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 β-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.

Existem poucos dados disponíveis sobre as propriedades farmacológicas da Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), nativa da região do pantanal brasileiro. O presente estudo investigou o efeito do tratamento oral com um extrato de H. aphrodisiaca (BST0298) sobre a memória e aprendizagem de ratos jovens (3-6 meses) e idosos (21-23 meses) e comparou a atividade antioxidante in vitro de três lotes, coletados em diferentes anos. Melhora quanto ao número de sessões necessárias para aprender a tarefa foi observada no teste de discriminação direita/esquerda em ratos idosos tratados por 45 dias com doses de 25 mg/kg (7,0 ± 0,5; p=0,005) e 50 mg/kg (7,6 ± 0,6; p=0,012) comparados com ratos idosos controle (11,0 ± 1,6). Por outro lado, o pré-tratamento com o extrato não melhorou o desempenho de camundongos tratados com escopolamina no teste da esquiva passiva. Em relação à avaliação da atividade antioxidante in vitro pelo teste do malonodialdeído, os três lotes analisados apresentaram atividade antioxidante semelhante. Os flavonóides astilbina, isoastilbina e neoastilbina foram isolados do extrato e podem contribuir para a atividade biológica. Estes resultados sugerem que a administração repetida de H. aphrodisiaca melhora a memória e aprendizagem provavelmente por um mecanismo não muscarínico.

Few data exists about the pharmacological properties of Heteropterys aphrodisiaca O. Mach. (Malpighiaceae), which is native to the scrubland regions of Brazil. The present study investigated the effects of oral treatment with H. aphrodisiaca extract (BST0298) on the learning and memory of young (3-6 months) and aged (21-23 months) rats, and compared the in vitro antioxidant activity of three lots collected in different years. An improvement in the number of sessions to learn the task was observed in the left/right discrimination test in aged rats treated for 45 days with 25 mg/kg (7.0 ± 0.5; p=0.005) or 50 mg/kg (7.6 ± 0.6; p=0.012) compared with control old rats (11.0 ± 1.6). On the other hand, pre-treatment did not improve the performance of scopolamine-treated mice in the passive avoidance test. The in vitro malondialdehyde test showed that all three different extracts presented similar antioxidant activity. The flavonoids astilbin, isoastilbin and neoastilbin were isolated from the extract and may contribute to the biological activity. These results suggest that repeated treatment with H. aphrodisiaca improves learning and memory, probably by a non-muscarinic mechanism.