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NCT Number: NCT02180022

Effects of Onion Peel Extract on Endothelial Function

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.

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Key information

Conditions

Healthy Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Obese Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

20 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Kyung Hee University Hospital

Seoul, 130-702, South Korea

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Placebo

Drug

After randomization, placebo was treated for 12 weeks

Onion peel extract

Drug

After randomization, onion peel extract was treated for 12 weeks

Other names: OPE

Primary outcomes

  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 outcomes

  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 outcomes

  1. The composite measure of change of blood pressure, heart rate, body weight and blood chemistry

    Time frame: up to 12 weeks

Sponsors and collaborators

Lead sponsor

Kyunghee University Medical Center

Other

Collaborators

  • Kyunghee University

Registry information

Official study title

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

Important dates

Study start
2013
Primary completion
2013
Study completion
2013
First posted
Jul 2, 2014
Registry last updated
Jul 2, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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