Chapter

Oxygen Transport to Tissue XXXII

Volume 701 of the series Advances in Experimental Medicine and Biology pp 283-289

Date:

Antioxidant Properties of Quercetin

  • Mei ZhangAffiliated withDepartment of Radiation Oncology, University of Florida
  • , Steven G. SwartsAffiliated withDepartment of Radiation Oncology, University of Florida
  • , Liangjie YinAffiliated withDepartment of Radiation Oncology, University of Florida
  • , Chaomei LiuAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
  • , Yeping TianAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
  • , Yongbing CaoAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
  • , Michael SwartsAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
  • , Shanmin YangAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
  • , Steven B. ZhangAffiliated withDepartment of Radiation Oncology, University of Florida
    • , Kunzhong ZhangAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , Shaoqing JuAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , David J. OlekJr.Affiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , Lisa SchwartzAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , Peter C. KengAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , Rob HowellAffiliated withDepartment of Radiation Oncology, University of Rochester Medical Center
    • , Lurong ZhangAffiliated withDepartment of Radiation Oncology, University of Florida
    • , Paul OkunieffAffiliated withDepartment of Radiation Oncology, University of Florida Email author 

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Abstract

Quercetin, a plant-derived aglycone form of flavonoid glycosides, has been used as a nutritional supplement and may be beneficial against a variety of diseases, including cancer. We examined the antioxidant properties of quercetin. The reduction potential of quercetin was measured at various pH values using voltammetric methods, and its total antioxidant capacity (TAC) was measured using the phosphomolybdenum method. The effect of quercetin on production of reactive oxygen species (ROS) and nitric oxide (NO) in LPS-stimulated human THP-1 acute monocytic leukemia cells was determined by flow cytometry using CM-H2DCFDA dye. The results were compared with curcumin, a natural product exhibiting a similar range of reported health benefits. Results: 1) Quercetin has a higher reduction potential compared with curcumin at three different pH settings and is comparable to Trolox at pH 7-9.5; 2) its TAC is 3.5 fold higher than curcumin; 3) it reduced LPS-induced ROS to near normal levels; 4) it reduced LPS-induced NO production. These data provide a physico-chemical basis for comparing antioxidants, with potential benefits individually or in combination.