belladonna

(bĕl'ə-dŏn'ə)

1. A poisonous Eurasian perennial herb (Atropa belladonna) having usually solitary, nodding, purplish-brown, bell-shaped flowers and glossy black berries. Also called deadly nightshade.
2. An alkaloidal extract or tincture derived from this plant and used in medicine.

[Italian : bella, feminine of bello, beautiful (from Latin bellus) + donna, lady; see Donna.]

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The drug and also the plant known as the deadly nightshade, Atropa belladonna, which belongs to the nightshade family (Solanaceae). This is a coarse, perennial herb native to the Mediterranean regions of Europe and Asia Minor, but now grown extensively in the United States, Europe, and India. During the blooming period, the leaves, flowering tops, and roots are collected and dried for use. The plant contains several important medicinal alkaloids, the chief one being atropine, which is much used to dilate the pupil of the eye. See also Atropine; Solanales.

The poisonous substance extracted from deadly nightshade (Atropa belladonna) and from which the drug atropine is obtained. Atropine has powerful effects on the parasympathetic nervous system, blocking nerve transmissions. With the parasympathetic nervous system out of action, the sympathetic system is left to function unopposed. Thus, atropine mimics some of the stimulatory actions of the sympathetic nervous system and adrenaline. Small doses cause the heart rate to increase. Atropine is used in some cough mixtures for the treatment of bronchitis and whooping cough. It is also used to dilate the pupils for eye examination, relieve peptic ulcers, and to relax the smooth muscle of the intestines and stomach before a general anaesthetic.

The poisonous substance obtained from deadly nightshade (Atropa belladonna) from which atropine is obtained.

n.

In Italian a beautiful lady; in English a deadly poison. A striking example of the essential identity of the two tongues.

Atropa belladonna (deadly nightshade), a plant that is the source of various alkaloids, e.g. atropine, hyoscyamine, etc.

• b. leaf — the dried leaves and fruiting tops of Atropa belladonna, used as an anticholinergic in the management of gastrointestinal disorders.
• b. poisoning — a severe toxic condition due to overdosage of belladonna or accidental ingestion of large amounts of the drug. Signs include dryness of the mouth, thirst, dilated pupils, tachycardia, fever and stupor.

• Herbaceous Plants
• PHARMACOLOGY - belladonna: atropine
• Drug Names and Forms - belladonna: psychoactive depressant derived from deadly nightshade