A simple synthetic route for the preparation of functional nanoscale graphene oxide (NGO), a novel nanocarrier for the loading and targeted delivery of anticancer drugs, is reported. The NGO is functionalized with sulfonic acid groups, which render it stable in physiological solution, followed by covalent binding of folic acid (FA) molecules to the NGO, thus allowing it to specifically target MCF-7 cells, human breast cancer cells with FA receptors. Furthermore, controlled loading of two anticancer drugs, doxorubicin (DOX) and camptothecin (CPT), onto the FA-conjugated NGO (FA-NGO) via pi-pi stacking and hydrophobic interactions is investigated. It is demonstrated that FA-NGO loaded with the two anticancer drugs shows specific targeting to MCF-7 cells, and remarkably high cytotoxicity compared to NGO loaded with either DOX or CPT only. Considering that the combined use of two or more drugs, a widely adopted clinical practice, often displays much better therapeutic efficacy than that of a single drug, the controlled loading and targeted delivery of mixed anticancer drugs using these graphene-based nanocarriers may find widespread application in biomedicine.

Functional Graphene Oxide as a Nanocarrier for Controlled Loading and Targeted Delivery of Mixed Anticancer Drugs

Seaweed is more than the wrap that keeps rice together in sushi. Seaweed biomass is already used for a wide range of other products in food, including stabilising agents. Biorefineries with seaweed as feedstock are attracting worldwide interest and include low-volume, high value-added products and vice versa. Scientific research on bioactive compounds in seaweed usually takes place on just a few species and compounds. This paper reviews worldwide research on bioactive compounds, mainly of nine genera or species of seaweed, which are also available in European temperate Atlantic waters, i.e. Laminaria sp., Fucus sp., Ascophyllum nodosum, Chondrus crispus, Porphyra sp., Ulva sp., Sargassum sp., Gracilaria sp. and Palmaria palmata. In addition, Undaria pinnatifida is included in this review as this is globally one of the most commonly produced, investigated and available species. Fewer examples of other species abundant worldwide have also been included. This review will supply fundamental information for biorefineries in Atlantic Europe using seaweed as feedstock. Preliminary selection of one or several candidate seaweed species will be possible based on the summary tables and previous research described in this review. This applies either to the choice of high value-added bioactive products to be exploited in an available species or to the choice of seaweed species when a bioactive compound is desired. Data are presented in tables with species, effect and test organism (if present) with examples of uses to enhance comparisons. In addition, scientific experiments performed on seaweed used as animal feed are presented, and EU, US and Japanese legislation on functional foods is reviewed.

Bioactive compounds in seaweed: functional food applications and legislation

Historically, nutrition principles and recommendations for diabetes and related complications have been based on scientific evidence and diabetes knowledge when available and, when evidence was not available, on clinical experience and expert consensus. Often it has been difficult to discern the level of evidence used to construct the nutrition principles and recommendations. Furthermore, in clinical practice, many nutrition recommendations that have no scientific supporting evidence have been and are still being given to individuals with diabetes. To address these problems and to incorporate the research done in the past 8 years, this 2002 technical review provides principles and recommendations classified according to the level of evidence available. It reviews the evidence from randomized, controlled trials; cohort and case-controlled studies; and observational studies, which can also provide valuable evidence (1,2), and takes into account the number of studies that have provided consistent outcomes of support. In this review, nutrition principles are graded into four categories based on the available evidence: those with strong supporting evidence, those with some supporting evidence, those with limited supporting evidence and those based on expert consensus.

Evidence-based nutrition recommendations attempt to translate research data and clinically applicable evidence into nutrition care. However, the best available evidence must still be moderated by individual circumstances and preferences. The goal of evidence-based recommendations is to improve the quality of clinical judgments and facilitate cost-effective care by increasing the awareness of clinicians and patients with diabetes of the evidence supporting nutrition services and the strength of that evidence, both in quality and quantity.

Before 1994, the American Diabetes Association’s (ADA’s) nutrition principles and recommendations attempted to define an “ideal” nutrition prescription that would apply to everyone with diabetes (3,4,5). Although individualization was a major principle of all recommendations, it was usually done within defined …

/pdf/evidence-based-nutrition-principles-and-recommendations-for-219364socu.pdf

Evidence-Based Nutrition Principles and Recommendations for the Treatment and Prevention of Diabetes and Related Complications

