Table 2.
TPC and antioxidant activity of the studied species
| Species name | TPC (mg GAE/g DW) | DPPH (I%) |
|---|---|---|
| 1 mL OH AuNPs | 6.25±0.57 | 70.61±4.39 |
| OVE | 21.58±0.11 | 46.80±2.20a |
| Vitamin C (10 μg/mL) | – | 89.53±4.47 |
Notes: Each value is the mean ± SD of three independent measurements.
a
For the DPPH tests, the extracts were diluted 69 times in order to have the same TPC as the colloids.
Abbreviations: TPC, total phenolic content; GAE, gallic acid equivalent; DW, dry weight plant material; DPPH, 2,2-diphenyl-1-picrylhydrazyl; OH, Origanum herba; AuNP, gold nanoparticle; OVE, Origanum vulgare extract; SD, standard deviation.