Ayahuasca and its major component harmine promote antinociceptive effects in mouse models of acute and chronic pain

ETHNOPHARMACOLOGICAL RELEVANCE

Ayahuasca (AYA) is a psychedelic brew used in religious ceremonies. It is broadly used as a sacred medicine for treating several ailments, including pain of various origins.

AIM OF THE STUDY

To investigate the antinociceptive effects of AYA and its mechanisms in preclinical models of acute and chronic pain in mice, in particular during experimental neuropathy.

MATERIALS AND METHODS

The antinociceptive effects of AYA administered orally were assessed in the following models of pain: formalin test, Complete Freund's Adjuvant (CFA)-induced inflammation, tail flick test, and partial sciatic nerve ligation model of neuropathic pain. Antagonism assays and Fos immunohistochemistry in the brain were performed. AYA-induced toxicity was investigated. AYA was chemically characterized. The antinociceptive effect of harmine, the major component present in AYA, was investigated.

RESULTS

AYA (24-3000 μL/kg) dose-dependently reduced formalin-induced pain-like behaviors and CFA-induced mechanical allodynia but did not affect CFA-induced paw edema or tail flick latency. During experimental neuropathy, single treatments with AYA (24-3000 μL/kg) reduced mechanical allodynia; daily treatments once or twice a day for 14 days promoted consistent and sustained antinociception. The antinociceptive effect of AYA (600 μL/kg) was reverted by bicuculline (1 mg/kg) and methysergide (5 mg/kg), but not by naloxone (5 mg/kg), phaclofen (2 mg/kg), and rimonabant (10 mg/kg), suggesting the roles of GABAA and serotonergic receptors. AYA increased Fos expression in the ventrolateral periaqueductal gray and nucleus raphe magnus after 1 h, but not after 6 h or 14 days of daily treatments. AYA (600 μL/kg) twice a day for 14 days did not alter mice's motor function, spontaneous locomotion, body weight, food and water intake, hematological, biochemical, and histopathological parameters. Harmine (3.5 mg/kg) promoted consistent antinociception during experimental neuropathy.

CONCLUSIONS

AYA promotes consistent antinociceptive effects in different mouse models of pain without inducing detectable toxic effects. Harmine is at least partially accountable for the antinociceptive properties of AYA.

Ayahuasca ceremony leaders' perspectives on special considerations for eating disorders

Eating disorders (EDs) are difficult conditions to resolve, necessitating novel treatments. Ayahuasca, a psychedelic plant medicine originating in Indigenous Amazonian communities, is being investigated. Aspects of ceremonial ayahuasca use (purging, dietary restrictions) appear similar to ED behaviors, raising questions about ayahuasca's suitability as an intervention for individuals with EDs. This study explored the perspectives of ayahuasca ceremony leaders on these and other considerations for ceremonial ayahuasca drinking among individuals with EDs. A qualitative content analysis of interviews was undertaken with 15 ayahuasca ceremony leaders, the majority of whom were from the West/Global North. Screening for EDs, purging and dietary restrictions, potential risks and dangers, and complementarity with conventional ED treatment emerged as categories. The findings offer ideas, including careful screening and extra support, to promote safe and beneficial ceremony experiences for ceremony participants with EDs. More research is needed to clarify the impacts of ceremony-related purging and preparatory diets. To evolve conventional models of treatment, the ED field could consider Indigenous approaches to mental health whereby ayahuasca ceremony leaders and ED researchers and clinicians collaborate in a decolonizing, bidirectional bridging process between Western and Indigenous paradigms of healing.

Psychedelic Therapy: A Primer for Primary Care Clinicians-N,N-Dimethyltryptamine and Ayahuasca

BACKGROUND

N,N-dimethyltryptamine (DMT) is a naturally occurring serotonergic psychedelic found in natural plants around the globe. As the main psychoactive component in ayahuasca, which also contains monoamine oxidase inhibitors, DMT has been consumed as plant-based brew by indigenous peoples for centuries. Further research is required to delineate the therapeutic utility of DMT.

AREAS OF UNCERTAINTY

Although previous research has shown that DMT is synthesized endogenously, it may not be produced at physiologically relevant concentrations. Additionally, the phenomenological similarities between the DMT-induced state and near-death experiences led to the popular hypothesis that endogenous DMT is released during the dying process. However, this hypothesis continues to be debated. Generally, DMT and ayahuasca seem to be physiologically and psychiatrically safe, although ayahuasca is known to cause transient vomiting.

THERAPEUTIC ADVANCES

A double-blind, randomized controlled trial showed that, within 1 week, ayahuasca causes remission in 36% of patients with treatment-resistant depression. According to top-line results from a recent phase IIa trial, 57% of patients with major depressive disorder experienced remission 12 weeks after receiving a single intravenous dose of DMT.

LIMITATIONS

There has only been a single published double-blind randomized controlled trial on ayahuasca and 2 on DMT. All clinical trials have had small sample sizes (≤34 participants). DMT requires further research to understand its therapeutic and clinical potential as a psychedelic.

CONCLUSIONS

Preliminary evidence indicates that ayahuasca and DMT may be more effective than existing antidepressants for treating major depressive disorder and treatment-resistant depression.

Emotion regulation effects of Ayahuasca in experienced subjects during implicit aversive stimulation: An fMRI study

ETHNOPHARMACOLOGICAL RELEVANCE

Ayahuasca is a beverage used in Amazonian traditional medicine and it has been part of the human experience for millennia as well as other different psychoactive plants. Although Ayahuasca has been proposed as potentially therapeutic as an anxiolytic and antidepressant, whilst no studies have been carried out so far investigating their direct effect on brain emotional processing.

AIM OF THE STUDY

This study aimed to measure the emotional acute effect of Ayahuasca on brain response to implicit aversive stimulation using a face recognition task in functional magnetic resonance imaging (fMRI).

MATERIALS AND METHODS

Nineteen male experienced Ayahuasca users participated in this study in two fMRI sessions before and after 50 min of the Ayahuasca ingestion. Subjects were presented with pictures of neutral (A) and aversive (B) (fearful or disgusted) faces from the Pictures of Facial Affect Series. Subjects were instructed to identify the gender of the faces (gender discrimination task) while the emotional content was implicit. Subjective mood states were also evaluated before Ayahuasca intake and after the second fMRI session, using a visual analogue mood scale (VAMS).

RESULTS

During the aversive stimuli, the activity in the bilateral amygdala was attenuated by Ayahuasca (qFDR<0.05). Furthermore, in an exploratory analysis of the effects after intake, Ayahuasca enhances the activation in the insular cortex bilaterally, as well as in the right dorsolateral prefrontal cortex (qFDR<0.05). In the psychometric VAMS scale, subjects reported attenuation of both anxiety and mental sedation (p < 0.01) during acute effects.

CONCLUSIONS

Together, all reported results including neuroimaging, behavioral data and psychometric self-report suggest that Ayahuasca can promote an emotion regulation mechanism in response to aversive stimuli with corresponding improved cognition including reduced anxiety and mental sedation.

