Untitled

Abstract

In fructose-induced hypertension in Wistar-Kyoto (WKY) rats, excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca2+ channels and increasing cytosolic free calcium and blood pressure. The thiol compound N-acetyl cysteine prevents fructose-induced hypertension by binding excess endogenous aldehydes and normalizing membrane Ca2+ channels and cytosolic free calcium. The aim of the present study was to investigate whether dietary supplementation of vitamin E and vitamin C which are known to increase tissue glutathione, a storage form of cysteine, prevents this hypertension and its associated biochemical and histopathological changes. Starting at 7 weeks of age, animals were divided into four groups of six animals each and treated as follows: control group, normal diet and normal drinking water; fructose group, normal diet and 4% fructose in drinking water; fructose + vitamin E group, diet supplemented with vitamin E (34 mg/ kg feed) and 4% fructose in drinking water; fructose + vitamin C group, diet supplemented with vitamin C (1,000 mg/kg feed) and 4% fructose in drinking water. At 14 weeks, systolic blood pressure, platelet [Ca2+]i and kidney and aortic aldehyde conjugates were significantly higher in the fructose group. These animals also displayed smooth muscle cell hyperplasia in the small arteries and arterioles of the kidneys. Dietary vitamin E and C supplementation in fructose-treated WKY rats prevented the increase in systolic blood pressure by normalizing cytosolic [Ca2+]i and kidney and aortic aldehyde conjugates and preventing adverse renal vascular changes.

Oxidative stress causes hypertension and activation of nuclear factor-κB after high-fructose and salt treatments

“…Several trials have been conducted to determine whether antioxidant treatment may reduce BP, but the results are conflicting242526. Extracellular SOD, the first-line endogenous defense, is normally present in living tissues and converts to hydrogen peroxide (H 2 O 2 ) that is degraded to water and molecular oxygen by CAT27.…”

Apocynin improves endothelial function and prevents the development of hypertension in fructose fed rat

“…Treatment with antioxidants has been shown to reduce blood pressure in this model. [2829] Recently, it has been reported that vascular superoxide production is increased in fructose-fed rat, and in vitro incubation with apocynin prevents this increase in vascular superoxide production. [9] Further, it has been found that NAD(P)H oxidase expression and activity are increased in cardiovascular tissues in fructose-fed animals.…”

Fructose and sugar: A major mediator of non-alcoholic fatty liver disease

“…While fruits contain fructose, they are less likely to induce metabolic syndrome due to the lower fructose content per fruit (compared to a soft drink) and also because they contain constituents (flavonols, epicatechin, ascorbate, and other antioxidants) that may combat the effects of fructose (58). …”

“…Likewise, there is evidence that many substances found in natural fruits, such as the flavanols, epicatechin, vitamin C and other antioxidants may also protect against fructose-induced metabolic syndrome (58, 144, 145). This may explain why intake of natural fruits are not associated with NAFLD.…”