Male C57BL/6J mice (25 days of age) were fed either a low-fat diet (10% kcal from fat) (LF) or a high-fat diet (45% kcal from fat) (HF45) for a period of 72 days. Blueberry juice or purified blueberry anthocyanins (0.2 or 1.0 mg/mL) in the drinking water were included in LF or HF45 treatments. Sucrose was added to the drinking water of one treatment to test if the sugars in blueberry juice would affect development of obesity. Total body weights (g) and body fat (%) were higher and body lean tissue (%) was lower in the HF45 fed mice compared to the LF fed mice after 72 days, but in mice fed HF45 diet plus blueberry juice or blueberry anthocyanins (0.2 mg/mL), body fat (%) was not different from those mice fed the LF diet. Anthocyanins (ACNs) decreased retroperitoneal and epididymal adipose tissue weights. Fasting serum glucose concentrations were higher in mice fed the HF45 diet. However, it was reduced to LF levels in mice fed the HF45 diet plus 0.2 mg of ACNs/mL in the drinking water, but not with blueberry juice. beta cell function (HOMA-BCF) score was lowered with HF45 feeding but returned to normal levels in mice fed the HF45 diet plus purified ACNs (0.2 mg/mL). Serum leptin was elevated in mice fed HF45 diet, and feeding either blueberry juice or purified ACNs (0.2 mg/mL) decreased serum leptin levels relative to HF45 control. Sucrose in drinking water, when consumption was restricted to the volume of juice consumed, produced lower serum leptin and insulin levels, leptin/fat, and retroperitoneal and total fat (% BW). Blueberry juice was not as effective as the low dose of anthocyanins in the drinking water in preventing obesity. Additional studies are needed to determine factors responsible for the differing responses of blueberry juice and whole blueberry in preventing the development of obesity.

Calcium is an essential ion in all organisms and participates in a variety of structural and functional roles. Calcium (re)absorption occurs in epithelia, including the intestine, kidney, mammary glands, placenta, and gills of fish. Its transport is regulated by a complex array of processes that are mediated by hormonal, developmental, and physiological factors involving the gastrointestinal tract, bone, kidney, and the parathyroids. Here we review the calcium transport mechanisms-paracellular, which is energy independent, and transcellular, which is energy dependent-primarily focusing on the intestine. We provide a new perspective on the facilitated diffusion and vesicular transport models to account for the emerging concepts on transcellular calcium transport. Finally, we discuss how 1,25(OH)2D3 and parathyroid hormone regulate calcium transport.

Blueberry juice processing by-products are a rich source of procyanidins, which comprise a group of compounds shown to possess numerous health benefits, including protection against coronary heart disease, type II diabetes, and obesity. Most of the procyanidins present in blueberry pomace, however, are large molecular weight compounds that are poorly absorbed and show weak bioactivity compared to the smaller molecular weight monomers and dimers. The objective of our study was to identify optimal extrusion variables to enhance the contents of monomers and dimers at the expense of large molecular weight procyanidin oligomers and polymers. Extrusion variables temperature (160 and 180 degrees C) and screw speed (150 and 200 rpm) were tested using mixtures of blueberry pomace with decorticated white sorghum flour at a ratio of 30 : 70 and 45% moisture content. Extrudates were analyzed for procyanidin composition and total anthocyanin content. Extrusion of blueberry pomace increased the monomer, dimer, and trimer contents considerably at both temperature and screw speeds. The highest monomer content, obtained at 180 degrees C and 150 rpm screw speed, was 84% higher than the nonextruded control. Significantly higher levels of dimer and trimer contents were also obtained under these conditions. Increases in monomer, dimer, and trimer contents apparently were the result of reduced polymer contents, which was approximately 40% lower for samples extruded at 180 degrees C temperature and 150 rpm screw speed. Extrusion processing reduced total anthocyanin contents by 33% to 42% indicating that additional treatments are needed to retain the pigments. These results demonstrate that extrusion processing can be used to increase procyanidin monomer and dimers in blueberry pomace.

