In the mid-19th century, the calabar bean was used in its native West Africa to bring about divine judgments: If the suspected criminal died from the bean being offered, he was guilty of the crime; if he survived and vomited, it was taken as proof of his innocence. The seeds of the calabar bean are the only poisonous parts of the climbing plant.
Occurrence and cultivation of the calabar bean.
Originally, the plant was found only in West Africa. From there, it made its way to India and Brazil. The calabar bean prefers locations on riverbanks and sometimes grows directly in the water. Calabar bean (Physostigma venenosum) is also called God’s verdict bean, because in the past it was used to find out whether a person was guilty of a certain crime or not. The perennial climbing plant with poisonous beans belongs to the legume family (Faboideae). It forms lianas about 15 meters long, five centimeters in diameter, woody at the base and herbaceous higher up. Its stem leaves have an oval, pointed shape and are about 15 centimeters long. The plant’s inflorescences hang down the side of the liana, stalked. Its dark purple flowers are curled up like a snail. The thick brown legumes of the calabar bean can grow up to 15 centimeters long and contain two or three kidney-shaped dark brown shiny seeds each. Originally, the plant was found only in West Africa. From there, it made its way to India and Brazil. The calabar bean prefers locations on riverbanks and sometimes grows directly in water. It also climbs rainforest trees.
Effect and application
The plant with poisonous seeds contains as its main active ingredient the alkaloid physostigmine (eserine), which was first isolated from the bean in 1864. It also contains essential oils, mucilages, resins, dodecanoic acid, linoleic, oleum, palmitic and stearic acid, potash. Furthermore, it contains the secondary alkaloids geneserin (0.1 percent), physovenin (0.1 percent), eseramin, calabarin, calabacin, calabarol, beta-sitosterol, stigmasterol, trifolianol, 48 percent starch, 23 percent proteins and 2.3 percent fats. Physostigmine and calabrin have a similar toxicity to strychnine and are found almost exclusively in the cotyledons of the bean. For reasons of high toxicity, only standardized finished preparations and homeopathic medicines containing the active ingredients are used today. In the past, physostigmine was used subcutaneously as an injection in extremely low doses and as a powder in eye treatment. The active ingredient causes constriction of the pupils (miosis) in pathologically dilated pupils and is also used as an antidote in atropine poisoning. As an acetylcholinesterase inhibitor, it has a cholinergic effect and stimulates the parasympathetic nervous system, resulting in increased muscle activity. Since the odorless, tasteless, and colorless active ingredient can also pass the blood–brain barrier, it ensures in the brain that the nerve messenger acetylcholine is not broken down by the enzyme. In higher doses, it causes a reduced heart rate, stimulates salivation, paralyzes the respiratory tract, constricts the pupils, and stimulates intestinal peristalsis in cases of intestinal weakness. In a dose of six to ten mg, physostigmine is lethal. This amount is contained in two to three calabar beans. In an administration of more than one milligram, the following side effects may occur when applied externally (for example, during eye treatment): Palpitations, sweating, muscle cramps and severe malaise. As a result, inflammation of the respiratory tract and eyes and hoarseness may occur. In case of severe physostigmine poisoning, which can cause death by respiratory paralysis, the patient must receive immediate intensive medical treatment. His stomach is flushed. He is given atropine as an antidote, activated charcoal, and sodium sulfate as needed. Diazepam helps against the cramps. Calabar bean remedies should not be used in bronchial asthma, gangrene, coronary heart disease, urinary and intestinal obstruction. In addition, pregnant women, nursing mothers, children and adolescents, as well as people with hypersensitivity to the active ingredient should not consume the remedy. If the drug is used with other cholinesterase inhibitors, an increase in effect occurs.
Health significance, treatment, and prevention.
The active ingredients of calabar bean are a proven antidote for atropine and curare poisoning.In very low doses (0.12 to 0.24 grams), they used to be used in the treatment of intestinal colic, glaucoma (glaucoma), neuralgia (especially trigeminal neuralgia), epilepsy, constipation, tetanus, paralysis (especially paralysis of the extremities caused by myelitis and progressive paralysis), chorea minor, locomotor ataxia, and hypertension. Physostigmine was used locally for eye diseases. Today, the remedy is administered homeopathically in the form of globules, dilution and tablets (teep), as it is well tolerated in this form. The application profile is similar to that of earlier times. The doctor or veterinarian uses it to eliminate fecal congestion with flatulence caused by intestinal weakness. In veterinary medicine, it is administered subcutaneously as a laxative for intestinal colic and flatulence. When the eyes are examined, pupil dilation caused by atropine is reversed. To prevent the physostigmine from entering the body, the doctor compresses the lacrimal duct on the lower eyelid. In ophthalmology, physostigmine sulfate is used as Eserinum sulfuricum in alternation with Euphrasia for mydriasis (pupil dilation), keratitis, iritis, iris prolapse, and corneal ulcers. Contrary to earlier practice, the calabar bean active ingredient is not used to treat glaucoma: its pupil-constricting and intraocular pressure-reducing effects do not last long enough to produce lasting health improvement in the patient. For internal use, the homeopath prescribes mother tincture and teep. The patient takes one tablet of these two to three times a day. To reduce blood sugar levels in diabetes and for Parkinson’s treatment, a dose of three level teaspoons in potency D2 is necessary.
