Antimutagenicity of green tea polyphenols in the liver of transgenic medaka

Environ Mol Mutagen. 2005 Aug;46(2):88-95. doi: 10.1002/em.20136.

Abstract

We examined the ability of a mixture of the predominant green tea polyphenolic compounds (GTP) to reduce benzo[a]pyrene (B[a]P)-induced mutations in the cII gene of the lambda transgenic medaka. Fish were treated with 50 ppb B[a]P for 24 hr, followed by exposure to 2 ppm or 10 ppm GTP for 28 days. cII mutations in livers of fish exposed to B[a]P were increased significantly, 2.6-fold above controls. In contrast, the addition of GTP significantly reduced the frequency of cII mutants by 84%, comparable to that of controls. The frequencies of mutations at G:C basepairs, mutations that are highly characteristic of B[a]P exposure, were elevated significantly in treated fish. By comparison, B[a]P-exposed fish also treated with GTP showed reductions in these mutations, demonstrating a protective effect of GTP against B[a]P-induced mutagenesis. The antioxidant mechanism of GTP possibly played an important role in the reduction of B[a]P mutagenicity. These results corroborate findings from rodent models, showing that the protective effects of green tea extend to different species, and suggesting that similar mechanisms of B[a]P mutagenesis and GTP antimutagenesis are shared among the models. These studies illustrate the utility of lambda transgenic medaka for in vivo mutation analyses and suggest that this fish may be a valuable model in chemoprevention studies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Antimutagenic Agents / chemistry
  • Antimutagenic Agents / pharmacology*
  • Benzo(a)pyrene / antagonists & inhibitors
  • Benzo(a)pyrene / toxicity
  • Carcinogens / antagonists & inhibitors
  • Carcinogens / toxicity
  • Flavonoids / chemistry
  • Flavonoids / pharmacology*
  • Liver / chemistry
  • Liver / drug effects*
  • Mutagenicity Tests
  • Mutation
  • Oryzias* / genetics
  • Phenols / chemistry
  • Phenols / pharmacology*
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Polyphenols
  • Tea / chemistry*

Substances

  • Antimutagenic Agents
  • Carcinogens
  • Flavonoids
  • Phenols
  • Plant Extracts
  • Polyphenols
  • Tea
  • Benzo(a)pyrene