None listed
Conditions
Brief summary
This project aims to determine if there is a dose-related effect of dietary derived quercetin-3-O-glucoside (commonly found in plant-based fruits and vegetables) on blood vessel function in human volunteers. Quercetin glucosides are the main form of quercetin in the human diet. Quercetin is a flavonoid found in foods such as apples and onions. Our previous short term studies using pure quercetin, or apples, show improved blood vessel function. We now wish to determine if there is a dose related response prior to conducting a large intervention trial. The doses of quercetin-3-O-glucoside to be given are 0mg, 50mg, 100mg, 200mg and 400mg. All of these doses are achievable through dietary changes.
Interventions
The study period is approximately 5 weeks and will require 5 separate visits to the School of Medicine and Pharmacology at Royal Perth Hospital. Each visit will take approximately 2 hours. Volunteers deemed suitable following the screening visit, will be randomised into the study. The study is a randomised, controlled, cross-over design. The subjects will receive each treatment once (0mg, 50mg, 100mg, 200mg and 400mg quercetin-3-O-glucoside), in a random order, with a one week washout period in
The study period is approximately 5 weeks and will require 5 separate visits to the School of Medicine and Pharmacology at Royal Perth Hospital. Each visit will take approximately 2 hours. Volunteers deemed suitable following the screening visit, will be randomised into the study. The study is a randomised, controlled, cross-over design. The subjects will receive each treatment once (0mg, 50mg, 100mg, 200mg and 400mg quercetin-3-O-glucoside), in a random order, with a one week washout period in between. The quercetin will be dissolved in warm water and volunteers will be asked to drink the mixture, blinded to the dose they are receiving. The doses given will be monitored by a study staff not blinded to the treatment. They will also make sure the drink has been finished in the allocated time (10 minutes). There are no known or expected side-effects. Each visit will involve measurement of blood vessel function by non-invasive ultrasound, before and 1 hour after receiving the treatment. Blood pressure will be measured prior to, and 1 hour after treatment; 5 supine measurements will be taken. Volunteers will also be required to give a small blood sample (10ml), 1.5 hours after the treatment, for biochemical analysis of plasma nitrate, nitrite and flavonoid metabolites. Nitrate and nitrite concentrations will be measured by gas chromatography-mass spectrometry (GC-MS). The concentration of flavonoid metabolites will be measured by mass-spectrometry methods.
Sponsors
University of Western Australia
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
20 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy volunteers Living in Perth, Western Australia, and able to visit the reserach centre
Exclusion criteria
Exclusion criteria included current or recent (less than 12 months) smoking; BMI less than 18 or greater than 35 kg/m2; history of cardiovascular or peripheral vascular disease; a systolic BPless than 100 orgreater than 160 mmHg; a diastolic BP less than 50 or greater than 100 mmHg; diagnosed diabetes, and non-diabetic individuals with fasting plasma glucose concentrationsgreater than 6 mmol/L; psychiatric illness or other major illnesses such as cancer; current or recent (within previous 6 months) significant weight loss or gain (greater than 6% of body weight) or actively trying to lose weight; alcohol intake greater than 210g per week for women and greater than 280 g per week for men; and women who are lactating, pregnant or wishing to become pregnant during the study.
Outcome results
None listed