Pre-clinical interaction of ayahuasca, a brew used in spiritual movements, with morphine and propofol

ABSTRACT Ayahuasca is a beverage with psychoactive properties used in religious and ceremonial rituals by some religious groups. The main active components of ayahuasca are dimethyltryptamine and the harmala alkaloids with ß-carboline structure acting as monoamine oxidase A inhibitors. This combination produces a pronounced activation of serotonergic pathways and presents potential interaction with other psychotropics. The objective of this study was to investigate the possible interactions between ayahuasca and agents employed in general anesthesia. The pharmacological interactions between ayahuasca and morphine or propofol were evaluated in mice using doses of 12, 120 and 1200 mg/kg (0.1 to 10 times the average dose consumed by humans in religious rituals). Ayahuasca alone showed an antinociceptive effect in the writhing and formalin tests, and intensified the analgesic effect of morphine in the hot plate test. Concerning the pharmacological interactions between ayahuasca and propofol, the results were opposite; ayahuasca intensified the depressant effect of propofol in the rotarod test, but decreased the sleeping time induced by propofol. These set of results showed the occurrence of some interactions between ayahuasca and the drugs morphine and propofol, possibly by both pharmacokinetics and pharmacodynamics mechanisms

Reproductive effects of the psychoactive beverage ayahuasca in male Wistar rats after chronic exposure

Abstract Ayahuasca is a psychoactive beverage used ancestrally by indigenous Amazonian tribes and, more recently, by Christian religions in Brazil and other countries. This study aimed to investigate the reproductive effects of this beverage in male Wistar rats after chronic exposure. The rats were treated by gavage every other day for 70 days at 0 (control), 1×, 2×, 4× and 8× the dose used in a religious ritual (12 animals per group), and animals euthanized on the 71st day. Compared to controls, there was a significant decrease in food consumption and body weight gain in rats from the 4× and 8× groups, and a significant increase in the brain and stomach relative weight at the 8× group. There was a significant increase in total serum testosterone, and a decrease in spermatic transit time and spermatic reserves in the epididymis caudae in the 4× group, but not in the highest dose group. No significant changes were found in the other reproductive endpoints (spermatozoid motility and morphology, total spermatozoid count and daily sperm production), and histology of testis and epididymis. This study identified a no-observed-adverse-effect-level for chronic and reproductive effects of ayahuasca in male Wistar rats at 2× the ritualistic dose, which corresponds in this study to 0.62 mg/kg bw N, N-dimethyltryptamine, 6.6 mg/kg bw harmine and 0.52 mg/kg bw harmaline. A potential toxic effect of ayahuasca in male rats was observed at the 4× dose, with a non-monotonic dose-response. Studies investigating the role of ayahuasca components in regulating testosterone levels are needed to better understand this action.

Chronic intermittent exposure to ayahuasca during aging does not affect memory in mice

The Quechua term ayahuasca refers to a beverage obtained from decoctions of the liana Banisteriopsis caapi with leaves of Psychotria viridis. The ritualistic use of ayahuasca is becoming a global phenomenon, with some individuals using this beverage throughout life, including in old age. Cognitive impairment is a common manifestation during aging. There are conflicting reports on the ability of some ayahuasca compounds to exert neuroprotective or neurotoxic effects that could improve or impair learning and memory. Animal models provide a relevant and accessible means of investigating the behavioral effects of ayahuasca without the environmental conditions associated with the ritualistic use of the beverage. In this study, we investigated the influence of chronic ayahuasca exposure throughout aging on the spatial reference and habituation memories of mice. Twenty-eight male c57bl/6 mice (6 months old) received ayahuasca or water (1.5 mL/kg, orally) twice a week for 12 months and were tested in the Morris water maze (MWM), open field and elevated plus maze (EPM) tasks before and after treatment. During aging, there was significant impairment in the evocation (but not acquisition) of spatial reference memory and in habituation to the open field. There was also a decrease in locomotor activity in the open field and EPM tests, whereas the anxiety parameters were unaltered. Ayahuasca treatment did not alter any of these parameters associated with aging. These findings indicate that chronic exposure to ayahuasca during aging did not affect memory in mice.

