Calcium intake, calcium homeostasis and health

Can baseline serum calcium levels predict outcomes of intracerebral hemorrhage? A systematic review and meta-analysis

OBJECTIVE

The prognostic role of baseline calcium levels in patients with intracerebral hemorrhage (ICH) is conflicting. We aimed to conduct the first meta-analysis in the literature to examine if baseline calcium levels can predict outcomes after ICH.

METHODS

English-language studies listed on the databases of Embase, PubMed, ScienceDirect, and Web of Science were searched up to 20th November 2023. Meta-analysis was conducted for baseline hematoma volume, hematoma expansion, unfavorable functional outcome, and mortality.

RESULTS

Ten studies were included. Meta-analysis showed that patients with hypocalcemia have significantly higher baseline hematoma volume (MD: 8.6 95 % CI: 3.30, 13.90 I2 = 88 %) but did not have a higher risk of hematoma expansion (OR: 1.82 95 % CI: 0.89, 3.73 I2 = 82 %). Meta-analysis of crude (OR: 1.86 95 % CI: 1.25, 2.78 I2 = 63 %) and adjusted data (OR: 2.05 95 % CI: 1.27, 3.28 I2 = 64 %) showed those with hypocalcemia had a significantly higher risk of unfavorable functional outcomes. Meta-analysis of both crude (OR: 2.09 95 % CI: 1.51, 2.88 I2 = 80 %) and adjusted data (OR: 1.38 95 % CI: 1.14, 1.69 I2 = 70 %) also demonstrated a significantly higher risk of mortality in patients with hypocalcemia.

CONCLUSION

Baseline serum calcium may have a prognostic role in ICH. Hypocalcemia at baseline may lead to large hematoma volume and poor functional and survival outcomes. However, there seems to be no relation between hypocalcemia and the risk of hematoma expansion. Further studies examining the role of calcium on ICH prognosis are needed.

Caffeine regulates both osteoclast and osteoblast differentiation via the AKT, NF-κB, and MAPK pathways

Background: Although caffeine generally offers benefits to human health, its impact on bone metabolism remains unclear. Aim and Methods: This study aimed to systematically evaluate the long-term effects of caffeine administration on osteoclasts, osteoblasts, and ovariectomy-induced postmenopausal osteoporosis (OP). Results: Our in vitro findings revealed that 3.125 and 12.5 μg/mL caffeine inhibited RANKL-mediated osteoclastogenesis in RAW 264.7 cells through the MAPK and NF-κB pathways, accompanied by the inactivation of nuclear translocation of nuclear factor NFATc1. Similarly, 3.125 and 12.5 μg/mL of caffeine modulated MC3T3-E1 osteogenesis via the AKT, MAPK, and NF-κB pathways. However, 50 μg/mL of caffeine promoted the phosphorylation of IκBα, P65, JNK, P38, and AKT, followed by the activation of NFATc1 and the inactivation of Runx2 and Osterix, ultimately disrupting the balance between osteoblastogenesis and osteoclastogenesis. In vivo studies showed that gavage with 55.44 mg/kg caffeine inhibited osteoclastogenesis, promoted osteogenesis, and ameliorated bone loss in ovariectomized mice. Conclusion: Conversely, long-term intake of high-dose caffeine (110.88 mg/kg) disrupted osteogenesis activity and promoted osteoclastogenesis, thereby disturbing bone homeostasis. Collectively, these findings suggest that a moderate caffeine intake (approximately 400 mg in humans) can regulate bone homeostasis by influencing both osteoclasts and osteoblasts. However, long-term high-dose caffeine consumption (approximately 800 mg in humans) could have detrimental effects on the skeletal system.

Characterization of flours from the aroeira leaf (Schinus terebinthifolius Raddi), obtained by different drying methods

The present work aimed at the development and characterization of aroeira leaf flour (Schinus terebinthifolius Raddi), obtained by lyophilization and drying in an air circulation oven. The technological, physical, physico-chemical, morphological, functional, and microbiological aspects were analyzed. Physico-chemical analysis identified the following properties with values provided respectively for fresh leaves (FOin) and flours (FES and FLIO): low water activity (0.984, 0.370, 0.387 g/100 g), moisture (64.52, 5.37, 7.97 g /100 g), ash (2.69, 6.51, and 6.89 g/100 g), pH (0.89, 4.45, 4.48 g/100 g), lipids (0.84, 1.67, 5.23 g/100 g), protein (3.29, 8.23, 14.12 g/100 g), carbohydrates (17.02, 53.12, 33.02 g/100 g), ascorbic acid (19.70, 34.20, 36.90 mg/100 g). Sources of fiber from plant leaves and flours (11.64, 25.1, 32.89 g/100 g) showed increased levels of luminosity. For NMR, the presence of aliphatic and aromatic compounds with olefinic hydrogens and a derivative of gallic acid were detected. The most abundant minerals detected were potassium and calcium. Micrographs identified the presence of irregular, non-uniform, and sponge-like particles. The main sugars detected were: fructose, glucose, and maltose. Malic, succinic, citric, lactic, and formic acids were found. Fifteen phenolic compounds were identified in the samples, highlighting: kaempferol, catechin, and caffeic acid. The values ​​found for phenolics were (447, 716.66, 493.31 mg EAG/100 g), flavonoids (267.60, 267.60, 286.26 EC/100 g). Antioxidant activity was higher using the ABTS method rather than FRAP for analysis of FOin, FES, and FLIO. Since the flours of the aroeira leaf have an abundant matrix of nutrients with bioactive properties and antioxidant activity, they have a potential for technological and functional use when added to food.

