Solanum nigrum(Solanaceae)- Manthakkali, Black Nightshade, Makoi

Nov 9, 2025
22 min read

Updated: Jul 9

Solanum nigrum is a widely distributed medicinal weed with a dual identity as both a nutritious food and a potent therapeutic agent. It has demonstrated significant anticancer activity through the action of steroidal glycoalkaloids like solasonine and solamargine. The plant exhibits potent anti-inflammatory and antioxidant properties and shows promise for diabetes management through hypoglycemic and enzyme-inhibiting effects. It has a well-documented history of hepatoprotective use. However, caution is paramount due to solanine toxicity in unripe berries, requiring proper harvesting and preparation. A rich phytochemical profile includes steroidal alkaloids, polyphenols, and glycoproteins. Significant research gaps exist in human clinical trials, pharmacokinetics, and standardized toxicity assessments. The plant has high commercial potential in pharmaceuticals and functional foods.

1. Taxonomic Insights

Species: Solanum nigrum L.

Family: Solanaceae (Nightshade Family)

Genus: Solanum

Synonyms: Solanum nodiflorum Jacq., Solanum americanum Mill.

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Botanical Description

Solanum nigrum is a polymorphic annual or short-lived perennial herb, exhibiting significant morphological variation. It typically reaches heights of 10 to 75 centimetres, occasionally up to 1 metre .

The stem is erect or decumbent, much branched, green or with a purplish tinge, and slightly pubescent. The leaves are simple, ovate to lanceolate in shape, measuring 4 to 10 centimetres in length and 2 to 7 centimetres in width. The leaf margin is entire or bluntly toothed, with a pointed apex and a cuneate base .

Key Identification Features:

The inflorescence is an extra-axillary, short raceme bearing 3 to 12 flowers. The flowers are small, white or rarely tinged with purple, with a stellate corolla 8 to 10 millimetres in diameter and yellow anthers . The fruit is a globose to ellipsoid berry, 6 to 8 millimetres in diameter, initially green and turning dull or shiny purplish-black when ripe. Each berry contains 25 to 45 seeds, which are 1.8 to 2.2 millimetres long .

Distribution: The species is native to Europe and western Asia and is now widely distributed throughout temperate and tropical regions, including North America, Africa, Asia, and Australia . It thrives as a common weed in open and disturbed places, fields, wastelands, and roadsides, from sea level up to 3,100 metres elevation .

Conservation Status: The plant is widely distributed and considered a weed. It is not currently assessed on the IUCN Red List but is classified as Least Concern based on its abundance and invasive potential.

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Etymology

The generic name Solanum is derived from the Latin word "solamen," meaning comfort or soothing, alluding to the narcotic properties of some species. The specific epithet nigrum means "black," referring to the colour of the ripe berries.

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2. Common Names

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3. Related Herbs from the Solanaceae Family

Solanum tuberosum (Potato): A globally important food crop. All parts contain toxic glycoalkaloids, especially solanine and chaconine, which accumulate in green or sprouted tubers .

Solanum melongena (Eggplant): A widely cultivated vegetable. Contains solanine but at low levels in edible fruit. Used traditionally for its antidiabetic, anti-inflammatory, and hypotensive properties .

Solanum lycopersicum (Tomato): A major food crop. The leaves and stems contain toxic glycoalkaloids, including alpha-tomatine .

Capsicum annuum (Chilli Pepper): A globally important spice and vegetable. Contains capsaicin, known for analgesic and anti-inflammatory properties.

Datura stramonium (Jimsonweed): A highly toxic plant with potent anticholinergic and hallucinogenic properties, used in traditional medicine for asthma and pain.

Nicotiana tabacum (Tobacco): A major commercial crop containing nicotine. Used traditionally but highly addictive and toxic.

The Solanaceae family is renowned for its production of tropane alkaloids and steroidal glycoalkaloids, many of which have significant medicinal and toxic properties. This family is characterized by its diverse array of medicinal, edible, and poisonous species.

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4. Medicinal Uses: Summary of Primary and Secondary Actions

Primary Actions:

Anticancer: Demonstrates potent antitumor activity through the action of steroidal glycoalkaloids (solasonine, solamargine, alpha-solanine), which induce apoptosis and inhibit proliferation in various cancer cell lines . Glycoproteins also contribute to anticancer abilities by blocking anti-apoptotic pathways .

Anti-inflammatory: The plant significantly inhibits pro-inflammatory mediators including nitric oxide (NO) production and cytokines, reducing inflammation and associated pain . Steroidal alkaloids, such as those from ripe berries, have demonstrated mild anti-inflammatory activity .

Antioxidant: The plant is rich in polyphenols and flavonoids, including gallic acid, catechin, rutin, and naringenin, which provide potent free radical scavenging activity, protecting cells from oxidative stress .

