1,25 dihydroxyvitamin D3 (1,25D3) is the most potent biologically active form of vitamin D3. Its actions on the mammary gland include cell growth inhibition and anti-cancer effects. This study's purpose was to explore the role of the 1,25D3-membrane associated rapid response steroid (MARRS) receptor in the mammary gland using a tissue-specific knockout mouse model and a vitamin D3 dietary intervention.
View Article and Find Full Text PDFMetabolic Syndrome (MetS) is a complex disorder that predisposes an individual to Cardiovascular Diseases and type 2 Diabetes Mellitus. Proteomics and bioinformatics have proven to be an effective tool to study complex diseases and mechanisms of action of nutrients. We previously showed that substitution of the majority of carbohydrate in a high fat diet by purple potatoes (PP) or purple carrots (PC) improved insulin sensitivity and hypertension in an animal model of MetS (obese Zucker rats) compared to a control sucrose-rich diet.
View Article and Find Full Text PDFThe protein disulfide isomerase ERp57 (GRp58/PDIA3/1,25D3-MARRS) has been implicated in a multitude of signaling pathways throughout the entire body. Most thoroughly studied for its protein-folding role, ERp57 has also been found to have multiple binding partners, and have significant effects on cellular growth. ERp57 has been studied n the context of several neurodegenerative disorders, metabolic conditions, and can be used as a prognosis marker in certain cancers.
View Article and Find Full Text PDFConsumption of highly colored fruits and vegetables rich in anthocyanins has been associated with numerous health benefits. Purple carrots (PC) and purple potatoes (PP) have higher anthocyanin concentrations and higher biological activities compared with less pigmented cultivars. We hypothesized that substitution of the majority of carbohydrate in a high fat diet with PP or PC, for 8 weeks, would improve insulin resistance and hypertension, major components of metabolic syndrome, compared with orange carrots (OC), white potatoes (WP) or a control, high fat, sucrose-rich diet (HFD) in obese Zucker rats.
View Article and Find Full Text PDFBackground: The links between dietary fat intake, polyunsaturated fatty acid intake and breast cancer risk remain equivocal, with some studies pointing to improvements in risk upon omega-3 supplementation. However, the background diet is poorly controlled in most studies, potentially confounding this link. Therefore, this study examined the hypothesis that in order to see the benefits of omega-3 fatty acid supplementation, the background diet must be low in fat.
View Article and Find Full Text PDFNumerous studies have demonstrated that tea catechins form complexes with milk proteins, especially caseins. Much less work has been conducted to understand the metabolic conversions of tea-milk complexes during gastro-duodenal digestion. The objective of this study was to determine the significance of this association on the digestibility of the milk proteins and on the bioaccessibility of the tea polyphenol epigallocatechin gallate (EGCG).
View Article and Find Full Text PDFCombining different foods may produce additive, synergistic, or antagonistic interactions that may modify certain physiological effects (i.e., anticancer properties).
View Article and Find Full Text PDFBackground: The cardio-health-promoting activity of some foods may be due to their specific antioxidant content. The antioxidant activity of a mixture of plant extracts has been shown to differ from the activity of the individual extracts. As a result, the activity of the mixture can be described as synergistic, antagonistic or additive.
View Article and Find Full Text PDFOverweight and obesity are growing problems both in Canada and around the world. Obesity is associated with a number of chronic diseases including type 2 diabetes and CVD, which puts a tremendous burden on the health care systems in place. The present study sought to investigate whether there were differences in the effectiveness of three low-fat, hypo- and isoenergetic diets differing in protein:carbohydrate ratio, low protein (LP, 1 g protein:4 g carbohydrate), normal protein (NP, 1 g protein:2 g carbohydrate) or high protein (HP, 1 g protein:1 g carbohydrate), on weight loss and markers of the metabolic syndrome (MetS) in overweight women.
View Article and Find Full Text PDFPomiferin and osajin are prenylated isoflavones from Osage orange fruit that both have potent antioxidant activity in a variety of assays. Pomiferin, in particular, has strong activity against the superoxide anion in a photochemiluminescence (PCL) assay system. In vitro, pomiferin, but not osajin, demonstrated selective antiproliferative activity against the tumorigenic breast epithelial cell line MCF-7 (IC(50) = 5.
View Article and Find Full Text PDFIn the past number of years, the anticancer activities of omega-3 polyunsaturated fatty acids (ω3-PUFAs) as well as Vitamin D have been intensively studied, but separately. Supplementation of Vitamin D and omega-3 PUFA via cod-liver oil, one of few natural sources of both of these molecules, may have additive and possibly synergistic anticancer effects. Cod-liver oil has been used effectively to treat diseases such as Rheumatism but has not been studied as an anticancer agent.
View Article and Find Full Text PDFDifferent foods possess different bioactive compounds with varied antioxidant capacities. When foods are consumed together, the total antioxidant capacity of food mixtures may be modified via synergistic, additive, or antagonistic interactions among these components, which may in turn alter their physiological impacts. The main objective of this study was to investigate these interactions and identify any synergistic combinations.
