1928 – The Banisterine Experiments of Pharmacologist Louis Lewin
Louis Lewin, a German pharmacologist who devoted his career to exploring the pharmacological effects of psychoactive plants and drugs, explored the properties of the ayahuasca vine Banisteriopsis caapi, from which he extracted an alkaloid that he called “banisterine”. Following experiments on animals and humans, he noted that banisterine produced an initial stimulation of the nervous system, to be followed, especially at high doses, by a marked depression.
Lewin was later informed by the German chemists of the pharmaceutical company Merck that banisterine was chemically identical to harmine, an alkaloid that had been isolated 87 years earlier from Peganum harmala. Initially, Lewin did not fully agree with this identification, and agreed only on the related properties of these two compounds to increase motor excitability to convulsions.
The urgency to clarify the formula of banisterine was due to the fact that, had it actually turned out to be identical to harmine, the latter would have been more available, since its Eurasian vegetable source – Peganum harmala – is much more common in Europe than the non-native Banisteriopsis caapi vine.
Meanwhile, J.A. Gunn, professor of pharmacology at the University of Oxford and a devoted researcher of harmala alkaloids, harmine and harmaline, had experimented with harmine on animals, thus having the opportunity to observe the strong correspondence of the pharmacological characteristics of harmine with those of banisterine. This definitely convinced Louis Lewin of the identity of the two compounds.
During the same decade, the harmala compounds then began being tested as potential Parkinson’s Disease medicines. In 1957, it was discovered that harmala alkaloid exist in the Amazonian brew ayahuasca. Then in the 1980s, its was confirmed that the alkaloids allowed the powerful psychedelic compound DMT entry to the blood stream when consumed at the same time as the ayahuasca vine.
Gunn J.A., (1929), A note on banisterine or harmine, Lancet:769-770.
Lewin Louis, (1928), Untersuchungen über Banisteria Caapi Spr., Archiv für Experimental Pathologie und Pharmacologie, 129: 133-49.