Dietary intake of polish organic and conventional fruit growers and their life partners - a pilot study

Diet is one of the elements that contribute to health and quality of life. There are significant discrepancies between the diets of people living in different regions, with different beliefs, or with different approaches to sustainability and ecology. There is a lack of research on dietary intake among organic and conventional fruit growers. The aim of our study was to examine the diets of orchardists and their immediate life partners in terms of meeting energy requirements, nutrient intake and fulfillment of dietary recommendations in this group. Fifty-three participants (28 in the organic group and 25 in the conventional group) took part in the study. Dietary data were obtained using the 3-day dietary record. Body mass and height were measured and BMI was calculated. Physical activity was estimated using a questionnaire method. The study group was aged 44 ± 8 years, with a body weight of 84 ± 16 kg and a height of 172 ± 9 cm. The mean BMI was 28 ± 4 kg/m2. Mean energy intake with diet was 2170 ± 606 kcal/day with needs of 3002 (1991-5144) kcal/day. A significant proportion of the study group did not fulfill their calcium and vitamin D requirements. In addition, a significant proportion of the conventional fruit growers did not cover their needs for potassium, magnesium and vitamins: E, C, and folate. Both groups had too high an intake of cholesterol and saturated fatty acids, and too low an intake of polyunsaturated fatty acids. In conclusion, the orchardists' diets mostly provided adequate amounts of nutrients, with inadequate intakes of calcium, vitamin D, cholesterol, and fatty acids. The diets of organic fruit growers were significantly richer in selected nutrients.

The role of dairy food intake for improving health among black Americans across the life continuum: A summary of the evidence

Decades of health data show major health disparities occurring at every life stage between Black and White Americans. These disparities include greater mortality rates among Black mothers and their offspring, higher levels of malnutrition and obesity among Black children and adolescents, and a higher burden of chronic disease and lower life expectancy for Black adults. Although nutrition is only one of many factors that influence human health and well-being across the life continuum, a growing body of research continues to demonstrate that consuming a healthy dietary pattern is one of the most dominant factors associated with increased longevity, improved mental health, improved immunity, and decreased risk for obesity and chronic disease. Unfortunately, large percentages of Black Americans tend to consume inadequate amounts of several essential nutrients such as vitamin A, vitamin D, calcium, and magnesium; and simultaneously consume excessive amounts of fast foods and sugar-sweetened beverages to a greater degree than other racial/ethnic groups. Therefore, strategies that can help improve dietary patterns for Black Americans could make up a major public health opportunity for reducing nutrition-related diseases and health disparities across the life course. A key intervention strategy to improve diet quality among Black Americans is to focus on increasing the intake of nutrient-rich dairy foods, which are significantly underconsumed by most Black Americans. Compared to other food group, dairy foods are some of the most accessible and affordable sources of essential nutrients like vitamin A, D, and B12, calcium, magnesium, potassium, selenium, and zinc in the food supply, as well as being some of the primary sources of several health-promoting bioactive compounds, including polar lipids, bioactive proteins and peptides, oligosaccharides, and live and active cultures in fermented products. Given the complex relationships that many Black Americans have with dairy foods, due to issues with lactose intolerance, and/or negative perceptions about the health effects of dairy foods, there is still a need to examine the role that dairy foods play in the health and well-being of Black Americans of all ages and life stages. Therefore, the National Medical Association and its partners have produced multiple reports on the value of including adequate dairy in the diet of Black Americans. This present summary paper and its associated series of evidence reviews provide an examination of an immense amount of research focused on dairy intake and health outcomes, with an emphasis on evidence-based strategies for improving the health of Black Americans. Overall, the findings and conclusions from this body of research continue to indicate that higher dairy intake is associated with reduced risk for many of the most commonly occurring deficiencies and diseases impacting each life stage, and that Black Americans would receive significantly greater health benefits by increasing their daily dairy intake levels to meet the national recommendations than they would from continuing to fall short of these recommendations. However, these recommendations must be considered with appropriate context and nuance as the intake of different dairy products can have different impacts on health outcomes. For instance, vitamin D fortified dairy products and fermented dairy products like yogurt - which are low in lactose and rich in live and active cultures - tend to show the greatest benefits for improved health. Importantly, there are significant limitations to these research findings for Black Americans, especially as they relate to reproductive and child health, since most of the research on dairy intake and health has failed to include adequate representation of Black populations or to sufficiently address the role of dairy intake during the most vulnerable life stages, such as pregancy, lactation, fetal development, early childhood, and older age. This population and these life stages require considerably more research and policy attention if health equity is ever to be achieved for Black Americans. Sharing and applying the learnings from this summary paper and its associated series of evidence reviews will help inform and empower nutrition and health practitioners to provide more evidence-based dietary recommendations for improving the health and well-being of Black Americans across the life course.

