Exploring the Use of Indigenous Wild Vegetables by the Basotho People of Southern Africa: A Comprehensive Review of the Literature and Nutritional Analysis of Selected Species

Wild indigenous vegetables have recently been receiving attention due to their accessibility and potential to fight malnutrition. The current study investigated the nutritional profile of 10 selected wild indigenous vegetables, namely Asclepias multicaulis, Lepidium africanum, Erucastrum austroafricanum, Solanum nigrum, Sonchus dregeanus, Sonchus integrifolius, Sonchus nanus, Rorippa fluviatilis, Tribulus terrestris, and Urtica lobulata, consumed by the Basotho people of southern Africa. This was done by first compiling a comprehensive literature review to identify the knowledge gaps and further analysing the selected vegetables for mineral contents and proximate compositions using standard analytical procedures of AOAC. The literature survey revealed that 90 wild plants are used as vegetables by the Basotho people, and there are knowledge gaps on the nutritional value of many species. Mineral analyses of the wild vegetables showed that Asclepias multicaulis and Sonchus dregeanus are rich in minerals such as Al, Ca, K, Mg, Na, P, and S and can compete favourably with commercialised vegetables such as lettuce and spinach in terms of mineral components. Also, all the wild vegetables studied have more than 12% recommended caloric protein value except Tribulus terrestris (10.07%) and Lepidium africanum (11.32%). The crude fat content in Asclepias multicaulis, Lepidium africanum, Rorippa fluviatilis, Erucastrum austroafricanum, and Urtica lobulata fall within the range required for healthy living. The concentrations of cadmium, copper, and lead in all the vegetables studied are below the detection level, thus making them non-toxic and safe for consumption.