Effects of Onion Peel Extract on Endothelial Function

Effect of Onion Peel Extract on Endothelial Function and Endothelial Progenitor Cells in Overweight and Obese Subjects

Acute or chronic intake of polyphenol-rich foods has been reported to improve endothelial function. Quercetin, found abundantly in onion, is a potent antioxidant flavonoid. This study was designed to investigate whether consumption of onion peel extract (OPE) improves endothelial function in healthy overweight and obese subjects.

Study Overview

• Status: Completed
• Conditions: Healthy; Overweight; Obese
• Intervention / Treatment: Drug: Placebo; Drug: Onion peel extract

Detailed Description

Epidemiological studies have shown a rapid increase in the prevalence of overweight and obesity, not only in adults but also in children and adolescents, thus increasing the risk of early development of cardiovascular disease (CVD). Quercetin, found abundantly in onion, prevents the induction of endothelial dysfunction, superoxide production, and overexpression by angiotensin II in the rat aorta. Furthermore, in our previous study we showed that supplementation with quercetin-rich onion peel extract (OPE) influenced adipokine expression, thus addressing its modulatory effect on obesity-induced inflammation, and improved insulin resistance by alleviating the metabolic dysregulation of free fatty acids, suppressing oxidative stress, upregulating glucose uptake, and downregulating inflammatory gene expression. But there are limited studies on the relationship between quercetin supplementation and endothelial dysfunction in humans.

• Study Type: Interventional
• Enrollment (Actual): 62
• Phase: Phase 4

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 130-702
    • Kyung Hee University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age 20 to 60 years
• BMI >23 kg/m2
• abdominal circumference > 90 cm in males or >85 cm in females

Exclusion Criteria:

• hypertension (>140/90 mmHg),
• diabetes
• any cardiovascular disease,
• kidney disease,
• thyroid disease
• cerebrovascular disease
• liver disease (bilirubin level >2 mg/dl)
• pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Patients treated with placebo for 12 weeks	Drug: Placebo; After randomization, placebo was treated for 12 weeks
Experimental: Onion peel extract; Patients treated with onion peel extract for 14 days	Drug: Onion peel extract; After randomization, onion peel extract was treated for 12 weeks; Other Names: OPE

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The difference of endothelial function	The difference of forearm FMD (flow meidated dilation) achieved following study drug treatment	12 weeks after study drug treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The difference of EPC (endothelial progenitor cell) counts	After appropriate gating based on low cytoplasmic granularity and low expression of CD45, CD34+VEGFR2+ cells were counted and expressed as the number of cells/106 total events or number of cells/100 µL of blood.	12 weeks after study drugs treatment

Other Outcome Measures

Outcome Measure	Time Frame
The composite measure of change of blood pressure, heart rate, body weight and blood chemistry	up to 12 weeks

Collaborators and Investigators

• Sponsor: Kyunghee University Medical Center
• Collaborators: Kyunghee University
• Investigators: Principal Investigator: Weon kim, MD, PhD, Kyung Hee University Hospital

Study record dates

Study Major Dates

• Study Start: April 1, 2013
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: June 28, 2014
• First Submitted That Met QC Criteria: July 1, 2014
• First Posted (Estimate): July 2, 2014

Study Record Updates

• Last Update Posted (Estimate): July 2, 2014
• Last Update Submitted That Met QC Criteria: July 1, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Keywords: volunteers; Endothelial function; Quercetin; Onion peel extract
• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: Onion-EPC; Seoul, Korea (Other Grant/Funding Number: No. 1111473)