Biodiversity of β-Carboline Profile of Banisteriopsis caapi and Ayahuasca, a Plant and a Brew with Neuropharmacological Potential

Ayahuasca, a psychoactive brew traditionally made from Banisteriopsis caapi vine and Psychotria viridis leaves, contains β-carboline alkaloids that inhibit monoamine oxidase and the psychedelic N,N-dimethyltryptamine (DMT). Analyzing 176 plant lianas (159 B. caapi) and 33 ayahuasca samples from Brazilian regions using LC-MS/MS, mean concentrations in B. caapi were 4.79 mg/g harmine, 0.451 mg/g harmaline, and 2.18 mg/g tetrahydroharmine (THH), with high variability (relative standard deviation 78.9–170%). Native samples had significantly higher harmine than cultivated ones; samples from Federal District/Goiás had more THH than those from Acre. Ayahuasca concentrations ranged widely: 0.109–7.11 mg/mL harmine, 0.012–0.945 mg/mL harmaline, 0.09–3.05 mg/mL THH, and 0.10–3.12 mg/mL DMT. Paired samples confirmed harmine reduces to harmaline and THH during brewing. This large study reveals substantial alkaloid variability, challenging standardization for ethnopharmacological research.

Study at a glance

Abstract

Ayahuasca is a psychoactive infusion with a large pharmacological application normally prepared with Banisteriopsis caapi, which contains the monoamine oxidase inhibitors β-carbolines, and Psichotria virids, which contains the serotonin receptor agonist N,N dimethyltryptamine (DMT). The objectives of this study were to investigate the chemical profile of B. caapi and of ayahuasca collected in various Brazilian regions. In total, 176 plant lianas, of which 159 B. caapi and 33 ayahuasca samples were analyzed. Dried liana samples were powdered, extracted with methanol, diluted, and analyzed by LC-MS/MS. Ayahuasca samples were diluted and analyzed. Mean concentrations in B. caapi were 4.79 mg/g harmine, 0.451 mg/g harmaline, and 2.18 mg/g tetrahydroharmine (THH), with a high variability among the samples (RSD from 78.9 to 170%). Native B. caapi samples showed significantly higher harmine concentrations than cultivated ones, and samples from the Federal District/Goiás had higher THH content than those collected in the State of Acre. The other Malpighiaceae samples did not contain β-carbolines, except for one D. pubipetala sample. Concentrations in ayahuasca samples ranged from 0.109 to 7.11 mg/mL harmine, 0.012 to 0.945 mg/mL harmaline, 0.09 to 3.05 mg/mL THH, and 0.10 to 3.12 mg/mL DMT. The analysis of paired ayahuasca/B. caapi confirmed that harmine is reduced to harmaline and to THH during the brew preparation. This is the largest study conducted with Malpighiaceae samples and showed a large variability in the main β-carbolines present in B. caapi. This biodiversity is a challenge for standardization of the material used in ethnopharmacological studies of B. caapi and ayahuasca.