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 language | English (US) |
|---|---|
| Pages (from-to) | 495-504 |
| Number of pages | 10 |
| Journal | In Vivo |
| Volume | 28 |
| Issue number | 4 |
| State | Published - Jul 1 2014 |
Keywords
- Antioxidant capacity
- Hepatocarcinogenesis
- Nrf2
- Peroxiredoxin 6
- Tea polyphenols
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Cancer Research
- Pharmacology