Antidiabetic (Hypoglycemic): Extracts have shown hypoglycemic effects, reducing blood sugar and serum lipid levels. The plant's leaf extract inhibits alpha-amylase and alpha-glucosidase, enzymes involved in carbohydrate metabolism, and may improve insulin sensitivity .

Hepatoprotective: The plant protects the liver from damage, reducing elevated liver enzymes and lipid peroxidation in models of hepatotoxicity . This action is attributed to its potent antioxidant and anti-inflammatory properties.

Antimicrobial: Exhibits significant activity against various bacterial and fungal pathogens, including Escherichia coli, Staphylococcus aureus, and Candida albicans . Methanol extracts often show stronger activity than aqueous extracts .

Analgesic: Used traditionally for pain relief, with scientific validation through its anti-inflammatory and antispasmodic mechanisms .

Secondary Actions:

Immunomodulatory: The plant demonstrates immunostimulant properties, enhancing antibody responses and neutrophil activity, with potential for disease prevention .

Neuroprotective: Emerging research shows protective effects against neurotoxicity, including lead-induced brain toxicity in animal models .

Antimalarial: Demonstrates antimalarial activity in animal studies .

Antiulcer: Traditional use for ulcer treatment supported by scientific studies .

Diuretic: The plant is traditionally used as a diuretic to promote urine flow .

Antipyretic: Used to reduce fever, attributed to its antioxidant and anti-inflammatory polyphenols .

Laxative: The ripe fruits are used as a laxative and appetite stimulant .

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Medicinal Parts

The whole plant is used, with specific applications for leaves, berries, and roots.

Leaves and Shoots: The most commonly used part, consumed as a vegetable or used in decoctions, infusions, and poultices. Used for their anti-inflammatory, antioxidant, antimicrobial, and wound-healing properties .

Berries: Ripe berries are edible and used as a tonic, laxative, appetite stimulant, and for treating asthma and diabetes . Unripe berries are highly toxic and should never be consumed. The fruit is used to make jams and preserves in some regions .

Roots: Used in traditional medicine to treat asthma, whooping cough, and inflammatory conditions .

Whole Plant: Used in decoctions and infusions for cancer, fever, stomach complaints, liver disorders, and skin diseases .

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5. Phytochemistry

5.1 Steroidal Glycoalkaloids (Major Bioactive Constituents)

Steroidal glycoalkaloids are the hallmark compounds of Solanum nigrum and are responsible for much of its pharmacological activity, particularly anticancer effects, and its toxicity. Over 46 alkaloids have been identified. Key compounds include:

Solasonine is a major glycoalkaloid with potent cytotoxic and antitumor activity. It is found in green berries and other plant parts. It contributes to the plant's anticancer properties and is a primary compound responsible for toxicity .

Solamargine demonstrates significant cytotoxic effects against cancer cells and exhibits anti-inflammatory properties. It is abundant in the whole plant and contributes to the antitumor effects .

Alpha-solanine is a steroidal glycoalkaloid that inhibits proliferation and induces apoptosis in tumor cells. It acts by modulating signaling pathways such as PI3K/Akt and reducing cell invasion .

Beta-solamargine is a glycoalkaloid that contributes to the plant's overall pharmacological profile and toxicity .

Solanigrine is an alkaloid specific to S. nigrum and contributes to its phytochemical diversity .

5.2 Polyphenols and Flavonoids

The plant is rich in phenolic compounds, which contribute significantly to its antioxidant, anti-inflammatory, and hepatoprotective activities. A total of 193 phenolic compounds have been identified. Key compounds include:

Gallic acid is a potent antioxidant and anti-inflammatory agent, contributing to the plant's hepatoprotective and anticancer activities .

Catechin demonstrates antioxidant and anti-inflammatory activities. It contributes to the plant's hepatoprotective and neuroprotective properties .

Rutin exhibits antioxidant, anti-inflammatory, and vasoprotective activities. It contributes to cardiovascular health and antidiabetic effects .

Naringenin shows antioxidant, anti-inflammatory, and immunomodulatory activities. It contributes to the plant's anti-inflammatory and anticancer effects .

Protocatechuic acid demonstrates antioxidant, anti-inflammatory, and neuroprotective activities .

Chlorogenic acid shows antioxidant, antidiabetic, and hepatoprotective activities. It inhibits the enzyme glucose-6-phosphatase, reducing hepatic glucose output .

5.3 Glycoproteins

Glycoproteins isolated from S. nigrum have demonstrated significant anticancer, immunomodulatory, and antioxidant activities. A 150-kDa glycoprotein has been shown to induce apoptosis in cancer cells and modulate immune responses .

5.4 Terpenoids and Phytosterols

Beta-sitosterol is a well-known phytosterol with proven anti-inflammatory and cholesterol-lowering properties. It works by inhibiting the synthesis of prostaglandins and competing with dietary cholesterol for absorption .

