title: Molecular mechanisms by which white tea prevents oxidative stress.
abstract: 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.
authors.affiliation: Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Campus de Espinardo, 30100, Murcia, Spain, cespinosa31416@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Espinosa
authors.forename: F
authors.initials: F
authors.lastname: Pérez-Llamas
authors.forename: F A
authors.initials: FA
authors.lastname: Guardiola
authors.forename: M A
authors.initials: MA
authors.lastname: Esteban
authors.forename: M B
authors.initials: MB
authors.lastname: Arnao
authors.forename: S
authors.initials: S
authors.lastname: Zamora
authors.forename: J A
authors.initials: JA
authors.lastname: López-Jiménez
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000633:toxicity; D028241:Camellia sinensis / Q000737:chemistry; D002374:Catalase / Q000378:metabolism; D004317:Doxorubicin / Q000633:toxicity; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D013662:Tea / Q000737:chemistry*
chemical_list: D000903:Antibiotics, Antineoplastic; D010936:Plant Extracts; D013662:Tea; D004317:Doxorubicin; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase