Determination of antioxidant activity of herbs by ESR.
Water extracts of 32 herbs that are constituents of curry and curry powder were screened for superoxide anion radical (O2.-) scavenging activity. Among the screened samples, only clove, allspice, and basil were shown to decrease DMPO-O2.- adduct yields by more than 50% at 0.25 mg/mL as measured by an ESR spin trapping technique based on the HPX-XOD reaction. To study the mechanism of the O2.- scavenging activity, Km values were obtained from a Lineweaver-Burk plot for XOD in the presence of different concentrations of HPX, and the IC50 values at different DMPO concentrations were compared. Clove and basil directly eliminated O2.- like superoxide dismutase (SOD), whereas allspice reduced the amount of O2.- by inhibition of formation of O2.-.
Graduate School of Life Science, Tokyo University of Pharmacy and Life Science: 1432-1, Horinouchi, Hachioji, Tokyo 192-0392, Japan.
Young Sook
YS
Yun
Yuki
Y
Nakajima
Etsuko
E
Iseda
Akira
A
Kunugi
D000975:Antioxidants / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000032:analysis; D018649:Ocimum basilicum / Q000737:chemistry; D027841:Pimenta / Q000737:chemistry; D017365:Spices / Q000032:analysis*; D027842:Syzygium / Q000737:chemistry
D000975:Antioxidants; D016166:Free Radical Scavengers