Diosgenin is a steroidal sapogenin used as a precursor for the synthesis of steroidal drugs. It has anti-inflammatory, immunomodulatory, and anticancer properties .

Gitogenin is a steroidal sapogenin found in S. nigrum, contributing to its overall phytochemical profile .

5.5 Saponins and Other Compounds

Saponins are present, contributing to antimicrobial and anti-inflammatory activities. They may also play a role in the plant's traditional use for wound healing .

Solanine (as a broader compound group) is present, known for its toxicity but also its medicinal potential, including antimicrobial and anti-inflammatory activities .

Tannins are present, acting as astringents, contracting tissues and reducing bleeding, with intrinsic antimicrobial activity .

Vitamins and Amino Acids: The plant contains various vitamins (including vitamins C and E) and amino acids (including L-glutamic acid), contributing to its nutritive value .

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6. Mechanisms of Action

6.1 Anticancer: Induction of Apoptosis and Cell Cycle Arrest

Solanum nigrum exerts its anticancer effects through multiple mechanisms involving steroidal glycoalkaloids and glycoproteins.

Alpha-solanine inhibits cancer cell proliferation and induces apoptosis by modulating signaling pathways such as the PI3K/Akt pathway, which is crucial for cell survival and growth. It also inhibits cell invasion by blocking epithelial-mesenchymal transition and matrix metalloproteinase expression .

Glycoproteins (e.g., 150-kDa glycoprotein) exert anticancer abilities by blocking the anti-apoptotic NF-kappaB pathway, activating caspase cascades, and increasing nitric oxide production. This triggers a programmed cell death response in cancer cells .

Solasonine and solamargine are cytotoxic to cancer cells, interfering with the structure and function of tumor cell membranes, disturbing the synthesis of DNA and RNA, and changing cell cycle distribution. These compounds have shown activity against various cancer cell lines, including cervical carcinoma (U14) and pancreatic cancer (PC-3) .

Aqueous extracts of S. nigrum have been shown to induce tumor cell cycle arrest in the G0/G1 phase, leading to apoptosis, in cervical carcinoma models . The chloroform leaf fraction has also demonstrated activity against pancreatic cancer cell lines .

6.2 Hypoglycemic: Enzyme Inhibition and Glucose Uptake

Solanum nigrum exhibits a multi-faceted approach to managing diabetes.

Alpha-glucosidase and alpha-amylase inhibition: The leaf extract inhibits these carbohydrate-digesting enzymes, reducing glucose absorption in the gut and lowering postprandial blood sugar levels .

Insulin sensitivity: The plant improves insulin sensitivity by stimulating signaling pathways such as AMPK and PI3K/Akt, which are involved in glucose uptake and metabolism .

GLUT4 translocation: S. nigrum extracts stimulate the translocation of glucose transporter proteins, particularly GLUT4, to the cell membrane in insulin-sensitive tissues like muscles and adipose tissue. This facilitates glucose absorption and helps clear blood glucose .

Lipid-lowering: The plant has been shown to decrease serum triglycerides, cholesterol, and sugar, while inhibiting fat deposits and oxidative stress in animal models fed a high-fat diet .

6.3 Anti-inflammatory: Cytokine and Nitric Oxide Inhibition

The anti-inflammatory effects are attributed to both polyphenols and steroidal alkaloids.

S. nigrum extracts significantly inhibit the production of pro-inflammatory cytokines, including IL-6, IL-1 beta, and TNF-alpha, in RAW264.7 macrophage cells . This is a key mechanism in reducing inflammation and associated pain.

Steroidal alkaloids from ripe berries (compounds 3 and 4) have been shown to inhibit nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells, indicating an anti-inflammatory potential .

Beta-sitosterol is a well-known phytosterol with proven anti-inflammatory activity, often compared to that of non-steroidal anti-inflammatory drugs. It works by inhibiting the synthesis of prostaglandins .

6.4 Antioxidant: Free Radical Scavenging

The high concentration of polyphenols and flavonoids gives the plant a strong capacity to protect cells from oxidative stress and damage.

The leaf extract demonstrates potent DPPH radical scavenging activity, which correlates with the high phenolic, flavonoid, and coumarin content. These compounds neutralize free radicals and protect cells from oxidative damage .

The antioxidant activity is central to the plant's hepatoprotective, anti-inflammatory, and neuroprotective properties, as well as its potential in mitigating age-related diseases .

6.5 Hepatoprotective: Membrane Stabilisation and Lipid Reduction

Hepatoprotective effects are mediated through antioxidant and anti-inflammatory mechanisms.

The plant reduces elevated liver enzymes (SGOT, SGPT, ALP) and lipid peroxidation in models of chemically-induced liver damage, demonstrating a protective effect on liver cells. This is attributed to the antioxidant activity of polyphenols and flavonoids, which scavenge free radicals and stabilize cell membranes .

Additionally, S. nigrum has lipid-lowering effects, reducing serum triglycerides and cholesterol, which supports liver health and reduces the risk of fatty liver disease .

