Contents:
Common Names | Parts Usually Used | Plant(s) & Culture | Where Found | Medicinal Properties | Biochemical Information
Legends, Myths and Stories | Uses | Formulas or Dosages | Nutrient Content | How Sold | Warning | Resource Links
Scientific Names
- Solanum scabrum
- Solanum guineense
- Solanum melanocerasum
- Solanum intrusum
Common Names
- African Nightshade
- Black Nightshade
- Garden Huckleberry
- Morelle de Guinée
- Morelle Noire
- Erva Moura
- Mnavu
Parts Usually Used
The leaves, young shoots, and occasionally the roots, stems, and berries are used for medicinal purposes. Only the fully ripened berries should be consumed, and even then with caution.
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Description of Plant(s) and Culture
African nightshade is an annual or short-lived perennial herb that grows erect and widely spreading, reaching up to 100-150 cm tall. The plant is unarmed with rounded or narrowly winged stems that may be glabrous or sparsely pubescent. The leaves are arranged spirally, sometimes almost opposite, and are rhomboid to ovate-lanceolate in shape, up to 22 cm long and 16 cm wide. The plant bears white flowers (sometimes flushed purple) with yellow-green stars at the base, arranged in extra-axillary, umbel-like cymes with 3-12 flowers. The fruits are glossy, globose berries, 10-16 mm in diameter, and deeply purple to purplish-black when mature.
African nightshade is cultivated through seeds and less commonly through cuttings. Seeds are either sown directly or in nurseries for later transplanting. Commercial cultivation typically involves the use of nurseries, with transplanting occurring 4-6 weeks after sowing when seedlings have 5-6 true leaves. The plant requires fertile soils rich in nitrogen and organic matter, with a pH of 6.0-6.5. It grows optimally at temperatures between 20-30°C and requires at least 500 mm of rainfall during the growing season.
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Where Found
African nightshade is native to and widely cultivated across Africa, particularly from Liberia to Ethiopia and south to Mozambique and South Africa. It is especially common in both lowland and highland regions of West and East Africa. Its wide diversity in Nigeria and Cameroon suggests its origins lie in the warm humid forest belt of West and Central Africa.
Outside of Africa, Solanum scabrum can be found in Europe, Asia (India, China, and the Philippines), Australia, New Zealand, North America, and the Caribbean. It grows from sea level to well over 2000 meters in altitude.
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Medicinal Properties
African nightshade possesses several important medicinal properties:
Antioxidant: Rich in polyphenols, carotenoids, and chlorophylls that provide strong antioxidant activity against various free radicals
Anti-genotoxic: Protects against DNA damage induced by carcinogens like aflatoxin B1 (AFB1)
Anti-inflammatory: Contains compounds that reduce inflammation
Anti-cancer/Chemopreventive: Shows potential in inhibiting the growth of cancer cells
Hepatoprotective: Offers protection to liver cells
Antimicrobial: Shows activity against certain bacteria and fungi
Analgesic: Provides pain relief when applied topically
Diuretic: Promotes urine production
Febrifuge: Helps reduce fever
Antiperiodic: Prevents the periodic return of diseases
Antiphlogistic: Reduces inflammation and fever
Emollient: Softens and soothes the skin
Narcotic: Contains compounds with sedative properties
Purgative: Stimulates bowel movements
– **Sedative: Produces a calming effect
Biochemical Information
African nightshade contains a variety of bioactive compounds that contribute to its medicinal properties:
1. Polyphenols and Phenolic Compounds:
Chlorogenic acid (caffeoylquinic acids)
Coumaric acid
Caffeic acid
Sinapic acid
Gallic acid
Quercetin and its derivatives
Kaempferol and its derivatives
Catechins
2. Carotenoids:
β-carotene
Lutein
Zeaxanthin
3. Chlorophylls:
Chlorophyll a
Chlorophyll b
4. Other Compounds:
Alkaloids (though in lower concentrations in the leaves compared to other Solanum species)
Glycoalkaloids (solanine and solanidine in green fruits)
Proteins (rich in methionine)
Vitamins (especially A, C, and riboflavin)
Minerals (calcium, iron, phosphorus)
The concentration of these compounds varies depending on growing conditions, plant maturity, post-harvest storage, and processing methods.
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Legends, Myths and Stories
African nightshade has long been used in traditional African medicine and cuisine. Although it belongs to the nightshade family, which includes many toxic plants, the cultivated African nightshade has been selectively bred to contain lower levels of toxic compounds.