Shared functional connectome fingerprints following ritualistic ayahuasca intake

The knowledge that brain functional connectomes are unique and reliable has enabled behaviourally relevant inferences at a subject level. However, whether such "fingerprints" persist under altered states of consciousness is unknown. Ayahuasca is a potent serotonergic psychedelic which produces a widespread dysregulation of functional connectivity. Used communally in religious ceremonies, its shared use may highlight relevant novel interactions between mental state and functional connectome (FC) idiosyncrasy. Using 7T fMRI, we assessed resting-state static and dynamic FCs for 21 Santo Daime members after collective ayahuasca intake in an acute, within-subject study. Here, connectome fingerprinting revealed FCs showed reduced idiosyncrasy, accompanied by a spatiotemporal reallocation of keypoint edges. Importantly, we show that interindividual differences in higher-order FC motifs are relevant to experiential phenotypes, given that they can predict perceptual drug effects. Collectively, our findings offer an example of how individualised connectivity markers can be used to trace a subject's FC across altered states of consciousness.

A quantitative textual analysis of the subjective effects of ayahuasca in naïve users with and without depression

Ayahuasca is a brew with psychoactive properties that has been used as an entheogen for centuries, with more recent studies suggesting it is a promising treatment for some clinical disorders. Although there is an emerging scientific literature on its effects, to the best of our knowledge no study has explored the self-reported experiences of first-time ayahuasca users with quantitative textual analysis tools. Accordingly, the current study aimed to analyze the subjective experience of naive individuals with depression and healthy controls after consuming ayahuasca. For this purpose, responses from a subsample of participants from a previous clinical trial to open-ended questions regarding their experience with ayahuasca underwent textual analysis. Data from nine patients with treatment-resistant depression and 20 healthy individuals were included, and quantitative textual analysis was performed using IRaMuTeQ 0.7 alpha 2 and R 3.1.2. The analysis identified five clusters: alterations in the state of consciousness, cognitive changes, somatic alterations, auditory experiences, and visual perceptual content. Additionally, findings suggest specific features of the experience of people with depression with ayahuasca, such as increased aversive bodily reactions. The results are consistent with previous findings indicating central axes of the psychedelic experience, and may inform therapeutic approaches using ayahuasca.

Altered State of Consciousness and Mental Imagery as a Function of N, N-dimethyltryptamine Concentration in Ritualistic Ayahuasca Users

Consumption of the psychedelic brew ayahuasca is a central ritualistic aspect of the Santo Daime religion. The current observational, baseline controlled study was designed to assess whether members (n = 24) of the Santo Daime church would show enhanced capacity for mental imagery during an ayahuasca experience. In addition, this study assessed whether the effects of ayahuasca on consciousness and mental imagery were related to peak serum concentration of N, N-dimethyltryptamine (DMT), the main psychoactive component. Measures of altered states of consciousness (5-Dimensional Altered States of Consciousness Questionnaire) and ego dissolution (Ego Dissolution Inventory [EDI]) as well as measures of mental imagery (visual perspective shifting, vividness of visual imagery, cognitive flexibility, associative thinking) were taken on two subsequent days on which members of Santo Daime were sober or drank a self-selected volume of ayahuasca. Measures of altered states of consciousness revealed that feelings of oceanic boundlessness, visual restructuralization, and EDI increased most prominently after drinking and shared a positive correlation with peak DMT concentration. Measures of mental imagery did not noticeably differ between the baseline and ayahuasca condition, although subjective ratings of cognitive flexibility were lower under ayahuasca. Two measures related to mental imagery, that is, perspective shifts and cognitive flexibility, were significantly correlated to peak DMT concentrations. Peak concentrations of DMT and other alkaloids did not correlate with ayahuasca dose. These findings confirm previous notions that the primary phenomenological characteristics of ayahuasca are driven by DMT. Compensatory or neuroadaptive effects associated with long-term ayahuasca intake may have mitigated the acute impact of ayahuasca in Santo Daime members on mental imagery.

Reports by explorers and travelers and the first scientific studies on ayahuasca (dating from 1850 to 1950) within the current debate on the "psychedelic renaissance"

This article describes the associations and controversies between indigenous and western uses of ayahuasca between 1850 and 1950 in relation to the "psychedelic renaissance." This movement has gained scientific attention since 2000, but hearkens back to the 1960s and 1970s, when anti-drug policy halted research on the "therapeutic potential" of psychoactive substances. Pioneering studies on ayahuasca date back to the early twentieth century and mention reports of expeditions to Amazonia from 1850 onward. Here, these articles and reports are analyzed according to the historical aspect of actor-network theory and recent studies. We infer that history casts light on the current political debate about indigenous uses, classifications, and meanings, pharmaceutical interest in ayahuasca, and the debate on "drugs."

Prevalence and therapeutic impact of adverse life event reexperiencing under ceremonial ayahuasca

The present study examined the safety and efficacy of the ceremonial use of ayahuasca in relation to reports of heightened life event reexperiencing under psychedelics. The study examined (1) the prevalence of specific types of adverse life event reexperiencing, (2) characteristics predictive of reexperiencing, (3) the psychological character of reexperiencing, and (4) the impact of reexperiencing on mental health. Participants were recruited from three ayahuasca healing and spiritual centers in South and Central America (N = 33 military veterans, 306 non-veterans) using self-report data at three timepoints (Pre-retreat, Post-retreat, 3-months post-retreat). Reexperiencing adverse life events under ayahuasca was common, with women showing particularly high probability of reexperiencing sexual assault, veterans reexperiencing combat-related trauma, and individuals with a self-reported lifetime diagnosis of post-traumatic stress disorder exhibiting a substantively higher prevalence of reexperiencing. Reexperiencing was associated with states of cognitive reappraisal, psychological flexibility, and discomfort during ceremonies, and participants who reexperienced adverse life events exhibited greater reductions in trait neuroticism following their ceremonies. Clinical implications of these results for the application of psychedelics to mood and stress disorders are discussed.

Examining the Therapeutic Effect of Ceremonial Ayahuasca on Narcissistic Personality and Antagonistic Externalizing in Adults

Changes in narcissistic traits (e.g., entitlement) following the ceremonial use of ayahuasca were examined across three timepoints (baseline, postretreat, 3-month follow-up) in a sample of 314 adults using self- and informant-report (N = 110) measures. Following ceremonial use of ayahuasca, self-reported changes in narcissism were observed (i.e., decreases in Narcissistic Personality Inventory [NPI] Entitlement-Exploitativeness, increases in NPI Leadership Authority, decreases in a proxy measure of narcissistic personality disorder [NPD]). However, effect size changes were small, results were somewhat mixed across convergent measures, and no significant changes were observed by informants. The present study provides modest and qualified support for adaptive change in narcissistic antagonism up to 3 months following ceremony experiences, suggesting some potential for treatment efficacy. However, meaningful changes in narcissism were not observed. More research would be needed to adequately evaluate the relevance of psychedelic-assisted therapy for narcissistic traits, particularly studies examining individuals with higher antagonism and involving antagonism-focused therapeutic approaches.

Application of machine learning and complex network measures to an EEG dataset from ayahuasca experiments

Ayahuasca is a blend of Amazonian plants that has been used for traditional medicine by the inhabitants of this region for hundreds of years. Furthermore, this plant has been demonstrated to be a viable therapy for a variety of neurological and mental diseases. EEG experiments have found specific brain regions that changed significantly due to ayahuasca. Here, we used an EEG dataset to investigate the ability to automatically detect changes in brain activity using machine learning and complex networks. Machine learning was applied at three different levels of data abstraction: (A) the raw EEG time series, (B) the correlation of the EEG time series, and (C) the complex network measures calculated from (B). Further, at the abstraction level of (C), we developed new measures of complex networks relating to community detection. As a result, the machine learning method was able to automatically detect changes in brain activity, with case (B) showing the highest accuracy (92%), followed by (A) (88%) and (C) (83%), indicating that connectivity changes between brain regions are more important for the detection of ayahuasca. The most activated areas were the frontal and temporal lobe, which is consistent with the literature. F3 and PO4 were the most important brain connections, a significant new discovery for psychedelic literature. This connection may point to a cognitive process akin to face recognition in individuals during ayahuasca-mediated visual hallucinations. Furthermore, closeness centrality and assortativity were the most important complex network measures. These two measures are also associated with diseases such as Alzheimer's disease, indicating a possible therapeutic mechanism. Moreover, the new measures were crucial to the predictive model and suggested larger brain communities associated with the use of ayahuasca. This suggests that the dissemination of information in functional brain networks is slower when this drug is present. Overall, our methodology was able to automatically detect changes in brain activity during ayahuasca consumption and interpret how these psychedelics alter brain networks, as well as provide insights into their mechanisms of action.