6.6 Antimicrobial: Bacterial and Fungal Inhibition

Methanol and water extracts of leaves and seeds have demonstrated significant activity against various bacterial and fungal pathogens, including E. coli, S. aureus, P. aeruginosa, and C. albicans . Methanol extracts typically show the highest activity, suggesting the bioactive compounds are more polar. This antimicrobial action supports the traditional use of the plant for treating wounds and infectious diseases.

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7. Traditional and Ethnobotanical Uses

7.1 Cancer Treatment (Antitumor)

Formulation: Whole plant decoction or extract.

Preparation and Use: In traditional Chinese medicine, S. nigrum is widely used to treat various cancers, including liver cancer. It is also used in other traditional systems as a remedy for tumors and cancerous sores .

Scientific Validation: Scientific research has validated the anticancer potential of S. nigrum. Studies show that its extracts and compounds (solasonine, solamargine, glycoproteins) can induce apoptosis, inhibit cancer cell proliferation, and modulate immune responses in various cancer cell lines, including cervical carcinoma, prostate cancer, and pancreatic cancer .

7.2 Liver Health (Hepatoprotective)

Formulation: Whole plant decoction or leaf extract.

Preparation and Use: In Chinese medicine and Indian traditional medicine, the plant is used to treat liver disorders, including hepatitis and jaundice .

Scientific Validation: The plant has demonstrated significant hepatoprotective activity, reducing elevated liver enzymes and lipid peroxidation in animal models of chronic hepatotoxicity .

7.3 Anti-inflammatory and Analgesic

Formulation: Leaf paste or juice.

Preparation and Use: The leaves are used as a poultice or the juice is applied topically to treat inflammation, burns, itching, and pain. Internally, the plant is used to treat rheumatic and gouty joints . In European traditional medicine, it was used as a strong sudorific and analgesic with narcotic properties .

Scientific Validation: The plant's anti-inflammatory and analgesic properties have been validated scientifically through its ability to inhibit pro-inflammatory cytokines, nitric oxide production, and prostaglandin synthesis .

7.4 Antidiabetic (Hypoglycemic)

Formulation: Leaf extract or fruit decoction.

Preparation and Use: In traditional systems, the fruit is considered a cure for diabetes, and the leaves are used to manage blood sugar levels .

Scientific Validation: Research confirms the hypoglycemic potential, demonstrating that leaf extracts inhibit alpha-glucosidase and alpha-amylase enzymes, improve insulin sensitivity, and increase glucose uptake .

7.5 Skin Health and Wound Healing

Formulation: Leaf poultice or juice.

Preparation and Use: The leaves and stems are used as a poultice to treat wounds, cuts, ulcers, cancerous sores, eczema, and dermatitis. The leaf juice is applied to inflamed parts and used as a skin soother .

Scientific Validation: The wound-healing properties are supported by the plant's antimicrobial and anti-inflammatory activities. Tannins act as astringents, while bioactive compounds promote tissue repair .

7.6 Gastrointestinal Disorders

Formulation: Whole plant decoction or leaf juice.

Preparation and Use: The plant is used to treat diarrhoea, dysentery, stomach complaints, and ulcers. In Papua New Guinea, cooked leaves and stems are given to infants suffering from diarrhoea .

Scientific Validation: The antispasmodic and astringent effects provide a mechanistic basis for its traditional use in relieving spasmodic conditions like diarrhoea and ulcers .

7.7 Fever and General Tonic

Formulation: Whole plant decoction.

Preparation and Use: An infusion of the whole plant is used to reduce fever. The ripe fruits are used as a tonic, laxative, and appetite stimulant .

Scientific Validation: The antipyretic action is attributed to its potent antioxidant and anti-inflammatory polyphenols .

7.8 Regional Ethnomedicinal Applications Summary

China: Used in traditional medicine for cancer, inflammation, oedema, mastitis, and liver cancer. Also used for urinary tract infections, bacillary dysentery, prostatitis, and chronic bronchitis .

India: Leaves used for inflammations, rheumatic and gouty joints, skin diseases, dropsy, heart diseases, piles, gonorrhoea, fevers, eye diseases, and chronic enlargement of liver and spleen. Roots are used in asthma, cough, toothache, and worm complaints .

Europe: Used as a strong sudorific, analgesic, and sedative with narcotic properties .

Southeast Asia: Used as a vegetable, and for diarrhoea, yaws, and diabetes .

Africa: Used in Cameroon to treat pneumonia, aching teeth, stomach ache, tonsillitis, wing worms, pain, inflammation, fever, and tumors .

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8. Healing Recipes, Teas, Decoctions, and Culinary Uses

8.1 Hepatoprotective Whole Plant Decoction

Purpose: To support liver health and treat jaundice.

