Potential Risks of Plant Constituents in Dietary Supplements: Qualitative and Quantitative Analysis of Peganum harmala Seeds

The illegal online trade of Peganum harmala seeds, which contain monoamine oxidase (MAO) inhibiting alkaloids used in hallucinogenic preparations like ayahuasca, poses forensic and safety challenges. This work demonstrates two complementary identification methods: optical and electron microscopy for visual seed identification, and a real-time qPCR test that detects P. harmala DNA with species specificity down to less than 1 picogram. The qPCR assay accurately quantifies the presence of P. harmala seeds or seed fragments in complex herbal mixtures, providing a reliable indication of a product's potential danger.

Study at a glance

Abstract

The free online trading of herbal mixtures useful for various purposes facilitates the circulation of dangerous herbs or plant parts. This is the case, for example, of the illegal trade in seeds of Peganum harmala (Pgh), which contain alkaloids capable of inhibiting monoamine oxidase (MAO) and are therefore used in hallucinogenic preparations, such as the psychedelic drink ayahuasca. The precise identification of these seeds and their distinction from other very similar but not dangerous seeds are necessary for forensic purposes and represents an advance in avoiding the adulteration of mixtures. In this work, we show the qualitative identification of Pgh seeds by optical and electron microscopy and the parallel development of a real-time qPCR test, which reveals, in a species-specific manner, the presence of Pgh DNA up to quantities lower than 1 pg. In addition to the species specificity and high sensitivity, the reaction accurately quantifies the presence of seeds or parts of seeds of Pgh in complex herbal mixtures, thus giving an indication of the danger or otherwise of the product.