Comparison of psychedelic and near-death or other non-ordinary experiences in changing attitudes about death and dying

Both psychedelic drug experiences and near-death experiences can occasion changes in perspectives on death and dying, but there have been few direct comparisons of these phenomena. This study directly compared psychedelic occasioned and non-drug experiences which altered individuals’ beliefs about death. Individuals who reported an experience that altered their beliefs about death occasioned by either a psychedelic drug or a near-death or other non-ordinary experience completed an online survey. Circumstances of the experience, mystical and near-death subjective features, changes in attitudes about death, and other persisting effects were evaluated. The study sample (n = 3192) included five groups: non-drug near-death or other non-ordinary experiences (n = 933), and drug experiences occasioned by lysergic acid diethylamide (LSD) (n = 904), psilocybin (n = 766), ayahuasca (n = 282), or N,N-dimethyltryptamine (DMT) (n = 307). Analyses of differences in experiences were adjusted statistically for demographic differences between groups. Compared to the psychedelic groups, the non-drug group was more likely to report being unconscious, clinically dead, and that their life was in imminent danger. The groups were remarkably similar in the reported changes in death attitudes attributed to the experience, including a reduced fear of death and high ratings of positive persisting effects and personal meaning, spiritual significance, and psychological insight. Although both psychedelic and non-drug participants showed robust increases on standardized measures of mystical and near-death experiences, these measures were significantly greater in the psychedelic participants. Non-drug participants were more likely to rate their experiences as the single most meaningful of their lives. Comparing across psychedelic substances, ayahuasca and DMT groups tended report stronger and more positive enduring consequences of the experience than the psilocybin and LSD groups, which were largely indistinguishable. These data provide a detailed characterization and comparison of psychedelic occasioned and non-drug experiences that changed attitudes about death and suggest the importance of future prospective psychedelic administration studies.

Ayahuasca-induced psychosis: A case report

Psychosis induced by ayahuasca is a rare occurrence. However, due to an increase in the access and distribution of this substance, it is necessary to highlight the cases in which it occurs. We describe the case of a 26-year-old man who was admitted to the psychiatric service after seven months of changes in behaviour, delusions and the subsequent exacerbation of symptoms, after participating in a ritual ceremony during which he consumed an ayahuasca concoction for the first time. Initially, he required hospital treatment to control the acute psychotic episode, but after tolerating and responding well to the antipsychotic treatment, he was discharged with an outpatient follow-up.

Effects of ayahuasca and its alkaloids on substance use disorders: an updated (2016-2020) systematic review of preclinical and human studies

Ayahuasca is a hallucinogenic/psychedelic traditionally used for ritual and therapeutic purposes. One such therapeutic use is related to Substance Use Disorders (SUDs). A previous systematic review of preclinical and human studies published until 2016 suggested that ayahuasca and its alkaloids have therapeutic effects in the treatment of SUDs. To conduct an update of this previous review. A systematic review of quantitative studies which analyzed the effects of ayahuasca and its alkaloids on drug use (primary outcome) and other measures (secondary outcomes) related to SUDs was conducted, including articles from 2016 to 2020. Nine studies (four preclinical, five observational) were included in the review. Preclinical studies in rodents reported reductions in amphetamine self-administration and anxiety, and in alcohol- and methylphenidate-induced conditioned place preference. Observational studies among healthy ritual ayahuasca users and patients with SUDs reported reductions in drug use, anxiety, and depression, and increases in quality of life and well-being. We replicated the findings of the previous review suggesting that ayahuasca and its alkaloids have therapeutic effects in the treatment of SUDs. However, translation of preclinical data to humans is limited, observational studies do not allow us to infer causality, and there is a lack of standardization on ayahuasca doses. Although promising, randomized, controlled trials are needed to better elucidate these results. The PROSPERO ID for this study is CRD42020192046.

Ayahuasca and tobacco smoking cessation: results from an online survey in Brazil

RATIONALE

Smoking-related disease is a major problem globally. Effective smoking cessation treatments are however limited. Increasing evidence suggests that psychedelics have potential as treatments for substance use disorders and may therefore prove an option in aiding smoking cessation.

OBJECTIVES

To establish which factors predict smoking cessation in people who reported quitting or reducing smoking following ayahuasca consumption.

METHODS

A retrospective cross-sectional mixed-method study (quantitative and qualitative design) was undertaken using data from an online survey evaluating peoples' experiences before and after drinking ayahuasca. Multivariate logistic regression was performed with smoking condition (cessation or reduction/relapse) as a dependent variable and demographics, smoking, ayahuasca-related variables and the mystical experience (MEQ30) as predicting factors.

RESULTS

A total of 441 responses were grouped according to self-reported smoking status: cessation (n = 305) or reduction/relapse (n = 136) smoking. Logistic regression showed that mystical experience (OR: 1.03; 95% CI [1.00-1.05]) and frequency of ayahuasca intake (OR: 2.16[1.00-4.70]) were protective factors, while positive mood (measured by the MEQ30) during the ayahuasca experience was a risk factor (OR: 0.91[0.85-0.97]). Qualitative thematic analysis identified eight themes (e.g. acquired awareness, spiritual experience, increased motivation) related to the ayahuasca experience and the process of smoking cessation/reduction.

CONCLUSIONS

Our results suggest that ayahuasca could be used as a potential tool for smoking cessation, and that effects may be mediated by mystical experience. Given the current burden of smoking-related disease and the limited treatment options, studies are needed to investigate the efficacy of psychedelics in smoking cessation.

Role of 5-HT2A receptors in the effects of ayahuasca on ethanol self-administration using a two-bottle choice paradigm in male mice

RATIONALE

Ayahuasca has been proposed as a potential treatment of alcohol (ethanol) use disorder (AUD). The serotonin 5-HT2A receptor agonist N,N-dimethyltryptamine (DMT) is the main psychoactive component of ayahuasca, suggesting that its therapeutic effects may be mediated by 5-HT2A receptors.

OBJECTIVES

The aim of the present study was to investigate the effects of ayahuasca on the expression of ethanol self-administration using a two-bottle choice procedure and the role of 5-HT2A receptors in those effects.

METHODS

Male mice had intermittent access to ethanol (10% v/v) in a two-bottle choice procedure for 30 days. Animals were then submitted to 3 treatment phases, each followed by ethanol re-exposure tests. During the treatment phase, every 3 days, animals received i.p. injections of either vehicle or the 5-HT2A receptor antagonist M100907 (M100, 1 mg/kg) followed by an i.g. (gavage) administration of vehicle or ayahuasca (100 mg/kg) and were exposed to the self-administration apparatus with no ethanol availability. During re-exposure tests, animals were submitted to the same conditions as during acquisition, with no treatments prior to those sessions.

