Effects of Onion Peel Extract on Endothelial Function

Phase 4

Completed

• Conditions: Obese; Healthy; Overweight
• Interventions: Drug: Placebo; Drug: Onion peel extract

• Registration Number: NCT02180022
• Lead Sponsor: 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.

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 Timeline

• Study Start: 2013-04
• Primary Completion: 2013-12
• Study Completion: 2013-12
• Status Verified: 2014-06
• Study First Submitted: 2014-06-28
• Study First Submitted QC: 2014-07-01
• Last Update Submitted: 2014-07-01
• Study First Posted: 2014-07-02
• Last Update Posted: 2014-07-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 62

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Patients treated with placebo for 12 weeks
Onion peel extract	Onion peel extract	Patients treated with onion peel extract for 14 days

Primary Outcome Measures

Name	Time	Method
The difference of endothelial function	12 weeks after study drug treatment	The difference of forearm FMD (flow meidated dilation) achieved following study drug treatment

Secondary Outcome Measures

Name	Time	Method
The difference of EPC (endothelial progenitor cell) counts	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.

Trial Locations

Locations (1)

Kyung Hee University Hospital; 🇰🇷 Seoul, Korea, Republic of