Vitamin C function and status in chronic disease

Position 228 in Paenibacillus macerans cyclodextrin glycosyltransferase is critical for 2-O-d-glucopyranosyl-l-ascorbic acid synthesis

The markedly stable l-ascorbic acid (L-AA) derivative 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) has been widely used in the fields of food, medicine, cosmetics, and husbandry. Cyclodextrin glycosyltransferase (CGTase) is considered suitable for the large-scale production of AA-2G. In this work, Paenibacillus macerans CGTase was used to produce AA-2G and the production was 13.5g/l. An amino-acid sequence alignment of α-, β-, and α⁄β-CGTase indicated that the Phe at position 228 of P. macerans CGTase was different from the amino acids at this position in other CGTases (Met, Val, or Ile). In addition, the CGTases from Anaerobranca gottschalkii and Bacillus circulans 251, which have Val and Met at position 228, were shown to produce 28.9 and 35.7g/l AA-2G, respectively, which verified the importance of this position for AA-2G synthesis. Subsequently, P. macerans CGTase mutants F228M and F228V were constructed and shown to produce 24.8g/l and 24.0g/l AA-2G, respectively, which are 84% and 78% higher than that of wild-type P. macerans CGTase, respectively. Kinetic analysis of AA-2G synthesis showed that affinities of the two mutants for L-AA and the catalytic efficiencies increased. Meanwhile, the mutants had lower cyclization activity but higher disproportionation activities, which is beneficial for AA-2G synthesis. All these results indicated that amino acid at position 228 of P. macerans CGTase is crucial to AA-2G synthesis.

Use of Saliva Biomarkers to Monitor Efficacy of Vitamin C in Exercise-Induced Oxidative Stress

Saliva is easily obtainable for medical research and requires little effort or training for collection. Because saliva contains a variety of biological compounds, including vitamin C, malondialdehyde, amylase, and proteomes, it has been successfully used as a biospecimen for the reflection of health status. A popular topic of discussion in medical research is the potential association between oxidative stress and negative outcomes. Systemic biomarkers that represent oxidative stress can be found in saliva. It is unclear, however, if saliva is an accurate biospecimen as is blood and/or plasma. Exercise can induce oxidative stress, resulting in a trend of antioxidant supplementation to combat its assumed detriments. Vitamin C is a popular antioxidant supplement in the realm of sports and exercise. One potential avenue for evaluating exercise induced oxidative stress is through assessment of biomarkers like vitamin C and malondialdehyde in saliva. At present, limited research has been done in this area. The current state of research involving exercise-induced oxidative stress, salivary biomarkers, and vitamin C supplementation is reviewed in this article.

Stabilization of anthocyanins in blackberry juice by glutathione fortification

Blackberry anthocyanins provide attractive color and antioxidant activity.

Vitamins, Are They Safe?

The consumption of a daily multivitamin among people all over the world is dramatically increasing in recent years. Most of the people believe that if vitamins are not effective, at least they are safe. However, the long term health consequences of vitamins consumption are unknown. This study aimed to assess the side effects and possible harmful and detrimental properties of vitamins and to discuss whether vitamins can be used as safe health products or dietary supplements. We performed a MEDLINE/PubMed, EMBASE, Scopus and Google Scholar search and assessed reference lists of the included studies which were published from 1993 through 2015. The studies, with an emphasis on RCTs (randomized controlled clinical trials), were reviewed. As some vitamins such as fat-soluble vitamins (vitamin A, vitamin D, vitamin E), and also some of the water-soluble vitamins like folic acid may cause adverse events and some like vitamin C is widely taken assuming that it has so many benefits and no harm, we included relevant studies with negative or undesired results regarding the effect of these vitamins on health. Our recommendation is that taking high-dose supplements of vitamins A, E, D, C, and folic acid is not always effective for prevention of disease, and it can even be harmful to the health.

Serum Biomarkers of (Anti)Oxidant Status for Epidemiological Studies

In this review, we disclose a selection of serum/plasma biomarkers of (anti)oxidant status related to nutrition, which can be used for measurements in large-scale epidemiological studies. From personal experience, we have come to the following proposal of a set of biomarkers for nutritional intake, (anti)oxidant status, and redox status. We have selected the individual antioxidant vitamins E and A, and the carotenoids which can be measured in large series by HPLC. In addition, vitamin C was selected, which can be measured by an auto-analyzer or HPLC. As a biomarker for oxidative stress, the ROM assay (reactive oxygen metabolites) was selected; for the redox status, the total thiol assay; and for the total antioxidant status the BAP assay (biological antioxidant potential). All of these biomarkers can be measured in large quantities by an auto-analyzer. Critical points in biomarker validation with respect to blood sampling, storage conditions, and measurements are discussed. With the selected biomarkers, a good set is presented for use in the risk assessment between nutrition and (chronic) diseases in large-scale epidemiological studies. Examples of the successful application of these biomarkers in large international studies are presented.