RESULTS

Treatment with ayahuasca blocked the expression of ethanol self-administration, decreasing ethanol intake and preference during re-exposure tests. Pretreatment with M100 blocked the effects of ayahuasca on ethanol drinking without significantly attenuating ethanol self-administration.

CONCLUSIONS

Treatment with ayahuasca during alcohol abstinence blocked the expression of alcohol self-administration in mice, and 5-HT2A receptor activation is critical for those effects to emerge. Our findings support a potential for ayahuasca and other 5-HT2A receptor agonists as adjunctive pharmacotherapies for the treatment of AUD.

N,N-dimethyltryptamine and Amazonian ayahuasca plant medicine

OBJECTIVE

Reports have indicated possible uses of ayahuasca for the treatment of conditions including depression, addictions, post-traumatic stress disorder, anxiety and specific psychoneuroendocrine immune system pathologies. The article assesses potential ayahuasca and N,N-dimethyltryptamine (DMT) integration with contemporary healthcare. The review also seeks to provide a summary of selected literature regarding the mechanisms of action of DMT and ayahuasca; and assess to what extent the state of research can explain reports of unusual phenomenology.

DESIGN

A narrative review.

RESULTS

Compounds in ayahuasca have been found to bind to serotonergic receptors, glutaminergic receptors, sigma-1 receptors, trace amine-associated receptors, and modulate BDNF expression and the dopaminergic system. Subjective effects are associated with increased delta and theta oscillations in amygdala and hippocampal regions, decreased alpha wave activity in the default mode network, and stimulations of vision-related brain regions particularly in the visual association cortex. Both biological processes and field of consciousness models have been proposed to explain subjective effects of DMT and ayahuasca, however, the evidence supporting the proposed models is not sufficient to make confident conclusions. Ayahuasca plant medicine and DMT represent potentially novel treatment modalities.

CONCLUSIONS

Further research is required to clarify the mechanisms of action and develop treatments which can be made available to the general public. Integration between healthcare research institutions and reputable practitioners in the Amazon is recommended.

Ayahuasca blocks ethanol preference in an animal model of dependence and shows no acute toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Ayahuasca, a psychoactive beverage prepared from Banisteriopsis caapi and Psychotria viridis, is originally used by Amazon-based indigenous and mestizo groups for medicinal and ritualistic purposes. Nowadays, ayahuasca is used in religious and shamanic contexts worldwide, and preliminary evidence from preclinical and observational studies suggests therapeutic effects of ayahuasca for the treatment of substance (including alcohol) use disorders.

AIM OF THE STUDY

To investigate the initial pharmacological profile of ayahuasca and its effects on ethanol rewarding effect using the conditioned place preference (CPP) paradigm in mice.

MATERIALS AND METHODS

Ayahuasca beverage was prepared using extracts of B. caapi and P. viridis, and the concentration of active compounds was assessed through high performance liquid chromatography (HPLC). The following behavioral tests were performed after ayahuasca administration: general pharmacological screening (13, 130, or 1300 mg/kg - intraperitoneally - i.p., and 65, 130, 1300, or 2600 mg/kg - via oral - v.o.); acute toxicity test with elevated doses (2600 mg/kg - i.p., and 5000 mg/kg - v.o.); motor activity, motor coordination, and hexobarbital-induced sleeping time potentiation (250, 500, or 750 mg/kg ayahuasca or vehicle - v.o.). For the CPP test, the animals received ayahuasca (500 mg/kg - v.o.) prior to ethanol (1.8 g/kg - i.p.) or vehicle (control group - i.p.) during conditioning sessions.

RESULTS

Ayahuasca treatment presented no significant effect on motor activity, motor coordination, hexobarbital-induced sleeping latency or total sleeping time, and did not evoke signs of severe acute toxicity at elevated oral doses. Ayahuasca pre-treatment successfully inhibited the ethanol-induced CPP and induced CPP when administered alone.

CONCLUSIONS

Our results indicate that ayahuasca presents a low-risk acute toxicological profile when administered orally, and presents potential pharmacological properties that could contribute to the treatment of alcohol use disorders.

Ayahuasca and the traveller: A scoping review of risks and possible benefits

BACKGROUND

Ayahuasca is a psychotropic drink made from the Amazonian vine Banisteriopsis caapi. Active components include beta-carboline alkaloids and the hallucinogen N-N-dimethyltryptamine (DMT). This review aimed to identify and summarize the literature on the safety and effectiveness of ayahuasca among recreational users.

METHOD

A comprehensive literature search was done on November 1, 2019 in the following six databases: PubMed(MEDLINE), Ovid Embase, Ovid International Pharmaceutical Abstracts, LILACS, Scopus, and Web of Science. Articles were included if they were original research published in English, Spanish, or Portuguese, among human participants using oral ayahuasca for neuropsychiatric effects. Chemical or pharmacological analyses, brain imaging studies, and studies examining the use of ayahuasca within a religious context were excluded.

RESULTS

5750 unique titles were identified through the database searches, with an additional 19 titles identified through manual searches. Ultimately, 39 met all the criteria for inclusion. Articles were organized into 4 themes: (1) Case reports and case series; (2) The use of ayahuasca for depression or grief; (3) The use of ayahuasca and other psychiatric or neuropsychological outcomes; and (4) Studies examining ayahuasca use and physiologic outcomes. Ayahuasca use is associated with a risk of both psychiatric and non-psychiatric events including hallucinations, agitation or aggression, vomiting, seizure, and rhabdomyolysis. Five fatalities have been reported in the literature following ayahuasca use. Open-label studies assessing ayahuasca use in depression found favorable results persisting across 21 days. Ayahuasca was also found to influence the MINDSENS scale for mindfulness, with mixed results observed for impact of ayahuasca on cognitive function and creativity, and benefits observed for measures of self-acceptance and overall wellbeing.

CONCLUSIONS

To date, evidence on benefits for the management of depression, anxiety, and other mental health disorders is mixed, with some evidence suggesting improvements in mindfulness measures and creativity that are generally short-lived, and multiple case reports suggesting the potential for harm and interactions.

In Vitro Study of the Bioavailability and Bioaccessibility of the Main Compounds Present in Ayahuasca Beverages

Ayahuasca is a psychoactive beverage that contains the psychoactive compound N,N-dimethyltryptamine and β-carboline alkaloids. This study aims at determining in vitro the bioavailability and bioaccessibility of the main compounds present in decoctions of four individual plants, in a commercial mixture and in four mixtures of two individual plants used in the preparation of Ayahuasca. The samples were subjected to an in vitro digestion process, and the Caco-2 cell line was used as an absorption model. The integrity and permeability of the cell monolayer were evaluated, as well as the cytotoxicity of the extracts. After digestion and cell incubation, the compounds absorbed by the cell monolayer were quantified by high-performance liquid chromatography coupled to a diode array detector. The results showed that compounds such as N,N-dimethyltryptamine, Harmine, Harmaline, Harmol, Harmalol and Tetrahydroharmine were released from the matrix during the in vitro digestion process, becoming bioaccessible. Similarly, some of these compounds, after being incubated with the cell monolayer, were absorbed, becoming bioavailable. The extracts did not show cytotoxicity after cell incubation, and the integrity and permeability of the cell monolayer were not compromised.

