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Effect of Dietary Coconut Oil and Conjugated Linoleic Acid on Liver Metabolic Phenotype in Mice
Author(s) -
Barnes Kimberly M.,
Engle Jake P.,
Chen Qiannan,
DiGregorio Anna M.,
McFadden Joseph W.
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.42.8
Subject(s) - conjugated linoleic acid , lipolysis , chemistry , linoleic acid , metabolite , metabolomics , metabolome , nefa , coconut oil , adipose tissue , food science , chromatography , biochemistry , fatty acid
Mice fed coconut oil (CO) lose more body fat when fed conjugated linoleic acid (CLA) than mice fed soy oil (SO), in part due to increased basal lipolysis. These mice also have increased liver fat content but changes in specific liver metabolites are largely unknown. Our objective was to use mass spectrometry‐based metabolomics to determine the metabolic profile of mice fed CO and/or CLA. Male mice from 4 common strains (CF‐1, Swiss Webster, ICR, and NIH; n=24 each) were obtained at weaning, fed either CO or SO for 6 wk, then 0 or 0.5% CLA for an additional 12 d. Following liver homogenization and methanol extraction, metabolites were profiled using electron impact ionization, gas chromatography, and mass spectrometry. Mass spectral analyses with standards resulted in a total of 37 identifiable metabolites. For untargeted metabolomics data, statistics were performed on the log of the normalized and autoscaled data. As reported previously, we detected an oil x CLA interaction (P < 0.05) on body fat, with CO+CLA‐fed mice being the leanest. Basal lipolysis was increased by both CO (P < 0.001) and CLA (P < 0.01), with CO+CLA‐fed mice having the greatest rate of NEFA release. Principle component analysis (PCA) revealed that the first three components accounted for 36% of the variation in the samples, and no more than three metabolites fell outside the 95% confidence ellipse. For the first three components, metabolites with variable importance of projection (VIP) scores greater than 2.0 were linoleic acid and oleic acid. PCA also indicated that dietary oil (CO or SO) had a greater effect on liver metabolites than CLA. CO‐fed mice also showed less variation in metabolites when fed CLA than did SO‐fed mice. Eleven metabolites were altered by diet, with fatty acid changes that correspond with the dietary oils being the most significant. Other metabolites altered include phosphoric acid (decreased by CO, P < 0.01), proline (decreased in CO+CLA‐fed mice vs all other diets, P < 0.05), β‐hydroxybutyrate (BHBA; increased in CO+CLA‐fed mice vs SO and SO+CLA‐fed mice with CO‐fed mice being intermediate, P < 0.05), and acetic acid and isoleucine (both decreased in CO+CLA‐fed mice vs SO and SO+CLA‐fed mice, P < 0.05). Very few differences were detected between the different strains of mice. The increased lipid mobilization in the CO+CLA‐fed mice may account for the increased ketone bodies and could require greater protein synthesis as well, thus accounting for the decreased amino acid concentrations. This is supported as BHBA was negatively correlated with linoleic acid, valine, and phosphoric acid (P<0.05; r = −0.34 to −0.24) and positively correlated with glycerol (P<0.05; r = 0.25).