Ayahuasca: uma revisão dos aspectos farmacológicos e toxicológicos / Ayahuasca: a review of pharmacological and toxicological aspects

A ayahuasca é uma bebida psicoativa originariamente utilizada em rituais de tribos indígenas da região amazônica. Esta bebida é preparada pela infusão de caules da Banisteriopsis caapi Morton, que contém Beta-carbolinas que são inibidoras da monoaminoxidase (MAO), e de folhas da Psychotria viridis Ruiz & Pavón, que contém o alucinógeno N,N-dimetiltriptamina (DMT). A enzima MAO degrada a DMT no fígado e intestino. No Brasil, a ayahuasca tem sido incorporada em rituais de grupos sincréticos religiosos e seu uso dentro do contexto religioso é amparado por lei federal. Atualmente, esses grupos têm se espalhado na Europa e Estados Unidos, chamando a atenção de pesquisadores internacionais quanto aos efeitos da ayahuasca. Estudos têm indicado que a ayahuasca poderia ter aplicações terapêuticas como no tratamento da farmacodependência e até sugerem seu uso seguro por adultos sadios. Entretanto, poucos estudos têm sido conduzidos para melhor avaliação de suas propriedades. O objetivo do artigo é mostrar uma revisão geral da história até as recentes descobertas envolvendo a farmacologia e a toxicologia da ayahuasca.

Ayahuasca (or caapi in Brazil) is a psychoactive plant beverage initially used by shamans in religious rituals practiced by indigenous peoples in the Amazon region. It is prepared by infusing the pounded stems of Banisteriopsis caapi Morton, a liana which contains beta-carbolines, alkaloids that are potent monoamine oxidase (MAO) inhibitors, together with the leaves of Psychotria viridis Ruiz & Pavón, which contains the psychedelic agent N,N-dimethyltryptamine (DMT). The enzyme MAO normally degrades DMT in the liver and gut. In Brazil, the use of ayahuasca within religious ceremonies is protected by law and it has been incorporated into rituals of syncretic religious groups. Some of these groups have established themselves in the United States and European countries, attracting international research interest in the effects of ayahuasca. Studies suggest that it may have therapeutic applications, such as in the treatment of drug addiction, and that it can be used safely by healthy adults. However, too few studies have been performed for a good assessment of its properties to be made. The aim of this article is to present a review of the history of ayahuasca, up to the recent discoveries concerning its pharmacology and toxicology.

Comparison of the Protective Effect of Indole beta-carbolines and R-(-)-deprenyl Against Nitrogen Species-Induced Cell Death in Experimental Culture Model of Parkinson's Disease

BACKGROUND: The membrane permeability transition of mitochondria has been suggested to be involved in toxic and oxidative forms of cell injury. Mitochondrial dysfunction is considered to play a critical role in neurodegeneration in Parkinson's disease. Despite the suggestion that indole beta-carbolines may be neurotoxic, these compounds provide a protective effect against cytotoxicity of other neurotoxins. In addition, the effect of indole beta-carbolines on change in the mitochondrial membrane permeability due to reactive nitrogen species (RNS), which may lead to cell death, has not been clarified. METHODS: Differentiated PC12 cells were used as the experimental culture model for the investigation of neuronal cell injury, which occurs in Parkinson's disease. The effect of indole beta-carbolines (harmalol and harmine) on differentiated PC12 cells against toxicity of S-nitroso-N-acetyl-DL-penicillamine (SNAP) was determined by measuring the effect on the change in transmembrane potential, cytochrome c release, formation of ROS, GSH contents, caspase-3 activity and cell viability, and was compared to that of R-(-)-deprenyl. RESULTS: Specific inhibitors of caspases (z-LEHD.fmk, z-DQMD.fmk) and antioxidants (N-acetylcysteine, dithiothreitol, melatonin, carboxy-PTIO and uric acid) depressed cell death in PC12 cells due to SNAP. beta-Carbolines and R-(-)-deprenyl attenuated the SNAP-induced cell death and GSH depletion concentration dependently with a maximal inhibitory effect at 25-50 microM. The compounds inhibited the nuclear damage, decrease in mitochondrial transmembrane potential, cytochrome c release and formation of reactive oxygen species caused by SNAP in PC12 cells. beta-Carbolines and R-(-)-deprenyl attenuated the H2O2-induced cell death and depletion of GSH. CONCLUSIONS: The results suggest that indole beta-carbolines attenuate the SNAP-induced viability loss in PC12 cells by inhibition of change in the mitochondrial membrane permeability, which may be caused by free radicals. Indole beta-carbolines appear to exert a protective effect against the nitrogen species-mediated neuronal cell injury in Parkinson's disease comparable to R-(-)-deprenyl.