TABLE 1.
Activities of selected compounds against MARV and EBOV and cytotoxicities for HeLa cellsa
| Compound | MARV |
EBOV |
Activity in macrophages IC50 (μM) | CC50 (μM) | ||
|---|---|---|---|---|---|---|
| Curve class | IC50 (μM) in HeLa cells | Curve class | IC50 (μM) in HeLa cells | |||
| MLS000078751 | 1.5 | 6.1 ± 0.75 | 1.3 | 25.6 ± 1.5 | ∼25 ± 3.5 | >50 |
| MLS000394177 | 1.3 | 12.9 ± 1 | 1.6 | 1.9 ± 0.25 | 8.6 ± 2 | >50 |
| MLS000534476 | 1.3 | 6.2 ± 0.5 | 1.6 | 24.4 ± 2 | 3.6 ± 0.8 | >50 |
| MLS000554255 | 1.3 | 6.4 ± 0.5 | 1.5 | 6.8 ± 0.75 | 6.0 ± 1.4 | >50 |
| MLS000555232 | 1.3 | 6.3 ± 0.6 | 1.6 | 1.7 ± 0.8 | 9.4 ± 1 | >50 |
| MLS000730532 | 1.3 | 1.9 ± 0.5 | 1.1 | 1.6 ± 0.2 | 9.5 ± 1 | >50 |
| MLS000733230 | 1.3 | 11.7 ± 1.2 | 1.3 | 6.7 ± 0.5 | 4.4 ± 0.3 | >50 |
| MLS000762907 | 1.3 | 12.5 ± 0.8 | 1.3 | 3.2 ± 3 | 23.4 ± 3 | >50 |
| MLS001101371 | 1.3 | 13.0 ± 2 | 1.3 | 12.9 ± 2 | 24.6 ± 2.5 | >50 |
Nine of the 17 compounds confirmed to be hits from the counterscreen were obtained from independent sources, and their activities against both EBOV and MARV were confirmed on HeLa cells. Both the quality of the dose-response curve (curve class, as defined in Fig. S3 in the supplemental material) and inhibitory potency (IC50) are shown. Activity against EBOV was also tested in primary monocyte-derived macrophages (last column). The cytotoxicities of the compounds were measured using a CytoTox-Fluor cytotoxicity assay (Promega). All compounds were found to be noncytotoxic at 50 μM when the viabilities of treated cells were compared to those of untreated cells. The IC50 values shown for MARV and EBOV in HeLa cells are averages ± standard deviations from 3 independent experiments, while the activity in human macrophages is the average ± standard deviations from 2 independent experiments.