Analysis of phosphatidylethanolamine, phosphatidylcholine, and plasmalogen molecular species in food lipids using an improved 2D high-performance liquid chromatography system.

Phospholipids are an important class of lipids in cell membranes and food. Several high-performance liquid chromatography (HPLC) methods have been developed to analyze phospholipids at the molecular species level. We developed a two-dimensional HPLC system with a charged aerosol detector and mass spectrometry (MS) to analyze phosphatidylethanolamine (PE), phosphatidylcholine (PC), and their plasmalogens (pls) extracted from food materials. Accordingly, the phospholipid molecular species can be analyzed in a single step despite using smaller samples. We confirmed that chromatogram peaks from soybean lecithin are mostly baseline separated, assigned, and quantified (24 molecular species for PE and 27 for PC). In addition, it was confirmed that chromatograms of lipids extracted from chicken breast meat include plasmalogen peaks. The PE fraction in lipids extracted from chicken breast meat contained 17 types of ethanolamine plasmalogens, corresponding to approximately 57% of the total by weight. The PC fraction contained only four choline plasmalogens, corresponding to approximately 11% of the total weight. The composition of the pls-PC molecular species differed from that of pls-PEs. The polyunsaturated fatty acids connected at the sn-2 positions of the pls-PEs consisted of 20.5% 20:4 fatty acid and were independent of the carbon chain at the sn-1 position. However, the 18:1 fatty acid at the sn-2 position was dependent on the carbon chain at the sn-1 position.

Inhibitory effects of eucalyptus and banaba leaf extracts on nonalcoholic steatohepatitis induced by a high-fructose/high-glucose diet in rats.

Nonalcoholic steatohepatitis (NASH) is a liver disease associated with metabolic syndrome. The aim of this work was to examine whether eucalyptus (Eucalyptus globulus) leaf extract (ELE) and banaba (Lagerstroemia speciosa L.) leaf extract (BLE) inhibited NASH induced by excessive ingestion of fructose in rats. Wistar rats were divided into four groups according to four distinct diets: starch diet (ST), high-fructose/high-glucose diet (FG), FG diet supplemented with ELE, or FG diet supplemented with BLE. All rats were killed after 5 weeks of treatment. Serum alanine aminotransferase and total cholesterol levels were significantly lower in the BLE group than in the FG group. Liver histopathology, including steatosis, lipogranulomas, and perisinusoidal fibrosis, was significantly attenuated in the ELE and BLE groups compared with the FG group. Levels of 2-thiobarbituric acid reactive substances (TBARS), which reflect oxidative injury to the liver, were significantly suppressed by ELE and BLE. Western blotting analysis indicated that interleukin-6 expression levels were significantly lower in the ELE and BLE groups than in the FG group. These results suggest that ELE and BLE reduced lipogenesis, oxidative stress, and inflammatory cytokine expression and thus inhibited NASH induced by excessive ingestion of fructose in rats.

Hypolipidemic effects of starch and γ-oryzanol from wx/ae double-mutant rice on BALB/c.KOR-Apoe(shl) mice.

waxy/amylose-extender (wx/ae) double-mutant japonica rice (Oryza sativa L.) produces resistant starch (RS) and a large amount of γ-oryzanol. Our previous study has shown the hypolipidemic effect of wx/ae brown rice on mice. To identify the functional constituents of the hypolipidemic activity in wx/ae rice, we prepared pure wx/ae starch and γ-oryzanol from wx/ae rice and investigated their effect on the lipid metabolism in BALB/c.KOR/Stm Slc-Apoe(shl) mice. The mice were fed for 3 weeks a diet containing non-mutant rice starch, non-mutant rice starch plus γ-oryzanol, wx/ae starch, or wx/ae starch plus γ-oryzanol. γ-Oryzanol by itself had no effect on the lipid metabolism, and wx/ae starch prevented an accumulation of triacylglycerol (TAG) in the liver. Interestingly, the combination of wx/ae starch plus γ-oryzanol not only prevented a TAG accumulation in the liver, but also partially suppressed the rise in plasma TAG concentration, indicating that wx/ae starch and γ-oryzanol could have a synergistic effect on the lipid metabolism.

Structure, physical, and digestive properties of starch from wx ae double-mutant rice.

Amylopectin is the principal component of starch. The amylose extender (ae) gene encodes the starch-branching enzyme IIb, which is critical in determining the fine structure of endosperm starch. To determine the relationship between the fine structure of amylopectin and its physical properties, rice mutant lines defective in the ae function with altered fine structure of amylopectin and in combination with the waxy (wx) background were selected for comparative studies with primary wild-type and ae starches. The ae mutant endosperms accumulated a high amylose content starch with long amylopectin chains. The ae and wx ae starches showed no significant difference in the unit chain-length distribution of amylopectin and starch granule morphology. The wx ae starch displayed a higher pasting temperature and higher peak viscosity. The gelatinization peak temperatures of the wx, ae, and wx ae starches were 2.2, 13.1, and 17.1 degrees C higher, respectively, than that of the wild-type starch, and the wx ae starch showed a retrogradation peak with a shorter cooling period than that of ae starch. The raw ae and wx ae starches were almost indigestible by alpha-amylase in vitro. Rats fed the wx ae starch showed slowly increasing blood glucose at a lower level than the rats fed the wx or wild-type starch. These results indicate that the primary structure of the rice wx ae amylopectin with enriched long chains changes the granular structure of the starch, including its crystal structure, and results in resistance to in vitro or in vivo degradation.