Preparation and Use: Take 20 grams of dried Solanum nigrum whole plant or a generous handful of fresh plant. Boil it in 500 millilitres of water for approximately 15 minutes. Strain the decoction and allow it to cool to a comfortable temperature. Take 100 millilitres of the decoction twice daily to support liver function and aid in recovery from jaundice.

Scientific Validation: Research demonstrates significant hepatoprotective effects, with the plant extract significantly lowering elevated liver enzymes, serum bilirubin, and lipid profiles in CCl4-induced liver injury .

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8.2 Antidiabetic Leaf Infusion

Purpose: To help manage blood sugar levels.

Preparation and Use: Take a handful of fresh Solanum nigrum leaves. Steep them in 250 millilitres of hot water for 5 to 10 minutes. Strain and drink this tea twice daily before meals to help manage postprandial glucose levels.

Scientific Validation: Research indicates that the leaf extract inhibits alpha-glucosidase and alpha-amylase, enzymes that break down carbohydrates, and improves insulin sensitivity .

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8.3 Wound Healing Poultice

Purpose: To heal wounds, cuts, and sores.

Preparation and Use: Wash a handful of fresh Solanum nigrum leaves thoroughly. Grind or crush the leaves into a smooth paste. Apply the paste directly to the affected area and cover with a clean cloth or bandage. Replace the poultice twice daily.

Scientific Validation: The plant's antimicrobial and anti-inflammatory properties support its traditional use for wound healing. Tannins act as astringents, while bioactive compounds promote tissue repair .

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8.4 Anti-inflammatory Leaf Juice

Purpose: To reduce inflammation and treat skin conditions.

Preparation and Use: Extract the juice from a handful of fresh Solanum nigrum leaves. Apply the juice topically to inflamed areas, burns, itching, or skin diseases. Alternatively, it can be taken internally in small doses for systemic inflammation.

Scientific Validation: The anti-inflammatory activity is attributed to the plant's ability to inhibit pro-inflammatory cytokines and nitric oxide production .

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8.5 Ripe Berry Tonic

Purpose: To improve appetite and digestion.

Preparation and Use: A small handful of fully ripe Solanum nigrum berries can be eaten fresh or made into a preserve to stimulate appetite and aid digestion.

Scientific Validation: Ripe berries are traditionally used as a tonic, laxative, and appetite stimulant . Only fully ripe berries should be consumed, as unripe berries contain high levels of toxic solanine.

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8.6 Black Nightshade Stir-fry

Purpose: A nutritious side dish that supports overall health.

Preparation and Use: Heat oil in a pan and temper with mustard seeds, garlic, and dried red chili. Add a generous amount of cleaned and chopped fresh Solanum nigrum leaves and shoots. Saute until the leaves wilt and are tender. Season with salt and a squeeze of lime juice. Consume with rice or roti.

Scientific Validation: The young leaves and shoots are consumed as a vegetable across Asia and Africa, valued for their nutritive and medicinal properties . They are rich in vitamins, minerals, and bioactive compounds.

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8.7 Decoction for Fever and Diarrhoea

Purpose: To reduce fever and provide relief from diarrhoea.

Preparation and Use: Boil a handful of the whole plant (leaves and stems) in 2 cups of water for 10 to 15 minutes. Strain and drink a half-cup of this warm decoction twice a day.

Scientific Validation: The antipyretic action is attributed to potent antioxidant and anti-inflammatory polyphenols . The antispasmodic and astringent effects support its traditional use for diarrhoea.

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8.8 Culinary Uses and Nutritional Information

Solanum nigrum is widely consumed as a nutritious leafy vegetable across Asia and Africa. The young leaves and shoots are the primary edible parts. They are consumed raw as a salad, steamed, or cooked in soups and stews.

Ripe berries are eaten fresh, used in pies, and made into preserves in some regions . They have a sweet and sour flavor and are nutritious.

The plant is a rich source of nutrients, containing per 100 grams of edible portion approximately 80 grams of water, providing 60 kilocalories of energy. The protein content is approximately 4.7 grams, fat content is approximately 0.8 grams, and carbohydrate content is approximately 11.8 grams. The fibre content is approximately 2.1 grams. The calcium content is approximately 146 milligrams and phosphorus content is approximately 45 milligrams .

Important Warning: Only fully ripe berries and properly cooked leaves should be consumed. Unripe berries and raw leaves contain high levels of toxic glycoalkaloids that can cause serious illness .

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9. Clinical Significance and Evidence Summary

9.1 Evidence Hierarchy by Activity

Anticancer: Strong evidence from in vitro and animal studies. Studies show significant antitumor activity against cervical carcinoma (U14), prostate cancer (PC-3), and other cancer cell lines . The chloroform leaf fraction demonstrated activity against pancreatic cancer cell lines . Human clinical trials are lacking. Steroidal glycoalkaloids (solasonine, solamargine, alpha-solanine) and glycoproteins are the key bioactive compounds .