1,25-Dihydroxvitamin D3 [1,25(OH)2D3] is the hormonally active form of vitamin D. The genomic mechanism of 1,25(OH)2D3 action involves the direct binding of the 1,25(OH)2D3 activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Numerous VDR co-regulatory proteins have been identified, and genome-wide studies have shown that the actions of 1,25(OH)2D3 involve regulation of gene activity at a range of locations many kilobases from the transcription start site. The structure of the liganded VDR/RXR complex was recently characterized using cryoelectron microscopy, X-ray scattering, and hydrogen deuterium exchange. These recent technological advances will result in a more complete understanding of VDR coactivator interactions, thus facilitating cell and gene specific clinical applications. Although the identification of mechanisms mediating VDR-regulated transcription has been one focus of recent research in the field, other topics of fundamental importance include the identification and functional significance of proteins involved in the metabolism of vitamin D. CYP2R1 has been identified as the most important 25-hydroxylase, and a critical role for CYP24A1 in humans was noted in studies showing that inactivating mutations in CYP24A1 are a probable cause of idiopathic infantile hypercalcemia. In addition, studies using knockout and transgenic mice have provided new insight on the physiological role of vitamin D in classical target tissues as well as evidence of extraskeletal effects of 1,25(OH)2D3 including inhibition of cancer progression, effects on the cardiovascular system, and immunomodulatory effects in certain autoimmune diseases. Some of the mechanistic findings in mouse models have also been observed in humans. The identification of similar pathways in humans could lead to the development of new therapies to prevent and treat disease.

/pdf/vitamin-d-metabolism-molecular-mechanism-of-action-and-1rmxk5ppvb.pdf

Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects.

Background: A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy. The purpose of this task force was to review the goals of levothyroxine therapy, the optimal prescription of conventional levothyroxine therapy, the sources of dissatisfaction with levothyroxine therapy, the evidence on treatment alternatives, and the relevant knowledge gaps. We wished to determine whether there are sufficient new data generated by well-designed studies to provide reason to pursue such therapies and change the current standard of care. This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment. Methods: Task force members identified 24 questions relevant to the treatment of hypothyroidism. The clinical literature relating to each question was then reviewed. Clinical reviews were supplemented, when relevant, with related...

Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement

Background In a previous study we demonstrated the inhibitory effect of 1,25-dihydroxyvitamin D (1,25(OH)(2)D(3)) and its less calcaemic analog 1,24(OH)(2)D(2) on the production of tumour necrosis factor alpha (TNFalpha) by human peritoneal macrophages. The aim of the present study is to examine whether this vitamin D inhibition of TNFalpha is mediated by its major transcription factor, nuclear factor-kappaB (NFkappaB). Methods Murine macrophage cells (P388D1) were incubated with 10(-7) M 1,25(OH)(2)D(3) or 1,24(OH)(2)D(2) and then stimulated with lipopolysaccharide. NFkappaB activity was assayed using a reporter gene and by electrophoretic mobility shift assay (EMSA). In addition, we evaluated mRNA and protein levels of NFkappaB-p65 and of IkappaBalpha, a potent NFkappaB inhibitor, and phosphorylated IkappaBalpha. Results Both 1,25(OH)(2)D(3) and 1,24(OH)(2)D(2) induced a 60% reduction of TNFalpha secretion. By using a reporter gene and EMSA we found that vitamin D markedly reduced NFkappaB activity. 1,25(OH)(2)D(3) or 1,24(OH)(2)D(2) decreased NFkappaB-p65 levels in the nucleus and increased NFkappaB-p65 levels in the cytosol; no changes were observed in the total levels of NFkappaB-p65 protein and mRNA. Concurrently, vitamin D induced a significant increase in mRNA and protein levels of IkappaBalpha (approximately 6.5- and 4.5-fold, respectively). Elevated levels of IkappaBalpha can be explained by the vitamin D-induced prolongation of IkappaBalpha-mRNA half-life from 110 to 190 min and by the decrease in IkappaBalpha phosphorylation. Conclusions Vitamin D up-regulates IkappaBalpha levels by increasing mRNA stability and decreasing IkappaBalpha phosphorylation. The increase in IkappaBalpha levels reduces nuclear translocation of NFkappaB and thereby downgrades its activity. Since NFkappaB is a major transcription factor of inflammatory mediators, these findings suggest that the less-calcaemic analog, 1,24(OH)(2)D(2) may be effective as an anti-inflammatory therapeutic agent.

Vitamin D decreases NFκB activity by increasing IκBα levels

Background. In a previous study we demonstrated the inhibitory effect of 1,25-dihydroxyvitamin D (1,25(OH)2D3) and its less calcaemic analog 1,24(OH)2D2 on the production of tumour necrosis factor alpha (TNFa) by human peritoneal macrophages. The aim of the present study is to examine whether this vitamin D inhibition of TNFa is mediated by its major transcription factor, nuclear factor-kB (NFkB). Methods. Murine macrophage cells (P388D1) were incubated with 10 � 7 M 1,25(OH)2D3 or 1,24(OH)2D2 and then stimulated with lipopolysaccharide. NFkB activity was assayed using a reporter gene and by electrophoretic mobility shift assay (EMSA). In addition, we evaluated mRNA and protein levels of NFkB-p65 and of IkBa, a potent NFkB inhibitor, and phosphorylated IkBa. Results. Both 1,25(OH)2D3 and 1,24(OH)2D2 induced a 60% reduction of TNFa secretion. By using a reporter gene and EMSA we found that vitamin D markedly reduced NFkB activity. 1,25(OH)2D3 or 1,24(OH)2D2 decreased NFkB-p65 levels in the nucleus and increased NFkB-p65 levels in the cytosol; no changes were observed in the total levels of NFkB-p65 protein and mRNA. Concurrently, vitamin D induced a significant increase in mRNA and protein levels of IkBa (� 6.5- and 4.5-fold, respectively). Elevated levels of IkBa can be explained by the vitamin Dinduced prolongation of IkBa-mRNA half-life from 110 to 190 min and by the decrease in IkBa phosphorylation. Conclusions. Vitamin D up-regulates IkBa levels by increasing mRNA stability and decreasing IkBa phosphorylation. The increase in IkBa levels reduces nuclear translocation of NFkB and thereby downgrades its activity. Since NFkB is a major transcription factor of inflammatory mediators, these findings suggest that the less-calcaemic analog, 1,24(OH)2D2 may be effective as an anti-inflammatory therapeutic agent.

