Scavenging of superoxide anion radical by chaparral.
Zang-LY; Cosma-G; Gardner-H; Starks-K; Shi-X; Vallyathan-V
Mol Cell Biochem 1999 Jun; 196(1):157-161
Chaparral is considered to act as an antioxidant. However, the inhibitory effects of chaparral on specific radical species are not well understood. Using electron paramagnetic resonance (EPR) spectroscopy in combination with spin trapping techniques, we have found that chaparral scavenges superoxide anion radical (O2·-) in a dose-dependent manner. 5,5-dimethyl-lpyrroline-N-oxide (DMPO) was used as a spin trapping agent and the reaction of xanthine and xanthine oxidase as a source of O2·-. The kinetic parameters, IC50 and Vmax, for chaparral scavenging of O2·- were found to be 0.899 g/mL and 8.4 ng/mL/sec, respectively. The rate constant for chaparral scavenging O2·- was found to be 1.22 x 106 g-1s-1. Our studies suggest that the antioxidant properties of chaparral may involve a direct scavenging effect of the primary oxygen radical, O2·-.
Antioxidants; Antioxidation; Dose-response; Health-care; Free-radicals; Dietary-effects; Statistical-analysis; Plant-substances; Plants
L.-Y. Zang, Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505-2888, USA
Molecular and Cellular Biochemistry