Novel Near-Infrared-II In Vivo Visualization Revealed Rapid Calcium Intestine Turnover in Daphnia magna with Delayed Impact by Cadmium and Acidification

Calcium is a highly demanded metal, and its transport across the intestine of Daphnia magna remains a significant unresolved question. Due to technical constraints, the visualization of the kinetic process of Ca passage through D. magna has been challenging. Here, we developed the second near-infrared Ca sensor (NIR-II Ca) and conducted real-time in vivo imaging of Ca in daphnids with a high signal-to-noise ratio, deep tissue penetration, and minimal damage. Through the utilization of the NIR-II Ca sensor, we for the first time visualized and quantified the kinetic process of Ca passage in the intestine in real time. The results revealed that trophically available Ca passed through the intestines in 24 h, whereas waterborne Ca required only 35 min. This rapid "flushing through" mechanism established waterborne Ca as the primary source of Ca absorption. However, environmental stressors such as water acidification and cadmium significantly delayed the Ca passage and absorption. The development of NIR imaging and sensors allows for real-time dynamic visualization of contaminants/nutrients in organisms and holds great potential as a powerful tool for future studies into material kinetic processes in living animals.

Neuroprotective effects of vitamin D in an Alzheimer's disease rat model: Improvement of mitochondrial dysfunction via calcium/calmodulin-dependent protein kinase kinase 2 activation of Sirtuin1 phosphorylation

Mitochondrial dysfunction is an early event in Alzheimer's disease (AD) pathogenesis. To assess the impact of vitamin D3 (Vit.D) on neurogenesis, we investigated its role in mitigating cognitive impairment and mitochondrial dysfunction through calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2)-mediated phosphorylation of Sirtuin1 (SIRT1) in an aluminum-chloride-D-galactose (AlCl3-D-gal)-induced AD rat model. Rats were distributed into four groups: control, AlCl3 + D-gal (10 + 60 mg/kg, ip), Vit.D (500 IU/kg, po), and AlCl3 + D-gal+Vit.D. Novel object recognition (NOR), Morris Water Maze, and passive avoidance (PA) tests were used to measure memory abilities. The hippocampal tissue was used to assess vitamin D3 receptor (VDR) and peroxisome-proliferator-activated-receptor-γ-coactivator-1α (PGC-1α) expression by quantitative real-time polymerase chain reaction (qRT-PCR), CAMKK2, p-SIRT1, phosphorylated-AMP-activated protein kinase (p-AMPK), dynamin-related-protein-1 (Drp1), and mitofusin-1 (Mnf1) proteins by western blot and Ca2+ levels, endothelial nitic oxide synthase (eNOS), superoxide dismutase (SOD), amyloid beta (Aβ), and phospho tau (p-Tau) via enzyme-linked immunosorbent assay(ELISA) in addition to histological and ultrastructural examination of rat's brain tissue. Vit.D-attenuated hippocampal injury reversed the cognitive decline and Aβ aggregation, and elevated p-Tau levels in the AlCl3 + D-gal-induced AD rat model. In AlCl3 + D-gal-exposed rats, Vit.D induced VDR expression, normalized Ca2+ levels, elevated CAMKK2, p-AMPK, p-SIRT1, and PGC-1α expression. Vit.D reduced Drp1, induced Mnf1, increased mitochondrial membrane potential, preserved mitochondrial structure, restored normal mitochondrial function, and retained normal eNOS level and SOD activity in AlCl3 + D-gal rats. In conclusion, our findings proved that Vit.D may ameliorate cognitive deficits in AlCl3 + D-gal-induced AD by restoring normal mitochondrial function and reducing inflammatory and oxidative stress via CAMKK2-AMPK/SIRT1 pathway upregulation.

Structural characterization and calcium absorption-promoting effect of sucrose-calcium chelate in Caco-2 monolayer cells and mice

Sucrose emerges as a chelating agent to form a stable sucrose-metal-ion chelate that can potentially improve metal-ion absorption. This study aimed to analyze the structure of sucrose-calcium chelate and its potential to promote calcium absorption in both Caco-2 monolayer cells and mice. The characterization results showed that calcium ions mainly chelated with hydroxyl groups in sucrose to produce sucrose-calcium chelate, altering the crystal structure of sucrose (forming polymer particles) and improving its thermal stability. Sucrose-calcium chelate dose dependently increased the amount of calcium uptake, retention, and transport in the Caco-2 monolayer cell model. Compared to CaCl2 , there was a significant improvement in the proportion of absorbed calcium utilized for transport but not retention (93.13 ± 1.75% vs. 67.67 ± 7.55%). Further treatment of calcium channel inhibitors demonstrated the active transport of sucrose-calcium chelate through Cav1.3. Cellular thermal shift assay and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays indicated that the ability of sucrose-calcium chelate to promote calcium transport was attributed to its superior ability to bind with PMCA1b, a calcium transporter located on the basement membrane, and stimulate its gene expression compared to CaCl2 . Pharmacokinetic analysis of mice confirmed the calcium absorption-promoting effect of sucrose-calcium chelate, as evident by the higher serum calcium level (44.12 ± 1.90 mg/L vs. 37.42 ± 1.88 mmol/L) and intestinal PMCA1b gene expression than CaCl2 . These findings offer a new understanding of how sucrose-calcium chelate enhances intestinal calcium absorption and could be used as an ingredient in functional foods to treat calcium deficiency. PRACTICAL APPLICATION: The development of high-quality calcium supplements is crucial for addressing the various adverse symptoms associated with calcium deficiency. This study aimed to prepare a sucrose-calcium chelate and analyze its structure, as well as its potential to enhance calcium absorption in Caco-2 monolayer cells and mice. The results demonstrated that the sucrose-calcium chelate effectively promoted calcium absorption. Notably, its ability to enhance calcium transport was linked to its strong binding with PMCA1b, a calcium transporter located on the basement membrane, and its capacity to stimulate PMCA1b gene expression. These findings contribute to a deeper understanding of how the sucrose-calcium chelate enhances intestinal calcium absorption and suggest its potential use as an ingredient in functional foods for treating calcium deficiency.

Calcium complexation by steroids involved in the steroidogenesis

Steroids that take part in the pathways of human steroidogenesis are involved in many biological mechanisms where they interact with calcium. In the present work, the binding selectivities and affinities for calcium of progestagens, mineralocorticoids, androstagens, and estrogens were studied by Electrospray Ionization-Mass Spectrometry (ESI-MS). The adduct profile of each steroid was characterized by high resolution and tandem mass spectrometry. The relative stability of the most important adducts was studied by threshold collision induced dissociation, E1/2. Doubly-charged steroid-calcium complexes [nM + Ca]2+ with n = 1-6 were predominant in the mass spectra. The adduct [5M + Ca]2+ was the base peak for most 3-keto-steroids, while ligands bearing hindered ketones or α-hydroxy-ketones also yielded [nM + Ca + mH2O]2+ with n = 3-4 and m = 0-1. Principal component analysis allowed us to spot the main differences and similarities in the binding behavior of these steroids. The isomers testosterone and dehydroepiandrosterone, androstanolone and epiandrosterone, and 17-α-hydroxyprogesterone and 11-deoxycorticosterone showed remarkable differences in their adduct profiles. Computational modeling of representative adducts was performed by density functional theory methods. The possible binding modes at low and high numbers of steroid ligands were determined by calcium Gas Phase Affinity, and through modeling of the complexes and comparison of their relative stabilities, in agreement with the experimental results.

EF-Hand Calcium Sensor, EfhP, Controls Transcriptional Regulation of Iron Uptake by Calcium in Pseudomonas aeruginosa

The human pathogen Pseudomonas aeruginosa poses a major risk for a range of severe infections, particularly lung infections in patients suffering from cystic fibrosis (CF). As previously reported, the virulent behavior of this pathogen is enhanced by elevated levels of Ca 2+ that are commonly present in CF nasal and lung fluids. In addition, a Ca 2+ -binding EF-hand protein, EfhP (PA4107), was partially characterized and shown to be critical for the Ca 2+ -regulated virulence in P. aeruginosa . Here we describe the rapid (10 min, 60 min), and adaptive (12 h) transcriptional responses of PAO1 to elevated Ca 2+ detected by genome-wide RNA sequencing and show that efhP deletion significantly hindered both rapid and adaptive Ca 2+ regulation. The most differentially regulated genes included multiple Fe sequestering mechanisms, a large number of extracytoplasmic function sigma factors (ECFσ) and several virulence factors, such as production of pyocins. The Ca 2+ regulation of Fe uptake was also observed in CF clinical isolates and appeared to involve the global regulator Fur. In addition, we showed that the efhP transcription is controlled by Ca 2+ and Fe, and this regulation required Ca 2+ -dependent two-component regulatory system CarSR. Furthermore, the efhP expression is significantly increased in CF clinical isolates and upon pathogen internalization into epithelial cells. Overall, the results established for the first time that Ca 2+ controls Fe sequestering mechanisms in P. aeruginosa and that EfhP plays a key role in the regulatory interconnectedness between Ca 2+ and Fe signaling pathways, the two distinct and important signaling pathways that guide the pathogen's adaptation to host.

