Molecular mechanisms by which white tea prevents oxidative stress

• Autores: Cristóbal Espinosa Ruiz, Francisca Pérez Llamas, Francisco Antonio Guardiola Abellán, María Ángeles Esteban Abad, Marino Bañón Arnao, Salvador Zamora Navarro, José Angel López Jiménez
• Localización: Journal of physiology and biochemistry, ISSN-e 1877-8755, ISSN 1138-7548, Vol. 70, Nº. 4, 2014, págs. 891-900
• Idioma: inglés
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• Resumen

  • The flavonoid content of tea (Camellia sinensis) has beneficial properties in the prevention of diseases. However, the mechanisms by which white tea can protect against oxidative stress remain unclear. To shed light on this issue, rats were given distilled water (controls), 0.15 mg/day (dose 1) or 0.45 mg/day (dose 2) of solid tea extract/kg body weight for 12 months. All the animals received an injection of adriamycin (ADR; 10 mg/kg body weight), except half of the control group, which were given an injection of saline solution. The expression of the nuclear factor, E2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (Nqo1), glutathione S-transferase (Gst), haem oxygenase-1 (Ho1), catalase (Cat), superoxide dismutase (Sod) and glutathione reductase (Gr) in liver was analysed by real-time PCR, and the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) was measured spectrophotometrically. ADR significantly increased the expression of Nrf2, Gst, Nqo1, Ho1, Cat, Sod and Gr with respect to the control levels and also increased the activity of CAT, SOD and GR. The intake of white tea increased in a higher degree the expression of Nrf2, Gst, Nqo1 and Ho1 in the tea + ADR group compared with the control group and C + ADR group. In addition, tea + ADR groups decreased the expression and activity of CAT, SOD and GR in a dose-dependent manner.