Ascorbic acid supplementation does not alter oxidative stress markers in healthy volunteers engaged in a supervised exercise program

The purpose of this study was to investigate the impact of ascorbic acid (AA) consumption on the oxidative stress status of untrained volunteers participating in a supervised exercise program. The study included 46 young adults (average age, 23.5 ± 0.59 years; 37 females, 9 males) who remained sedentary (n = 16) or participated in 30 min of outdoor aerobic running (n = 30) at an intensity corresponding to 65%-75% of maximum heart rate for 3 times per week for 12 weeks. Exercised subjects were randomly assigned to an exercise group without AA supplementation (control; n = 10) or received either 250 mg (n = 10) or 500 mg (n = 10) of AA supplementation previous to each exercise session. Blood samples were taken on day 0 and day 84 to evaluate metabolic profiles and antioxidant status. Sedentary subjects underwent in a single bout of aerobic running to determine total antioxidant status (TAS) and malondiadehyde (MDA) at pre- and postexercise with or without AA supplementation. No significant change in TAS was observed. Plasma MDA significantly increased at postexercise (P < 0.05), and AA supplementation decreased MDA level significantly (P < 0.05). After 3 months of exercise, there was no significant change in blood glucose, lipid profile, MDA, TAS, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities amongst groups. Supplementation of AA was associated with minor and inconsistent reductions in SOD, GPx, and catalase activities (P < 0.05). These findings indicate that pre-exercise supplementation of ascorbic acid does not alter oxidative stress markers in the plasma and erythrocytes of young adults engaged in a supervised exercise program.

Prenatal vitamins: what is in the bottle?

Nearly all obstetricians routinely prescribe prenatal vitamins to their pregnant patients at the time of the first prenatal visit. Many times, patients' understanding of the health benefits of prenatal vitamins differs substantially from that of the prescribing physician. The following is a review of the most common ingredients found in prenatal vitamins and their purported health benefits.

Traditional Chinese medicine formulas for irritable bowel syndrome: from ancient wisdoms to scientific understandings

Traditional Chinese Medicine (TCM) serves as the most common alternative therapeutic approach for Western medicine and benefits IBS patients globally. Due to the lack of scientific evidence in the past, TCM formulas were not internationally well recognized as promising IBS remedies. In this review, firstly, we present the etiology and therapy of IBS in terms of traditional Chinese medical theory. Secondly, we summarize the clinical randomized controlled trials (RCTs) of TCM formulas for IBS patients that are available in the literature (from 1998 to September 2013), in which 14 RCTs conducted of high quality were discussed in detail. Of the 14 selected trials, 12 of those concluded that TCM formulas provided superior improvement in the global symptoms of IBS patients over the placebo or conventional medicines. As well, all 14 RCTs suggested that TCM formulas have good safety and tolerability. Last but not least, we explore the pharmacological mechanisms of the anti-IBS TCM formulas available in the literature (from 1994 to September, 2013). Collectively, in combating IBS symptoms, most TCM formulas exert multi-targeting actions including the regulation of neurotransmitters and hormones in the enteric nervous system (ENS), modulation of smooth muscle motility in the gastrointestinal (GI) tract, modulation of the hypothalamic-pituitary-adrenal (HPA) axis, attenuation of intestinal inflammation and restoration of intestinal flora, etc. In conclusion, TCM formulas appear to be promising for IBS treatment. This review provides a useful reference for the public in furthering a better understanding and acceptance of TCM formulas as IBS remedies.

High-dose vitamin C supplementation increases skeletal muscle vitamin C concentration and SVCT2 transporter expression but does not alter redox status in healthy males

Antioxidant vitamin C (VC) supplementation is of potential clinical benefit to individuals with skeletal muscle oxidative stress. However, there is a paucity of data reporting on the bioavailability of high-dose oral VC in human skeletal muscle. We aimed to establish the time course of accumulation of VC in skeletal muscle and plasma during high-dose VC supplementation in healthy individuals. Concurrently we investigated the effects of VC supplementation on expression levels of the key skeletal muscle VC transporter sodium-dependent vitamin C transporter 2 (SVCT2) and intramuscular redox and mitochondrial measures. Eight healthy males completed a randomized placebo-controlled, crossover trial involving supplementation with ascorbic acid (2×500 mg/day) over 42 days. Participants underwent muscle and blood sampling on days 0, 1, 7, and 42 during each treatment. VC supplementation significantly increased skeletal muscle VC concentration after 7 days, which was maintained at 42 days (VC 3.0±0.2 (mean±SEM) to 3.9±0.4 mg/100 g wet weight (ww) versus placebo 3.1±0.3 to 2.9±0.2 mg/100 g ww, p=0.001). Plasma VC increased after 1 day, which was maintained at 42 days (VC 61.0±6.1 to 111.5±10.4 µmol/L versus placebo 60.7±5.3 to 59.2±4.8 µmol/L, p<0.001). VC supplementation significantly increased skeletal muscle SVCT2 protein expression (main treatment effect p=0.006) but did not alter skeletal muscle redox measures or citrate synthase activity. A main finding of our study was that 7 days of high-dose VC supplementation was required to significantly increase skeletal muscle vitamin C concentration in healthy males. Our findings implicate regular high-dose vitamin C supplementation as a means to safely increase skeletal muscle vitamin C concentration without impairing intramuscular ascorbic acid transport, antioxidant concentrations, or citrate synthase activity.