Ayahuasca, an ancient substance with traditional and contemporary use in neuropsychiatry and neuroscience

Ayahuasca is a botanical hallucinogenic preparation traditionally used for ritual and therapeutic purposes by native populations of the Northwestern Amazon. In the last decades, ayahuasca use has spread to Europe, the United States, Asia, and Africa, and interest in the possible therapeutic uses of ayahuasca for treating anxiety and mood disorder and substance-use disorders has increased both among the general public and the scientific community. Indeed, preclinical, observational, and preliminary clinical studies have corroborated some of these findings. In the present article, we present an overview of these studies and highlight the current uses of ayahuasca in neuroscience, such as a tool in the investigation of the neural basis of introspection and other complex cognitive processes.

Ancient psychoactive plants in a global village: The ritual use of cannabis in a self-managed community in Catalonia

BACKGROUND

Cannabis is a plant with a rich history of medical, recreational, industrial and spiritual uses. This paper aims to explore drug use rituals as methods of community-controlled use that help maintain a self-regulated and healthy relation to the substance in questions. Furthermore, it explores how cannabis is used in developing spirituality and a sense of community. The ritual use of cannabis is discussed in the context of drug policy.

METHODS

Ethnographic research methods, such as fieldwork, participant observation, in-depth interviews, and qualitative analysis, were used to research a phenomenological community in rural Catalonia, where ancient psychoactive plants (APP), such as ayahuasca and cannabis, are regularly used in a ritual context.

RESULTS

Cannabis has a long history of ritual/spiritual uses and is still being used for such purposes in Catalonia. The rituals are effective harm reduction techniques and can even generate beneficial effects for the individual as well as the community by strengthening bonds between community members. The rituals associated with APP are seen as spiritual or religious practices, as well as forms of self-care and community-care, rather than involving drug dependence or addiction.

CONCLUSION

The contemporary use of APP in Western societies is gaining popularity. International drug policies and the schedule of controlled drugs claim to be based on scientific evidence, but this evidence is limited. The contemporary myopic focus on the risks and harms of drugs overlooks important realities, such as the benefits of non-problematic drug use. These omissions could in part be rectified through the consideration of scientific findings from the field of ethnography regarding the spiritual and community dimensions of drug use.

Determination of the Elemental Composition of Ayahuasca and Assessments Concerning Consumer Safety

The consumption of ayahuasca, a brew prepared from the decoction of two Amazon plants, has increased worldwide in the last decades. This fact raised questions about the safety in its oral administration. In this sense, information concerning the chemical composition of ayahuasca is essential to find a comprehensive reply. Therefore, the aim of this study consisted of determining the elemental composition of ready-to-consume ayahuasca samples produced in Brazil, in order to evaluate the safety in the oral administration of this beverage, considering recommended macroelement and microelement daily intake values and the permitted limits of potentially toxic heavy metals. Real ayahuasca samples, obtained from Brazilian religious groups, underwent microwave radiation-assisted acid decomposition, and Li, Al, Mn, Fe, Co, Cu, Zn, As, Cd, Hg, and Pb concentrations were determined by ICP-MS, while Ca, Mg, K, and P concentrations were determined by ICP OES. Method accuracy was assessed by analyte addition and recovery assays. Recoveries ranged from 80 and 118%, indicating satisfactory accuracy. Limit of detection (LOD) and limit of quantification (LOQ) values were lower than 1 mg L^-1 for the macroelements determined by ICP OES and lower than 3.5 μg L^-1 for the microelements determined by ICP-MS. The concentrations of the elements determined in the samples were lower than the recommended or tolerable limits; hence, it is possible to affirm that ayahuasca presents safe administration levels regarding total elemental content.

The pharmacological interaction of compounds in ayahuasca: a systematic review

Ayahuasca is a South American psychoactive plant brew used as traditional medicine in spiritual and in cultural rituals. This is a review of the current understanding about the pharmacological mechanisms that may be interacting in ayahuasca. Searches were performed using PubMed, PsycINFO, and Web of Science databases and 16 papers were selected. As hypothesized, the primary narrative in existing research revolved around prevention of deamination of N,N-dimethyltryptamine (N,N-DMT, also referred to as DMT) by monoamine oxidase inhibitors (MAOIs) in ayahuasca. Two of the constituents, DMT and harmine, have been studied more than the secondary harmala alkaloids. At present, it is unclear whether the pharmacological interactions in ayahuasca act synergistically or additively to produce psychoactive drug effects. The included studies suggest that our current understanding of the preparation's synergistic mechanisms is limited and that more complex processes may be involved; there is not yet enough data to determine any potential synergistic interaction between the known compounds in ayahuasca. Our pharmacological understanding of its compounds must be increased to avoid the potential risks of ayahuasca use.

Who Turns to Amazonian Medicine for Treatment of Substance Use Disorder? Patient Characteristics at the Takiwasi Addiction Treatment Center

OBJECTIVE

Complementary medicines are an emergent field in the treatment of substance use disorders (SUDs) and include Amazonian medicines, such as ayahuasca. The aim of this multimodal cross-sectional study was to investigate characteristics of people who seek treatment for SUDs at an accredited healthcare facility that applies Amazonian medicines along with conventional psychotherapy.

METHOD

We collected clinical and sociodemographic data of consecutive admissions at the Takiwasi Addiction Treatment Center (Tarapoto, Peru) using structured questionnaires, interviews, and letters submitted upon program application describing motivation for treatment.

RESULTS

The sample of 50 male participants admitted between 2014 and 2016 was culturally heterogeneous, including patients from Peru (42%), other Latin American countries (34%), and North America/Europe (24%). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria indicated dependencies on cannabis (72%), alcohol (52%), cocaine/base paste (48%), and others; multiple substance use was common (84%). Self-reported depression and anxiety scores showed moderate elevation. Comparison of Addiction Severity Index composite scores to a large U.S. sample suggested somewhat more severe problems in the drug and psychiatric domains. Common motives for selecting the program included interest in Amazonian medicine, the Takiwasi concept of treatment, and unfavorable experiences with past treatments. Being motivated by family, a desire for self-transformation, and spiritual/existential motives were common themes for treatment initiation.

CONCLUSIONS

Our results suggest that the Amazonian medicine-based therapy attracts a diverse patient group not limited to regional residents and may be particularly appealing to more impaired SUD patients with a history of unsuccessful treatment. The sample's cultural diversity suggests an existing interest in such therapies among international SUD treatment-seeking patients. These findings are relevant in light of the need for improved SUD therapies and contribute to the emergent research literature on ayahuasca-based treatments.

The 'enigma' of Richard Schultes, Amazonian hallucinogenic plants, and the limits of ethnobotany

This story is about the twentieth-century ethnobotanist, Richard Evans Schultes (1915-2001), and his research on hallucinogenic plants. Ethnobotany can contribute directly to science and technology studies in that the discipline makes cultural ways of knowing its scientific subject. Ethnobotanists must learn about plants through people, and are not able to conceal their interactions with indigenous informants and other ethnobotanists. I focus on an 'enigma' that Schultes presented, concerning the peculiar ability of indigenous Amazonians to distinguish between local varieties of vine that he was unable to tell apart, notably those used to prepare the hallucinogenic beverage ayahuasca. The enigma describes a complicated and irresolvable question thrown up at the uneasy intersection between different ways of knowing about the world, and shows how modern scientific travellers might navigate - or fail to navigate - the uncertain passage between them. Together with Schultes's accounts of his own non-ordinary states of consciousness elicited by ayahuasca, and his writings on the Victorian botanist Richard Spruce, I chart an epistemological gulf between Schultes's modern scientific cosmology and that of his Amazonian informants. In describing his inability to learn about the ayahuasca varieties from Amazonians, Schultes's enigma traces the very limits of the ethnobotanical discipline and reveals the fragility of the processes by which scientific naturalists might impose categories such as 'nature' and 'culture'.

