Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/29/2010
Publication Date: 2/9/2010
Citation: Kim, H., Bartley, G.E., Rimando, A.M., Yokoyama, W.H. 2010. Hepatic Gene Expression Related to Lower Plasma Cholesterol in Hamsters Fed High Fat Diets Supplemented with Blueberry Pomace and Extract. Journal of Agricultural and Food Chemistry. 58 (7), pp 3984–3991. DOI: 10.1021/jf903230s. Interpretive Summary: Diets containing natural bioactive compounds with anti-inflammatory and antioxidant properties have recently received much attention for the reduction of cardiovascular disease risk. Blueberries (fruits of various Vaccinium species) are particularly rich in antioxidant and anti-inflammatory phytochemicals such as anthocyanins, proanthocyanidins, phenolic acid derivatives and flavonoids. Blueberry peel residues left after juice extractions include a high concentration of anthocyanins and flavonoids, and BB pulps have a great amount of procyanidins. In the present study, natural blueberry peel byproducts showed significant cholesterol-lowering effects in an animal model used to study dietary components that affect cholesterol metabolism.
Technical Abstract: We analyzed plasma lipid profiles, and genes related to cholesterol and bile acid metabolism, and inflammation in livers as well as adipose tissue from Syrian Golden hamsters fed high-fat diets supplemented with blueberry (BB) pomace byproducts including 8% dried whole blueberry peels (BBPWHL), 2% dried extract of peels (BBPX; 95% ethanol extract), and 6% residue from extracted peel (BBPEXT) compared to a diet containing 5% (w/w) microcrystalline cellulose (control). All BB diets significantly lowered plasma VLDL- and total-cholesterol concentration. Interestingly, BB diets increased fecal lipid excretion. Hepatic bile acid synthesis was increased by up-regulation of CYP7A1 expression. Cholesterol synthesis was increased by up-regulation of CYP51 expression in BBPX and BBPEXT diets. No significant changes in adipocyte gene expression related to inflammatory markers were observed with all BB diets. These data suggest that hepatic modulation of bile acid and cholesterol synthesis primarily contributes to the cholesterol-lowering effect of BB pomace byproducts.