Antihypertensive and cognitive effects of grape polyphenols in estrogen-depleted, female, spontaneously hypertensive rats

Abstract

Both endogenous and dietary estrogens reduce hypertension and enhance cognitive abilities in estrogen-depleted female spontaneously hypertensive rats (SHR). Many of the beneficial effects of estrogens/phytoestrogens also appear to be provided by other polyphenols (e.g., proanthocyanidins) in grape seed, which lack appreciable estrogenic receptor binding. The present study tested the hypothesis that similar to phytoestrogens, proanthrocyanidins in grape seed polyphenols reduce salt-sensitive hypertension in young, estrogen-depleted SHR. SHR were ovariectomized at 4 wk of age and placed on phytoestrogen-free diets with or without 0.5% grape seed extract added and with high (8.0%) or basal (0.6%) NaCl. After 10 wk on the diets, grape proanthrocyanidin supplementation significantly reduced arterial pressure in the rats fed the basal (10 mmHg) and high (26 mmHg)-NaCl diet, compared with the nonsupplemented controls. In vitro superoxide production was significantly reduced (23%) by the grape seed polyphenols. Spatial learning (8-arm-radial maze) in the SHR on the basal NaCl diets was improved by dietary grape seed polyphenols. These results indicate that grape seed polyphenols decrease arterial pressure in SHR, probably via an antioxidant mechanism.

Effects of Grape Seed Proanthocyanidin on 5-Hydroxytryptamine3 Receptors in NCB-20 Neuroblastoma Cells

“…10) Proanthocyanidin is a kind of phenolic compound (oligonols are catechin-type monomers, dimmers and trimers, as well as oligomeric proanthocyanidins) present in plants, especially highly present in the grape seed, that has received attention recently. 11,12) Experimental and clinical studies have revealed that proanthocyanidin has antioxidant, antinociceptive, anti-emetic, and cardioprotective properties, without inducing significant toxicological effects. [13][14][15][16] In view of the above reports, we try to investigate whether proanthocyanidin has any effects on the activity of 5-HT 3 receptors.…”

Grape Seed Proanthocyanidin Extracts Enhance Endothelial Nitric Oxide Synthase Expression through 5′-AMP Activated Protein Kinase/Surtuin 1–Krüpple Like Factor 2 Pathway and Modulate Blood Pressure in Ouabain Induced Hypertensive Rats

“…The superoxide anion scavenging activity of GSPE was stronger than vitamin C, vitamin E or any other antioxidant. 1) It has been reported to have protective effects on various cardiac disorders, correct dyslipidemia associated with high-fat diet, 2) decrease arterial pressure in estrogen-depleted female spontaneously hypertensive rats, 3) prevent diabetic nephropathy and neuropathy from progressing, 4,5) and most importantly, ameliorate atherosclerosis, 6) possibly attributed to its endothelial protective potential.…”

Plant derived therapeutics for the treatment of Metabolic Syndrome

“…Grape seed extract (GSE) is a rich botanical source of polyphenols (approximately 90% of which are procyanidins and 7% other polyphenol compounds) [52], and has become popular for the treatment and prevention of heart disease and other disorders. In vivo, the hypotensive effects of GSE were demonstrated in spontaneously hypertensive rats fed a 0.5% GSE-supplemented diet with basal (0.6%) or high (8.0%) NaCl, leading to a reduction in mean arterial pressure of 10 and 26 mmHg, respectively, compared with nonsupplemented groups [52].…”

“…In vivo, the hypotensive effects of GSE were demonstrated in spontaneously hypertensive rats fed a 0.5% GSE-supplemented diet with basal (0.6%) or high (8.0%) NaCl, leading to a reduction in mean arterial pressure of 10 and 26 mmHg, respectively, compared with nonsupplemented groups [52].…”