Micronutrients after burn injury: a review

Supplementation of micronutrients after burn injury is common practice in order to fight oxidative stress, support the immune system, and optimize wound healing. Assessing micronutrient status after burn injury is difficult because of hemodilution in the resuscitation phase, redistribution of nutrients from the serum to other organs, and decreases in carrier proteins such as albumin. Although there are many preclinical data, there are limited studies in burn patients. Promising research is being conducted on combinations of micronutrients, especially via the intravenous route.

Low temperature storage affects the ascorbic acid metabolism of cherry tomato fruits

Tomato fruits are an important source of l-Ascorbic acid, which is an essential compound of human diet. The effect of the widespread practice of cold storing (5-10 °C) tomato fruits was monitored to determine its impact on the concentration and redox status of l-Ascorbic acid. Total l-Ascorbic acid levels were well maintained in both attached fruits and cold treated fruits, while in other treatments its levels were considerably reduced. However, low temperature storage conditions enhanced the expression of most genes coding for enzymes involved in l-Ascorbic acid biosynthesis and redox reactions. The findings suggest that the transcriptional up-regulation under chilling stress conditions of most genes coding for l-Ascorbic acid biosynthetic genes galactono-1,4-lactone dehydrogenase, GDP-d-mannose 3,5-epimerase but also for the isoenzymes of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase enzyme, glutathione reductase that are strongly correlated to the l-Ascorbic redox status. Moreover, fruits stored at 10 °C exhibited higher levels of transcript accumulation of MDHAR2, DHAR1, DHAR2, GR1 and GR2 genes, pointing to a better ability to manage chilling stress in comparison to fruits stored at 5 °C.

High plasma levels of vitamin C and E are associated with incident radiographic knee osteoarthritis

BACKGROUND

Previous studies suggest that the antioxidants vitamins C and E may protect against development of knee osteoarthritis (OA). We examined the association of circulating levels of vitamin C and E with incident whole knee radiographic OA (WKROA).

METHODS

We performed a nested case-control study of incident WKROA in MOST, a cohort of 3,026 men and women aged 50-79 years with, or at high risk of, knee OA. Incident cases were knees without either tibiofemoral (TF) or patellofemoral (PF) OA at baseline that developed TF and/or PF OA by 30-month follow-up. Two control knees per case were selected from those eligible for WKROA that did not develop it. Vitamin C and E (alpha-tocopherol) assays were done on baseline supernatant plasma (PCA) and serum samples, respectively. We examined the association of gender-specific tertiles of vitamin C and E with incident WKROA using logistic regression with GEE, adjusting for age, gender, and obesity.

RESULTS

Subjects without WKROA at baseline who were in the highest tertile of vitamin C had a higher incidence of WKROA [adjusted OR = 2.20 (95% CI: 1.12-4.33); P-value = 0.021], with similar results for the highest tertile of vitamin E [adjusted OR = 1.89 (1.02-3.50); P-value = 0.042], compared to those in the lowest tertiles. P-values for the trend of vitamin C and E tertiles and incident WKROA were 0.019 and 0.030, respectively.

CONCLUSIONS

Higher levels of circulating vitamin C and E did not provide protection against incident radiographic knee OA, and may be associated with an increased risk of knee OA.

Improved growth, productivity and quality of tomato (Solanum lycopersicum L.) plants through application of shikimic acid

A field experiment was conducted to investigate the effect of seed presoaking of shikimic acid (30, 60 and 120 ppm) on growth parameters, fruit productivity and quality, transpiration rate, photosynthetic pigments and some mineral nutrition contents of tomato plants. Shikimic acid at all concentrations significantly increased fresh and dry weights, fruit number, average fresh and dry fruit yield, vitamin C, lycopene, carotenoid contents, total acidity and fruit total soluble sugars of tomato plants when compared to control plants. Seed pretreatment with shikimic acid at various doses induces a significant increase in total leaf conductivity, transpiration rate and photosynthetic pigments (Chl. a, chl. b and carotenoids) of tomato plants. Furthermore, shikimic acid at various doses applied significantly increased the concentration of nitrogen, phosphorus and potassium in tomato leaves as compared to control non-treated tomato plants. Among all doses of shikimic acid treatment, it was found that 60 ppm treatment caused a marked increase in growth, fruit productivity and quality and most studied parameters of tomato plants when compared to other treatments. On the other hand, no significant differences were observed in total photosynthetic pigments, concentrations of nitrogen and potassium in leaves of tomato plants treated with 30 ppm of shikimic acid and control plants. According to these results, it could be suggested that shikimic acid used for seed soaking could be used for increasing growth, fruit productivity and quality of tomato plants growing under field conditions.

Transcriptomic analysis of cultured whale skin cells exposed to hexavalent chromium [Cr(VI)]

Hexavalent chromium Cr(VI) is known to produce cytotoxic effects in humans and is a highly toxic environmental contaminant. Interestingly, it has been shown that free ranging sperm whales (Phyester macrocephalus) may have exceedingly high levels of Cr in their skin. Also, it has been demonstrated that skin cells from whales appear more resistant to both cytotoxicity and clastogenicity upon Cr exposure compared to human cells. However, the molecular genetic mechanisms employed in whale skin cells that might lead to Cr tolerance are unknown. In an effort to understand the underlying mechanisms of Cr(VI) tolerance and to illuminate global gene expression patterns modulated by Cr, we exposed whale skin cells in culture to varying levels of Cr(VI) (i.e., 0.0, 0.5, 1.0 and 5.0 μg/cm²) followed by short read (100 bp) next generation RNA sequencing (RNA-seq). RNA-seq reads from all exposures (≈280 million reads) were pooled to generate a de novo reference transcriptome assembly. The resulting whale reference assembly had 11K contigs and an N50 of 2954 bp. Using the reads from each dose (0.0, 0.5, 1.0 and 5.0 μg/cm²) we performed RNA-seq based gene expression analysis that identified 35 up-regulated genes and 19 down-regulated genes. The experimental results suggest that low dose exposure to Cr (1.0 μg/cm²) serves to induce up-regulation of oxidative stress response genes, DNA repair genes and cell cycle regulator genes. However, at higher doses (5.0 μg/cm²) the DNA repair genes appeared down-regulated while other genes that were induced suggest the initiation of cytotoxicity. The set of genes identified that show regulatory modulation at different Cr doses provide specific candidates for further studies aimed at determination of how whales exhibit resistance to Cr toxicity and what role(s) reactive oxygen species (ROS) may play in this process.

Carbohydrate-binding module-cyclodextrin glycosyltransferase fusion enables efficient synthesis of 2-O-d-glucopyranosyl-l-ascorbic acid with soluble starch as the glycosyl donor

In this study, we achieved the efficient synthesis of 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) from soluble starch by fusing a carbohydrate-binding module (CBM) from Alkalimonas amylolytica α-amylase (CBMAmy) to cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans. One fusion enzyme, CGT-CBMAmy, was constructed by fusing the CBMAmy to the C-terminal region of CGTase, and the other fusion enzyme, CGTΔE-CBMAmy, was obtained by replacing the E domain of CGTase with CBMAmy. The two fusion enzymes were then used to synthesize AA-2G from soluble starch as a cheap and easily soluble glycosyl donor. Under the optimal conditions, the AA-2G yields produced using CGTΔE-CBMAmy and CGT-CBMAmy were 2.01 g/liter and 3.03 g/liter, respectively, which were 3.94- and 5.94-fold of the yield from the wild-type CGTase (0.51 g/liter). The reaction kinetics of the two fusion enzymes were analyzed and modeled to confirm the enhanced specificity toward soluble starch. It was also found that, compared to the wild-type CGTase, the two fusion enzymes had relatively high hydrolysis and disproportionation activities, factors that favor AA-2G synthesis. Finally, it was speculated that the enhancement of soluble starch specificity may be related to the changes of substrate binding ability and the substrate binding sites between the CBM and the starch granule.

Biosynthesis of 2-O-D-glucopyranosyl-l-ascorbic acid from maltose by an engineered cyclodextrin glycosyltransferase from Paenibacillus macerans

In this work, the specificity of cyclodextrin glycosyltransferase (CGTase) of Paenibacillus macerans towards maltose was improved by the site-saturation engineering of lysine 47, and the enzymatic synthesis of 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) with l-ascorbic acid and maltose as substrates was optimized. Compared to the AA-2G yield of the wild-type CGTase, that of the mutants K47F (lysine→phenylalanine), K47P (lysine→proline), and K47Y (lysine→tyrosine) was increased by 17.1%, 32.9%, and 21.1%, respectively. Under the optimal transformation conditions (pH 6.5, temperature 36°C, the mass ratio of l-ascorbic acid to maltose 1:1), the highest AA-2G titer by the K47P reached 1.12g/L, which was 1.32-fold of that (0.85g/L) obtained by the wild-type CGTase. The reaction kinetics analysis confirmed the enhanced maltose specificity of the mutants K47F, K47P, and K47Y. It was also found that compared to the wild-type CGTase, the three mutants had relatively lower cyclization activities and higher disproportionation activities, which was favorable for AA-2G synthesis. As revealed by the interaction structure model of CGTase with substrate, the enhancement of maltose specificity may be due to the removal of hydrogen bonding interactions between the side chain of residue 47 and the sugar at -3 subsite. The obtained mutant CGTases, especially the K47P, has a great potential in the large-scale production of AA-2G with maltose as a cheap and soluble substrate.

