ABSTRACT
N-Acylethanolamines (NAEs) are endogenous lipid-signaling molecules involved in satiety and energetics; however, how diet impacts circulating NAE concentrations and their downstream metabolic actions in humans remains unknown. Objectives were to examine effects of diets enriched with high-oleic canola oil (HOCO) or HOCO blended with flaxseed oil (FXCO), compared with a Western diet (WD), on plasma NAE levels and the association with energy expenditure and substrate oxidation. Using a randomized controlled crossover design, 36 hypercholesterolemic participants consumed three isoenergetic diets for 28 days, each containing 36% energy from fat, of which 70% was HOCO, FXCO, or WD. Ultra-performance liquid chromatography-MS/MS was used to measure plasma NAE levels and indirect calorimetry to assess energy expenditure and substrate oxidation. After 28 days, compared with WD, plasma oleoylethanolamide (OEA) and alpha-linolenoyl ethanolamide (ALEA) levels were significantly increased in response to HOCO and FXCO (P = 0.002, P < 0.001), respectively. Correlation analysis demonstrated an inverse association between plasma OEA levels and percent body fat (r = -0.21, P = 0.04), and a positive association was observed between the plasma arachidonoyl ethanolamide (AEA)/OEA ratio and android:gynoid fat (r = 0.23, P = 0.02), respectively. Results suggest that plasma NAE levels are upregulated via their dietary lipid substrates and may modulate regional and total fat mass through lipid-signaling mechanisms.
Subject(s)
Adiposity , Dietary Fats/metabolism , Endocannabinoids/blood , Energy Metabolism , Hypercholesterolemia/metabolism , Oleic Acids/blood , Overweight/physiopathology , Polyunsaturated Alkamides/blood , Up-Regulation , Adult , Body Mass Index , Cohort Studies , Cross-Over Studies , Endocannabinoids/metabolism , Fatty Acids, Monounsaturated/metabolism , Female , Humans , Hypercholesterolemia/blood , Hypercholesterolemia/etiology , Linseed Oil/metabolism , Male , Middle Aged , Oleic Acids/metabolism , Oxidation-Reduction , Patient Dropouts , Polyunsaturated Alkamides/metabolism , Rapeseed Oil , Single-Blind MethodABSTRACT
The objectives of the study were to develop a reverse-phase high-performance liquid chromatography method for the simultaneous analyses of trans-/cis-resveratrol, emodin, and quercetin and to determine the concentrations of these polyphenols in 28 resveratrol supplements. Samples were separated within 15 min in a C18 reversed-phase column using mobile phases containing 0.1% formic acid and methanol/0.1% formic acid. The calibration graphs for all four compounds were linear from 0.1 to 410 µg/mL (r2=0.99). The concentration of resveratrol as stated on the labels was often different from the analytical results, with 21 and 11% of the total supplements having low or high values, respectively. Many of the supplements also contained variable but generally low levels of emodin, a compound known to cause diarrhea. The proposed method is a rapid, sensitive, accurate, and cost-effective procedure that can be used for the simultaneous quantification of four polyphenols in resveratrol supplements.
