Bitter leaf consists of the fresh or dried leaves of Vernonia amygdalina .A shrub or small tree, 2-5 m high with striate pubescent branches, becoming glabrous on maturity; leaves alternate, obovate-lanceolate, entire or finely toothed. Bitterleaf is a highly appreciated vegetable in West and Central Africa and can be consumed in various dishes. Leaf decoctions are used to treat fever, malaria, diarrhoea, dysentery, hepatitis and cough, as a laxative and as a fertility inducer. One of the most common medicinal uses of Vernonia amygdalina is as a treatment against intestinal worms including nematodes. In Zimbabwe a root infusion is used to treat sexually transmitted diseases. The bitterness is caused by sesquiterpene lactones (e.g. vernodalin, vernolepin and vernomygdin) and steroid glucosides (vernoniosides). Some of these compounds have significant antiparasitic activity, especially vernodalin and vernonioside B1. Vernolepin showed platelet anti-aggregating properties. Vernodalin and vernomygdin have cytotoxic activity.Aqueous leaf extracts containing the peptides, edotides, have been found to be potent inhibitors of mitogen-activated protein kinases (MAPK), important agents for the growth of breast cancer cells; the anti-oestrogen drug, tamoxifen, is known to be an MAPK modulator (Atanaskova et al., 2002; Mandlekar and Kong, 2001). Leaf extracts showed inhibitory activity against Trichomonas vaginalis (Hakizamungu et al., 1992) and the aqueous leaf extracts caused reductions in blood sugar levels of normoglycaemic and alloxan diabetic rabbits (Akah andOkafor, 1992).