Vitamin D decreases NFiB activity by increasing IiBa levels

The biomass of the red alga Porphyridium sp.constitutes a unique combination of soluble sulfatedpolysaccharide that accounts for about 70% of thealgal dry weight, and various polyunsaturatedfatty acids (PUFA) such as arachidonic andeicosapentaenoic acid (AA, 20:4 ω6 and EPA,20:5 ω3). In view of earlier results in ourlaboratory showing a reduction in serum cholesteroland triglyceride levels in rodents fed with red algalbiomass, we set out to examine the influence of algalbiomass as a feed additive on the metabolism ofchickens, with an emphasis on blood and eggcholesterol levels. For that purpose, lyophilizedalgal biomass was fed to 12–13, 30-week-old, WhiteLeghorn chickens for 10 days at a proportion of 5% or10% of the standard chicken diet. Twelve chickensfed with unsupplemented diet served as the control. No differences in body weight, egg number, and eggweight were found between the algal-fed chickens (atboth concentrations) and the control. However,chickens fed with algal biomass consumed 10% lessfood for both groups, and their serum cholesterollevels were significantly lower (by 11% and 28% forthe groups fed with 5% and 10% supplement,respectively) as compared with the respective valuesof the control group. Egg yolk of chickens fed withalgae tended to have reduced cholesterol levels (by10%) and increased linoleic acid and arachidonic acidlevels (by 29% and 24%, respectively). In addition,the color of the egg yolk was darker as a result ofthe higher carotenoid levels (2.4 fold higher) forchickens that fed with 5% supplement. Theseresults encourage the development of an improvedchicken feed having dietary fibers and polyunsaturatedfatty acids.

Chickens fed with biomass of the red microalga Porphyridium sp. have reduced blood cholesterol level and modified fatty acid composition in egg yolk.

Marked increase in plasma high-density-lipoprotein cholesterol after prolonged fasting during Ramadan.

Menopause and estrogen deficiency are associated with apparent intestinal resistance to vitamin D, which can be reversed by estrogen replacement. The in vivo influence of estrogens on duodenal vitamin D receptor (VDR) was studied in three groups of rats: ovariectomized (OVX), sham-operated, and ovariectomized rats treated daily with estrogen (40 microg/kg BW) for 2 weeks (OVX + E). Estrogen administration to OVX rats resulted in a 2-fold increase in VDR messenger RNA transcripts. 1,25(OH)2D3 was shown to bind specifically to one class of receptors in duodenal mucosal extracts, with a dissociation constant of 0.03 nM. Binding was significantly increased in duodenal extracts from OVX + E rats, compared with OVX rats (735 +/- 81 vs. 295 +/- 26 fmol/mg protein; P < 0.001); a comparable, 1.5- to 2-fold increase in VDR protein expression was observed in Western blot analyzes of the duodenal mucosa. Markers of VDR activity were increased in estrogen-exposed rats: calbindin-9k messenger RNA transcript content was 1.4- to 1.6-fold higher, and alkaline phosphatase activity was 1.4- to 3-fold higher in sham-operated and OVX + E, respectively, compared with OVX. 25(OH)D, 1,25(OH)2D, or PTH levels were not altered by estrogen treatment. Cumulatively, these findings suggest that estrogen up-regulates VDR expression in the duodenal mucosa and concurrently increases the responsiveness to endogenous 1,25(OH)2D. Modulation of intestinal VDR activity by estrogen, and subsequent influence on intestinal calcium absorption, could be one of the major protective mechanisms of estrogen against osteoporosis.

/pdf/estrogen-increases-1-25-dihydroxyvitamin-d-receptors-5am0gx1gsd.pdf

Shraga Shany

Papers

Vitamin D decreases NFκB activity by increasing IκBα levels

Vitamin D decreases NFiB activity by increasing IiBa levels

Chickens fed with biomass of the red microalga Porphyridium sp. have reduced blood cholesterol level and modified fatty acid composition in egg yolk.

Marked increase in plasma high-density-lipoprotein cholesterol after prolonged fasting during Ramadan.

Estrogen increases 1,25-dihydroxyvitamin D receptors expression and bioresponse in the rat duodenal mucosa