On Banisterine, an Intoxicating Substance from Banisteria Caapi

On an intoxicating substance, banisterine, extracted from Banisteria Caapi

Note by Louis Lewin.

A South American plant, little known and not yet studied from a chemical and toxicological point of view, adds an interesting new member to the list of narcotic and stimulant principles. It is the liana Banisteria Caapi, of the family Malpighiaceae — a family in which no species of pronounced, even narcotic, toxicity had previously been recognized.

It grows wild or cultivated from the Orinoco to the Rio Negro and the Cordilleras, across a vast territory that takes in parts of Colombia, Ecuador, Peru, southern Venezuela, western British Guiana, Brazil, and so on. In these countries, very diverse tribes use Banisteria Caapi as an intoxicant alongside tobacco, alcoholic drinks, and on occasion coca. By boiling and filtering the shredded, pulverized wood of the liana for seven or eight hours, they brew a potion drunk not only at communal festivals but also in private households. As much as a liter is sometimes consumed. It is said that this drink causes a trance state in which the drinker experiences agreeable and novel sensations. Ordinarily only men drink it; some tribes forbid it to women altogether. Two minutes after ingestion the Indian is seen to turn pale, tremble in every limb, sweat heavily, and fall into a violent fury. This excitation, lasting about ten minutes and accompanied by shouting, dancing, and perhaps cramps, is followed by exhaustion and a dreaming narcosis. At first one feels alternating sensations of heat and cold, with hallucinations and multiform visions and phantoms.

The active principle of Banisteria Caapi, banisterine, can be obtained in crystallized form, as prisms.

Its composition is as follows: C₁₃H₁₂ON₂. The melting point of the free base is 256°–257°; the hydrochloride melts at 264° while decomposing. According to Merck, this alkaloid is identical to harmine, extracted from Peganum Harmala. Pure sulfuric acid dissolves banisterine hydrochloride, producing a green fluorescence that soon disappears. After a few hours the colorless solution turns slightly violet.

The experiments I carried out on cold- and warm-blooded animals — including monkeys — showed without exception strong motor excitation accompanied by increased reflexes. Above all one notes tremors, which appear as early as 3–10 minutes and persist for up to two hours. Dogs fell into such a state of exasperation that they seemed rabid, and would have been killed had the cause of their condition not been known. To my knowledge, harmine does not produce comparable effects.

The men on whom I performed the experiment felt, after an injection of 0.02–0.07 g, a sensation of warmth and heaviness in the head and general lassitude. A woman suffering from hemiplegia had a spontaneous sensation of lightness; after the second injection she believed she could walk better and asked for a third. Professor Wilmans and Mr. Beringer carried out more extensive experiments. They found that banisterine slows the pulse, something I had already observed in animals and which may be of interest for the therapy of heart disease. But above all, persons suffering from an inflammation of the brain (encephalitis lethargica), the so-called cerebral influenza, felt better and lighter when treated with banisterine. The rigidity of the muscles, the most conspicuous symptom of this disease, diminished. Gait became freer and speech more distinct. At 0.04 g the rigidity nearly disappeared entirely. The remedies used up to now fall far short of banisterine.

It is not yet possible to specify the therapeutic applications of banisterine. It is likely that its use will meet with some success in certain paralyses.

[Author's footnote in the original:] Mr. R. Hamet has studied some of the properties of Banisteria Caapi (Comptes rendus, 184, 1927, p. 1266).

--- Translator's note: prepared for the archive from the French original; a careful working translation that has not yet been checked by a specialist reader.