Gnetum africanum: A Wild Food Plant from the African Forest with Many Nutritional and Medicinal Properties

Abstract

Gnetum africanum is a forest liana that grows abundantly in Central Africa, South America, and tropical and subtropical Asia. Its leaves are eaten as a vegetable, either raw or finely chopped and cooked; they are also widely used as an ingredient in soups and stews and are much in demand for their nutritional and therapeutic properties. In the latter application, various fractions of G. africanum are used medicinally to treat many different illnesses. Many studies have also shown that the chemical composition of the leaves of this plant gives it significant nutritional properties, and its high fiber, protein, and calorie content support these claims. Several molecular compounds related to the families of stilbenes, glycosylflavones, and flavonostilbenes have been isolated and identified in the leaf extract of this plant. These molecules give the plant its interesting properties and biological activities.

Acute and sub-chronic oral toxicity studies on the methanol leaf extract of Gnetum africanum Welw in wistar rats.

“…Although G. africanum has been reported to contain anti-nutritional and toxic components, they occur at levels below their toxicity thresholds. Ali, Assanta and Robert [13] reported that whereas the toxicity level for hydrocyanic acid is 35 mg/10 g dry matter, the level of this acid in the leaves of this plant is only 0-5.4 mg/100g. Also for oxalate to be toxic, it must be present in concentrations of the order of 2-5 g/100 g dry matter, whereas in G. africanum concentrations of 16-68 mg/100 g DM were detected [13].…”

“…Ali, Assanta and Robert [13] reported that whereas the toxicity level for hydrocyanic acid is 35 mg/10 g dry matter, the level of this acid in the leaves of this plant is only 0-5.4 mg/100g. Also for oxalate to be toxic, it must be present in concentrations of the order of 2-5 g/100 g dry matter, whereas in G. africanum concentrations of 16-68 mg/100 g DM were detected [13]. However, many toxicity studies on Gnetum africanum in the literature were done using 3-30-day toxicity tests [25][26][27].…”

“…They are eaten raw as local salad, and shredded and used in preparing soups and stews [10]. It is a good source of protein and has been noted as an anti-inflammatory, anti-carcinogenic, and antioxidant [13]. It is widely used by people of southern Nigeria as therapy and food for diabetics [12].…”

Intake of Gnetum Africanum and Dacryodes Edulis, Imbalance of Oxidant/Antioxidant Status and Prevalence of Diabetic Retinopathy in Central Africans

“…They are collected in the wild rather than cultivated throughout tropical Africa. The Asutan variety is very rich in crude fibers [50], [51].…”

Wild Food, Prices, Diets and Development: Sustainability and Food Security in Urban Cameroon

“…Most wild foods available in markets throughout the country originate from the forest zone. For example, leafy green vegetables are "mainstays in the diets of rural and urban households across most of Africa" more generally, and are especially important in Central Africa [133][134][135]. Wild leafy vegetables may be the major source of micronutrients for the majority of resource-poor people throughout the region [12,71,135,136].…”