title: Oral administration of trans-resveratrol to guinea pigs increases cardiac DT-diaphorase and catalase activities, and protects isolated atria from menadione toxicity.
abstract: Resveratrol (3,4',5-trihydroxy-trans-stilbene) is a natural phytoalexin found in grapes and wine. It has antioxidant and antiproliferative activities, and has been shown to induce NAD(P)H:quinone oxidoreductase, also known as DT-diaphorase, in cultured mouse hepatoma cells. DT-diaphorase is a detoxifying enzyme for quinone-containing substances, due to its ability to prevent their one-electron reduction and the consequent generation of reactive oxygen species (ROS). The aim of the present study was to investigate whether oral administration of trans-resveratrol to guinea pigs (60 mg/l in tap water for 16 days, ad libitum) increases cardiac DT-diaphorase and, consequently, reduces the response of isolated atria to 2-methyl-1,4-naphthoquinone (menadione), the positive inotropic effect of which is related to the amount of ROS generated by its cardiac metabolism. In the cardiac tissue of resveratrol-treated animals, DT-diaphorase activity was significantly higher than that measured in control animals, the V(max) of the enzyme reaction being 75.47 +/- 3.87 and 50.73 +/- 0.63 nmoles/mg protein/min, respectively (p < 0.05). Resveratrol administration also significantly increased the activity of cardiac catalase (32.20 +/- 2.39 vs. 25.14 +/- 3.85 units/mg protein in treated and control animals, respectively; p < 0.001). As a consequence, menadione metabolism by the cardiac homogenate obtained from resveratrol-treated animals generated a smaller amount of ROS and, in electrically driven left atria, menadione produced a significantly lower increase in the force of contraction than in atria isolated from control animals. These results indicate that oral administration of resveratrol exerts cardioprotection against ROS-mediated menadione toxicity.
authors.affiliation: Department of Pharmacology and Anesthesiology, University of Padova, Largo Meneghetti 2, 35131, Padova, Italy. maura.floreani@unipd.it <maura.floreani@unipd.it>
authors.forename: Maura
authors.initials: M
authors.lastname: Floreani
authors.forename: Eleonora
authors.initials: E
authors.lastname: Napoli
authors.forename: Luigi
authors.initials: L
authors.lastname: Quintieri
authors.forename: Pietro
authors.initials: P
authors.lastname: Palatini
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects / Q000473:pathology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000201:enzymology*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D024483:Vitamin K 3 / Q000037:antagonists & inhibitors* / Q000633:toxicity*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D017382:Reactive Oxygen Species; D013267:Stilbenes; D024483:Vitamin K 3; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D016660:NAD(P)H Dehydrogenase (Quinone); D005980:Glutathione Reductase; D005978:Glutathione; D000077185:Resveratrol