Effects of the hallucinogenic beverage ayahuasca on voluntary ethanol intake by rats and on cFos expression in brain areas relevant to drug addiction

Ayahuasca is a hallucinogenic infusion used in religious rituals that has serotoninergic properties and may be a potential therapeutic option for drug addiction. In this study, Wistar rats had intermittent access to ethanol for 8 weeks, receiving water (control), naltrexone (NTX, 2 mg/kg body weight [bw] intraperitoneally [i.p.]) or ayahuasca (Aya) at 0.5x, 1x, or 2x the ritual dose in the final 5 days. A naïve group had access only to water. Ethanol intake was estimated throughout the experiment, and cFos expression was evaluated in medial orbital cortex (MO), ventral orbital cortex (VO), lateral orbital cortex (LO), nucleus accumbens (NAc), and striatum. Treatment with either NTX or Aya (oral) did not decrease ethanol intake compared to the baseline level (5th to 7th week), but the NTX group intake was significantly lower than controls (p < 0.05). Ethanol significantly increased cFos expression in the MO region for control (p < 0.0001), NTX (p < 0.05), Aya1 (p < 0.001), and Aya2 (p < 0.0001) groups. This increase was also observed in the VO for the Aya1 group (p = 0.035), in the LO for the Aya2 group (p < 0.01), and in NAc for NTX and ayahuasca groups (p < 0.005). Furthermore, NTX and Aya0.5 treatment decreased cFos expression compared to controls in the MO region (p < 0.05 and p < 0.01, respectively), but only the ayahuasca group reached levels not significantly different from the naïve group. Studies using other protocols and dose regime are necessary to better investigate the impact of ayahuasca on alcohol intake by rats to support the observations in humans. Additionally, the role of ayahuasca in mediating cFos expression in other selected brain regions and its relationship with the serotoninergic/dopaminergic systems and drug addiction need further investigation.

Therapeutic potential of ayahuasca in grief: a prospective, observational study

RATIONALE

Recent studies have assessed the therapeutic potential of ayahuasca for the treatment of depression with promising preliminary results.

OBJECTIVES

Here, we examine the course of grief over 1 year of follow-up in a bereaved sample that attended a center in Peru to participate in indigenous Shipibo ayahuasca ceremonies. We also explore the roles of experiential avoidance and decentering as mechanisms of change.

METHODS

Bereaved participants who attended the ayahuasca center responded to an online survey that included the Texas Revised Inventory of Grief, Symptom Assessment-45, WHO Quality of Life-Bref, Acceptance and Action Questionnaire, and Decentering. Baseline assessment was completed by 50 individuals (T0). Of these, 39 completed the post-assessment at 15 days (T1), 31 at 3 months (T2), 29 at 6 months (T3), and 27 at 12 months (T4) after leaving the retreat. Pearson's analysis was performed to examine the relationship between the severity of grief and mechanisms of change during the period of T0 and T1.

RESULTS

A significant decrease in Texas Revised Inventory was observed at all time points (T1: Cohen's d = 0.84; T2: Cohen's d = 1.38; T3: Cohen's d = 1.16; T4: Cohen's d = 1.39). We found a relationship between experiential avoidance (r = 0.55; p < .01), decentering (r = - 0.47; p < .01), and a reduction in the severity of grief.

CONCLUSIONS

Our results suggest that the ceremonial use of ayahuasca has therapeutic value by reducing the severity of grief. Acceptance and decentering are both psychological processes that mediate the improvement of grief symptoms.

[Three forms of Dionysus: recreational, medical and religious use of ayahuasca]

Ayahuasca is a psychoactive tea that is rapidly gaining in popularity. Its effects are, however, widely different in various sets and settings, leading to various imaginings.<br/> AIM: To distinguish between the recreational, medical and religious use of ayahuasca, and further investigate its religious use.<br/> METHOD: Nietzsche's three forms of the Greek God Dionysus are used in order to describe and analyze the three contexts for ayahuasca use.<br/> RESULTS: The religious use of ayahuasca, for example in the Santo Daime church, can be understood as a contemporary form of Gnosticism.<br/> CONCLUSION: Research needs to take the various sets and settings of ayahuasca use into account. More research into the religious use of ayahuasca is needed.

Acute effects of ayahuasca in a juvenile non-human primate model of depression

OBJECTIVE

The incidence rate of major depression in adolescents reaches approximately 14%. This disorder is usually recurrent, without remission of symptoms even after pharmacological treatment, and persists throughout adult life. Since the effects of antidepressants take approximately 2 weeks to begin, new pharmacological therapies are under continuous exploration. Recent evidence suggests that psychedelics could produce rapid antidepressant effects. In this study, we evaluated the potential antidepressant effects of ayahuasca in a juvenile non-human primate model of depression.

METHODS

While living with their families, juvenile marmosets (8 males; 7 females) were observed on alternate days for four weeks during a baseline phase. This was followed by 8 weeks of an induced depressive state protocol, the social isolated context (IC), in which the animals were monitored in the first and last weeks. Subsequently, five males and four females were randomly selected for treatment, first with a single administration of saline vehicle (1.67 mL/300 g of body weight, via gavage), followed by a single dose of ayahuasca (1.67 mL/300 g of body weight, via gavage). Both phases lasted 1 week and the animals were monitored daily. A third week of sampling was called the tardive-pharmacological effects phase. In all phases the marmosets were assessed for behavior, fecal cortisol levels, and body weight.

RESULTS

After IC, the animals presented typical hypocortisolemia, but cortisol recovered to baseline levels 24 h after an acute dose of ayahuasca; this recovery was not observed in vehicle-treated animals. Additionally, in males, ayahuasca, but not the vehicle, reduced scratching, a stereotypic behavior, and increased feeding. Ayahuasca treatment also improved body weight to baseline levels in both sexes. The ayahuasca-induced behavioral response had long-term effects (14 days). Thus, in this translational juvenile animal model of depression, ayahuasca presented beneficial effects.

CONCLUSIONS

These results can contribute to the validation of ayahuasca as an antidepressant drug and encourage new studies on psychedelic drugs as a tool for treating mood disorders, including for adolescents with early-onset depression.

Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial

BACKGROUND

Recent open-label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression.

METHODS

To test the antidepressant effects of ayahuasca, we conducted a parallel-arm, double-blind randomized placebo-controlled trial in 29 patients with treatment-resistant depression. Patients received a single dose of either ayahuasca or placebo. We assessed changes in depression severity with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating scale at baseline, and at 1 (D1), 2 (D2), and 7 (D7) days after dosing.

RESULTS

We observed significant antidepressant effects of ayahuasca when compared with placebo at all-time points. MADRS scores were significantly lower in the ayahuasca group compared with placebo at D1 and D2 (p = 0.04), and at D7 (p < 0.0001). Between-group effect sizes increased from D1 to D7 (D1: Cohen's d = 0.84; D2: Cohen's d = 0.84; D7: Cohen's d = 1.49). Response rates were high for both groups at D1 and D2, and significantly higher in the ayahuasca group at D7 (64% v. 27%; p = 0.04). Remission rate showed a trend toward significance at D7 (36% v. 7%, p = 0.054).

CONCLUSIONS

To our knowledge, this is the first controlled trial to test a psychedelic substance in treatment-resistant depression. Overall, this study brings new evidence supporting the safety and therapeutic value of ayahuasca, dosed within an appropriate setting, to help treat depression. This study is registered at http://clinicaltrials.gov (NCT02914769).