Anti-inflammatory: Strong evidence from in vitro studies. The plant significantly inhibits pro-inflammatory cytokines and nitric oxide production in RAW264.7 macrophage cells . Human clinical trials are lacking. Steroidal alkaloids and polyphenols contribute to this activity .

Antioxidant: Strong evidence from in vitro studies. The plant demonstrates potent free radical scavenging activity, protecting cells from oxidative stress . Polyphenols and flavonoids are the key bioactive compounds .

Antidiabetic (Hypoglycemic): Moderate evidence from in vitro and animal studies. The leaf extract inhibits alpha-glucosidase and alpha-amylase enzymes, improves insulin sensitivity, and increases glucose uptake . Animal studies show significant reduction in blood sugar and lipid levels . Human clinical trials are lacking .

Hepatoprotective: Moderate evidence from animal studies. The plant protects the liver from damage, reducing elevated liver enzymes and lipid peroxidation in models of hepatotoxicity . Human clinical trials are lacking.

Antimicrobial: Moderate evidence from in vitro studies. The plant shows significant activity against various bacterial and fungal pathogens . Methanol extracts show the highest activity . Clinical trials are lacking.

Analgesic: Moderate evidence from traditional use and pharmacological studies. The anti-inflammatory and antispasmodic mechanisms support its use for pain relief . Clinical trials are lacking.

Immunomodulatory: Moderate evidence from in vitro and animal studies. The plant enhances antibody responses and neutrophil activity . Clinical trials are lacking.

Neuroprotective: Preliminary evidence from animal studies. The plant shows protective effects against lead-induced brain toxicity . Human studies are lacking.

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9.2 Anticancer Potential: Key Studies

Cervical Carcinoma: Aqueous extract of S. nigrum inhibited the growth of cervical carcinoma (U14) in tumor-bearing mice by modulating immune response and inducing tumor cell cycle arrest in the G0/G1 phase, leading to apoptosis .

Prostate Cancer: Alpha-solanine from S. nigrum was found to inhibit the invasion of PC-3 pancreatic cancer cells by blocking epithelial-mesenchymal transition and matrix metalloproteinase expression. It also reduced ERK and PI3K/Akt signaling pathways .

Breast Cancer: A glycoprotein isolated from S. nigrum (150-kDa) demonstrated antioxidant and cytotoxic effects in MCF-7 cells .

Pancreatic Cancer: Chloroform leaf fraction demonstrated cytotoxic effects on pancreatic cancer cell lines .

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9.3 Hypoglycemic Activity

In vitro studies demonstrated that S. nigrum leaf extract inhibits alpha-amylase and alpha-glucosidase enzymes, which are involved in carbohydrate metabolism . The plant extract also stimulated the translocation of glucose transporter proteins (GLUT4), facilitating glucose absorption .

In animal studies, chronic administration of the extract at 250 mg per kg body weight significantly decreased blood sugar levels compared to controls . Aqueous extracts of leaves and fruit demonstrated significant hypoglycemic effects in a dose-dependent manner in Sprague Dawley rats . The plant also decreased serum triglycerides, cholesterol, and sugar, while inhibiting fat deposits and oxidative stress in mice fed with a high-fat diet .

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10. Safety and Toxicology

10.1 Toxicity Profile

Solanum nigrum has a long history of use as a food and medicine, but its safety is heavily dependent on the plant part, its maturity, and preparation.

Acute Toxicity: Unripe berries and raw leaves contain high levels of the toxic glycoalkaloid solanine. Ingestion can cause severe gastrointestinal and neurological symptoms. Doses of 200 to 400 mg of solanine can induce gastroenterosis, tachycardia, dyspnea, vertigo, sleepiness, lethargy, twitching, and cramps . Symptoms include nausea, diarrhoea, vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, headache, dizziness, hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils, and hypothermia . Doses of 3 to 6 mg per kg body weight of solanine can be fatal .

Livestock Toxicity: Mortality or severe poisoning has been reported in cattle, chickens, horses, sheep, and swine after consuming the plant .

Clinical Safety: Properly cooked leaves and fully ripe berries are generally considered safe for consumption . However, caution is essential.

Teratogenicity: Solanine is reported to exhibit teratogenic properties .

Overall Assessment: The plant is safe for consumption as food and for medicinal use only when properly prepared. All green parts and unripe berries should be avoided. Cooking reduces the toxicity of the leaves. As with any medicinal plant, concentrated extracts should be used with caution.

10.2 Contraindications and Precautions

Pregnancy and Lactation: Insufficient safety data exists. The plant should be avoided during pregnancy and lactation due to potential toxicity and teratogenic effects .

Gastrointestinal Sensitivity: Individuals with sensitive stomachs should use caution, as the plant may cause gastrointestinal distress .

Known Hypersensitivity: Individuals with known hypersensitivity to Solanum species or the Solanaceae family should avoid use.