IMPORTANCE

Pseudomonas aeruginosa ( Pa ) poses a major risk for severe infections, particularly in patients suffering from cystic fibrosis (CF). For the first time, kinetic RNA sequencing analysis identified Pa rapid and adaptive transcriptional responses to Ca 2+ levels consistent with those present in CF respiratory fluids. The most highly upregulated processes include iron sequestering, iron starvation sigma factors, and self-lysis factors pyocins. An EF-hand Ca 2+ sensor, EfhP, is required for at least 1/3 of the Ca 2+ response, including all the iron uptake mechanisms and production of pyocins. Transcription of efhP itself is regulated by Ca 2+ , Fe, and increases during interactions with host epithelial cells, suggesting the protein's important role in Pa infections. The findings establish the regulatory interconnectedness between Ca 2+ and iron signaling pathways that shape Pa transcriptional responses. Therefore, understanding Pa's transcriptional response to Ca 2+ and associated regulatory mechanisms will serve the development of future therapeutics targeting Pa dangerous infections.

Impact of deoxynivalenol in a calcium depletion and repletion nutritional strategy in piglets

This study evaluated the effect of dietary calcium (Ca) levels and deoxynivalenol (DON) contamination on Ca and phosphorus (P) utilization and bone mineralization in piglets. During an initial 13-d depletion phase, 64 piglets (15.7 ± 0.7 kg) received a control (DON-) or DON-contaminated treatment (DON+, 2.7 mg DON/kg) with either a low Ca (Ca-, 0.39%) or normal Ca level (Ca+, 0.65%) with a constant digestible P level (0.40%). A second group of 16 piglets received DON- or DON+ treatments for 9 d for gene expression analysis. During the subsequent 14-d repletion phase, all piglets were fed a Ca+ DON- diet containing 0.65% Ca and 0.35% digestible P without DON. After 5 d of the depletion phase, the absorption of P (DON × Ca; P < 0.05) and Ca was increased by the Ca- (P < 0.01) and DON+ (P < 0.01) diet. After 13 d, feed conversion ratio (P < 0.01) and average daily feed intake (P = 0.06) tended to decrease with the Ca- diet. The bone mineral content (BMC) gain was decreased by Ca, especially with Ca- DON + (DON × Ca, P < 0.05). The P absorption was increased by Ca- DON + (DON × Ca, P < 0.01), although the P retention efficiency was only increased by Ca+ DON + (DON × Ca, P < 0.001). The absorption of Ca was increased by DON+ (P < 0.001), and the Ca efficiency was increased by Ca- DON- (DON × Ca, P < 0.01). After 9 d, the gene expression of intestinal claudin 12 (P < 0.01) and CYP24A1 (P < 0.05), femur cortical RANKL (P < 0.05) and OPG (P = 0.06), and renal calbindin D9K (P < 0.05) and Klotho (P = 0.07) were decreased by DON+. The Ca (P = 0.06) and magnesium (P < 0.01) concentrations were decreased by DON+, and the Ca (P = 0.06) and P digestibility (P < 0.01) were increased. After the repletion phase, Ca- piglets recovered their BMC deficit, but not those receiving DON+ (DON × Ca; P = 0.06). The Ca (P < 0.05) and P (P = 0.06) retention efficiency tended to increase with Ca-. The absorption of Ca and P was increased by Ca- and DON+ (DON × Ca, P < 0.05). The results show that piglets increased their Ca and P utilization efficiency, allowing them to recover the BMC deficit caused by Ca-, but not when the piglets were exposed to DON. Pigs previously receiving Ca-deficient diet with DON still have lower body Ca and P, leading to elevated calcitriol concentrations and enhanced Ca and P intestinal absorption. The fact that DON decreased the expression of genes implicated in Ca intestinal and renal transport and P excretion after 9 d can potentially explain the reduced plasma Ca concentration.

Coupling of renal sodium and calcium transport: a modeling analysis of transporter inhibition and sex differences

