α‐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 α‐eleostearic acid (α‐ESA, cis 9, trans 11, tran s13‐18:3) and punicic acid (PA, cis 9, trans 11, cis 13‐18:3) 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 α‐ESA or PA in the form of triacylglycerols for 6 weeks. The accumulation of PA in all tissues examined was significantly higher than α‐ESA; in both groups it was found that cis 9, trans 11‐conjugated linoleic acid ( cis 9, trans 11‐18:2) was detected in all tissues examined. The relative conversion rate of α‐ESA into cis 9, trans 11‐18:2 was significantly higher than that of PA. The highest conversion rate of α‐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 α‐ESA and PA are effectively metabolized into cis 9, trans 11‐18:2 in mice. These conjugated dietary fatty acids might be useful sources of CLAs in tissues owing to the natural abundance of α‐ESA and PA in some seeds. Copyright © 2009 Society of Chemical Industry