alpha-Eleostearic acid is more effectively metabolized into conjugated linoleic acid than punicic acid in mice

BACKGROUND: The objective of this study was to investigate the metabolism of cc-eleostearic acid (alpha-ESA, cis9,trans11,trans13-18 : 3) and punicic acid (PA, cis9,trans11,cis13-18 : 3) and to compare the relative conversion efficiency of these fatty acids into conjugated linoleic acids (CLAs) in mice. RESULTS: Twenty-four male ICR mice were fed either a control diet or one of two experimental diets supplemented with 10 g kg(-1) alpha-ESA or PA in the form of triacylglycerols for 6 weeks. The accumulation of PA in all tissues examined was significantly higher than alpha-ESA; in both groups it was found that cis9,trans11-conjugated linoleic acid (cis9,trans11-18 : 2) was detected in all tissues examined. The relative conversion rate of a-ESA into cis9,trans11-18 : 2 was significantly higher than that of PA. The highest conversion rate of a-ESA was found in adipose tissue (91.8%), spleen (91.4%) and kidney (90.7%), and the lowest in the heart (84.6%). The highest conversion rate of PA occurred in the liver (76.2%) and the lowest occurred in the heart (54.5%). CONCLUSION: The present results indicate that both alpha-ESA and PA are effectively metabolized into cis9,trans11-18 : 2 in mice. These conjugated dietary fatty acids might be useful sources of CLAs in tissues owing to the natural abundance of alpha-ESA and PA in some seeds. (c) 2009 Society of Chemical industry