Ca2+ transport along the nephron occurs via specific transcellular and paracellular pathways and is coupled to the transport of other electrolytes. Notably, Na+ transport establishes an electrochemical gradient to drive Ca2+ reabsorption. Hence, alterations in renal Na+ handling, under pathophysiological conditions or pharmacological manipulations, can have major effects on Ca2+ transport. An important class of pharmacological agent is diuretics, which are commonly prescribed for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate Na+ transport but also indirectly affect renal Ca2+ handling. To better understand the underlying mechanisms, we developed a computational model of electrolyte transport along the superficial nephron in the kidney of a male and female rat. Sex differences in renal Ca2+ handling are represented. Model simulations predicted in the female rat nephron lower Ca2+ reabsorption in the proximal tubule and thick ascending limb, but higher reabsorption in the late distal convoluted tubule and connecting tubule, compared with the male nephron. The male rat kidney model yielded a higher urinary Ca2+ excretion than the female model, consistent with animal experiments. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occurred in parallel, but those processes were dissociated in the distal convoluted tubule. Additionally, we conducted simulations of inhibition of channels and transporters that play a major role in Na+ and Ca2+ transport. Simulation results revealed alterations in transepithelial Ca2+ transport, with differential effects among nephron segments and between the sexes.NEW & NOTEWORTHY The kidney plays an important role in the maintenance of whole body Ca2+ balance by regulating Ca2+ reabsorption and excretion. This computational modeling study provides insights into how Ca2+ transport along the nephron is coupled to Na+. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occur in parallel, but those processes were dissociated in the distal convoluted tubule. Simulations also revealed sex-specific responses to different pharmacological manipulations.

Strontium chloride improves bone mass by affecting the gut microbiota in young male rats

Introduction

Bone mass accumulated in early adulthood is an important determinant of bone mass throughout the lifespan, and inadequate bone deposition may lead to associated skeletal diseases. Recent studies suggest that gut bacteria may be potential factors in boosting bone mass. Strontium (Sr) as a key bioactive element has been shown to improve bone quality, but the precise way that maintains the equilibrium of the gut microbiome and bone health is still not well understood.

Methods

We explored the capacity of SrCl2 solutions of varying concentrations (0, 100, 200 and 400 mg/kg BW) on bone quality in 7-week-old male Wistar rats and attempted to elucidate the mechanism through gut microbes.

Results

The results showed that in a Wistar rat model under normal growth conditions, serum Ca levels increased after Sr-treatment and showed a dose-dependent increase with Sr concentration. Three-point mechanics and Micro-CT results showed that Sr exposure enhanced bone biomechanical properties and improved bone microarchitecture. In addition, the osteoblast gene markers BMP, BGP, RUNX2, OPG and ALP mRNA levels were significantly increased to varying degrees after Sr treatment, and the osteoclast markers RANKL and TRAP were accompanied by varying degrees of reduction. These experimental results show that Sr improves bones from multiple angles. Further investigation of the microbial population revealed that the composition of the gut microbiome was changed due to Sr, with the abundance of 6 of the bacteria showing a different dose dependence with Sr concentration than the control group. To investigate whether alterations in bacterial flora were responsible for the effects of Sr on bone remodeling, a further pearson correlation analysis was done, 4 types of bacteria (Ruminococcaceae_UCG-014, Lachnospiraceae_NK4A136_group, Alistipes and Weissella) were deduced to be the primary contributors to Sr-relieved bone loss. Of these, we focused our analysis on the most firmly associated Ruminococcaceae_UCG-014.

Discussion

To summarize, our current research explores changes in bone mass following Sr intervention in young individuals, and the connection between Sr-altered intestinal flora and potentially beneficial bacteria in the attenuation of bone loss. These discoveries underscore the importance of the "gut-bone" axis, contributing to an understanding of how Sr affects bone quality, and providing a fresh idea for bone mass accumulation in young individuals and thereby preventing disease due to acquired bone mass deficiency.

Unraveling the Gut Microbiome-Diet Connection: Exploring the Impact of Digital Precision and Personalized Nutrition on Microbiota Composition and Host Physiology

The human gut microbiome, an intricate ecosystem housing trillions of microorganisms within the gastrointestinal tract, holds significant importance in human health and the development of diseases. Recent advances in technology have allowed for an in-depth exploration of the gut microbiome, shedding light on its composition and functions. Of particular interest is the role of diet in shaping the gut microbiome, influencing its diversity, population size, and metabolic functions. Precision nutrition, a personalized approach based on individual characteristics, has shown promise in directly impacting the composition of the gut microbiome. However, to fully understand the long-term effects of specific diets and food components on the gut microbiome and to identify the variations between individuals, longitudinal studies are crucial. Additionally, precise methods for collecting dietary data, alongside the application of machine learning techniques, hold immense potential in comprehending the gut microbiome's response to diet and providing tailored lifestyle recommendations. In this study, we investigated the complex mechanisms that govern the diverse impacts of nutrients and specific foods on the equilibrium and functioning of the individual gut microbiome of seven volunteers (four females and three males) with an average age of 40.9 ± 10.3 years, aiming at identifying potential therapeutic targets, thus making valuable contributions to the field of personalized nutrition. These findings have the potential to revolutionize the development of highly effective strategies that are tailored to individual requirements for the management and treatment of various diseases.

