Showing papers on "Dietary Polyphenol published in 2006"

Effects of dietary apple polyphenol on adipose tissues weights in Wistar rats.

Abstract: In this study, we investigated whether dietary apple polyphenol (APP) had an effect on adipose weights.Twenty-four Wistar male rats (10 weeks of age) were assigned to three groups: (1) the 5%APP group (diet containing 5% APP, N=8); (2) the 0.5%APP group (diet containing 0.5% APP, N=8); and (3) the control group (N=8) so that average weights of the groups were the same. After a three-week experimental period, adipose tissue weights were measured. Pathological and plasma characteristics were also examined. Retroperitoneal and epididymal adipose tissue weights in the 5%APP group were significantly lower than those of the control (P<0.05). Pathological examination showed that form-like cells were observed only in the control group, suggesting the existence of proliferating pre-adipocytes only in the control group. Lipid-related plasma profiles showed no statistical differences. Dietary polyphenol did not induce any anorectic effects as reported in studies concerning tea polyphenol. We conclude that dietary APP has an anti-adipogenic effect in Wistar rats without any anorectic phenomenon.

Effects of Dietary Procyanidins and Tea Polyphenols on Adipose Tissue Mass and Fatty Acid Metabolism in Rats on a High Fat Diet

Abstract: Large amounts of procyanidins, made up of catechin oligomers, are consumed on a daily basis via various plant-based diets. Recent studies show that tea polyphenol (TP) exerts anti-obesity effect; however, the biological functions of procyanidins have not yet been established. In this study, we examined the high dose effects of procyanidins from apple polyphenol (AP), hop polyphenol (HP), and tea polyphenol (TP) on obesity using normal Sprague-Dawley rats on a high fat (HF) diet. We measured adipose tissue mass and tissue lipid parameters in rats on polyphenol-free low fat (LF) (7%) or HF (27.8%) diets with or without 1% of each polyphenol for 9 weeks. Dietary AP, HP, and TP suppressed the increase in white adipose tissue. Dietary TP increased the level of fatty acids excreted into feces; however, this was not observed in the AP- or HP-fed group. Each dietary polyphenol tended to reduce fatty acid synthesis and promote fatty acid β-oxidation as compared with a HF diet alone. Moreover, each dietary polyphenol tended to increase the level of peroxisome proliferator-activated receptor alpha (PPARα) in the liver and decreased the levels of PPARγ in brown and white adipose tissues. Therefore, we speculate that procyanidins from AP or HP may reduce the increase in white adipose tissue induced by an HF diet through a combination of the agonist-like action of PPARα and antagonist-like action of PPARγ. On the other hand, TP may exert an anti-obesity effect via the combined effect of PPARα and PPARγ described above as well as the promotion of fatty acid excretion into feces.