Table 3.
O2•−-scavenging activity of shikonin
| O2•−-scavenging activity† | ||
|---|---|---|
| kAOx/kCYPMPO | relative to Trolox | |
| Shikonin | 3,460 ± 530 | 42.0 ± 8.8‡ |
| Alkannin | 3,550 ± 480 | 43.0 ± 8.5‡ |
†The scavenging of O2•− generated by illumination of riboflavin was determined by EPR in a competition assay with CYPMPO, as described in Materials and Methods. Assay conditions are the same as described in Fig. 2. The kAOx/kCYPMPO of Trolox was 83 ± 12 (n = 5). kAOx/kCYPMPO values are means ± SD (n = 5). ‡Scavenging activities relative to Trolox are expressed as means ± propagated error, to reflect both the standard deviations of the antioxidant and Trolox.