Growth kinetics and cytocidal/cytostatic activity

The compounds (at 1 μg/ml) were tested for their effects on the growth kinetic pattern against the promastigotes of L. donovani. The parasite cells (2 x 10⁵ cells/ml) were incubated at 25° C in the presence of the test compounds in M199 supplemented with 10% FBS. Amphotericin B treated parasites (0–50 μg/ml) were used as the positive control while the untreated promastigotes in medium alone served as the negative control. Viable cells were counted every 24 hrs for a total of 120 hrs as indicated in previous studies [14, 16].

The cytocidal/cytostatic effect of the test compounds were assessed by analyzing the treated and untreated parasites after 120 hrs of incubation. Cells were washed twice with fresh M199, resuspended in complete M199 media and incubated further for 96 hrs. The viable cells were then counted microscopically [14, 16, 19].