Bittersweet Nightshade

Scientific Name(S): Solanum dulcamara L. Family: Solanaceae

Common Name(S): Bittersweet nightshade, deadly nightshade, bittersweet, bitter nightshade, felonwort, violet-bloom, woody nightshade, fellen, scarlet berry, snake berry, mortal, fever twig, dulcamara

Bittersweet Nightshade is an herbal medicine used to treat a skin problem called eczema.

Botany: The bittersweet is a member of the same family as the potato and tomato. A number of members of the genus have been identified. This plant is found throughout Eurasia, the United States and Canada. Bittersweet is a vine-like perennial that grows to heights of 10 feet. It has alternating heart-shaped oval leaves that usually have two small ear-like segments at their bases. Its star-shaped flowers bloom from April to September; the flowers are pinkish-purple with bright yellow stamens. The flowers produce green berries that turn bright red upon maturing.

History: The Latin name "dulcamara" refers to the flavor of the berries, which are first bitter, then unpleasantly sweet. Although the plant has long been recognized as being highly toxic, it has been used as an external remedy for skin abrasions. Its use to treat "felons" (inflammations around nail beds) may be the source of the name "felonwort." The plant has been investigated for possible antirheumatic, diuretic, narcotic and sedative activity, but these actions are linked to the toxicity of the plant and therefore have not been exploited.

Uses of Bittersweet Nightshade

Bittersweet has been used as a traditional external remedy.

Side Effects of Bittersweet Nightshade

The plant is toxic. Ingestion of unripened berries should be considered a medical emergency. Toxic symptoms may be delayed for several hours.

Pharmacology/Toxicology: The FDA classifies bittersweet as an unsafe poisonous herb because of the presence of the toxic compounds solanine, solanidine and dulcamarin.

Solanine is poorly absorbed from the gastrointestinal tract and is rapidly eliminated in the urine and feces of animals. Because of its structural similarity to cardiac glycosides, solanine has weak cardiotonic activity. Like saponin, solanine causes hemolytic and hemorrhagic damage to the gastrointestinal tract. Although a 200 mg oral dose of solanine has not been associated with toxicity in man, the oral LD50 in rats is about 590 mg/kg. Solanine poisoning is often confused with bacterial gastroenteritis, with symptoms appearing only after a latent period of several hours following ingestion. The most common source of solanine poisoning has been the tuber of the potato. Symptoms of solanine poisoning include headache, convulsions, cyanosis, stomach ache, scratchy throat, subnormal temperature, paralysis, dilated pupils, vertigo, vomiting, diarrhea, speech difficulties, shock, circulatory and respiratory depression and death.

Adults appear to be relatively resistant to the toxicity of solanine, but fatal intoxications are more common in children.

Emesis, fluid replacement and supportive care as for gastroenteritis should be given. Despite this typically aggressive therapy, the results of one study in mice fed ripened fruit suggested that because no gastrointestinal or neurologic toxicity was observed, aggressive treatment of children who ingest ripened berries may not be necessary. Nevertheless, these investigators found significant neurologic and pathologic gastrointestinal toxicity when mice were fed unripened fruits, indicating that poisoning with this plant should be considered a critical situation. Other investigators have confirmed the pathologic changes in the gastrointestinal tract (glandular mucosal necrosis and necrosis of the small intestine) in hamsters fed ground bittersweet.

Concern has emerged linking the glycosides of certain solanum species (ie, potato) to fetal malformations in animals and humans. Extracts of bittersweet have been shown to cause an elevated incidence of craniofacial malformations in hamsters, which was statistically significant compared to controls. The alkaloids solasodine, soladulcine and related compounds were linked to the malformations.

Summary: Bittersweet is a toxic plant that grows wild throughout most of the United States. Although the plant has been used in traditional medicine, its use was generlly limited to external application. Ingestion of the unripened berries, particularly by children, constitutes a medical emergency; other parts of the plant are also toxic. The toxicity is caused by solanine and related glycoalkaloids.