Belladonna

The plant

Atropa bella-donna is a branching herbaceous perennial, often growing as a subshrub from a fleshy rootstock. Plants can reach a height of 2 m, more commonly 1.5 m, and have ovate leaves up to 18 cm long. The bell-shaped flowers are dull purple tinged yellow-green toward the base. The fruits are berries, green ripening to a shiny black and approximately 1.5 cm in diameter. The berries are sweet and are eaten by animals, mainly birds, that disperse the seeds in their droppings. A rare variant has pale-yellow flowers and pale yellow fruit. The plant is native to Europe and Western Asia, including Turkey, and extends from England in the west to western Ukraine and the Iranian province of Gilan in the east.

Chemistry and toxicity

All parts of the plant contain tropane alkaloids. The toxins include atropine, scopolamine and hyoscyamine, which cause delirium and hallucinations. By fresh weight, roots hold up to 1.3% tropane alkaloids, leaves 1.2%, stalks 0.65%, flowers 0.6%, ripe berries 0.7% and seeds 0.4%. The root is generally the most toxic part, though this can vary from one specimen to another. Deadly nightshade is one of the most toxic plants known. Ingestion of a leaf can be fatal to an adult. The berries pose the greatest danger to children because they look attractive and have a somewhat sweet taste. In 2009, an adult woman mistook belladonna berries for blueberries, and the six berries she ate were documented to result in severe anticholinergic syndrome. Symptoms of poisoning include dilated pupils, tachycardia, hallucinations, blurred vision, loss of balance, a feeling of flight and staggering. Many animals, such as rabbits, birds and deer, seem to eat the plant without suffering harmful effects, though dogs and cats are affected.

Name and uses

The common name belladonna originates from its historic use by women, as bella donna is Italian for beautiful woman. Belladonna drops act as a muscarinic antagonist, blocking receptors in the muscles of the eye that constrict pupil size. Belladonna is currently rarely used cosmetically, as it causes minor visual distortions, inability to focus on near objects, and increased heart rate. Prolonged usage was reputed to cause blindness. The plant is an important source of atropine, an effective treatment for the effects of poisoning by cholinesterase inhibitors. Atropine occurs naturally in a number of plants of the nightshade family, including deadly nightshade and jimsonweed.

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