Characterization of NIST food-matrix Standard Reference Materials for their vitamin C content

The vitamin C concentrations in three food-matrix Standard Reference Materials (SRMs) from the National Institute of Standards and Technology (NIST) have been determined by liquid chromatography (LC) with absorbance detection. These materials (SRM 1549a Whole Milk Powder, SRM 1849a Infant/Adult Nutritional Formula, and SRM 3233 Fortified Breakfast Cereal) have been characterized to support analytical measurements made by food processors that are required to provide information about their products' vitamin C content on the labels of products distributed in the United States. The SRMs are primarily intended for use in validating analytical methods for the determination of selected vitamins, elements, fatty acids, and other nutrients in these materials and in similar matrixes. They can also be used for quality assurance in the characterization of test samples or in-house control materials, and for establishing measurement traceability. Within-day precision of the LC method used to measure vitamin C in the food-matrix SRMs characterized in this study ranged from 2.7% to 6.5%.

Systems engineering of tyrosine 195, tyrosine 260, and glutamine 265 in cyclodextrin glycosyltransferase from Paenibacillus macerans to enhance maltodextrin specificity for 2-O-(D)-glucopyranosyl-(L)-ascorbic acid synthesis

In this work, the site saturation mutagenesis of tyrosine 195, tyrosine 260 and glutamine 265 in the cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans was conducted to improve the specificity of CGTase for maltodextrin, which can be used as a cheap and easily soluble glycosyl donor for the synthesis of 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G). Specifically, the site-saturation mutagenesis of three sites-tyrosine 195, tyrosine 260, and glutamine 265-was performed, and it was found that the resulting mutants (containing the mutations Y195S [tyrosine → serine], Y260R [tyrosine → arginine], and Q265K [glutamine → lysine]) produced higher AA-2G yields than the wild type and the other mutant CGTases when maltodextrin was used as the glycosyl donor. Furthermore, double and triple mutations were introduced, and four mutants (containing Y195S/Y260R, Y195S/Q265K, Y260R/Q265K, and Y260R/Q265K/Y195S) were obtained and evaluated for the capacity to produce AA-2G. The Y260R/Q265K/Y195S triple mutant produced the highest titer of AA-2G at 1.92 g/liter, which was 60% higher than that (1.20 g/liter) produced by the wild-type CGTase. The kinetics analysis of AA-2G synthesis by the mutant CGTases confirmed the enhanced maltodextrin specificity, and it was also found that compared with the wild-type CGTase, all seven mutants had lower cyclization activities and higher hydrolysis and disproportionation activities. Finally, the mechanism responsible for the enhanced substrate specificity was explored by structure modeling, which indicated that the enhancement of maltodextrin specificity may be related to the changes of hydrogen bonding interactions between the side chain of residue at the three positions (195, 260, and 265) and the substrate sugars. This work adds to our understanding of the synthesis of AA-2G and makes the Y260R/Q265K/Y195S mutant a good starting point for further development by protein engineering.

Site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase from Paenibacillus macerans to enhance substrate specificity towards maltodextrin for enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G)

In this work, the site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans was conducted to improve the specificity of CGTase towards maltodextrin, which can be used as a cheap and easily soluble glycosyl donor for the enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G) by CGTase. When using maltodextrin as glycosyl donor, four mutants K47F (lysine→ phenylalanine), K47L (lysine→ leucine), K47V (lysine→ valine) and K47W (lysine→ tryptophan) showed higher AA-2G yield as compared with that produced by the wild-type CGTase. The transformation conditions (temperature, pH and the mass ratio of L-ascorbic acid to maltodextrin) were optimized and the highest titer of AA-2G produced by the mutant K47L could reach 1.97 g/l, which was 64.2% higher than that (1.20 g/l) produced by the wild-type CGTase. The reaction kinetics analysis confirmed the enhanced maltodextrin specificity, and it was also found that compared with the wild-type CGTase, the four mutants had relatively lower cyclization activities and higher disproportionation activities, which was favorable for AA-2G synthesis. The mechanism responsible for the enhanced substrate specificity was further explored by structure modeling and it was indicated that the enhancement of maltodextrin specificity may be due to the short residue chain and the removal of hydrogen bonding interactions between the side chain of residue 47 and the sugar at -3 subsite. Here the obtained mutant CGTases, especially the K47L, has a great potential in the production of AA-2G with maltodextrin as a cheap and easily soluble substrate.

Biological mechanisms for nutritional regulation of maternal health and fetal development

This review paper highlights mechanisms for nutritional regulation of maternal health and fetal development. Malnutrition (nutrient deficiencies or obesity) in pregnant women adversely affects their health by causing or exacerbating a plethora of problems, such as anaemia, maternal haemorrhage, insulin resistance, and hypertensive disorders (e.g. pre-eclampsia/eclampsia). Maternal malnutrition during gestation also impairs embryonic and fetal growth and development, resulting in deleterious outcomes, including intrauterine growth restriction (IUGR), low birthweight, preterm birth, and birth defects (e.g. neural tube defects and iodine deficiency disorders). IUGR and preterm birth contribute to high rates of neonatal morbidity and mortality. Major common mechanisms responsible for malnutrition-induced IUGR and preterm birth include: (i) abnormal growth and development of the placenta; (ii) impaired placental transfer of nutrients from mother to fetus; (iii) endocrine disorders; and (iv) disturbances in normal metabolic processes. Activation of a series of physiological responses leading to premature and sustained contraction of the uterine myometrium also results in preterm birth. Recent epidemiologic studies have suggested a link between IUGR and chronic metabolic disease in children and adults, and the effects of IUGR may be carried forward to subsequent generations through epigenetics. While advanced medical therapies, which are generally unavailable in low-income countries, are required to support preterm and IUGR infants, optimal nutrition during pregnancy may help ameliorate many of these problems. Future studies are necessary to develop effective nutritional interventions to enhance fetal growth and development and alleviate the burden of maternal morbidity and mortality in low- and middle-income countries.

