Table 2.
The differing IC50 values indicated that Cryptolepis sanguinolenta, Artemisia annua, and Scutellaria baicalensis showed different inhibitory effects in 30%, 60%, and 90% ethanol extracts.
| Natural product extracts | IC50 values |
|---|---|
| Cryptolepis sanguinolenta (30% EE) | 0.039% (v/v) |
| Cryptolepis sanguinolenta (60% EE) | 0.0041% |
| Cryptolepis sanguinolenta (90% EE) | 0.0046% |
| Artemisia annua (30% EE) | 0.0091% |
| Artemisia annua (60% EE) | 0.0097% |
| Artemisia annua (90% EE) | 0.030% |
| Scutellaria baicalensis (30% EE) | 0.034% |
| Scutellaria baicalensis (60% EE) | 0.038% |
| Scutellaria baicalensis (90% EE) | 0.0097% |
| Cryptolepine | 3.4 µM |
| Artemisinin | 14 µM |
| Baicalein | 12 µM |
| Quinine | 10 µM |
| Clindamycin | 37 µM |
Growth was evaluated by SYBR Green stain at day three after B. duncani exposure to natural product extracts. Each natural product concentration was made in triplicate. IC50 values were calculated in GraphPad Prism (version 7.0). EE, ethanol extract.