Table 3. Anti-HSV type-1 and HSV type-2 activity (EC50) of LabyA1.
| Virus strain | EC50 (µM)a | |||
| LabyA1 | Cidofovir | Acyclovir | ||
| HSV-1 wild-type | KOS (reference strain) | 0.56±0.05 | 0.48±0.11 | 0.18±0.09 |
| RV-174 (clinical isolate) | 2.7±1.0 | 1.3±0.1 | 0.31±0.02 | |
| RV-175 (clinical isolate) | 2.8±0.5 | 1.1±0.1 | 0.18±0.03 | |
| C559142 (clinical isolate) | 0.45±0.02 | 0.53±0.09 | 0.09±0.02 | |
| Median EC50 | 1.6 µM | 0.82 µM | 0.18 µM | |
| HSV-1 TK−b | RV-294 (clinical isolate) | 0.31±0.00 | 0.30±0.02 | 25±0.0 |
| RV-179 (clinical isolate) | 1.9±0.3 | 0.39±0.12 | 89±0.0 | |
| RV-117 (clinical isolate) | 1.9±0.6 | 0.50±0.12 | >79 | |
| Median EC50 | 1.9 µM | 0.39 µM | >79 µM | |
| HSV-2 wild-type | G (reference strain) | 0.32±0.05 | 0.60±0.10 | 0.27±0.01 |
| RV-124 (clinical isolate) | 1.4±0.4 | 1.3±0.3 | 0.40±0.06 | |
| RV-24 (clinical isolate) | 0.41±0.28 | 1.1±0.3 | 0.13±0.09 | |
| Median EC50 | 0.41 µM | 1.1 µM | 0.27 µM | |
| HSV-2 TK−b | RV-129 (clinical isolate) | 0.32±0.19 | 0.55±0.20 | 74±12 |
| BA19026589 (clinical isolate) | 0.29±0.10 | 0.95±0.24 | 29±9 | |
| Median EC50 | 0.31 µM | 0.75 µM | 52 µM | |
a
EC50, 50% effective concentration or compound concentration required to reduce virus-induced cytopathicity (CPE) by 50%. Mean EC50± SEM up to 3 independent experiments are shown. Cidofovir and acyclovir are used as reference compound.
b
TK−: thymidine kinase-deficient HSV strains (resistant to acyclovir, see [32] for more detail).