Mathematical modeling of calcium homeostasis in female rats: An analysis of sex differences and maternal adaptations

Calcium plays a vital role in various biological processes, including muscle contractions, blood clotting, skeletal mineralization, and cell signaling. While extracellular calcium makes up less than 1% of total body calcium, it is tightly regulated since too high or too low extracellular calcium concentration can have dangerous effects on the body. Mathematical modeling is a well-suited approach to investigate the complex physiological processes involved in calcium regulation. While mathematical models have been developed to study calcium homeostasis in male rats, none have been used to investigate known sex differences in hormone levels nor the unique physiological states of pregnancy and lactation. Calcitriol, the active form of vitamin D, plays a key role in intestinal calcium absorption, renal calcium reabsorption, and bone remodeling. It has been shown that, when compared to age-matched male rats, females have significantly lower calcitriol levels. In this study we first seek to investigate the impact of this difference as well as other known sex differences on calcium homeostasis using mathematical modeling. Female bodies differ from male bodies in that during their lifetime they may undergo massive adaptations during pregnancy and lactation. Indeed, maternal adaptations impact calcium regulation in all mammals. In pregnant rodents, intestinal absorption of calcium is massively increased in the mother's body to meet the needs of the developing fetus. In a lactating rodent, much of the calcium needs of milk are met by bone resorption, intestinal absorption, and renal calcium reabsorption. Given these observations, the goal of this project is to develop multi-scale whole-body models of calcium homeostasis that represents (1) how sex differences impact calcium homeostasis in female vs. male rats and (2) how a female body adapts to support the excess demands brought on by pregnancy and lactation. We used these models to quantify the impact of individual sex differences as well as maternal adaptations during pregnancy and lactation. Additionally, we conducted "what if" simulations to test whether sex differences in calcium regulation may enable females to better undergo maternal adaptations required in pregnancy and lactation than males.

Antidotes in Clinical Toxicology-Critical Review

Poisoning and overdose are very important aspects in medicine and toxicology. Chemical weapons pose a threat to civilians, and emergency medicine principles must be followed when dealing with patients who have been poisoned or overdosed. Antidotes have been used for centuries and modern research has led to the development of new antidotes that can accelerate the elimination of toxins from the body. Although some antidotes have become less relevant due to modern intensive care techniques, they can still save lives or reduce the severity of toxicity. The availability of antidotes is crucial, especially in developing countries where intensive care facilities may be limited. This article aims to provide information on specific antidotes, their recommended uses, and potential risks and new uses. In the case of poisoning, supportive therapies are most often used; however, in many cases, the administration of an appropriate antidote saves the patient's life. In this review, we reviewed the literature on selected antidotes used in the treatment of poisonings. We also characterised the antidotes (bio)chemically. We described the cases in which they are used together with the dosage recommendations. We also analysed the mechanisms of action. In addition, we described alternative methods of using a given substance as a drug, an example of which is N-acetylcysteine, which can be used in the treatment of COVID-19. This article was written as part of the implementation of the project of the Polish Ministry of Education and Science, "Toxicovigilance, poisoning prevention, and first aid in poisoning with xenobiotics of current clinical importance in Poland", grant number SKN/SP/570184/2023.

Purification, Identification, Chelation Mechanism, and Calcium Absorption Activity of a Novel Calcium-Binding Peptide from Peanut (Arachis hypogaea) Protein Hydrolysate

A novel calcium-binding peptide was purified from peanut protein hydrolysate using gel filtration chromatography and identified using HPLC-MS/MS. Its amino acid sequence was determined as Phe-Pro-Pro-Asp-Val-Ala (FPPDVA, named as FA6) with the calcium-binding capacity of 15.67 ± 0.39 mg/g. Then, the calcium chelating characteristics of FPPDVA were investigated using ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, particle size, and zeta potential. The results showed that FPPDVA interacted with calcium ions, the chelation of calcium ions induced FPPDVA to fold and form a denser structure, the calcium-binding sites may mainly involve oxygen atoms from the carboxyl residues of Asp and Ala, and Phe possessed contact energy and carbonyl residues of Val. Microstructure analysis showed that FPPDVA-calcium chelate exhibited a regularly ordered and tightly aggregated sheets or block structures. Additionally, FPPDVA-calcium chelate had good gastrointestinal digestive stability and thermal stability. The results of everted rat intestinal sac and Caco-2 cell monolayer experiments showed that FPPDVA-calcium chelate could promote calcium absorption and transport through the Cav1.3 and TRPV6 calcium channels. These data suggest that FPPDVA-calcium chelate possesses the potential to be developed and applied as calcium supplement.

Calcium channelopathies in neurodegenerative disorder: an untold story of RyR and SERCA

INTRODUCTION

Recent neuroscience breakthroughs have shed light on the sophisticated relationship between calcium channelopathies and movement disorders, exposing a previously undiscovered tale focusing on the Ryanodine Receptor (RyR) and the Sarco/Endoplasmic Reticulum Calcium ATPase (SERCA). Calcium signaling mainly orchestrates neural communication, which regulates synaptic transmission and total network activity. It has been determined that RyR play a significant role in managing neuronal functions, most notably in releasing intracellular calcium from the endoplasmic reticulum.

