Acute toxicity associated with the use of South African traditional medicinal herbs

Abstract

Traditional medicines, mainly of plant origin, are regularly taken in South Africa by 60–80% of the population. The materia medica that underpins this ancient practice is drawn almost entirely from natural stands of vegetation, and large volumes of plant material are traded annually on informal markets, some 750 species being in common use. These medicines are at present neither regulated nor subject to formal quality control measures. The World Health Organisation (WHO), the South African Health Ministry and its regulatory body, the Medicines Control Council, require that traditional remedies be subject to the same criteria applied to all medicines: those of quality, safety and efficacy. Medicines safety is of paramount concern and toxicological studies are necessary to establish safety profiles of indigenous traditional remedies. This paper reviews some of the available data, which suggest that indigenous traditional medicines are mostly without harmful side effects, but that some 40 plant species may be a cause for concern. Inappropriate use of these species is associated with a high mortality rate, particularly among paediatric patients. There is also a need to give attention to possible interactions between traditional and Western allopathic medicines taken concurrently, as well as to infraspecific variation in plant secondary biochemistry, with the occurrence of particularly potent biotypes. Pending the outcome of toxicological studies, interim preventive measures, aimed at reducing the number of hospital admissions due to poisoning by traditional remedies, are suggested.