Grape‐Enriched Diets Alter Cardiac Pathology and Cardiac Glutathione Dynamics in Hypertensive Rats

Abstract

Increased fruit and vegetable intake can reduce hypertension, but its effect upon hypertensive cardiac pathology is unknown. This relationship was tested in the Dahl‐Salt Sensitive rat fed a high‐salt diet. Provision of 3% (w:w) whole table grape powder for 18 weeks reduced blood pressure, reduced cardiac hypertrophy, improved cardiac function, and increased cardiac glutathione, a key endogenous antioxidant. Provision of vasodilator hydralazine matched the blood pressure reduction of grape but failed to similarly reduce cardiac pathology. In vitro, phytochemicals found in grapes can alter genes related to Phase I/II metabolism, impacting glutathione dynamics. However, cardiac effects with a whole food are unknown. RT‐PCR analysis indicated that grape provision altered genes for oxidoreductases, transferases, sulfotransferases and peroxidases which affect glutathione dynamics, which on balance, would favor elevated glutathione. Key expression changes are confirmed by immunoblot. Importantly, these changes were conserved in grape‐fed, healthy (low‐salt fed) rats, further supporting the nutrigenomic effects of grape intake. In conclusion, physiologically relevant phytochemical intake reduced hypertensive cardiac pathology and altered cardiac transcripts related to glutathione dynamics, which may be vital to its cardioprotective effects. California Table Grape Commission, NIH‐NHLBI.Grant Funding SourceNIH‐NHLBI, California Table Grape Commission