View Article and Find Full Text PDF1,25 Dihydroxyvitamin D(3) (1,25D(3)) primes NB4 promyelocytic leukemia cells to differentiate along the monocyte/macrophage lineage through a non-genomic mechanism. Here we show that NB4 cells express high levels of the recently identified membrane receptor for 1,25D(3), which is a distinct gene product from the classical nuclear vitamin D receptor. This 57 kDa protein, named 1,25D(3)-MARRS (Membrane Activated Rapid Response to Steroids)/ERp57/PIA3 appears to associate in a complex with the transcription factor, nuclear factor kappa B (NFkappaB).
View Article and Find Full Text PDFIn addition to classical roles in calcium homeostasis and bone development, 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] inhibits the growth of several cancer types, including breast cancer. Although cellular effects of 1,25(OH)2D3 traditionally have been attributed to activation of a nuclear vitamin D receptor (VDR), a novel receptor for 1,25(OH)2D3 called 1,25D3-MARRS (membrane-associated, rapid response steroid-binding) protein was identified recently. The purpose of this study was to determine if the level of 1,25D3-MARRS expression modulates 1,25(OH)2D3 activity in breast cancer cells.
View Article and Find Full Text PDFBackground: Most studies of Attention-deficit hyperactivity disorder (ADHD) have focused on either young children or older adults. The current study compared 11 ADHD adolescents with 12 age-matched controls. The purpose was to examine differences in dietary intake, particularly of essential fatty acids, and determine whether this could explain the typical abnormalities in red blood cell fatty acids observed in previous studies of young children.
View Article and Find Full Text PDFGuanosine initiated apoptosis in NB4 cells in a transport-dependent manner. Apoptosis was partially attributed to an imbalance in nucleosides with some protection upon the addition of pyrimidines. The effect of guanosine on cell proliferation and viability was biphasic whereby cells were able to recover from an initial cell cycle arrest and re-enter the cell cycle upon removal of guanosine in a time-dependent fashion.
View Article and Find Full Text PDFThe purpose of this study was to examine the effects of 3:1 and 1:1 carbohydrate to protein ratios, hypocaloric diets with and without exercise, and risk factors associated with the Metabolic Syndrome in overweight and obese Canadian women. Groups were designated as control diet (CON), control diet with exercise (CONEx), high-protein (HP), or high-protein with exercise (HPEx). Free-living women from the Guelph community were studied in a university health and fitness facility.
View Article and Find Full Text PDFNB4 cells express multiple nucleoside transporters (NTs), including: hENT1 (es), and hENT2 (ei), and the CNT subtype referred to as, csg; a concentrative sensitive guanosine specific transporter. csg activity is a distinguishing feature of the NB4 cell line and its presence suggests a particular requirement of these cells for guanosine salvage. Proliferation and differentiation pathways determine, in part, the number of NTs in cells and tissues.
View Article and Find Full Text PDFBackground: Ageing can be associated with poor dietary intake, reduced nutrient absorption, and less efficient utilization of nutrients. Loss of memory and related cognitive function are also common among older persons. This study aimed to measure the prevalence of inadequate vitamin status among long-term care patients and determine if an association exists between vitamin status and each of three variables; cognitive function, vitamin supplementation, and medications which alter gastric acid levels.
View Article and Find Full Text PDFBackground: The nucleoside analogue arabinosylcytosine (araC) has been used for many years in the treatment of acute leukemia. Evidence in the literature suggests that araC may inhibit the growth of human colon carcinoma cell lines as well. Because araC action interferes with normal nucleoside metabolism, it is highly toxic to a number of normal cell types including bone marrow and intestinal mucosa cells.
View Article and Find Full Text PDFThis study examined the effect of diet and exercise on tumour growth, and the effect of dietary fatty acids on glucose uptake. Male Fischer 344 rats were divided into 4 dietary groups and fed for 2 weeks. The diets were 5% (wt/wt) safflower oil, 10% safflower oil, 5% docosahexaenoic acid(DHA)-rich, and 10% DHA-rich.
View Article and Find Full Text PDFOverweight and obese men and women (24-61 yr of age) were recruited into a randomized trial to compare the effects of a low-fat (LF) vs. a low-carbohydrate (LC) diet on weight loss. Thirty-one subjects completed all 10 wk of the diet intervention (retention, 78%).
View Article and Find Full Text PDFThis study examines the role of 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and the natural compound, bryostatin-1, on the monocytic differentiation of NB4 acute promyelocytic leukemia cells. We previously showed that 1,25(OH)(2)D(3) primes NB4 cells to mature along the monocyte/macrophage pathway in response to the tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). This maturation response involves protein kinase C (PKC) signaling, activation of the transcription factor nuclear factor kappaB (NFkB), and intracellular calcium and calpain activity.
View Article and Find Full Text PDF