Figure 1.
Kinetics of parasitaemia (asexual stages only, black dots) and gametocytaemia (stages 1–5; black squares) by microscopic observation, represented as a percentage of total erythrocytes.
The number of asexual forms increased up to maximum parasitaemia on day 11. From that time onwards, a rapid decrease occurred leading to a parasitaemia (asexual stages) close to zero on day 17. Sexual forms were first detected on day 7, and gametocytaemia reached a peak of 1.69% on day 13. The gametocytes, initially in early forms, developed into mature stages reaching stages IV and V from day 15 to 20. After day 15, more than 70% of the gametocytes are in stage IV–V.
Figure 2.
Giemsa-stained culture of gametocytes on day 15 after both Nycoprep and magnetic purification steps, (1000×).
Figure 3.
ATP level per gametocyte number (R2 = 0.99) counted with the luminometer after serial dilution.
Gametocytes were counted using a Neubauer chamber. Each point represents mean values of 3 replicates ± SD.
Figure 4.
Comparison of the dose-response curves of artesunate and methylene blue obtained with the ATP bioluminescence assay (black dots) or by microscopic counting (open circles).
Each point represents mean values of 4 replicates ± SD.
Table 1.
Comparison of the activity against mature gametocytes (IC50) using either the ATP bioluminescence assay or the microscopical enumeration.
Table 2.
In vitro activity of the compounds against asexual stages, mature gametocytes and assessment of cytotoxicity in the HepG2 cell line.