Antiprotozoal activity and cytotoxicity of metabolites from leaves of Teclea trichocarpa

Chromatographic separation of the leaves of Teclea trichocarpa (Engl.) Engl. (Rutaceae) used traditionally by Akamba tribe in Kenya yielded three acridone alkaloids, a furoquinoline alkaloid and two triterpenoids. The total extract (methanol) of the leaves of this plant and the isolated compounds were screened for in vitro for cytotoxicity and against parasitic protozoa, Plasmodium falciparum, Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. Among the compounds -amyrin had the best anti-plasmodial activity (IC50 = 0.96 g/ml), normelicopicine and skimmianine had the best anti-trypanosomal activity against T. b. rhodesiense (IC50 = 5.24 g/ml) and T. cruzi (IC50 = 14.50 g/ml), respectively. Normelicopicine also exhibited best anti-leishmanial activity (IC50 = 1.08 g/ml). Arborinine exhibited moderate cytotoxicity (IC50 = 12.2 g/ml) against L-6 cells. The compounds with low anti-protozoal and high cytotoxicity IC50 values are potential source of template drug against parasitic protozoa.