Chronic intake of a phytochemical-enriched diet reduces cardiac fibrosis and diastolic dysfunction caused by prolonged salt-sensitive hypertension

Abstract

Salt-sensitive hypertension is common in the aged population. Increased fruit and vegetable intake reduces hypertension, but its effect on eventual diastolic dysfunction is unknown. This relationship is tested in the Dahl Salt-Sensitive (Dahl-SS) rat model of salt-sensitive hypertension and diastolic dysfunction. Table grape powder contains phytochemicals that are relevant to human diets. For 18 weeks, male Dahl-SS rats were fed one of five diets: low salt (LS), a low salt + grape powder (LSG), high salt (HS), a high salt + grape powder (HSG), or high salt + vasodilator hydralazine (HSH). Compared to the HS diet, the HSG diet lowered blood pressure and improved cardiac function; reduced systemic inflammation; reduced cardiac hypertrophy, fibrosis, and oxidative damage; and increased cardiac glutathione. The HSH diet similarly reduced blood pressure but did not reduce cardiac pathogenesis. The LSG diet reduced cardiac oxidative damage and increased cardiac glutathione. In conclusion, physiologically relevant phytochemical intake reduced salt-sensitive hypertension and diastolic dysfunction.

Figures

Figure 1

Serial body weight. Each value given is the mean from 12 rats per group. Shown without error bars to preserve visualization. Both the high salt (HS) and high salt + vasodilator hydralazine (HSH) groups were significantly affected, *p < .05 vs low salt (LS) group. LSG = low salt + grape powder diet group; HSG = high salt + grape powder diet group.

Figure 2

Systolic blood pressure. Each value given is an average from 12 rats per group ± standard error of the mean. *At least p < .05 vs low salt (LS) group; **p < .05 vs high salt (HS) group. HSG=high salt+grape powder diet group; HSH = high salt + vasodilator hydralazine diet group; LSG = low salt + grape powder diet group.