Twenty cows were used in a randomized block design experiment for 6 wk to determine the influence of feeding partial ruminally inert Ca salts of palm and fish oil (Ca-PFO), alone or in combination with extruded full-fat soybeans or soybean oil, on milk fatty acid (FA) methyl esters composition and consumer acceptability of milk and Cheddar cheese. Cows were fed either a diet containing 44% forage and 56% concentrate (control) or a diet supplemented with 2.7% Ca-PFO (FO), 5% extruded full-fat soybeans + 2.7% Ca-PFO (FOESM), or 0.75% soybean oil + 2.7% Ca-PFO (FOSO). Total dietary FA content in the control, FO, FOESM, and FOSO diets were 4.61, 6.28, 6.77, and 6.62 g/100 g, respectively. There was no difference in nutrient intake, milk yield, or milk composition among treatments. Conjugated linoleic acid (CLA) C(18:2) cis-9, trans-11 isomer, C(18:1) trans-11 (VA), and total n-3 FA in milk from cows on the control, FO, FOESM, and FOSO treatments were 0.56, 1.20, 1.36, and 1.74; 3.29, 4.66, 6.34, and 7.81; 0.62, 0.69, 0.69, and 0.67 g/100 g of FA, respectively. Concentrations of CLA, VA, and total n-3 FA in cheese were similar to milk. A trained sensory panel detected no difference in flavors of milk and cheese, except for acid flavor below a slightly perceptible level in cheese from all treatments. Results suggest that feeding Ca-PFO alone or in combination with extruded full-fat soybeans or soybean oil enhanced the CLA, VA, total unsaturated and n-3 FA in milk and cheese without negatively affecting cow performance and consumer acceptability characteristics of milk and cheese.

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ERp57/GRp58 is a thiol-protein disulphide oxidoreductase and has been studied in many clinically relevant systems, both as a chaperone protein and as a membrane receptor for the steroid hormone, 1,25(OH)2D3. Our laboratory investigates phenomena associated with rapid, membrane-initiated signaling by steroid hormones synthesized from vitamin D (cholecalciferol). We have recently reported that the cell surface receptor for the metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], which we have termed the 1,25D3-MARRS (Membrane Associated, Rapid Response Steroid binding) receptor, is in fact identical to ERp57/GRp58. Here we review the dynamic role ERp57/GRp58/1,25D3-MARRS receptor plays in a variety of cellular processes. Starting with its structure at the DNA and protein levels, we review the available literature about its role as a chaperone protein, in immune function through the assembly of MHC class I molecules, DNA binding, and its function as the 1,25D3-MARRS receptor. Finally, we present the role it may play in relation to important disease states. While ERp57/GR58/1,25D3-MARRS receptor is a pivotal protein in many cell functions, it has yet to be determined whether-and to what extent-these phenomena are regulated by the vitamin D endocrine system. However, 1,25(OH)2D3 is involved in differentiation of certain cancer cells and in muscle function, and ERp57/1,25D3-MARRS protein has been reported to be involved in such processes. Thus, medicinal chemistry aimed at the 1,25D3-MARRS receptor in lymphocytes, cancer cells, bone, intestinal epithelia, and kidney may add to the current therapeutic regimens for various disease states.

Extrusion processing can be used to increase procyanidin monomer and dimer contents in grape seed and pomace. Procyanidins in grape by-products have many health benefits, but most are present as large molecular weight compounds, which are poorly absorbed. Extrusion processing appears to be a promising technology to increase levels of the bioactive low molecular weight procyanidins.

Membrane-initiated signaling by steroid hormones is now widely accepted. Current debate is centered upon which protein moieties act as membrane-associated receptors. In this review, we consider evidence for the classical vitamin D receptor (VDR) in this role, as well as the more recently identified 1,25D3-MARRS (membrane-associated, rapid response steroid binding) receptor, also known as ERp57/GRp58. The structure of the 1,25D3-MARRS receptor is discussed, with emphasis on two thioredoxin domains that promote dimerization and ligand binding. We then summarize recent studies on a 24,25(OH)2D3 binding protein--catalase--and how ligand-induced decreases in enzymatic activity produce increased reactive oxygen species that target both the 1,25D3-MARRS receptor--but not the VDR--and the protein kinase C signaling pathway. Finally, we briefly discuss the available literature suggesting that the metabolite 25(OH)D3 may also be biologically active.