Effect of Brewing Duration on the Antioxidant and Hepatoprotective Abilities of Tea Phenolic and Alkaloid Compounds in a t-BHP Oxidative Stress-Induced Rat Hepatocyte Model.
Molecules
; 20(8): 14985-5002, 2015 Aug 17.
Article
em En
| MEDLINE
| ID: mdl-26287152
ABSTRACT
Tea is an interesting source of antioxidants capable of counteracting the oxidative stress implicated in liver diseases. We investigated the impact of antioxidant molecules provided by a mixture of teas' leaves (green, oolong, pu-erh) after different infusion durations in the prevention of oxidative stress in isolated rat hepatocytes, by comparison with pure epigallocatechin-3-gallate (EGCG), the main representative of tea catechins. Dried aqueous tea extracts (ATE) obtained after 5, 15 and 30 min infusion time were characterized for total polyphenols (gallic acid equivalent), catechins, gallic acid and caffeine (HPLC-DAD/ESI-MS) contents, and for scavenging ability against 2,2-diphenyl-1-picrylhydrazyl free radical. Hepatoprotection was evaluated through hepatocyte viability tests using tert-butyl hydroperoxide as a stress inducer, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, neutral red uptake, real-time cellular impedance) and mitochondrial function tests. We showed that a 5-min incubation time is sufficient for an optimal bioaccessibility of tea compounds with the highest antioxidative ability, which decreases for longer durations. A 4-h pretreatment of cells with ATE significantly prevented cell death by regulating reactive oxygen species production and maintaining mitochondrial integrity. Pure EGCG, at doses similar in ATE (5-12 µM), was inefficient, suggesting a plausible synergy of several water-soluble tea compounds to explain the ATE beneficial effects.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenóis
/
Chá
/
Estresse Oxidativo
/
Substâncias Protetoras
/
Hepatócitos
/
Alcaloides
/
Antioxidantes
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Molecules
Assunto da revista:
BIOLOGIA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
França