Sub-acute and long-term effects of ayahuasca on affect and cognitive thinking style and their association with ego dissolution

RATIONALE

Ayahuasca is a psychotropic plant tea from South America used for religious purposes by indigenous people of the Amazon. Increasing evidence indicates that ayahuasca may have therapeutic potential in the treatment of mental health disorders and can enhance mindfulness-related capacities. Most research so far has focused on acute and sub-acute effects of ayahuasca on mental health-related parameters and less on long-term effects.

OBJECTIVES

The present study aimed to assess sub-acute and long-term effects of ayahuasca on well-being and cognitive thinking style. The second objective was to assess whether sub-acute and long-term effects of ayahuasca depend on the degree of ego dissolution that was experienced after consumption of ayahuasca.

RESULTS

Ayahuasca ceremony attendants (N = 57) in the Netherlands and Colombia were assessed before, the day after, and 4 weeks following the ritual. Relative to baseline, ratings of depression and stress significantly decreased after the ayahuasca ceremony and these changes persisted for 4 weeks. Likewise, convergent thinking improved post-ayahuasca ceremony up until the 4 weeks follow-up. Satisfaction with life and several aspects of mindfulness increased the day after the ceremony, but these changes failed to reach significance 4 weeks after. Changes in affect, satisfaction with life, and mindfulness were significantly correlated to the level of ego dissolution experienced during the ayahuasca ceremony and were unrelated to previous experience with ayahuasca.

CONCLUSION

It is concluded that ayahuasca produces sub-acute and long-term improvements in affect and cognitive thinking style in non-pathological users. These data highlight the therapeutic potential of ayahuasca in the treatment of mental health disorders, such as depression.

Ayahuasca's entwined efficacy: An ethnographic study of ritual healing from 'addiction'

BACKGROUND

A range of studies has demonstrated the efficacy of the psychoactive Amazonian brew ayahuasca in addressing substance addiction. These have revealed that physiological and psychological mechanisms are deeply enmeshed. This article focuses on how interactive ritual contexts support the healing effort. The study of psychedelic-assisted treatments for addiction has much to gain from ethnographic analyses of healing experiences within the particular ecologies of use and care, where these interventions are rendered efficacious.

METHODS

This is an ethnographically grounded, qualitative analysis of addiction-recovery experiences within ayahuasca rituals. It draws on long-term fieldwork and participant observation in ayahuasca communities, and in-depth, semi-structured interviews of participants with histories of substance misuse.

RESULTS

Ayahuasca's efficacy in the treatment of addiction blends somatic, symbolic and collective dimensions. The layering of these effects, and the direction given to them through ritual, circumscribes the experience and provides tools to render it meaningful. Prevailing modes of evaluation are ill suited to account for the particular material and semiotic efficacy of complex interventions such as ayahuasca healing for addiction. The article argues that practices of care characteristic of the ritual spaces in which ayahuasca is collectively consumed, play a key therapeutic role.

CONCLUSION

The ritual use of ayahuasca stands in strong contrast to hegemonic understandings of addiction, paving new ground between the overstated difference between community and pharmacological interventions. The article concludes that fluid, adaptable forms of caregiving play a key role in the success of addiction recovery and that feeling part of a community has an important therapeutic potential.

Medicine, religion and ayahuasca in Catalonia. Considering ayahuasca networks from a medical anthropology perspective

Ayahuasca is a psychoactive beverage from the Amazon, traditionally used by indigenous and mestizo populations in the region. Widespread international use of the beverage began in the 1990s in both secular contexts and religious/spiritual networks. This article offers an analysis of these networks as health care systems in general and for the case of Spain and specifically Catalonia, describing the emergence and characteristics of their groups, and the therapeutic itineraries of some participants. The medical anthropology perspective we take enables us to reflect on the relationship between medicine and religion, and problematize the tensions between medicalization and medical pluralism. Closely linked to the process of medicalization, we also analyze prohibitionist drug policies and their tensions and conflicts with the use of ayahuasca in ritual and 'health care' contexts. The paper ends with a reflection on the problem of ayahuasca as 'medicine', since the connection between religion and medicine is a very difficult one to separate.

Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans

Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus β-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans.

[The potential use of ayahuasca in psychiatry]

Ayahuasca is a decoctum made of admixture plants containing dimethyltryptamine and harmine. For millennia it has been used as a central element of spiritual, religious, initiation, and other - foremost healing - rituals, originally by the indigenous groups of the Amazon basin and later by the mestizo populations of the region. During the last two decades the brew has raised increased scientific and lay interest about its healing potentials within the framework of Western therapeutic settings. The typical ayahuasca effects consist of strong somatic reactions, vivid visions, relived personal memories, cathartic emotions, and insightful, introspective experiences when the emerging mental contents take different context and get deeper perspectives. The ayahuasca-experience can be exhausting necessitating the presence of an experienced leader for helping participants to pass difficult phases and for maximizing therapeutic benefits. No health damaging adverse effect has been confirmed thus far as result of its well-structured, institutionalized use. The scientific investigation of ayahuasca is hindered by legal issues, methodical problems, and sociocultural preconceptions. The present review outlines the therapeutic potentials of ayahuasca use in psychiatry with its psychobiological and spiritual background.

[Psychedelics and quasi-psychedelics in the light of contemporary research: medical cannabis, MDMA, salvinorin A, ibogaine and ayahuasca]

In lack of professional research and appropriate concepts our scientific knowledge of psychedelic agents is limited. According to the long-held official view these drugs are entirely harmful and have no medical use. However, a recent surge of clinical and pharmacological studies in the field indicates that many psychedelic-like agents have therapeutic potentials under proper circumstances. In this paper, from a biomedical and psychological perspective, we provide a brief review of the general effects and promising treatment uses of medical cannabis, 3,4-methylenedioxy-methamphetamine (MDMA), salvinorin A, ibogaine and the dimethyltryptamine-(DMT)-containing ayahuasca. In Hungary - similarly to many other countries - these compounds are classified as "narcotic drugs" and their research is difficult due to strict regulations.

Forbidden therapies: Santo Daime, ayahuasca, and the prohibition of entheogens in Western society

Santo Daime, a Brazilian religion organized around a potent psychoactive beverage called ayahuasca, is now being practiced across Europe and North America. Deeming ayahuasca a dangerous "hallucinogen," most Western governments prosecute people who participate in Santo Daime. On the contrary, members of Santo Daime (called "daimistas") consider ayahuasca a medicinal sacrament (or "entheogen"). Empirical studies corroborate daimistas' claim that entheogens are benign and can be beneficial when employed in controlled contexts. Following from anthropology's goal of rendering different cultural logics as mutually explicable, this article intercedes in a misunderstanding between policies of prohibition and an emergent subculture of entheogenic therapy.

Indigenous healing practice: ayahuasca. Opening a discussion

This essay frames an invitation to pastoral counselors and pastoral theologians to examine connections and perhaps interactions between themselves and traditional shamanic healers who use ayahuasca in their healing ceremonies. Indigenous people in South America have used ayahuasca for centuries, and the ritual has become common among the mestizo populations in urban areas of the Amazon, particularly as a curing ritual for drug addiction (Dobkin de Rios, 1970; Moir, 1998). Like peyote in the United States (Calabrese, 1997) ayahuasca use amongst the indigenous people of the Amazon is a form of cultural psychiatry. A review of the literature reveals very little commentary or discussion of shamanic practice in Pastoral Counseling (Pastoral Theology). The scant literature identifies an antithetical relationship at best. The current authors wonder about the possibility of to including shamanic practices in the context of pastoral counseling? This essay seeks to provide some basic information about the ritual use of ayahuasca and to offer a rationale for pastoral counselors to engage in a dialogue about its utility.

