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 hallucinogenic beverage made from Banisteriopsis caapi vine and admixture plants such as Psychotria viridis, contains beta-carbolines (harmine, harmaline, tetrahydroharmine) that inhibit monoamine oxidase (MAO), protecting the hallucinogen DMT from degradation and enabling oral activity. Analysis of eight Peruvian ayahuasca samples using chromatography found DMT and beta-carboline levels an order of magnitude higher than previously reported. In vitro assays showed ayahuasca is an extremely effective MAO inhibitor, with inhibition directly correlated to beta-carboline concentration. Combinations of beta-carbolines produced additive, not synergistic or antagonistic, effects.