Palaeopathology of human remains from the Roman Imperial Age

The increasing attention of archaeological and anthropological research towards palaeopathological studies has allowed to focus the examination of many skeletal samples on this aspect and to evaluate the presence of many diseases afflicting ancient populations. This paper describes the most interesting diseases observed in skeletal samples from five necropolises found in urban and suburban areas of Rome during archaeological excavations in the last decades, and dating back to the Imperial Age. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumors, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, palaeopathology allowed highlighting the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

Vitamin composition of ethnic foods commonly consumed in Europe

BACKGROUND

Vitamin analyses are particularly important for estimating dietary intakes, determining nutritional status and regulating food labelling. Due to the increased popularity of ethnic foods, the vitamin composition of these foods is required to ensure that national food databases are up-to-date.

OBJECTIVES

The key objective of this study was to generate new and reliable data on the contents of fat-soluble vitamins, including vitamins A (all trans-retinol), D(3) & E (α-tocopherol) and those that are water-soluble (vitamins B(6), B(12), C, biotin, folate, niacin, pantothenic acid, riboflavin, and thiamin) in ethnic foods commonly consumed in Europe.

DESIGN

Thirty commonly-consumed ethnic foods in Europe (from Belgium, France, Israel, Italy, The Netherlands, and the UK) were analysed using harmonised methodologies for identification of representative foods, sampling, data scrutiny and documentation to generate reliable data. Analyses were carried out using International standard methods.

RESULTS

CERTAIN VITAMINS WERE PRESENT IN APPRECIABLE AMOUNTS: β-carotene in tayer leaves (7919µg/100g), thiamin in frik dry (0.24mg/100g), riboflavin in mbinzo worms (0.79mg/100g,) and niacin in commercial soy patty (17.5mg/100g). However, retinol, pantothenic acid, vitamins D and B(12) were below detectable levels in the majority of the foods analysed.

CONCLUSIONS

The majority of the foods contained most of the water-soluble vitamins but lacked fat-soluble vitamins. However, these preliminary data represent only a small number of foods per country and so no conclusions about vitamin imbalances can be drawn. Additional data are required on a much wider range of commonly-consumed ethnic foods to make firm conclusions about adequacy of diets.

The efficacy of vitamin C supplementation on reducing total serum cholesterol in human subjects: a review and analysis of 51 experimental trials

OBJECTIVE

Observational studies in humans have shown an inverse relationship between plasma vitamin C concentration and total serum cholesterol. However, experimental studies have shown inconsistent results regarding the ability of vitamin C to reduce total serum cholesterol.

METHODS

Published reports of trials studying the effects of vitamin C on serum lipids were identified by a search of Medline from 1966 to 2004. Data from 51 experimental studies comprising of 1666 pooled subjects were selected for analysis.

RESULTS

A very strong negative association was observed between baseline total serum cholesterol and the percent change in cholesterol (r = -0.585, p<0.001). When subjects were divided into 4 groups based on their baseline total serum cholesterol levels, the following weighted mean percent changes in cholesterol from baseline were observed: normal cholesterol (<199mg/dl): 0.91+/-6.8% (n=508); borderline high cholesterol (200-239mg/dl): 3.90+/-5.78% (n=605); high cholesterol (240-279mg/dl): 11.40+/-7.96% (n=300); severe cholesterol (>280mg/dl): 14.30+/-8.36% (n=253). A significant inverse relationship was found between the baseline plasma vitamin C concentrations and mean percent change in total cholesterol from baseline (r = -0.500, p<0.005). It was also observed that the high and severe baseline cholesterol groups possessed lower baseline plasma vitamin C concentrations than those in the normal cholesterol groups (0.79 and 0.55 versus 1.24 mg/dl respectively).

CONCLUSION

This finding strengthens the hypothesis that the cholesterol lowering and cardio-protective benefit of vitamin C supplementation may be in its ability to elevate plasma vitamin C concentrations in those patients who initially possess lower than normal vitamin C plasma concentrations.

