DNA fragmentation and cell cycle analysis.

(a) Detection of DNA fragmentation by TUNEL assay. Parasites (2×106 ml-1) were cultured with CBD and pentamidine (34 μg ml-1) for 72 h at 22°C. The TUNEL staining was carried out as described in methods. ***PL. donovani promastigotes (2×106 ml-1) were treated with test fraction and pentamidine (34 μg ml-1). Post 72 h, the cells were processed for PI staining and flow cytometry analysis as described in methods. (c) Bar graph depicting changes in cell population in different stages of interphase in treated as well as untreated samples. ***P<0.001 with respect to parasite control.