title: Dietary green tea extract increases phase 2 enzyme activities in protecting against myocardial ischemia-reperfusion.
abstract: Green tea catechins are dietary antioxidant compounds that have been shown to protect against myocardial ischemia-reperfusion (IR) injury. Considering reports that catechins can induce phase 2 enzymes in cultured cells and some organs, we hypothesized that part of the protection to heart against IR injury may involve elevation of phase 2 enzyme activities. Rats were fed for 10 days with either control diet (sham and control groups) or the diet mixed with 0.25% green tea extract. At the end of 10 days, hearts were excised and subjected to global ischemia for 20 min followed by reperfusion for 2 hours. The hearts were compared for indices of cell death, oxidative stress, and phase 2 enzyme activities. Hearts from the green tea group had a 65% to 85% decrease in markers of apoptosis, a tendency to higher total glutathione, and higher activities of the phase 2 enzymes glutamate cysteine ligase and quinone reductase. The results support a possible involvement of phase 2 enzymes in the protection by green tea catechins against myocardial IR injury.
authors.affiliation: School of Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Akhlaghi
authors.forename: Brian
authors.initials: B
authors.lastname: Bandy
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives; D004032:Diet; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000201:enzymology; D015428:Myocardial Reperfusion Injury / Q000201:enzymology / Q000517:prevention & control*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D013662:Tea / Q000737:chemistry
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D013662:Tea; D002392:Catechin; D016660:NAD(P)H Dehydrogenase (Quinone); D005721:Glutamate-Cysteine Ligase; D005978:Glutathione