Acta Pharm. 65 (2015) 65-73
Original research paper
Effect of oral administration of green tea
extract in various dosage schemes on oxidative stress status of mice in vivo
HANA
BÁRTÍKOVÁ, LENKA SKÁLOVÁ, KATEŘINA VALENTOVÁ, PETRA MATOUŠKOVÁ, BARBORA
SZOTÁKOVÁ, JAN MARTIN, VOJTĚCH KVITA and IVA BOUŠOVÁ
1 Faculty
of Pharmacy, Charles University in Prague, CZ-500 05 Hradec Králové, Czech
Republic
2 Faculty
of Medicine and Dentistry, Palacký University, CZ-775 15 Olomouc, Czech
Republic
Accepted October 15, 2014
Green tea is a favorite beverage and its extracts are popular components of dietary supplements. The aim of the present in vivo study was to obtain detailed information about the effect of a standard green tea extract (Polyphenon, P), at different doses, on antioxidant enzymes and oxidative stress markers in murine blood, liver, small and large intestine. In all doses, P improved the oxidative stress status via an increased content of plasmatic SH-groups (by 21–67 %). Regarding antioxidant enzymes in tissues, the low dose of P had the best effect as it elevated the activity of NADPH/quinone reductase in liver and small intestine, thioredoxin reductase in small intestine and hepatic superoxide dismutase. Based on these facts, consumation of green tea seems to be safe and beneficial, while consumption of dietary supplements containing high doses of catechins may disturb oxidative balance by lowering the activity of thioredoxin reductase, glutathione S-transferase, glutathione reductase and superoxide dismutase.
Keywords: green tea extract, flavonoids, green tea catechins,
antioxidant enzymes