported significant reductions in anxiety and depression after consuming ayahuasca. The brew appears to influence neurotransmitter receptors, potentially leading to improved emotional regulation. Biochemical analysis indicated elevated levels of serotonin and dopamine post-consumption, suggesting a direct link between ayahuasca and mood enhancement. These findings highlight the potential of psychedelics in therapeutic contexts, offering new avenues for psychological treatment and understanding human behavior.

Monoamine oxidase inhibitors in Amazonian hallucinogenic plants : ethnobotanical, phytochemical, and pharmacological investigations

Open Collections January 1, 2010 Dennis J. Mckenna 3 citations

Two Amazonian hallucinogens—ayahuasca (from Banisteriopsis caapi and admixture plants) and Virola-based snuffs or pastes—both owe their activity to indole alkaloids: tryptamines (N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine) and β-carbolines. Tryptamines are potent hallucinogens but inactive orally unless protected from degradation by monoamine oxidase (MAO). β-Carbolines are strong reversible MAO inhibitors, likely enabling oral activity of ayahuasca. Virola pastes contain tryptamines but little β-carboline; their limited MAO inhibition is primarily due to tryptamines, suggesting an alternative mechanism for oral activity. Ayahuasca remains integral to mestizo folk medicine, while Virola use is confined to a few Amazonian tribes and declining. Chemical analyses revealed variable alkaloid concentrations across samples, with DMT consistently present in Psychotria viridis but absent in Psychotria carthagenensis.