Publications (4)5.59 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: Administration of black-tea polyphenols (BTP) at 100 and 200 mg/kg of body weight in rats suppressed postprandial hypertriacylglycerolemia in a dose-dependent manner. Administration of BTP also suppressed lymphatic recovery of (14)C-trioleoylglycerol in rats that were cannulated in the thoracic duct. BTP dose-dependently inhibited the activity of pancreatic lipase in vitro with an IC50 of 0.254 mg/mL. When purified theaflavins, which are components of BTP, were used, theaflavins with galloyl moieties, but not those without galloyl moiety, inhibited the activity of pancreatic lipase. Theaflavin-3,3'-digallate (TFDG) was more effective in inhibiting the activity of pancreatic lipase than epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and a mixture of EGCG and ECG. BTP and TFDG had a similar effect in inhibiting the activity of pancreatic lipase when the total polyphenol amount was adjusted to the same. BTP had no effect on micellar solubility of hydrolysis products of triacylglycerol. These results suggest that BTP suppressed postprandial hypertriacylglycerolemia by reducing triacylglycerol absorption via the inhibition of pancreatic lipase activity.
- [Show abstract] [Hide abstract] ABSTRACT: Dietary soy protein isolate (SPI) and its undigested high molecular fraction (HMF) exhaustively digested with proteases, compared with casein (CAS), significantly reduced serum and liver cholesterol concentration in rats. Biliary excretion of cholesterol was significantly higher in rats fed SPI and HMF than in those fed CAS. Hepatic expression of ATP-binding cassette transporter G5 (ABCG5) and ATP-binding cassette transporter G8 (ABCG8) mRNA was significantly higher in rats fed SPI and HMF than in those fed CAS. These observations suggest that increased biliary excretion of cholesterol in SPI and HMF groups is caused by the enhanced expression of Abcg5/Abcg8.
- [Show abstract] [Hide abstract] ABSTRACT: Intestinal absorption of various plant sterols was investigated in thoracic duct-cannulated normal rats. Lymphatic recovery was the highest in campesterol, intermediate in brassicasterol and sitosterol, and the lowest in stigmasterol and sitostanol. Higher solubility in the bile salt micelle was observed in sitosterol, campesterol, and sitostanol than in brassicasterol and stigmasterol. The solubility of the latter two sterols was extremely low. When the affinity of plant sterols for the bile salt micelle was compared in an in vitro model system, which assessed sterol transfer from the micellar to the oil phase, the transfer rate was the highest in brassicasterol, intermediate in campesterol and stigmasterol, and lowest in sitosterol and sitostanol. Although no significant correlations between lymphatic recovery of plant sterols and their micellar solubility or transfer rate from the bile salt micelle were observed, highly positive correlation was obtained between the lymphatic recovery and the multiplication value of the micellar solubility and the transfer rate. These observations strongly suggest that both solubility in and affinity for the bile salt micelle of plant sterols are important determinants of their intestinal absorption in rats.
- [Show abstract] [Hide abstract] ABSTRACT: Dietary soy protein isolate (SPI) and undigested high molecular fraction of SPI exhaustively digested with proteases (HMF), compared with casein (CAS), increased mRNA expression of ATP-binding cassette transporter (ABC) G5 and ABCG8 in rat liver, but not in the intestine. Biliary excretion of cholesterol was significantly higher in rats fed SPI and HMF than in those fed CAS. Fecal excretion of acidic steroids was higher in rats fed SPI and HMF. The mRNA expression of hepatic cholesterol 7α- hydroxylase (CYP7A1) in the HMF group was significantly higher and that in the SPI group tended to be higher than in the CAS group. In contrast, mRNA expression of hepatic small heterodimer partner (SHP) was significantly lower in the feeding of SPI and HMF. It has been known that the reduction of SHP activates liver receptor homologue (LRH)-1, which binds to the promoter of CYP7A1 and increases its mRNA expression. Since it was recently reported that LRH-1 activates the promoter of ABCG5 and ABCG8, it is thought that the increase of their mRNA expression in the liver was induced by the activation of LRH-1. Soy Protein Research, Japan 9, 108-112, 2006.
Sendai, Kagoshima, Japan
- Division of Bioscience and Biotechnology for Future Bioindustries