Physostigma venenosum, Calabar bean, physostigma, ordeal bean, chop nut

Physostigma venenosum with many common names including Calabar bean, physostigma, ordeal bean, chop nut, esere nut, faba calabarica, Fève of Calabar, Jewish de l’Ordalie, Legume and Physostigma is a large, evergreen climbing perennial native to West Africa, especially southeastern Nigeria and is cultivated in India and parts of South America. It is a dark brown, kidney-shaped seed of a leguminous plant often considered poisonous to humans. It derives the first part of its scientific name from a curious beak-like appendage at the end of the stigma, in the center of the flower; this appendage, though solid, was supposed to be hollow (hence the name from φῦσα, a bladder, and stigma). Seeds are toxic to humans and prove fatal most of the time.

Plant Description

Calabar bean is a large, evergreen, herbaceous, scrambling or climbing perennial with the stem woody at the base, up to 2 inches (5 cm) in diameter. The plant is found growing in closed rain-forests, primary and secondary, dry and wet; riparian seasonally flooded forest and marshes. The plant has a habit like the scarlet runner, and attains a height of about 50 feet (15 m) climbing high among the trees. The plant has large, pinnate, trifoliate leaves. The flowers, resting on axillary peduncles, are large, about an inch long, grouped in pendulous, fascicled racemes pale-pink or purplish, and beautifully veined. The fruit is a dark brown pod that grows to about 6 or 7 inches (15 or 18 cm) in length. Each pod contains from 2 to 3 seeds. The dark brown or blackish kidney-shaped seeds are about 2.5 cm long and have an extremely hard shell. They are rounded at the ends, uneven and somewhat polished with the hilum extending along the whole convex side. The cotyledons are whitish.

History

This plant is native to an area of Africa around Nigeria once known as Calabar. The plant is widely known in Africa because the seeds had been used as an “ordeal poison” to determine if a person was a witch or controlled by evil spirits. When used for this purpose, the victim was made to ingest several beans; if the person vomited the beans and survived the “ordeal,” his innocence was declared. Western settlers who were captured by native tribes and who underwent the “ordeal” soon learned not to chew the bean, but to swallow the kidney-shaped bean intact, thus not permitting the release of the toxic constituents. The plant has been long recognized as a commercial source of the alkaloid physostigmine, first isolated in 1864.

Traditional uses and benefits of Calabar bean

• It is also used as a stimulant to the unstriped muscles of the intestines in chronic? constipation?.
• It is a narcotic herb that depresses the central nervous system, mimics the para-sympathetic nervous system, contracts the pupil of the eye, raises blood pressure and stimulates peristalsis.
• It is used in eye drops to reduce pressure on the eyeball in treating conditions such as glaucoma.
• It is also recommended for internal use in the treatment of neuromuscular diseases, especially myasthenia gravis, and for treating post-operative constipation?.
• It has been used in the treatment of conditions such as tetanus, epilepsy and rheumatism.
• It has also been used as internal medications in the treatment of certain kinds of nervous complaints.
• It is used in treating retinitis accompanying problems like photophobia.
• It is used to treat photophobia accompanied by strumous ophthalmia.
• It is used to treat granular and irritable lids.
• It is used in the treatment of ulceration along the margins of the cornea.
• It is used in the treatment of prolapsus affecting the iris.
• Calabar bean is being studied as a treatment for Alzheimer’s disease.
• It is used to treat related disorder symptoms such as muscle soreness and pain? in the head or upper neck. সহজ বাংলা: মাথাব্যথা।" data-rx-term="headache" data-rx-definition="Headache means pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।">headache?.
• It is useful in tympanities and flatulence that may be present during menopause.
• It is used for its depressant action in anxiety, epilepsy and cholera.
• It is also used to treat myasthenia gravis.
• It helps in treating emphysema and in asthma with great muscular relaxation.
• It increases the contractility of the muscles of the bladder and uterus walls.
• It is use in the treatment of Alzheimer’s disease to reduce memory loss.

Usual dose for calabar bean

The dose for calabar bean may be different for every patient. The dose that you take depends on your age, health, and several other conditions. Herbs are not always safe. Please discuss with your herbalist or doctor for your appropriate dosage?. Since the herb is considered toxic used very carefully and minor doses.

Precautions

• When used in excess, it causes muscular weakness?, respiratory failure and cardiac arrest.
• Calabar bean can cause excess saliva and sweat, reducing the size of the pupil of the eye, nausea?, vomiting?, diarrhea? beats irregular heart, changes in blood pressure, confusion, convulsions, coma, severe muscle weakness?, paralysis, severe breathing problems and death.
• Avoid calabar bean if you are pregnant or breast-feeding.
• Avoid calabar bean if you have Parkinson’s disease.
• Avoid calabar bean if you have heart disease or slow heartbeat.
• Avoid calabar bean if you have blockage of the intestinal tract.
• Lethal doses can cause muscle twitching, spasms, tachycardia? and cyanosis? through asphyxiation.

References