Table 2 Cytotoxicity against Caco-2 cells (LC50, mg/mL) and Selectivity Index (SI) of the nine selected acetone crude extracts. Selectivity index values ≥1 show that an extract is more toxic to the pathogens than to the mammalian cells. The higher the SI, the less cytotoxic the extract, indicating possible enhanced safety
| Â | Â | Selectivity index (SI) | Â | ||||||
|---|---|---|---|---|---|---|---|---|---|
Cytotoxicity | STA, F6 | EAST1 | STA | STX2E, STA | Sta, EAST-1, AIDA 1 | STA, STB, LTB, EAST 1, O149, F4 | E. coli (ATCC) | Mean SI | |
E. erythrophylla | 0.29 | 1.84 | 7.35 | 3.68 | 3.68 | 3.68 | 1.23 | 2.76 | 3.46 |
E. natalitia | 0.03 | 0.45 | 0.45 | 0.89 | 0.45 | 0.45 | 0.22 | 0.22 | 0.45 |
E. woodii | 0.18 | 2.25 | 2.25 | 2.25 | 2.25 | 2.25 | 2.25 | 1.12 | 2.09 |
E. umtamvunensis | 0.59 | 3.76 | 7.53 | 7.53 | 3.76 | 15.06 | 2.51 | 1.88 | 6.01 |
E. zeyheri | 0.66 | 16.91 | 8.46 | 8.46 | 4.23 | 4.23 | 2.82 | 5.07 | 7.17 |
S. legatii | 0.17 | 4.47 | 4.47 | 4.47 | 4.47 | 4.47 | 2.98 | 2.23 | 3.94 |
S. masukuense | 0.07 | 0.95 | 1.90 | 1.90 | 0.47 | 0.95 | 0.95 | 0.95 | 1.15 |
S. sp. | 0.07 | 0.84 | 1.68 | 1.68 | 1.68 | 1.68 | 0.56 | 0.84 | 1.28 |
S. gerrardii | 0.40 | 2.54 | 1.27 | 2.54 | 10.17 | 1.27 | 6.78 | 1.27 | 3.69 |
Doxorubicin (μM) | 0.76 | NA | NA | NA | NA | NA | NA | NA | NA |