Autoimmune Conditions: The immunomodulatory effects could theoretically affect autoimmune conditions. Caution is advised.

10.3 Potential Drug Interactions

Antidiabetic Medications (Metformin, Sulphonylureas, Insulin): The mechanism involves additive glucose-lowering effect via alpha-glucosidase inhibition and improved insulin sensitivity. The clinical significance is the risk of hypoglycaemia. The recommendation is to monitor blood glucose and consider reducing the dose of antidiabetic medications .

Antihypertensive Medications (ACE inhibitors, ARBs, Calcium Channel Blockers): The mechanism involves additive vasodilatory effect. The clinical significance is that the plant may potentiate hypotensive effects. The recommendation is to monitor blood pressure and consider dose adjustment of antihypertensive medications.

Immunosuppressants: The immunomodulatory effects of the plant could potentially interfere with immunosuppressant therapy. Caution is advised.

Anticoagulants and Antiplatelet Drugs (Warfarin, Aspirin, Clopidogrel): The plant may have mild antiplatelet effects. The clinical significance is that it may increase bleeding risk. The recommendation is to exercise caution and monitor INR if used with warfarin.

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11. Quality Control Parameters

11.1 Marker Compounds for Standardisation

Key compounds suitable as quality markers include Solasonine, Solamargine, Alpha-solanine, Catechin, Rutin, Gallic acid, and Naringenin . These compounds provide a foundation for standardising extracts and ensuring consistent quality.

11.2 Recommended Analytical Methods

High-performance liquid chromatography (HPLC) with diode array detection (DAD) or liquid chromatography with tandem mass spectrometry (LC-MS/MS) can be used for quantification of marker compounds, particularly for steroidal glycoalkaloids . The total phenolic content assay using the Folin-Ciocalteu method is recommended for determining total phenolic content. The total flavonoid content assay using aluminium chloride colorimetric method is recommended for determining total flavonoid content. The antiglucosidase activity assay can serve as a functional quality parameter.

11.3 Suggested Specifications

For the leaf extract, the total phenolic content should be greater than 60 mg GAE per gram of dry weight. The antiglucosidase EC50 should be less than 0.60 mg per mL. The DPPH EC50 should be less than 15 microgram per mL. Glycoalkaloid content should be within safe limits, with solanine levels below 200 mg per kg for edible products.

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12. Cultivation and Sustainability

12.1 Growth Requirements

Climate: The plant thrives in tropical and subtropical climates.

Habitat: It prefers damp environments, open and disturbed places, fields, wastelands, and roadsides .

Altitude: It grows from sea level to 3,100 metres elevation .

Soil: The plant is adaptable to various soil types but prefers well-drained sandy loam soil .

Propagation: It is easily propagated from seeds. Seeds are sown in a nursery and transplanted when 30 days old with a height of 10 to 15 centimetres and at least 6 leaves. The recommended spacing is 60 x 45 centimetres .

12.2 Sustainable Harvesting

Plant parts harvested: The young shoots, leaves, and fully ripe berries are the primary edible and medicinal parts.

Harvesting method: Cut above the nodes to allow regrowth, ensuring sustainable harvesting.

Season: The plant can be harvested year-round in suitable climates. The berries are harvested when fully ripe (purplish-black).

Caution: Only harvest from clean, uncontaminated areas to minimise heavy metal exposure. Proper identification is crucial to avoid confusion with other Solanum species.

12.3 Conservation Status

The plant is not currently assessed on the IUCN Red List but is considered a weed in many countries, indicating its abundance and invasive potential.

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13. Cultivar Comparison: Key Forms

There are several varieties of S. nigrum, including the common black-berried type and red-berried types (sometimes classified as S. nigrum var. rubrum or S. americanum). The red varieties are often marketed as "Red Nightshade" and are used similarly.

Colour of berries: The most common type has black or purplish-black ripe berries . Some varieties have red ripe berries.

Traditional medicinal focus: The black-berried type is widely used in traditional medicine across various systems. Red-berried varieties may have similar uses.

Culinary use: The red varieties are often used in preserves and for their aesthetic appeal.

Phytochemical profile: The red varieties contain anthocyanins, which are responsible for their colour and contribute to their antioxidant activity.

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14. Research Gaps and Future Directions

14.1 Critical Research Gaps

Human Clinical Trials: Comprehensive clinical trials are lacking for most therapeutic claims, including anticancer, hepatoprotective, and antidiabetic effects. There is a need for Phase I, II, and III clinical trials to establish safety, efficacy, and dosing in human populations .

Pharmacokinetics: Limited data exists on absorption, metabolism, and bioavailability of key compounds, particularly steroidal glycoalkaloids. Understanding the pharmacokinetics is essential for developing safe and effective formulations .

Standardised Formulations: There is a need for stable, standardised phytopharmaceutical preparations with consistent quality and efficacy.