Banisteriopsis caapi, a unique combination of MAO inhibitory and antioxidative constituents for the activities relevant to neurodegenerative disorders and Parkinson's disease

AIM OF THE STUDY

Parkinson's disease is a neurological disorder mostly effecting the elder population of the world. Currently there is no definitive treatment or cure for this disease. Therefore, in this study the composition and constituents of the aqueous extract of Banisteriopsis caapi for monoamine oxidases (MAO) inhibitory and antioxidant activities were assessed, which are relevant to the prevention of neurological disorders, including Parkinsonism.

MATERIALS AND METHODS

The aqueous extract of Banisteriopsis caapi stems was standardized and then fractionated using reversed-phase (RP) chromatography. Pure compounds were isolated either by reversed-phase (RP) chromatography or centrifugal preparative TLC, using a Chromatotron. Structure elucidation was carried out by 1D and 2D NMR, Mass, IR and Circular Dichroism spectroscopy and chemical derivatization. Chemical profiling of the extract was carried out with RP-HPLC. The inhibitory activity of MAO-A, MAO-B, acetylcholinesterase, butyrylcholinesterase and catechol-O-methyl transferase enzymes, as well as antioxidant and cytotoxic activities of both Banisteriopsis caapi extract and isolated compounds was evaluated.

RESULTS

An examination of the aqueous extracts of Banisteriopsis caapi cultivar Da Vine yielded two new alkaloidal glycosides, named banistenoside A (1) and banistenoside B (2), containing "azepino[1,2-a]tetrahydro-beta-carboline" unique carbon framework. One additional new natural tetrahydronorharmine (4), four known beta-carbolines harmol (3), tetrahydroharmine (5), harmaline (6) and harmine (7), two known proanthocyanidines (-)-epicatechin (8) and (-)-procyanidin B2 (9), and a new disaccharide beta-d-fructofuranosyl-(2-->5)-fructopyranose (14) together with known sacharose (15) and beta-d-glucose (16) were also isolated. In addition, the acetates of 1, 2, 8, 9, 14 and 15 (compounds 10-13, 17, 18) were also prepared. Harmaline (6) and harmine (7) showed potent in vitro inhibitory activity against recombinant human brain monoamine oxidase (MAO)-A and -B enzymes (IC(50) 2.5 and 2.0 nM, and 25 and 20 microM, respectively), and (-)-epicatechin (8) and (-)-procyanidin B2 (9) showed potent antioxidant and moderate MAO-B inhibitory activities (IC(50)<0.13 and 0.57 microg/mL, and 65 and 35 microM). HPLC analysis revealed that most of the dominant chemical and bioactive markers (1, 2, 5, 7-9) were present in high concentrations in dried bark of large branch. Analysis of regular/commercial Banisteriopsis caapi dried stems showed a similar qualitative HPLC pattern, but relatively low content of dominant markers 1, 2, 7, and 9, which led to decreased MAO inhibitory and antioxidant potency.

CONCLUSION

Collectively, these results give additional basis to the existing claim of Banisteriopsis caapi stem extract for the treatment of Parkinsonism, including other neurodegenerative disorders.

Ayahuasca versus violence--a case report

We have limited resources available for the treatment and prevention of violent behavior. The usefulness of the most commonly used medications, namely the selective serotonin-reuptake inhibitor [SSRI] agents for the above purpose is a debated issue in the psychiatric literature. The aim of this case report is to add an ethnopharmacological perspective to the management of human aggression. Particularly, attention is called to the potential prosocial effect of the Amazonian beverage, ayahuasca--a decoctum, which has been used traditionally for multiple medico-religious purposes by numerous indigenous groups of the Upper Amazon--and has been found to be useful in crisis intervention, achieving redemption, as well as eliciting cathartic feelings with moral content.

Interview with Jeffrey Bronfman, representative mestre for the União do Vegetal Church in the United States. Interview by Marlene Dobkin de Rios and Charles S Grob

A telephone interview was held in November of 2004 with Mr. Jeffrey Bronfman, representative mestre for the União do Vegetal Church in the United States, which utilizes ayahuasca as a religious sacrament. At the time of this writing, the U.S. Supreme Court has agreed to hear a case in which a large quantity of the ayahuasca tea was seized in the U.S. destined for sacramental use in church ritual. Mr. Bronfman discusses his church's attempt to seek remediation in the courts on this freedom of religion issue, in conflict with current drug legislation outlawing the ayahuasca tea as a scheduled drug.

Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges

Ayahuasca is a hallucinogenic beverage that is prominent in the ethnomedicine and shamanism of indigenous Amazonian tribes. Its unique pharmacology depends on the oral activity of the hallucinogen, N,N-dimethyltryptamine (DMT), which results from inhibition of monoamine oxidase (MAO) by beta-carboline alkaloids. MAO is the enzyme that normally degrades DMT in the liver and gut. Ayahuasca has long been integrated into mestizo folk medicine in the northwest Amazon. In Brazil, it is used as a sacrament by several syncretic churches. Some of these organizations have incorporated in the United States. The recreational and religious use of ayahuasca in the United States, as well as "ayahuasca tourism" in the Amazon, is increasing. The current legal status of ayahuasca or its source plants in the United States is unclear, although DMT is a Schedule I controlled substance. One ayahuasca church has received favorable rulings in 2 federal courts in response to its petition to the Department of Justice for the right to use ayahuasca under the Religious Freedom Restoration Act. A biomedical study of one of the churches, the Uñiao do Vegetal (UDV), indicated that ayahuasca may have therapeutic applications for the treatment of alcoholism, substance abuse, and possibly other disorders. Clinical studies conducted in Spain have demonstrated that ayahuasca can be used safely in normal healthy adults, but have done little to clarify its potential therapeutic uses. Because of ayahuasca's ill-defined legal status and variable botanical and chemical composition, clinical investigations in the United States, ideally under an approved Investigational New Drug (IND) protocol, are complicated by both regulatory and methodological issues. This article provides an overview of ayahuasca and discusses some of the challenges that must be overcome before it can be clinically investigated in the United States.

Activities of extract and constituents of Banisteriopsis caapi relevant to parkinsonism

Dopamine deficiency is characteristic of Parkinson's disease (PD) and treatments aim at elevating levels by administration of its precursor L-dihydroxyphenylalanine (L-DOPA), or inhibiting monoamine oxidases (MAOs), thus preventing its breakdown. Reports of improvements in PD patients treated with Banisteriopsis caapi extracts stimulated investigation of B. caapi stem extract and its two ingredients, harmine and harmaline for these activities. Tests for MAO inhibition using liver homogenate showed that extract and harmaline showed a concentration-dependent inhibition of MAO A (IC(50) 1.24 microg/ml and IC(50) 4.54 nM, respectively) but had little effect on MAO B activity. The extract at 2.5 mg/ml caused a highly significant increase in release of [3H]dopamine from rat striatal slices, as did 200 microM harmine and 6 microM harmaline. In both these experiments, the amount of harmine present could not account for the total activity of the extract. The ability of harmine and harmaline to stimulate dopamine release is a novel finding. These results give some basis to the reputed usefulness of B. caapi stem extract in the treatment of PD.