Skip to content

Mauricio Yonamine

Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo (USP), São Paulo, Brazil.

10 papers in the library · 86 citations · publishing 0-2026

Papers

Ayahuasca Pretreatment Prevents Sepsis-Induced Anxiety-Like Behavior, Neuroinflammation, and Oxidative Stress, and Increases Brain-Derived Neurotrophic Factor.

Molecular neurobiology May 1, 2025 Rick Wilhiam de Camargo, Larissa Joaquim, Richard Simon Machado et al. 13 citations

Pretreatment with the psychoactive decoction Ayahuasca (AYA) for three days before inducing sepsis in rats reduced anxiety-like behaviors and neuroinflammation. AYA increased time spent in the open arms of an elevated plus maze and prevented excessive grooming and rearing, indicating anxiolytic effects. It raised levels of the anti-inflammatory cytokine interleukin-4 in the prefrontal cortex and cortex and brain-derived neurotrophic factor in the cortex. AYA also increased myeloperoxidase activity in the prefrontal cortex and hippocampus while decreasing nitrite/nitrate concentrations across multiple brain regions, suggesting enhanced neutrophil activation and reduced nitric oxide signaling. Additionally, AYA prevented lipid peroxidation in the prefrontal cortex, hippocampus, and cortex. These findings suggest AYA may protect against sepsis-induced neuroinflammation, oxidative stress, and anxiety-like symptoms.

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

Journal of ethnopharmacology February 10, 2024 Tiago Arruda Sanchez, Lucas Rego Ramos, Felipe Araujo et al. 12 citations

Ayahuasca, a traditional Amazonian beverage, attenuates brain activity in the amygdala—a region central to fear processing—when people view aversive (fearful or disgusted) faces, while enhancing activation in the insular cortex and right dorsolateral prefrontal cortex. Nineteen experienced male users underwent fMRI before and 50 minutes after ingesting ayahuasca. Self-reported anxiety and mental sedation also decreased. The findings suggest ayahuasca may promote emotion regulation in response to negative stimuli, with corresponding improvements in cognition.

Fast Hollow Fiber Liquid-Phase Microextraction as a Greener Alternative for the Determination of N,N-Dimethyltryptamine and Harmala Alkaloids in Human Urine.

Frontiers in chemistry January 1, 2020 Gabriela de Oliveira Silveira, Felipe Rebello Lourenço, Vitor Bruno et al. 12 citations

A greener, faster method using hollow fiber liquid-phase microextraction (HF-LPME) and LC-MS/MS was developed to measure DMT and three harmala alkaloids in human urine. The method avoids large amounts of toxic solvents. It detects DMT at 1.0 ng/ml and harmala alkaloids at 2.0 ng/ml, with a quantifiable range of 5-200 ng/ml. Precision, accuracy, and recovery (above 80%) met acceptance criteria. Analysis of urine from four subjects confirmed the method's feasibility. The approach offers a simple, time-saving alternative for studying ayahuasca components in biological samples.

Interactive Effects of Ayahuasca and Cannabidiol in Social Cognition in Healthy Volunteers: A Pilot, Proof-of-Concept, Feasibility, Randomized-Controlled Trial.

Journal of clinical psychopharmacology Giordano Novak Rossi, Juliana Mendes Rocha, Flávia L Osório et al. 12 citations

In a small preliminary trial, ayahuasca—with or without a 600 mg dose of cannabidiol (CBD) given 90 minutes beforehand—did not produce interactive effects on emotion recognition or empathy tasks. Both groups showed faster reaction times on these tasks and reported reduced anxiety, sedation, and discomfort, but there were no differences between the group that received CBD and the one that did not. Ayahuasca was well tolerated, causing mainly nausea and gastrointestinal discomfort, with no clinically significant changes in heart or liver measures. The safety of the combination suggests that both drugs could be tested in larger trials for anxiety disorders.

Long-term ayahuasca use is associated with preserved global cognitive function and improved memory: a cross-sectional study with ritual users.

European archives of psychiatry and clinical neuroscience March 1, 2025 Arilton Martins Fonseca, Rafael Guimarães Dos Santos, Lívia Soman de Medeiros et al. 10 citations

Long-term ritualistic ayahuasca use, spanning over 20 years, does not impair cognition and may be linked to better working memory compared to short-term use. In a study of 48 participants from a Santo Daime church in Brazil, experienced users (over 20 years) scored higher on tests of verbal and visuospatial working memory than beginners (under 3 years). No evidence of cognitive decline was found among ayahuasca users. The control group, matched by sex, age, and education, showed similar cognitive performance. The brew's botanical identities and alkaloid content were confirmed.

