Antioxidant effects of lipophilic tea polyphenols on diethylnitrosamine/phenobarbital-induced hepatocarcinogenesis in rats

Fan Zhou, Ting Shen, Ting Duan, Yu Ying Xu, Soo Chin Khor, Jin Li, Juan Ge, Yi Fan Zheng, Stephen Hsu, Jamie Ann De Stefano, Jun Yang, Li Hong Xu, Xin Qiang Zhu

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Background: The purpose of the present study was to compare the antioxidant potential of lipophilic tea polyphenols (LTP) against the one of naturally-occurring watersoluble green tea polyphenols (GTP) in a two-stage model of diethylnitrosamine (DEN)/phenobarbital (PB)-induced hepatocarcinogenesis in Sprague-Dawley rats. Materials and Methods: GTP/LTP was given 5-times weekly by oral gavage with tea polyphenols equivalent to 0-, 40- and 400-mg/kg of body weight/day. GTP/LTP treatment was started 2 weeks prior to the initiation of DEN and continued for 30 weeks. Results: Histopathological and electron microscopic examination of liver tissue confirmed the protective effect of LTP on DEN/PBinduced liver damage and pre-carcinogenesis. LTP treatment significantly increased total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) activity in liver tissues. Immunohistochemical detection of cellular nuclear factor erythroid-2-related factor-2 (Nrf2) and peroxiredoxin-6 (P6) indicated a down-regulation in Nrf2 and up-regulation of P6 expression in the liver of LTP-supplemented rats. Conclusion: The present study provides evidence for the first time, that LTP exerts significant antioxidant effects on DEN/PB-induced liver damage and hepatocarcinogenesis through elevating T-AOC levels, enhancing GSH-Px activity and inducing P6 expression in rat liver tissues.

Original languageEnglish (US)
Pages (from-to)495-504
Number of pages10
JournalIn Vivo
Volume28
Issue number4
StatePublished - Jul 1 2014

Keywords

  • Antioxidant capacity
  • Hepatocarcinogenesis
  • Nrf2
  • Peroxiredoxin 6
  • Tea polyphenols

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • Cancer Research
  • Pharmacology

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