Table 3.
Antioxidant activities of extracts and some isolated compounds from R. abyssinicus
| Extracts/compounds | DPPH free radical scavenging activity (EC50, μg/mL) | Gallic acid equivalent antioxidant capacity (GEAC, μg/mL) |
|---|---|---|
| MeOH extract | 62.11 ± 0.39a | 73.23 ± 0.61a |
| EtOAc fraction | 72.29 ± 0.71b | 58.44 ± 0.38b |
| n-BuOH fraction | 76.54 ± 0.78c | 40.46 ± 0.74c |
| 1 | 4.52 ± 0.36d | 104.87 ± 1.43d |
| 2 | 3.08 ± 0.44e | 106.03 ± 0.87d |
| 4 | 10.69 ± 0.51f | 79.54 ± 1.26e |
| 5 | 9.88 ± 0.62f | 81.09 ± 0.93e |
| 6 + 7 | 7.63 ± 1.27g | 83.38 ± 0.22f |
| Vitamin C | 1.81 ± 0.19h | / |
EC50: Equivalent concentrations of test samples scavenging 50% of DPPH radical. Data represent the mean ± SD of three independent experiments carried out in triplicate. In the same column, values affected by different superscript letters (a-h) are significantly different according to one way ANOVA and Waller Duncan test; p < 0.05; /: not determined