Table 3.
Comparison of EC50s of a range of plant extracts known to contain cysteine proteinase activity
| Enzyme | EC50(μM) |
| Milkweed latex extract | 3 |
| Ficin | 5 |
| Pineapple fruit extract | 5 |
| Chymopapain | 7.5 |
| Papain | 7.5 |
| Crude papaya latex | 12.5 |
| Stem bromelain | 75 |
| Ficus benjamina latex | 140 |
| Ficus carica latex | 150 |
| Kiwi fruit extract | None |
All values are in micromolar concentrations of enzyme activity, as determined by active site titration, that caused 50% reduction in motility after 90 minutes of incubation with H. bakeri