African Nightshade (Solanum nigrumcomplex species)

Abstract

African nightshades belong to the Solanum nigrum complex species which is characterized by taxonomical complexity. Species such as Solanum scabrum, Solanum villosum, Solanum americanum, Solanum eldorettii, Solanum chenopodioides, Solanum retroflexum, Solanum florulentum, Solanum grossidentatum, Solanum tarderemotum, Solanum physalifolium and Solanum nigrum have been regarded as African nightshades due to their origin or naturalization in Africa. Some species grow as weeds and some are cultivated. They are sensitive to low soil moisture levels and are not considered to be drought tolerant. African nightshades can be used to contribute to daily nutrient requirements as they are good sources of proteins (2.5% to 39.7%), fibre (1.3% to 19%), minerals and vitamins. Furthermore, they can contribute up to about 1485.3 kJ of energy per 100 g of vegetable portion. These species are also beneficial beyond their nutritional value as they possess phytochemicals with antioxidant and anti-inflammatory bioactivities. Some species possess anti-cancer, anti-diabetic and hepatoprotective activities. The consumption of these species is hindered by the presence of antinutritional compounds such as phytates, oxalates, steroidal glycoalkaloids and saponins. However, processing methods such as boiling and blanching have been found to reduce the concentration of antinutrients to non-toxic levels.