Hyperglycemia-induced oxidative stress and heart disease-cardioprotective effects of rooibos flavonoids and phenylpyruvic acid-2-O-β-D-glucoside

Abstract

Diabetic patients are at an increased risk of developing heart failure when compared to their non-diabetic counter parts. Accumulative evidence suggests chronic hyperglycemia to be central in the development of myocardial infarction in these patients. At present, there are limited therapies aimed at specifically protecting the diabetic heart at risk from hyperglycemia-induced injury. Oxidative stress, through over production of free radical species, has been hypothesized to alter mitochondrial function and abnormally augment the activity of the NADPH oxidase enzyme system resulting in accelerated myocardial injury within a diabetic state. This has led to a dramatic increase in the exploration of plant-derived materials known to possess antioxidative properties. Several edible plants contain various natural constituents, including polyphenols that may counteract oxidative-induced tissue damage through their modulatory effects of intracellular signaling pathways. Rooibos, an indigenous South African plant, well-known for its use as herbal tea, is increasingly studied for its metabolic benefits. Prospective studies linking diet rich in polyphenols from rooibos to reduced diabetes associated cardiovascular complications have not been extensively assessed. Aspalathin, a flavonoid, and phenylpyruvic acid-2-O-β-D-glucoside, a phenolic precursor, are some of the major compounds found in rooibos that can ameliorate hyperglycemia-induced cardiomyocyte damage in vitro. While the latter has demonstrated potential to protect against cell apoptosis, the proposed mechanism of action of aspalathin is linked to its capacity to enhance the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression, an intracellular antioxidant response element. Thus, here we review literature on the potential cardioprotective properties of flavonoids and a phenylpropenoic acid found in rooibos against diabetes-induced oxidative injury.

The impact of coenzyme Q10 on metabolic and cardiovascular disease profiles in diabetic patients: A systematic review and meta‐analysis of randomized controlled trials

“…NO is broadly considered as one of the most vital molecules produced in the human body, and its acts as an essential regulator in a vast array of crucial physiological functions, especially the maintenance of vascular tone . Research over the years has led to the identification of several ROS generating systems that could potentially be modulated in conditions of hyperglycaemia . However, therapeutic approaches currently being used to improve cardiovascular function, including maintenance of vascular tone such as aspirin and statins present with limited antioxidant properties to protect against oxidative stress .…”

Trolox prevents high glucose‐induced apoptosis in rat myocardial H9c2 cells by regulating GLUT‐4 and antioxidant defense mechanism

“…GPx is susceptible to free radical‐mediated OS, and it is obvious that in the present study, GPx activity is significantly decreased in H9c2 cells treated with high glucose concentration time‐dependently. Earlier reports have indicated that reduced GPx is responsible for hyperglycemia‐induced OS and heart disease …”

Molecular Mechanism of Functional Ingredients in Barley to Combat Human Chronic Diseases

“…Lignans in barley have high anti-inflammatory abilities in endothelial cells by reducing nuclear factor-κB and extracellular signal as well as regulating kinase phosphorylation [156]. The polyphenols such as (+)-catechin, protocatechuate, and quercetin in barley not only have hepatoprotective effect [130] but also prevent coronary heart disease by reducing oxidativeinduced tissue damage through modulating intracellular signaling pathways [157]. Polyphenols play an important role in alleviating cardiovascular diseases due to their antiradical scavenging abilities [18].…”