Botanical Name
Solanum nigrum Linn.
Synonyms
Solanum rubrum, Solanum incertum. [1]
Family
Vernacular Names
| Malaysia | Terong Meranti |
| India | Kakmachi (Sanskrit & Bengali); Makor, Gurkamai (Hindi); Piludu (Gujerat); kamanchi-chettu, Kanchi-pandu, Kanchi (Telagu); Manattakkali, Munna-takali-pullum, Milagu-takkali (Tamil) |
| English | Black nightshade, common nightshade, garden nightshade |
| Arab | Anausathaliba, Anb-us-dalap |
| French | Morelle niore, brede martin, berbe a calalou |
| Portuguese | Erva moura. [1] [4] |
Description
Solanum nigrum is a member of the Solanaceae family. It is an annual herb that can grow up to 70 cm tall. The stem is decumbent or erect, glabrous to long-hairy with simple multicellular hairs. The leaves are arranged spirally, they are simple with petiole 0.5 – 6.5 cm long and slightly winged towards the apex. The leaf-blade is ovate to lanceolate-rhombic measuring 2.5 – 10 cm x 2 – 7 cm with cuneate base and obtuse apex. The margins are entire to wavy toothed. The inflorescence comprise of an extra-axillary raceme-like cyme with 23 – 12 flowers. The flowers are bisexual, regular, 5-merous; pedicel recurved in fruit. The calyx is campanulate up to 2.5 mm long with ovate lobes, deflexed or adhering to the base of the mature fruit. The corolla is stellate, 0.5 – 1 cm in diameter, white with yellow-green basal star, lobes 1.5 – 4 mm long; stamens are inserted on the corolla throat; filaments up to 1.5 mm long, anthers up to 2.5 mm long; ovary is superior, globose to ellipsoid about 1 mm in diameter. The fruit is globose to ovoid berry 6 – 10 mm in diameter, dull purple to blackish. The seeds are flattened, obovid 2 mm long, creamy and minutely pitted. [1]
Distribution
The plant is distributed globally especially in the tropical and subtropical belts. [1]
Plant Use
The whole plant is considered medicinal and the leaves are eaten as vegetable in Southeast Asia. The leaves and ripe fruit has been used as herbal treatments for toothache, skin lesions, burns, scabies and anxiety, in the Middle east, North Africa, India and Southeast Asia. [7]
Toxic Parts
Solanum nigrum contains toxic glycoalkaloids including solanine in the plant. The highest concentration is in the green immature berries. [7]
Toxin
Solanine
Solanine glycoalkaloids [1] .Alpha-solanine and alpha-chaconine was found to be reversible inhibitors of human plasma cholinesterase. However, solanine toxicity is not classically associated with cholinergic syndromes. This is probably due to the fact that solanine is poorly absorbed in the gastrointestinal tract rendering its elimination rapid. They are considered corrosive to the gastrointestinal tract, acutely toxic upon absorption due to several mechanisms.
All parts of Solanum nigrum contain two major glycoalkaloids, alpha-solanine and alpha-chaconine. The amount of the toxic compound in the plant depends on the climate, soil type, season and maturity of the plant. [6] [7] [8] [10]
Risk Management
Children seem to be the most vulnerable to toxic effects of the fruits and leaves of S. nigrum. There have been many reported cases of poisoning and some fatal. Caution should be taken should we want to use the plant as vegetable especially when feeding children. This plant should not be one for the garden. [4] [6] [7] [8]
Clinical Findings
Presenting symptoms following ingestion of unripe berries may include fever, sweating, vomiting, abdominal pain, diarrhoea, restlessness, confusion and drowsiness. The symptoms normally appear after 6 to 12 hours post-ingestion.
Its leaves and berries, when eaten by children, have given rise to symptoms of an acrid, narcotic nature. Symptoms start with abdominal pain, nausea, vomiting, and restlessness, followed by delirium. Pulse was quick, and scarcely perceptible, the respiration hurried, the face pale, and the pupils widely dilated. Convulsions of the limbs followed, which ends in coma and death. [3]
Management
Treatment of solanine poisoning is mainly supportive. Those with intractable vomiting and diarrhoea may suffer from dehydration and electrolyte imbalance. Those seriously affected should be put under close monitoring including cardiac monitoring.
It is recommended that treatment should be instituted is there is more than 3 unripe berries per kilogramme body weight had been ingested or following ingestion of significantly large amount of ripe berries or other plant parts.
Measures to be taken would include
1. Fluid and electrolyte balance – intravenous hydration if there is dehydration and electrolyte imbalance.
2. Antiemetic if vomiting is intractable
3. Neurological involvement, delirium and hallucination may not require pharmaceutical intervention. [4] [7] [9]
References
1. Schmelzer GH, Fakim AG. PROTA 11 – Medicinal Plants I, Plant Resources of Tropical Africa, Wagenigen 2008 pg. 528 – 530.
2. Canadian Poisonous Plants Information System. Available from http://www.cbif.gc.ca/pls/pp/ppack.info?p_psn=56&p_type=all&p_sci=comm. Accessed on: 4th March 2013.
3. Reese J. A Manual of Toxicology, Applewood Books, Carlisle 1874 pg. 449 – 450.
4. Nelson LS, Shih RD, Ballick MJ. Handbook of poisonous and Injurios Plants, Springer Verlah, Berlin pg. 274 – 278.
5. Barceloux DG. Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants and Venomous Animals, John Wiley & Sons, Hoboken, 2012.
6. Brimer L. Chemical Food Safety, CABI Wallingford 2011 pg. 112.
7. Barceloux DG. Medical Toxicology of Natural Substances: Food, Fungi, Medicinal Herbs, Wiley & Son, Hoboken 2008 pg. 78.
8. Brandenberger H, Maes R. Analytical Toxicology: For Clinical, Forensic, and Pharmaceutical Chemist, Walter de Gruyter Berlin 1997 pg. 639.
9. Contaminant berries in frozen vegetables. Available from http://www.nzma.org.nz/journal/122-1292/3547/. Accessed on 4th March 2013.
10. Jain R, Sharma A, Gupta A, Sarethy IP, Gabrani R. Solanum nigrum: Current Perspective on Therapeutic properties. Alternative Medicine Review Volume 16(1):78 – 85.
