FBS0701 inhibits early stage not late stage gametocytes.

<p>Gametocyte cultures of <i>P. falciparum</i> NF54 strain were initiated at 0.5% asexual parasitemia and 4% hematocrit in 24 well culture plates. Gametocytes were visualized and counted on Day 18 with no drug (A) or 100 uM FBS0701 dosed in wells at Days 9–10 (B) or Days 14–15 (C) post-culture initiation. Dose dependent inhibition is more pronounced with early gametocyte stage I and II (day 9–10 dosing) than gametocyte late stages III-IV (day 14–15 dosing) (D). Gametocytes were inoculated at 0.5% parasitemia, resulting in gametocyte induction, followed by dosing of FBS0701 on indicated days. Gametocytes per 10 high power fields (excess of 1000 erythrocytes) in each of three replicate wells for each condition were counted on Day 18. Control wells had 7.4% mean gametocytes. Data expressed as percent inhibition of control. Standard deviation <u>of triplicate observations</u> for each of the three wells is shown.