The antiepimastigote activity test

The antiepimastigote activity test was carried out in 96-well microplates with exponentially growing cultures as described by Vega, Rolón, Martínez-Fernández, Escario, and Gómez-Barrio
(2005). CD39 was inoculated at a concentration of 1 105 cells/mL in 200 lL of tryptose broth medium. The plates were incubated with the drugs at concentrations of 100 and 500 lg/mL at 28 C for72 h. Afterwards, 50 lL of CPRG substrate solution (chlorophenol red-b-D-galactopyranoside) were added, for a final concentration of 200 lM. The plates were incubated for an additional 6 h at 37 C and read at 595 nm. The efficiency of each compound was estimated by linear regression analysis, which indicated the concentration of extract needed for 50% maximal effect (CE50).