White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Effects of Quercetin on Uric Acid Metabolism

Shi, Yuanlu (2015) Effects of Quercetin on Uric Acid Metabolism. PhD thesis, University of Leeds.

Thesis_Yuanlu Shi_2015.pdf - Final eThesis - complete (pdf)
Available under License Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales.

Download (100Mb) | Preview


Background and Objective: High blood uric acid (hyperuricemia) is a common phenomenon in populations with hypertension, hyperglycemia, obesity and/or dyslipidemia. This study was to investigate the effects of quercetin supplementation on blood uric acid level and the biochemical mechanism behind it. Methods: A pilot trial confirmed the delivery of quercetin from a supplement tablet in healthy males (n=6). Randomised, double-blind, cross-over, placebo-controlled 4-week dietary intervention trial with the same supplement tablet containing 500 mg quercetin d-1 was conducted in selected healthy males (n=22, with higher blood uric acid but within normal range). Changes of uric acid and glucose were analysed in fasting blood plasma at 0, 2 and 4 weeks. Plasma metabolomics were profiled by 1H-NMR. Where quercetin and its metabolites may affect in the pathway of uric acid metabolism was investigated in vitro and ex vivo. Results: At the end of the 4-week trial, plasma uric acid levels were significantly reduced (mean change -26.5 µM, 95% CI -7.6 to -45.5, P = 0.008, n=22), as were diastolic blood pressures in normotensive subjects (-3.1 mm Hg, -0.5 to -5.8, P = 0.048, n=10). Paired plasma 1H-NMR spectrum showed lowered glutamine (P = 0.008), acetoacetate (P = 0.005) and lactate (P = 0.03) after quercetin treatment. A dose-dependent inhibition of quercetin, quercetin-3'-O-sulfate and 3,4-dihydroxyphenylacetic acid on xanthine oxidase in vitro and a mild inhibitory effect of quercetin on plasma adenosine deaminase was found. Conclusions: Quercetin supplementation can maintain blood uric acid level and blood pressure within a low-risk range. It is probably a result of regulated purine metabolism by quercetin, its microbial derivatives and their metabolites.

Item Type: Thesis (PhD)
Keywords: uric acid, gout, quercetin, fasting glucose, blood pressure, NMR, xanthine oxidase, adenosine deaminase, purine nucleoside phosphorylase
Academic Units: The University of Leeds > Faculty of Maths and Physical Sciences (Leeds) > Food Science (Leeds)
Identification Number/EthosID: uk.bl.ethos.666590
Depositing User: Dr Yuanlu Shi
Date Deposited: 21 Sep 2015 10:44
Last Modified: 25 Jul 2018 09:51
URI: http://etheses.whiterose.ac.uk/id/eprint/9693

You do not need to contact us to get a copy of this thesis. Please use the 'Download' link(s) above to get a copy.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)