In vitro activity of Triclisia patens and some bisbenzylisoquinoline alkaloids against Leishmania donovani and Tryanosoma brucei brucei

In the search for antiprotozoal compounds from natural sources, Triclisia patens displayed activity against L. donovani promastigotes (IC50 = 1.5 mug/mL) and T.b. brucei blood stream trypomastigote forms (IC50 = 31.25 mug/mL). In addition, a total of 20 bisbenzylisoquinoline alkaloids were screened for antileishmanial and antitrypanosomal activity in vitro. Fangchinoline (IC50 = 0.39 muM) was found to be as active as the standard pentamidine against Leishmania donovani promastigotes. Phaeanthine was threefold more active IC50 = 2.41 muM; 1.5 mug/mL) than the standard drug Pentostam against L. donovani amastigotes, but at this concentration was toxic to murine macrophages. In contrast, cocsoline IC50 = 12.3 muM; 6.76 mug/mL) was as active as Pentostam, and was not toxic to macrophages at this concentration. Thalisopidine showed the strongest activity (IC50) = 1.14 muM) against Trypanosoma brucei brucei blood stream form trypomastigotes, but was less active than pentamidine. Copyright (C) 2002 John Wiley Sons, Ltd.