Introduction to Solanum nigrum: nightshade and its relevance
Solanum nigrum, popularly known as nightshade, is a herbaceous plant belonging to the Solanaceae family. Its presence covers almost all temperate and subtropical regions of the world, demonstrating its remarkable capacity for adaptation and resistance. Since ancient times, nightshade has been part of popular culture for its uses in traditional medicine, its toxic potential and its food uses in certain regions, which makes it a species of great botanical and ethnobotanical interest.
Botanical characteristics of Solanum nigrum
Nightshade is a annual or, exceptionally, perennial plant, which usually reaches between 10 and 80 centimeters in height, although in ideal conditions it can exceed this range. Its bearing is generally erect, with branched stems that can be pubescent or glabrousThere are numerous morphological variations, depending on environmental factors and the ecotype, which has led to the existence of different subspecies and taxonomic synonyms attributed by various botanists.
- Leaves: Alternate, ovate or lanceolate, with an entire margin, wavy or slightly toothed, with a dark green color. Their length varies between 2,5 and 7 cm, and they have petioles of 1 to 4 cm.
- Tallos: They can sometimes be woody at the base, erect and branched, with a tendency to be more flexible the younger they are.
- Flores: Arranged in clusters (racemiform cymes) of 3 to 10 small, white, hermaphrodite flowers with prominent yellow anthers, similar to those of the potato. The corolla is rotaceous, with five, usually open petals.
- Fruits: Subglobose berries, up to 1 centimeter in diameter, that start out green and turn black, smooth, and shiny as they ripen. Inside, they contain numerous tiny, compressed, beige or orange seeds.
It flowers and bears fruit most of the year, depending on the local climate, and is commonly found in Roadsides, disturbed land, waste dumps, crop borders and ruralized environmentsThanks to its hardiness, it can even grow in poor soils.
Identification, distribution and habitat
El Solanum nigrum It is native to Eurasia, but has established itself in the Americas, Australasia, Africa, and other parts of the world. It is one of the most common weeds in temperate regions, having naturalized outside its original range. It typically grows from sea level to approximately 1200 meters above sea level, adapting to both sunny and shady environments.
Some of its vernacular names include: devil's tomatillo, dog grape, black nightshade, nightshade, Borda tomato plant, black tomatillo and others, varying according to the region. In Galicia it is known as herba das bagas, herba dona, herba da fistola, herba negral y can grapes.
Chemical composition and active ingredients
- alkaloids: They highlight the solanine, solasonine, solanigrin and solamargineThey are largely responsible for its pharmacological effects and toxicity.
- Saponins: With emollient and anti-inflammatory properties.
- Tannins: With astringent properties, used in phytotherapy to control bleeding or irritation.
- Citric acid: It plays an antioxidant role and is common in many plants of the family.
- Nitrates and asparagine: They contribute to its medicinal action and can influence its toxicity.
This combination of compounds gives nightshade a wide variety of pharmacological effects, but also explains its potential risk if not handled with caution.
Traditional medicinal properties of Solanum nigrum
Solanum nigrum It has been used in traditional medicine systems on various continents, although its toxicity currently limits its use to preparations made under professional supervision. The parts used include leaves, stems, and, to a lesser extent, fruits. The following are the attributed therapeutic effects:
- Internal use:
- Analgesic and sedative: Traditionally it has been used to calm stomach pain, liver pain, gallstones and colic. It was used as a sedative in cases of insomnia or anxiety.
- Antispasmodic: Indicated to relieve muscle spasms and digestive discomfort.
- Anti-inflammatory and antipyreticLeaf preparations (teas, infusions) were used to lower fever and treat internal inflammatory processes.
- Purgative and diuretic: Its mild laxative effect in small doses and as a stimulant of liquid elimination have been described.
- Expectorant and stomach tonic: Used to improve bronchial and digestive conditions.
- Aphrodisiac and restorativeAlthough less documented, some popular traditions attribute a general stimulating effect to it.
- External use:
- Poultices and decoctions: Applied to the skin to relieve eczema, psoriasis, ulcers, rashes, pustules, burns, herpes, cracks and other skin lesions due to its emollient and anti-inflammatory effect.
- Local analgesia: For the treatment of bumps, bruises, arthritis and abscesses.
- Toothache relief: Rinses and gargles with infusions have been used.
- Skin disorders and wounds: Its effectiveness in controlling skin infections is attributed to its natural antimicrobial active ingredients.
Specific applications in folk medicine and industry
In some regions of Central and South America, especially in El Salvador, the cooked leaves of Solanum nigrum They are used in the preparation of soups and stews, since prolonged cooking reduces toxicity by degrading solanine. In addition, in the pharmaceutical industry Solasodine, extracted from the berries and fresh leaves, has been used for the synthesis of steroids. The most valued medicinal properties include its emollient effect, soothing rheumatic pain and antineuralgic.
The following are mentioned: recognized main applications:
- Traditional skin treatment: eczema, psoriasis, wounds, abscesses, herpes.
- Relief of joint and muscle pain through plasters.
- Symptomatic relief of fever, colds and bronchitis.
- Complementary external use for insect bites, especially wasp bites.
- Use as a natural insecticide and molluscicide in domestic agriculture.
Toxicity and precautions for use
La solanine and other alkaloids present in nightshade are potent toxins. toxicity It depends on the ripeness of the fruit, the terrain, the harvest season, and the plant's nutritional status. Symptoms of poisoning include vomiting, stomach pain, fever, drowsiness, paralysis, and even death in extreme cases. It is essential to note that:
- Eating green fruits is particularly dangerous. due to its high alkaloid content.
- Solanum nigrum should not be given to pregnant or nursing women or young children., due to its sensitivity.
- The margin between the therapeutic dose and the toxic dose is very narrow, so its use is only recommended under professional supervision.
- Their homemade preparations are not recommended; for the treatment of minor ailments, there are safer phytotherapeutic alternatives.
Solanine has also been used as an insecticide and molluscicide in agricultural practices, given its neurotoxic properties for various pests.
The nightshade, Solanum nigrum, represents one of the most unique medicinal and wild plants due to its combination of beneficial properties and potential risks. It has been used in traditional medicine and the pharmaceutical industry, although its toxicity requires caution and in-depth knowledge of the plant for proper handling. Its widespread distribution, variety of popular names, and wealth of active ingredients make it a resource of both ethnobotanical and scientific interest, maintaining its relevance today as an object of study and a historical reference in the use of medicinal plants.