Medical School

Postgraduate research profiles

Contact

Nicola Bondonno

Phone: (+61 8) 9224 0342


Start date

Mar 2014

Submission date

Mar 2017

Curriculum vitae

Nicola Bondonno CV
[doc, 43.44 kb]
Updated 06 Oct 2014

Nicola Bondonno

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Thesis

An investigation of the effects of quercetin glucoside on risk factors for cardiovascular disease and potential mechanisms of action

Summary

Epidemiological studies suggest that increased consumption of fruit and vegetables is associated with a low incidence of cardiovascular disease (CVD). Flavonoids are derived from plant-based foods and are thought to be the key compounds behind the health benefits of consuming fruit and vegetables. Endothelial dysfunction is an early hallmark of cardiovascular disease and is associated with increased coronary atherosclerosis and risk of coronary events. A major dietary flavonoid, quercetin, has been shown to have beneficial effects on both endothelial function and blood pressure. Quercetin-3-O-glucoside is an important form of quercetin in foods and has a high bioavailability. Peak plasma concentrations of quercetin are reached within an hour of consumption of quercetin-3-O-glucoside. The acute effects of quercetin on blood pressure and blood vessel function have been investigated, however few studies have looked at the effects of chronic supplementation with quercetin or have used the glycoside form. I wish to determine if there is a dose related response prior to conducting a large intervention trial. Using the optimum dose, I wish to investigate both the acute and chronic effect of quercetin glucoside on blood pressure, endothelial function and formation of quercetin metabolites in a population with at least one risk factor for CVD. I will also investigate the mechanism of any beneficial effects via the measurement of plasma levels of nitric oxide and biochemical markers of vascular function and oxidative stress.

Why my research is important

While most human intervention studies examining the effects of polyphenols on vascular function have used whole foods or beverages, few studies have looked at individual components. Further research needs to be done to determine which compounds are involved. The flavonoid quercetin is a potential molecule involved in the protection against CVD that we have associated with a diet high in fruit and vegetables. Long-term studies are needed to determine if these observed effects can be sustained over a period of weeks and to investigate the mechanisms involved. This is important as acute studies are normally carried out while flavonoid metabolites are at peak levels in the circulation; it is less clear if longer term exposure will lead to similar improvements. Many of these studies used quercetin aglycone, when in fact quercetin is usually found in foods bound to sugar molecules. To date no studies have investigated the dose-response of quercetin glucoside, the more bioavailable form of quercetin.


Atherosclerotic lesion (aorta)