Efficiency of traditionally used South African plants against schistosomiasis.

Urinary schistosomiasis is treated traditionally by means of herbal remedies. Forty-eight South African plant species were identified as possible antischistosomic plants. Twenty-one of these plant species were collected in order to investigate their antischistosomal properties. Crude extracts of the plant materials were screened against the schistosomula of the species Schistosoma haematobium. Cercariae were obtained from Bulinus africanus snails through an in vitro technique. By subjecting the cercariae to a sheering stress, they were transformed into schistosomula. The schistosomula were placed into a culture medium to which the plant extracts were added. The results obtained indicated that the plant extracts from Berkheya speciosa (Asteraceae), Euclea natalensis (Ebenaceae) and Trichilia emetica (Meliaceae) are lethal to the schistosomula.