There has been much confusion in the literature about African nightshade (Solanum scabrum) and other species in the Solanum section. In Africa, the name Solanum nigrum is often incorrectly applied to almost all species of section Solanum with blackish fruits, including Solanum scabrum. This confusion has likely been worsened by the use of similar vernacular names for different species.
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Uses
Medicinal Uses:
Digestive Issues: Leaf extracts are used to treat diarrhea in children
Eye Infections: Applied topically to treat certain eye infections
Jaundice: Used as a treatment for jaundice
Stomach Ailments: In East Africa, the raw fruit is chewed and swallowed to treat stomach ulcers or stomach-ache
Dental Issues: Infusions of leaves and seeds are rubbed onto the gums of children who have developed crooked teeth
Skin Conditions: The leaves, stems, and roots are used in the treatment of leucoderma, wounds, and cancerous sores
Pain Relief: Extracts of the plant are analgesic and used for toothaches
Inflammation: Used for its anti-inflammatory properties
Cancer Prevention: Research shows potential in inhibiting cancer cell growth
Culinary Uses:
Leaves and fresh shoots are widely used as a cooked vegetable
Served with various staple foods such as corn ‘fufu’, plantains, sweet potatoes, potatoes, yams, maize, or pounded cocoyams
Popular in Côte d’Ivoire (known as ‘fouet’), Benin (‘ogomoh’), Nigeria (‘ogunmo’ or ‘odu’), and Cameroon (‘osan’ or ‘zom’)
Other Uses:
Fodder: Used as fodder for cattle and goats
Dyes: Both the leaves and fruits are a source of dyes, with the anthocyanin pigments in the purple to black fruits used as a dye or ink
Agricultural: Cultivated as a commercial crop in many African countries
Formulas or Dosages
Specific standardized dosages for African nightshade are not well established in scientific literature. Traditional usage involves:
For Digestive Issues: Fresh leaf extracts consumed in small amounts
For Eye Infections: Diluted leaf extracts applied topically
For Skin Conditions: Crushed leaves applied directly to affected areas
For Stomach Ulcers: Raw mature fruits chewed (with caution)
For Dental Applications: Infusions of leaves and seeds rubbed onto gums
Modern research suggests that fermentation and cooking of the leaves can enhance their health-promoting potential.
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Nutrient Content
Per 100g edible portion of African nightshade leaves:
Water: 87.8g
Energy: 163 kJ (39 kcal)
Protein: 3.2g (rich in methionine)
Fat: 1.0g
Carbohydrate: 6.4g
Fiber: 2.2g
Calcium: 200mg
Phosphorus: 54mg
Iron: 0.3mg
Beta-carotene: 3.7mg
Ascorbic Acid (Vitamin C): 24mg
The dry matter content varies greatly, from 6-18% depending on plant age, soil moisture, and fertilizing regime.
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How Sold
African nightshade is sold in various forms:
Fresh leaves and shoots in local markets
Dried leaf powder (less common)
Occasionally as part of herbal preparations and remedies
Seeds for cultivation
In commercial settings, the produce is tied in bundles and sent to markets, where traders split those bundles into smaller retail units.
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Warning
Several important cautions should be observed when using African nightshade:
Alkaloid Content: Green fruits contain significant amounts of glycoalkaloids (solanine and solanidine), which can be toxic. Initial effects of solanine poisoning include diarrhea and vomiting, and frequent consumption can lead to liver accumulation, causing dizziness, mental confusion, loss of speech, and potentially blindness. The acceptable limit for these alkaloids is 20 mg per 100g fresh weight.
Unripe Fruits: Unripe fruits should never be consumed as they contain higher concentrations of toxins.
Processing: Heating or frying will not reduce the toxic effects of solanine and solanidine.
Pregnancy: Use during pregnancy should be avoided due to potential toxicity.
Proper Identification: Care should be taken to correctly identify the plant, as it is often confused with other Solanum species that may have different toxicity profiles.
Medicinal Use: When used medicinally, the plant should be used with caution and preferably under the guidance of someone knowledgeable about traditional herbal medicine.
Cultivar Variations: Toxicity can vary considerably according to where the plant is grown and the cultivar being grown.
Resource Links
Traditional Medicine Offers Hope for Kenya’s Diabetes Crisis
PROTA4U – Solanum scabrum Mill.
Natural Medicinal Herbs – Garden Huckleberry
