In testing for antiparasitic activity, Leishmania promastigotes in cell culture were grown in RMPI medium. The test compounds were dissolved in DMSO and serially diluted twofold in 96-well
microplates. The promastigotes were then added at a final concentration of 106 cells/mL, and their growth was evaluated after 72 h by direct counting of cells and compared with an untreated control.The efficiency of each compound was estimated by linear regression analysis, which indicated the concentration of extract needed for50% maximal effect (CE50).