Table 3. Half maximal inhibitory concentration (IC50) values and selectivity index values of methanol and oil herbal extracts.
| Herbal extracts | IC50 (µg/ml) on HFF cells | IC50 (µg/ml) on RH-GFP | Selectivity index (SI) |
|---|---|---|---|
| Citronella oil | 38.16 ± 8.16 | 2.54 ± 1.01 | 15.02 |
| Citrullus colocynthis (Colocynth) | 27.74 ± 0.74 | 22.86 ± 3.43 | 1.21 |
| Laurus nobilis (Bay laurel) | 173.50 ± 55.57 | 31.35 ± 17.01 | 5.53 |
| Lemon grass oil | 28.76 ± 2.67 | 4.57 ± 0.21 | 6.25 |
| Marjoram oil | 148.95 ± 61.87 | 26.24 ± 7.63 | 5.67 |
| Matricaria chamomilla (German chamomile) | 464 ± 9.05 | 3.56 ± 2.21 | 130.33 |
| Sulfadiazine | >1,000* | 99.40* | N.D. |
IC50 values were calculated based on three independent experiments. Data are expressed as mean ± SD. *Data from [47]. N.D.=not detected. HFF, human foreskin fibroblast; RH-GFP, a green fluorescent protein expressing-RH strain of T. gondii.