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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: The Influence of Citrus Liminoids on Blood Concentration of Cholesterol and Inflammatory Responses in Humans

Location: Immunity and Disease Prevention Research Unit

2012 Annual Report


1a.Objectives (from AD-416):
The pilot study will examine the metabolism, safety and efficacy of increased intake of citrus liminoids by human subjects. The main study will determine their health benefits, particularly the effects on serum lipids and markers of inflammation.


1b.Approach (from AD-416):
In the pilot study 6 healthy subjects (18-65y) with LDL cholesterol greater than 130 mg/dL will be recruited and fed citrus liminoids. The metabolites of limonoids in the serum and urine samples will be determined by the use of mass spectrometry. NMR technology will be used to determine the number and sizes and of different lipoprotein fractions in plasma. Markers of inflammation in the serum and also their ex-vivo production after stimulation of blood cells with mitogens will be determined by ELISA and flowcytometry methods. The design, number of subjects, and the dose of liminoids to be used will depend upon the results obtained from the pilot study.


3.Progress Report:

This agreement supports the goal of objective 1 of the parent project, dealing with the effects of dietary fatty acids on inflammation and prevention of chronic disease. This study investigates the metabolism of limonoid glucoside (LG) in dyslipidemic human subjects, and the effects of LG on plasma markers of inflammation, oxidative stress, and risk factors for cardiovascular disease. We needed ten subjects to complete this cross over study involving eight week supplementation with each of the placebo and limonoid glucoside containing drinks. We have completed sample collection from all ten subjects, and analysis of samples and data for health safety, markers of inflammation, blood lipids, blood chemistries (the major focus of the project), targeted proteomics and gene arrays. We need to confirm the gene array data by RTPCR, and our collaborator needs to analyze the plasma and urine samples for limonoid metabolites. Limonoid glucoside consumption at 500 mg/day for 8 weeks was safe and did not have any adverse effects. It did not alter most of the response variables of interest. However, we discovered that limonoid glucoside supplementation decreased the concentrations of several risk factors associated with a number of chronic diseases caused by increased oxidative stress. A patent application has been entered into ARIS, on June 23, 2012, to protect intellectual property rights.


Last Modified: 8/1/2014
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