Regulation of the human ascorbate transporter SVCT2 exon 1b gene by zinc-finger transcription factors

The sodium-dependent vitamin C transporter (SVCT) 2 is crucial for ascorbate uptake in metabolically active and specialized tissues. This study focused on the gene regulation of SVCT2 exon 1b, which is ubiquitously expressed in human and mouse tissues. Although the human SVCT2 exon 1b promoter does not contain a classical TATA box, we found that it does contain a functional initiator that binds Yin Yang-1 (YY1) and interacts with upstream Sp1/Sp3 elements in the proximal promoter region. These elements in turn play a critical role in regulating YY1-mediated transcription of exon 1b. Formation of YY1/Sp complexes on the promoter is required for its optional function. YY1 with Sp1 or Sp3 synergistically enhanced exon 1b promoter activity as well as the endogenous SVCT2 protein expression. Further, in addition to Sp1/Sp3, both EGR-1 and EGR-2 were detected in the protein complexes that bound the three GC boxes bearing overlapping binding sites for EGR/WT1 and Sp1/3. The EGR family factors WT1 and MAZ were found to differentially regulate exon 1b promoter activity. These results show that differential occupancy of transcription factors on the GC-rich consensus sequences in the SVCT2 exon 1b promoter contributes to the regulation of cell and tissue expression of SVCT2.

Nutrient deficiencies as a risk factor in Taiwanese patients with postherpetic neuralgia

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ). The aim of the present study was to compare the nutritional status of PHN patients with that of healthy controls, and then to identify risk factors for PHN using multivariate multiple logistic regressions. In the present cross-sectional study, we prospectively enrolled fifty PHN patients for at least 3 months and fifty healthy controls. We selected nine circulating nutrients including ionised Ca, Zn, retinol, folic acid, vitamin B12, vitamin C, α-tocopherol, γ-tocopherol and lycopene associated with both immunity and the modulation of neuropathic pain, and measured their concentrations in plasma/serum. Concentrations of ionised Ca, Zn, vitamin C and vitamin B12 were significantly lower in PHN patients than in controls after excluding those patients receiving supplements since the outbreak of HZ. The prevalence of either mild/marginal or severe deficiencies for any of the nine selected circulating nutrients in PHN patients (92 %) was much higher than that in controls (46 %) (P < 0·001). Lower concentrations of vitamin C ( ≤ 45·0 μmol/l), ionised Ca ( ≤ 1·05 mmol/l) and Zn ( ≤ 0·91 g/l) were found to increase independently the risk of PHN using binary variable (dichotomy) analyses with both PHN patients and controls in a multivariate logistic regression analysis. No significant correlations existed between the risks of PHN and the concentrations of retinol, folic acid, vitamin B12, lycopene or α:γ-tocopherol ratios. Thus, lower concentrations of circulating nutrients, namely vitamin C, ionised Ca or Zn, are probably a risk factor in Taiwanese patients with PHN.

Vitamin C: Overview and Update

Vitamin C functions in enzyme activation, oxidative stress reduction, and immune function. There is considerable evidence that vitamin C protects against respiratory tract infections and reduces risk for cardiovascular disease and some cancers. Current trials are examining the efficacy of intravenous vitamin C as cancer therapy. Many experts believe that the recommended intakes for vitamin C (45 to 90 mg daily) are several orders of magnitude too low to support optimal vitamin C functionality. Also, there is a misperception that vitamin C deficiency disease (scurvy) is largely historical and rarely observed in developed nations. Physical symptoms of scurvy include swelling of the lower extremities, bleeding gums, fatigue, and hemorrhaging, as well as psychological problems, including depression, hysteria, and social introversion. The long-term safety of vitamin C supplementation seems evident as large investigations have noted reduced risk of mortality in vitamin C supplementing populations and in those with elevated plasma vitamin C concentrations.

Effects of grapefruit, grapefruit juice and water preloads on energy balance, weight loss, body composition, and cardiometabolic risk in free-living obese adults

BACKGROUND

Reducing dietary energy density has proven to be an effective strategy to reduce energy intakes and promote weight control. This effect appears most robust when a low energy dense preload is consumed before meals. Yet, much discussion continues regarding the optimal form of a preload. The purpose of the present study was to compare effects of a solid (grapefruit), liquid (grapefruit juice) and water preload consumed prior to breakfast, lunch and dinner in the context of caloric restriction.

METHODS

Eighty-five obese adults (BMI 30-39.9) were randomly assigned to (127 g) grapefruit (GF), grapefruit juice (GFJ) or water preload for 12 weeks after completing a 2-week caloric restriction phase. Preloads were matched for weight, calories, water content, and energy density. Weekly measures included blood pressure, weight, anthropometry and 24-hour dietary intakes. Resting energy expenditure, body composition, physical performance and cardiometabolic risk biomarkers were assessed.

RESULTS

The total amount (grams) of food consumed did not change over time. Yet, after preloads were combined with caloric restriction, average dietary energy density and total energy intakes decreased by 20-29% from baseline values. Subjects experienced 7.1% weight loss overall, with significant decreases in percentage body, trunk, android and gynoid fat, as well as waist circumferences (-4.5 cm). However, differences were not statistically significant among groups. Nevertheless, the amount and direction of change in serum HDL-cholesterol levels in GF (+6.2%) and GFJ (+8.2%) preload groups was significantly greater than water preload group (-3.7%).

