Scavenging of superoxide anion radical by chaparral

Lun Yi Zang, Greg Cosma, Henry Gardner, Kenneth Starks, Xianglin Shi, Val Vallyathan

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


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 V(max), for chaparral scavenging of O2·- were found to be 0.899 μg/mL and 8.4 ng/mL/sec, respectively. The rate constant for chaparral scavenging O2·- was found to be 1.22 x 106 g-1 s-1. Our studies suggest that the antioxidant properties of chaparral may involve a direct scavenging effect of the primary oxygen radical, O2·-.

Original languageEnglish
Pages (from-to)157-161
Number of pages5
JournalMolecular and Cellular Biochemistry
Issue number1-2
StatePublished - 1999

Bibliographical note

Funding Information:
This work was supported by US Army Center for Health Research and National Institute for Occupational Safety and Health funding to Colorado State University.


  • Chaparral
  • EPR
  • Spin trapping
  • Superoxide anion radical

ASJC Scopus subject areas

  • Molecular Biology
  • Clinical Biochemistry
  • Cell Biology


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