Alcaloides e o chá de ayahuasca: uma correlação dos "estados alterados da consciência" induzido por alucinógenos / Alkaloids and ayahuasca tea: a correlation of hallucinogen-induced "altered states of consciousness"

Dentre as inúmeras plantas alucinógenas utilizadas por populações indígenas da bacia amazônica, talvez nenhuma delas seja mais interessante ou complexa em termos botânicos, químicos ou etnográficos, como a bebida alucinógena conhecida como ayahuasca, hoasca, medicina, vegetal ou daime. Ayahuasca é bebida psicotrópica da América do Sul de destacado uso no xamanismo de muitas tribos indígenas da Amazônia, obtida pela fervura da casca do cipó de Banisteriopis caapi com a mistura de folhas de Psycotria, principalmente P. viridis. No Brasil, ocupa posição de destaque na etnomedicina. A natureza química dos compostos ativos, bem como, a maneira de utilização faz com que essa bebida ocupe posição de destaque nos atuais estudos da neurofarmacologia, neurofisiologia e psiquiatria. Alucinógenos e substâncias relacionadas constituem poderosa base experimental para investigar a correlação biológica dos estados alterados de consciência. O estudo de alucinógenos em humanos é de suma importância porque as substâncias com essas propriedades afetam certas funções cerebrais que tipicamente caracterizam a mente humana, incluindo a cognição, volição, ego e auto-percepção. As várias manifestações dos "desequilíbrios do ego" são especialmente características psicodélicas proeminentes, que acabam naturalmente criando psicoses. Sumarizamos nessa revisão alguns aspectos importantes no estudo do chá de ayahuasca em humanos, as indicações e contra-indicações para fins terapêuticos e religiosos.

Among the numerous hallucinogenic plants utilized by indigenous populations of the Amazon Basin, perhaps none is as interesting or complex in terms of botany, chemistry or ethnography as the hallucinogenic beverage known as ayahuasca, hoasca, medicine, vegetable or daime. Ayahuasca is a South American psychotropic beverage that is prominent in the shamanism of many indigenous Amazonian tribes and is obtained by boiling the bark of the liana Banisteriopsis caapi together with the mixture of leaves of Psychotria, principally P. viridis. In Brazil, it occupies a central position in ethnomedicine. The chemical nature of its active constituents and the manner of its use makes it relevant to contemporary studies in neuropharmacology, neurophysiology, and psychiatry. Hallucinogens and related substances constitute a powerful experimental basis to investigate the biological correlation of altered states of consciousness. The study of hallucinogens in humans is important because these substances affect a number of brain functions that typically characterize the human mind, including cognition, volition, ego, and self-consciousness. The several manifestations of "ego disorders" are especially prominent psychedelic features that naturally lead to psychoses. In the present review, we summarize some of the important aspects in the study of ayahuasca tea in humans, its indications and contraindications for therapeutic and religious purposes.

Role of H2O2 and cell wall monoamine oxidases in germination of Vigna radiata seeds.

Plant cell wall expresses monoamine oxidases (MAOs) that catalyze oxidation of secreted amines and produce H2O2 in the process. The H2O2, so produced is used by cell wall peroxidases for lignification of cell wall or for plant defense. The natural substrates for these MAOs are elusive, but polyamines and certain catecholamines have been proposed as candidates. Reactive oxygen species are also known to act as signaling molecules controlling plant metabolism. Mungbean (Vigna radiata) has long served as the plant model of choice while studying molecular programs followed during germination and seed development. In this study, we tested the effect of externally added MAO substrates epinephrine and H2O2 on storage protein mobilization in germinating seeds of Vigna radiata. The seeds were imbibed in the presence of 50 M epinephrine and 10 M H2O2. These low concentrations of the two compounds were used to exclude direct effects on proteolysis and were arrived at after testing a range of the two and choosing the most effective concentration. These seeds showed 11% and 7% decrease in fresh weight respectively, indicating greater storage mobilization and a corresponding 19% and 46% increase in axis length as compared to untreated seeds. Soluble protein in seeds treated with epinephrine and H2O2 decreased significantly by 34% and 33% as compared to untreated seeds. Electrophoretic analysis of seed proteins revealed a startling and selective depletion of storage proteins in treated seeds. The results indicated a clear involvement of H2O2 in storage protein mobilization in the cotyledons. We propose that H2O2 generated within cell walls of seeds serves as a signaling molecule guiding germination events, including protein reserve mobilization.