Beyond the Psychoactive Effects of Ayahuasca: Cultural and Pharmacological Relevance of Its Emetic and Purging Properties.

The herbal preparation ayahuasca has been an important part of ritual and healing practices, deployed to access invisible worlds in several indigenous groups in the Amazon basin and among mestizo populations of South America. The preparation is usually known to be composed of two main plants, Banisteriopsis caapi and Psychotria viridis, which produce both hallucinogenic and potent purging and emetic effects; currently, these are considered its major pharmacological activities. In recent decades, the psychoactive and visionary effect of ayahuasca has been highly sought after by the shamanic tourism community, which led to the popularization of ayahuasca use globally and to a cultural distancing from its traditional cosmological meanings, including that of purging and emesis. Further, the field of ethnobotany and ethnopharmacology has also produced relatively limited data linking the phytochemical diversity of ayahuasca with the different degrees of its purging and emetic versus psychoactive effects. Similarly, scientific interest has also principally addressed the psychological and mental health effects of ayahuasca, overlooking the cultural and pharmacological importance of the purging and emetic activity. The aim of this review is therefore to shed light on the understudied purging and emetic effect of ayahuasca herbal preparation. It firstly focuses on reviewing the cultural relevance of emesis and purging in the context of Amazonian traditions. Secondly, on the basis of the main known phytochemicals described in the ayahuasca formula, a comprehensive pharmacological evaluation of their emetic and purging properties is presented.

Evaluating herbal medicine preparation from a traditional perspective: insights from an ethnopharmaceutical survey in the Peruvian Amazon.

The field of medical ethnobotany has historically contributed to the advancement of modern pharmaceutical and biomedical science through bringing discoveries from the field into the laboratory. In ethnopharmacology, a sub-field of ethnobotany, there is a concerning lack of ethnographic methods reported in the literature. The ethnographic approach is essential for detailing traditional methods of preparation and administration of plant medicines, yet pharmaceutical researchers overemphasize western epistemologies of medicinal discovery and production. In the present work, we propose an ethnopharmaceutical survey as a model to investigate the culturally recognized standards necessary for the formulation of herbal medicines. Fieldwork based on participant observation and semi-structured interviews examined the modes of preparation employed by traditional healers in the Amazonian region of San Martín, Peru. The authors draw on anthropological insight into plural epistemological encounters and propose an ethnopharmaceutical approach that takes seriously the Amazonian methods and perceptions for the preparation of traditional plant medicines.