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Effects of Onion Peel Extract on Endothelial Function

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02180022
Recruitment Status : Completed
First Posted : July 2, 2014
Last Update Posted : July 2, 2014
Kyunghee University
Information provided by (Responsible Party):
Weon Kim, Kyunghee University Medical Center

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Healthy Overweight Obese Drug: Placebo Drug: Onion peel extract Phase 4

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 62 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Supportive Care
Official Title: Effect of Onion Peel Extract on Endothelial Function and Endothelial Progenitor Cells in Overweight and Obese Subjects
Study Start Date : April 2013
Actual Primary Completion Date : December 2013
Actual Study Completion Date : December 2013

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 Name: OPE

Primary Outcome Measures :
  1. The difference of endothelial function [ Time Frame: 12 weeks after study drug treatment ]
    The difference of forearm FMD (flow meidated dilation) achieved following study drug treatment

Secondary Outcome Measures :
  1. The difference of EPC (endothelial progenitor cell) counts [ Time Frame: 12 weeks after study drugs treatment ]
    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.

Other Outcome Measures:
  1. The composite measure of change of blood pressure, heart rate, body weight and blood chemistry [ Time Frame: up to 12 weeks ]

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02180022

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Korea, Republic of
Kyung Hee University Hospital
Seoul, Korea, Republic of, 130-702
Sponsors and Collaborators
Kyunghee University Medical Center
Kyunghee University
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Principal Investigator: Weon Kim, MD, PhD Kyung Hee University Hospital

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Responsible Party: Weon Kim, Professor, Kyunghee University Medical Center Identifier: NCT02180022    
Other Study ID Numbers: Onion-EPC
Seoul, Korea ( Other Grant/Funding Number: No. 1111473 )
First Posted: July 2, 2014    Key Record Dates
Last Update Posted: July 2, 2014
Last Verified: June 2014
Keywords provided by Weon Kim, Kyunghee University Medical Center:
Endothelial function
Onion peel extract
Additional relevant MeSH terms:
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Body Weight
Signs and Symptoms