Lucy is back in Brazil with a new dress.

Forensic science international December 1, 2022 Luiz Ferreira Neves Junior, André Luis Fabris, Ingrid Lopes Barbosa et al. 10 citations

LSD prodrugs are emerging as new psychoactive substances in Brazil. Nine blotter paper samples seized by police in São Paulo State were analyzed using gas chromatography-mass spectrometry, infrared spectroscopy, and liquid chromatography-mass spectrometry. The compound was identified as ALD-52 (1A-LSD), an LSD prodrug not controlled by Brazilian legislation, with no other active substances detected. These findings indicate a rising strategy in the designer drug market that warrants attention.

Solvent-free parallel artificial liquid membrane extraction for drugs of abuse in plasma samples using LC-MS/MS.

Analytica chimica acta May 1, 2024 André Luis Fabris, Stig Pedersen-Bjergaard, Elisabeth Leere Øiestad et al. 9 citations

A 96-well plate extraction method called parallel artificial liquid membrane extraction (PALME) can be made greener by replacing organic solvents with an essential oil. Fourteen essential oils were tested; the blend smart & sassy gave the best recovery for multiple drugs of abuse in plasma, including amphetamines, synthetic cathinones, and designer benzodiazepines. After optimization, the method achieved a linear range of 1-100 ng/mL, accuracy within ±16.4%, and limits of detection between 0.1 and 0.75 ng/mL. The technique eliminated hazardous organic solvents, provided effective sample clean-up, and met international validation guidelines, offering a sustainable tool for toxicological analysis.

Effects of a Single Dose of Ayahuasca in College Students With Harmful Alcohol Use: A Single-blind, Feasibility, Proof-of-Concept Trial.

Journal of clinical psychopharmacology Lucas Silva Rodrigues, José Augusto Silva Reis, Giordano Novak Rossi et al. 8 citations

A single dose of ayahuasca, a plant hallucinogen containing N,N-dimethyltryptamine and harmine, was given with psychological support to 11 college students who drank alcohol harmfully. The treatment was well tolerated and produced strong psychoactive effects. Days of alcohol consumption per week dropped from about 2.9 to 2.1 between weeks 2 and 3, but this reduction was not statistically significant after correcting for multiple comparisons. No other measures—craving, anxiety, impulsivity, self-esteem, or social cognition—showed significant changes, except faster reaction time on an empathy task. The small sample and mild baseline drinking likely limited the findings. The study demonstrates the protocol is feasible for future larger trials.

Single Ayahuasca administration attenuates alcohol relapse and associated behavioral, neurochemical, and oxidative alterations in rats

Progress in Neuro-Psychopharmacology and Biological Psychiatry July 1, 2026 Guilherme Lodetti, Rafael Mariano de Bitencourt, Antonio Inserra et al.

A single dose of Ayahuasca reduced relapse-like alcohol drinking in alcohol-dependent rats, with effects varying by sex and alcohol concentration. It also lessened anxiety- and depression-like behaviors caused by alcohol withdrawal, increased dopamine in the striatum of both male and female rats, and restored serotonin levels in the cortex primarily in males. Ayahuasca partially reversed alcohol-related drops in brain-derived neurotrophic factor and reduced markers of oxidative stress in the frontal cortex, hippocampus, and striatum. However, antioxidant enzyme activities were not consistently altered, and some neurochemical and oxidative stress measures showed only partial normalization. The findings suggest Ayahuasca modulates multiple neurobiological pathways disrupted by chronic alcohol exposure, with region- and sex-dependent effects.

A dispersive liquid-liquid microextraction method for the determination of ayahuasca alkaloids (N,N-dimethyltryptamine and β-carbolines) in human hair.

Talanta January 27, 2026 Fabiana Pereira Santos, Beatriz Aparecida Passos Bismara Paranhos, Thaisa Meira Sandini et al.

A greener analytical method using dispersive liquid-liquid microextraction and LC-MS/MS was developed to measure N,N-dimethyltryptamine (DMT) and three β-carbolines (harmine, harmaline, tetrahydroharmine) in human hair. The method was sensitive, with limits of quantification from 3 to 8 pg/mg, and linear up to 1000 pg/mg. Recovery was low (36-58%), but selectivity showed no interference. Applied to six real samples, DMT concentrations ranged from 21.5 to 204.4 pg/mg, while β-carbolines were generally higher, with harmine reaching over 1000 pg/mg. The method uses less organic solvent than conventional hair extraction, advancing green analytical toxicology for psychoactive alkaloids.