Table 7.
Comparative overview of IC50 values as well as total antioxidant capacities of Thymus ethanolic extracts, polyphenolic compounds, and reference antioxidants.
| Samples | IC50 (μg/mL) | Total antioxidant capacity (mg AAE/g)∗ | ||||
|---|---|---|---|---|---|---|
| DPPH radical scavenging activity | NO radical scavenging activity | Reducing power | Iron chelating activity | Inhibition of lipid peroxidation | ||
| T. longicaulis | 3.01 ± 0.02a | 71.57 ± 4.85a | 11.84 ± 0.11a | 271.85 ± 7.94a | 34.30 ± 7.37a | 293.82 ± 11.64a,b |
| T. praecox subsp. polytrichus | 3.41 ± 0.16b | 139.04 ± 5.69b | 15.10 ± 0.64b | 388.77 ± 3.28b | 78.74 ± 7.08b | 287.72 ± 12.52b,c |
| T. pulegioides | 4.18 ± 0.02c | 69.77 ± 4.38a | 11.39 ± 0.07a | 277.10 ± 1.03a | 34.83 ± 7.36a | 251.26 ± 0.75d,e |
| T. serpyllum subsp. serpyllum | 6.01 ± 0.44d | 176.59 ± 8.09c | 14.55 ± 0.57b | 342.04 ± 6.89c | 80.00 ± 9.93b | 238.16 ± 2.50d |
| T. striatus | 4.06 ± 0.04c | 91.09 ± 5.34d | 14.68 ± 0.38b | 333.14 ± 4.39c | 63.01 ± 7.44b | 276.04 ± 3.38c |
| T. vulgaris | 5.60 ± 0.07e | 97.93 ± 2.93d | 14.41 ± 0.19b | 125.91 ± 2.50d | 69.60 ± 5.14b | 257.87 ± 5.76e |
| Rosmarinic acid | 0.66 ± 0.03f | 15.67 ± 0.44e | 2.67 ± 0.10c | na | 21.07 ± 1.63a | 598.34 ± 8.26f |
| Luteolin | 0.73 ± 0.11f | 18.31 ± 1.02e | 4.51 ± 0.07d | na | 2.03 ± 0.23c | 67.72 ± 3.00g |
| Trolox | 1.67 ± 0.09g | 53.91 ± 0.13f | 6.64 ± 0.36e | na | — | 307.89 ± 2.00a |
| EDTA | — | — | — | 5.34 ± 0.10e | — | — |
∗Results are calculated for sample concentration of 100 μg/mL.
—: not tested; na: no activity. Mean values in the same column followed by different letters are significantly different from each other (P < 0.05).