Toxicological Assessment: Comprehensive toxicity studies are needed, particularly for chronic use and for specific populations (pregnant women, children) .

Mechanistic Studies: Further elucidation of molecular pathways is needed, particularly for anticancer and neuroprotective mechanisms .

14.2 Future Research Priorities

Cancer: Phase I and Phase II clinical trials for anticancer efficacy are needed to establish dosing, efficacy, and safety in human populations.

Diabetes: Clinical studies on antidiabetic efficacy are needed to validate the traditional use for diabetes management and to establish therapeutic protocols .

Liver Health: Clinical studies on hepatoprotective effects are needed to validate the traditional use for liver disorders and to establish therapeutic protocols .

Nanotechnology: Development of nanoformulations to enhance the bioavailability and therapeutic efficacy of bioactive compounds (e.g., glycoalkaloids) is a promising area of research .

Neuroprotection: Further investigation of neuroprotective properties is needed to explore potential applications in neurodegenerative diseases .

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15. Commercial Applications

15.1 Pharmaceutical and Nutraceutical Potential

Solanum nigrum has significant potential for development as a complementary medicine for cancer, diabetes, and liver disorders. It can be developed as nutraceutical ingredients for functional foods, standardised extracts for dietary supplements, and topical formulations for wound healing .

15.2 Product Development Potential

Anticancer Formulations: Standardised extracts rich in steroidal glycoalkaloids (solasonine, solamargine) could be developed as adjunctive cancer therapies .

Antidiabetic Teas: Leaf extracts could be developed as functional teas or supplements for managing blood sugar levels .

Hepatoprotective Products: Formulations for liver health could be developed as dietary supplements .

Wound Healing Creams: Topical formulations containing S. nigrum extracts could be developed for wound healing and skin conditions .

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16. Related Plants for Further Study

Solanum americanum (American Black Nightshade): A closely related species with similar uses and toxicity profiles. It is often confused with S. nigrum and shares many phytochemical and medicinal properties.

Solanum scabrum (African Nightshade): An important leafy vegetable in Africa with similar nutritional and medicinal properties. It is closely related and often used interchangeably with S. nigrum.

Solanum villosum (Red Nightshade): A species with red berries, used similarly to S. nigrum and with comparable phytochemical profiles.

Solanum tuberosum (Potato): A globally important food crop with high levels of glycoalkaloids in green parts. It is used as a source of starch and has potential for pharmaceutical applications.

Solanum melongena (Eggplant): A widely cultivated vegetable with antidiabetic, anti-inflammatory, and hypotensive properties. It is a good comparative plant for studying the therapeutic potential of Solanum species.

Solanum lycopersicum (Tomato): A major food crop with antioxidant and anti-inflammatory properties. It is a source of lycopene and other bioactive compounds.

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17. Reference Literature

Primary Research

Wang, J., Pan, J., Luan, F., et al. (2025). Progress in Solanum nigrum L. research: Traditional uses, phytochemistry, pharmacological activities, quality control, and clinical applications. Journal of Ethnopharmacology.

Liu, L.Y., Peng, Q., Yang, Y.K., et al. (2025). Seven previously undescribed steroidal alkaloids from the fruit of Solanum nigrum L. and their biological activities. Phytochemistry.

Paul, P., Kamal, R., Rai, A., et al. (2025). Phytochemical marvels: Solanum nigrum's journey from plant to diabetes treatment. South African Journal of Botany.

Chen, X., Dai, X., Liu, Y., et al. (2022). Solanum nigrum Linn.: An Insight into Current Research on Traditional Uses, Phytochemistry, and Pharmacology. Frontiers in Pharmacology.

Jain, R., Sharma, A., Gupta, S., et al. (2011). Solanum nigrum: current perspectives on therapeutic properties. Alternative Medicine Review.

Key Monographs and Floras

FAO. (1995). The use of spices and medicinals as bioactive protectants for grains. Chapter 3h.

PROSEA. (1999). Plant Resources of South-East Asia No 12(1): Medicinal and poisonous plants 1.

Kirtikar, K.R. and Basu, B.D. (1935). Indian Medicinal Plants.

Wealth of India: The Raw Materials Series. Publications and Information Directorate, CSIR.

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18. Disclaimer

Solanum nigrum is considered safe for moderate use only when properly prepared. Unripe berries and raw leaves contain toxic glycoalkaloids and should be avoided.

This information is for educational and academic purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Pregnant or nursing women should consult a healthcare professional before use.

Individuals on medication, especially antidiabetics, antihypertensives, and immunosuppressants, should consult a qualified healthcare practitioner before use.

Do not discontinue prescribed medications without consulting your doctor.

Proper identification is crucial to avoid confusion with potentially toxic species.

Always consult a qualified healthcare practitioner before using any plant for medicinal purposes.

PREHEALING

Solanum nigrum(Solanaceae)- Manthakkali, Black Nightshade, Makoi

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