CONCLUSIONS

These data indicate that incorporating consumption of a low energy dense dietary preload in a caloric restricted diet is a highly effective weight loss strategy. But, the form of the preload did not have differential effects on energy balance, weight loss or body composition. It is notable that subjects in GF and GFJ preload groups experienced significantly greater benefits in lipid profiles.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00581074.

Sea lettuces: culinary uses and nutritional value

In many countries, sea lettuces are commonly consumed as food by human since the beginning of times. Sea lettuces contain significant amount of nutrients which are essential for human body. Moreover, several studies have provided insight into biological activities and health promoting effects of sea lettuces. Despite having so much health beneficial effects, sea lettuces are still identified as an underexploited plant resources for food purposes. Hence, sea lettuces have a great potential for further development as products in foods and pharmaceutical areas. Further, potential applications of polysaccharides, protein and amino acid, lipid and fatty acid, mineral and vitamin contents may increase the sea lettuces value. This contributions presents information on the currently culinary use of sea lettuces worldwide and nutritional aspects of sea lettuces.

Haptoglobin genotype modifies the association between dietary vitamin C and serum ascorbic acid deficiency

BACKGROUND

Haptoglobin (which is encoded by the Hp gene) is a hemoglobin-binding protein that has antioxidant properties and a common polymorphism that consists of 2 structurally different alleles: Hp1 and Hp2. The capacity of Hp2 to inhibit oxidation and vitamin C depletion is less than that of Hp1, but the influence on vitamin C requirements remains unknown.

OBJECTIVE

This study aimed to determine whether the Hp polymorphism modifies the association between dietary vitamin C and serum ascorbic acid deficiency (<11 μmol/L).

DESIGN

Nonsmoking men and women (n = 1046) between 20 and 29 y of age participated in the Toronto Nutrigenomics and Health Study. Blood samples were collected after the subjects had fasted overnight to determine serum ascorbic acid concentrations by HPLC and for genotyping. A 196-item food-frequency questionnaire was used to estimate vitamin C intake.

RESULTS

A gene-diet interaction on serum ascorbic acid was observed (P = 0.02). The overall odds ratio (95% CI) for serum ascorbic acid deficiency was 2.84 (1.73, 4.65) for subjects who did not meet the Recommended Dietary Allowance for vitamin C compared with those who did. The corresponding odds ratios were 4.77 (2.36, 9.65) for the Hp2-2 genotype and 1.69 (0.80, 3.63) for carriers of the Hp1 allele.

CONCLUSIONS

Individuals with the Hp2-2 genotype had an increased risk of deficiency if they did not meet the Recommended Dietary Allowance for vitamin C, whereas carriers of the Hp1 allele did not. The findings suggest that the greater antioxidant capacity of Hp1 might spare serum ascorbic acid.

Micronutrients and HIV infection

The immune system requires several essential micronutrients to maintain an effective immune response. HIV infection destroys the immune system and promotes nutritional deficiencies, which further impair immunity. This article reviews the role of several micronutrients (vitamins A, C, E and D, the B vitamins, and minerals, selenium, iron and zinc) that are relevant for maintaining immune function. In addition, the deficiencies of these micronutrients have been associated with faster progression of HIV-1 disease. This review examines the evidence from observational studies of an association between micronutrient status and HIV disease, as well as the effectiveness of micronutrient supplementation on HIV-disease progression, pregnancy outcomes and nutritional status, among others, utilizing randomized clinical trials. Each micronutrient is introduced with a summary of its functions in human physiology, followed by the presentation of studies conducted in HIV-infected patients in relation to this specific micronutrient. Overall findings and recommendations are then summarized.

Assessment of total antioxidant capacity and the use of vitamin C in the treatment of non-smokers with chronic periodontitis

BACKGROUND

Several recent studies have indicated that total antioxidant capacity (TAOC) of plasma seems to be compromised in chronic periodontitis (ChP). The aim of this study is to investigate plasma TAOC in patients with ChP and to assess the effects of vitamin C as an adjunct to non-surgical periodontal treatment.

METHODS

The study population consisted of 60 subjects: 30 diagnosed with ChP and 30 matched controls. Furthermore, patients from the ChP group were randomly allocated into ChP1 (15 patients received non-surgical treatment with adjunctive dose of vitamin C) and ChP2 (15 patients received non-surgical periodontal treatment alone). Plasma TAOC levels were measured by an ABTS assay at baseline and 1 month post-therapy.

RESULTS

Plasma TAOC levels were significantly lower in ChP patients than controls (P <0.001). The periodontal therapy resulted in increasing plasma TAOC and improvements in clinical measures among both ChP1 and ChP2 groups (P <0.001). However, the adjunctive dose of vitamin C did not offer additional effect (P >0.05).

CONCLUSIONS

ChP is significantly associated with lower levels of plasma TAOC. The non-surgical periodontal therapy seems to reduce the oxidative stress during the periodontal inflammation. However, the use of adjunctive vitamin C still needs further investigation.