Absorption and Metabolism of Olive Leaf Extract and Its Effect on Vascular Reactivity and Cytokine Concentrations

The purpose of this study is to determine how olive leaf is absorbed and metabolised and also whether it has any effect on the elasticity of blood vessels and the immune system.

Study Overview

• Status: Completed
• Conditions: Absorption and Metabolism; Effect on Vascular Function; Effect on Cytokine Concentrations
• Intervention / Treatment: Dietary supplement: Olive leaf extract capsules

Detailed Description

The purpose of this study is to determine how olive leaf is absorbed and metabolised and also whether it has any effect on vascular function and cytokine concentrations.

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Berkshire
    • Reading, Berkshire, United Kingdom, RG6 5SG
      • Hugh Sinclair Unit of Human Nutrition, University of Reading

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 17 years to 38 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 19-40 years, non-smokers, able to swallow capsules, have a Body Mass Index (BMI) of 18.5-30, have a normal liver function and haematology and a max alcohol intake of <21 units/week

Exclusion Criteria:

• Those who suffer from any form of disease, including endocrine disease, liver disease, diabetes mellitus, myocardial infarction, blood clotting disorder, reproductive disorder, gastrointestinal disease or a chronic gastrointestinal disorder.
• Individuals who are vegetarian, have dietary restrictions or on a weight reducing diet will not be recruited.
• Subjects who have been taking antibiotics in previous 3 months before study will not be included in the study
• Females who may be pregnant, or if of childbearing potential and are not using effective contraceptive precautions will be excluded.
• Blood pressure > 150/90 mmHg
• Haemoglobin < 125 g/l for male, < 110 g/l for female
• Gamma GT (liver enzymes) > 80 IU/l
• Cholesterol > 6.5 mmol/l
• Had suffered a myocardial infarction or stroke in the previous 12 months
• On any lipid-modifying medication
• On any medication affecting blood clotting
• Individuals taking vitamin and/or fish oil supplements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo capsule; Four placebo capsules containing safflower oil only	Dietary supplement: Olive leaf extract capsules; Four capsules taken at baseline each containing 4mg oleuropein
Active Comparator: Olive leaf extract capsule; Four olive leaf capsules. Each containing 4mg oleuropein plus safflower oil.	Dietary supplement: Olive leaf extract capsules; Four capsules taken at baseline each containing 4mg oleuropein

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Absorption and metabolism	Olive leaf polyphenol metabolites measured in blood and urine samples	0. 0.5, 1, 1.5, 2, 3, 4, 6, 8 hours post ingestion (blood) 0, 0-4, 4-8 and 8-24 hours post ingestion (urine)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vascular function	Vascular function was assessed via two methods: Laser Doppler Iontophoresis (LDI) and Digital Volume Pulse (DVP)	0, 2, 4, 6 hours post ingestion (LDI) 0, 0.5, 1, 1.5, 2, 3, 4, 6 and 8 hours post ingestion (DVP)
Cytokine concentration	Concentrations of IL-8, IL-1beta, IL-6, IL-10 and TNF-alpha will be measured in whole blood stimulated with LPS.	0, 1, 3 and 6 hours post ingestion

Collaborators and Investigators

• Sponsor: University of Reading
• Collaborators: Comvita UK
• Investigators: Principal Investigator: Ian Rowland, PhD, University of Reading; Principal Investigator: Parveen Yaqoob, PhD, University of Reading

Study record dates

Study Major Dates

• Study Start: June 1, 2011
• Primary Completion (Actual): October 1, 2011
• Study Completion (Actual): October 1, 2011

Study Registration Dates

• First Submitted: November 22, 2011
• First Submitted That Met QC Criteria: November 22, 2011
• First Posted (Estimate): November 24, 2011

Study Record Updates

• Last Update Posted (Estimate): November 24, 2011
• Last Update Submitted That Met QC Criteria: November 22, 2011
• Last Verified: November 1, 2011

More Information

Terms related to this study

• Keywords: Bioavailability; Cytokines; Polyphenols; Vascular function; Olive leaf extract
• Other Study ID Numbers: OLE study