Inhibitory effect of oolong tea on the oxidative state of low density lipoprotein (LDL)

Biol Pharm Bull. 2003 May;26(5):739-42. doi: 10.1248/bpb.26.739.


In the present study, we investigated the anti-oxidant activity of oolong tea in an oxidation model using human low-density lipoprotein (LDL). Oolong tea suppressed the oxidation of LDL induced by 2-2'-azobis 4-methoxy-2,4-dimethyvaleronitrile (V70) in a dose-dependent manner, that is, it prolonged the lag time to 114.3%, 138% and 199.9% as compared with the control group at 0.5 microg/ml, 1.0 microg/ml, and 2.5 microg/ml, respectively. We also determined the scavenging effect of oolong tea on active oxygen radicals using the electron spin resonance (ESR) technique with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent. The intensity of the ESR signals for the DMPO-OOH adduct formed by the hypoxanthine/xanthine oxidase reaction system with DMPO decreased in the presence of oolong tea. The IC(50) of oolong tea was 19.9 microg/ml. These findings suggested that oolong tea has beneficial effects on health related to its anti-oxidative action.

Publication types

  • Comparative Study

MeSH terms

  • Antioxidants / chemistry*
  • Free Radical Scavengers / chemistry
  • Humans
  • Lipoproteins, LDL / chemistry*
  • Male
  • Oxidation-Reduction
  • Plant Extracts / chemistry
  • Superoxides / chemistry
  • Tea / chemistry*


  • Antioxidants
  • Free Radical Scavengers
  • Lipoproteins, LDL
  • Plant Extracts
  • Tea
  • Superoxides