Wild Eggplant

The Origins

Solanum torvum (family name Solanaceae), also known by the Latin name Solanum ferrugineum Jacq., is a small shrub native to Mexico, the West Indies and throughout tropical regions of South America. It is also called Turkey berry.

‍

Indigenous Knowledge

In west Mexico it is called “Berenjena”, the same word for its cousin the edible eggplant. The leaves of Solanum torvum are widely regarded for their use as a tea postpartum or mixed with ahuilote (Vitex mollis) for menstrual cramps.

‍

Biomedical Science

The active ingredients in the wild eggplant include ascorbic acid, beta-carotene, niacin, riboflavin, solasodine and thiamin. The seed of Solanum torvum is rich in protein. It contains significant amounts of ascorbic acid, alpha-tocopherol, and sugars. Solanum torvum fruit is a source of polyphenolic antioxidants with free radical scavenging properties. The fruit, leaves, or seeds are commonly extracted into methanol, ethanol, and aqueous preparations for scientific study.

Fruit and juice are used in Cameroon ethnomedicine in the treatment of hypertension, gastric ulcer, tooth decay, fever, and skin infections.

Solanum torvum fruit was studied in vitro (in human liver cells) to reduce oxidative stress in people with diabetes (Kusirisin et al., 2009). A protein extracted from the dried, powdered seeds was also demonstrated to be a powerful antioxidant (Sivapriya and Srinivas, 2006). Dosage and toxicity of Solanum torvum need further study (Kusirisin et al., 2009)

Another study showed that ethanolic extract of Solanum torvum reduced high blood pressure and reversed metabolic alterations induced by fructose in rats (Mohan et al., 2009). The extract prevented and reversed insulin resistance and hyperinsulinemia (Mohan et al., 2009). Injection of aqueous and methanol extracts of Solanum torvum fruit resulted in sudden drops in blood pressure in rats (Nguelefack et al., 2009).

The aqueous solution reversed activity related to the clustering of platelets in the blood that can lead to blood clots. The extract still needs further testing in human trials for its efficacy in the treatment of thrombosis, cardiovascular disease, and hypertension.

Aqueous and methanol extracts of the leaves of Solanum torvum exhibited anti-ulcerogenic properties in rats, most likely by strengthening the stomach mucosal barrier (Nguelefack et al., 2008). Another study done on rats with an aqueous solution of the leaves of Solanum torvum supported the Cameroon ethnomedicinal use of the plant in reducing pain and inflammation (Ndebia et al., 2007). The effect was similar to that of morphine, or opioid-like.

The leaves, roots and bark of Solanum torvum, extracted in a methanol solution, exhibited a broad spectrum effect against microorganisms (Wiart et al., 2004). Similarly, a methanolic flavonoids extract from the fruit was injected in human and animal microorganisms including staph, strep, E. coli, salmonella and fungi Candida, and exhibited strong growth-inhibiting activity against these bacteria (Chah et al., 2000).

A polyphenolic compound with antioxidant properties was isolated from a Solanum torvum fruit extraction (Arthan et al., 2002). The anti-viral activity of the compound against herpes simplex virus type 1 in animals has also been demonstrated (Arthan et al., 2002). A particular steroidal glycoside was also isolated from the same extraction.

An aqueous extract of Solanum torvum fruit was studied for interest as a natural antibody treatment against antigens in the gut (Israf et al., 2004). The extract enhanced the mucous lining in the stomach, which functions as a secretor of antibodies against harmful antigens (certain bacteria, yeasts, and dietary proteins). The study compared the mucosal adjuvant activity of Solanum torvum to cholera toxin, a powerful supporter of mucosal immunity with toxic elements removed. The extract was equivalent in effect to the toxin (Israf et al., 2004). Solanum torvum also exhibited possible stimulation of cytokine cells, which create an immune response against antigens. Enteric immunity was also shown to enhance lung immunity, as these two immune systems are related (Israf et al., 2004). No acute toxic effects were noted, despite a dose equivalent to 30-40 grams for a 60-80 kg. person (Israf et al., 2004).

A single in vitro study noted that a water extract of the seed of Solanum torvum exhibited an iron-chelating effect comparable to EDTA (ethylenediaminetetraacetic acid) (Sivapriya and Srinivas, 2006). EDTA is used to remove excess iron from the body.