In the final assay mixture, fluorescein (40 nM) was used as a target of free radical attack with either 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH, 20 mM) as a peroxyl radical generator in peroxyl radical-scavenging capacity (ORACROO·) assay [22] or with H2O2-CuSO4 (H2O2, 0.75%; CuSO4, 5 µM) as a hydroxyl radical generator in hydroxyl radical-scavenging capacity (ORACHO·) assay