AREAS COVERED

It highlights the involvement of calcium channels such as RyR and SERCA in physiological and pathophysiological conditions.

EXPERT OPINION

Links between RyR and SERCA activity dysregulation, aberrant calcium levels, motor and cognitive dysfunction have brought attention to the importance of RyR and SERCA modulation in neurodegenerative disorders. Understanding the obscure function of these proteins will open up new therapeutic possibilities to address the underlying causes of neurodegenerative diseases. The unreported RyR and SERCA narrative broadens the understanding of calcium channelopathies in movement disorders and calls for more research into cutting-edge therapeutic approaches.

Vitamin D Supplementation Impacts Calcium and Phosphorus Metabolism in Piglets Fed a Diet Contaminated with Deoxynivalenol and Challenged with Lipopolysaccharides

Using alternative feed ingredients in pig diets can lead to deoxynivalenol (DON) contamination. DON has been shown to induce anorexia, inflammation, and-more recently-alterations in the vitamin D, calcium, and phosphorus metabolisms. Adding vitamin D supplementation in the form of vitamin D₃ and 25-OH-D₃ to the feed could modify the effects of DON in piglets. In this study, vitamin D₃ or 25-OH-D₃ supplementation was used in a control or DON-contaminated treatment. A repetitive exposure over 21 days to DON in the piglets led to disruptions in the vitamin D, calcium, and phosphorus metabolisms, resulting in a decreased growth performance, increased bone mineralization, and the downregulation of genes related to calcium and to phosphorus intestinal and renal absorption. The DON challenge also decreased blood concentrations of 25-OH-D₃, 1,25-(OH)₂-D₃, and phosphate. The DON contamination likely decreased the piglets' vitamin D status indirectly by modifying the calcium metabolism response. Vitamin D supplementations did not restore vitamin D status or bone mineralization. After a lipopolysaccharide-induced inflammatory stimulation, feeding a 25-OH-D₃ supplementation increased 25-OH-D₃ concentration and 1,25-(OH)₂-D₃ regulations during the DON challenge. DON contamination likely induced a Ca afflux by altering the intestinal barrier, which resulted in hypercalcemia and hypovitaminosis D. The vitamin D supplementation could increase the calcitriol production to face the combined LPS and DON challenge.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Calcium is a noncompetitive inhibitor of DMT1 on the intestinal iron absorption process: empirical evidence and mathematical modeling analysis

Iron absorption is a complex and highly controlled process where DMT1 transports nonheme iron through the brush-border membrane of enterocytes to the cytoplasm but does not transport alkaline-earth metals such as calcium. However, it has been proposed that high concentrations of calcium in the diet could reduce iron bioavailability. In this work, we investigate the effect of intracellular and extracellular calcium on iron uptake by Caco-2 cells, as determined by calcein fluorescence quenching. We found that extracellular calcium inhibits iron uptake by Caco-2 cells in a concentration-dependent manner. Chelation of intracellular calcium with BAPTA did not affect iron uptake, which indicates that the inhibitory effect of calcium is not exerted through intracellular calcium signaling. Kinetic studies performed, provided evidence that calcium acts as a reversible noncompetitive inhibitor of the iron transport activity of DMT1. Based on these experimental results, a mathematical model was developed that considers the dynamics of noncompetitive inhibition using a four-state mechanism to describe the inhibitory effect of calcium on the DMT1 iron transport process in intestinal cells. The model accurately predicts the calcein fluorescence quenching dynamics observed experimentally after an iron challenge. Therefore, the proposed model structure is capable of representing the inhibitory effect of extracellular calcium on DMT1-mediated iron entry into the cLIP of Caco-2 cells. Considering the range of calcium concentrations that can inhibit iron uptake, the possible inhibition of dietary calcium on intestinal iron uptake is discussed.

Calcium complexes of oxicams: new dimensions in rheumatoid arthritis treatment

Various metals have been complexed with drugs to improve their cellular impact. Inflammatory diseases like rheumatoid arthritis (RA) are characterized by unbalanced production of proinflammatory cytokines (PICs) and prostaglandins with decreased levels of vitamin D and calcium. The inflammation can be suppressed through targeting the formation of PICs or related enzymes by various treatment strategies that involve the use of corticosteroids, disease-modifying antirheumatic drugs and NSAIDs. We present a detailed review on the impact of calcium complexes of oxicams as an advanced treatment strategy for RA. The calcium complexes demonstrate promising capabilities to cure the disease, improve the strength of bones and suppress PICs in RA.

Protection of the DNA from Selected Species of Five Kingdoms in Nature by Ba(II), Sr(II), and Ca(II) Silica-Carbonates: Implications about Biogenicity and Evolving from Prebiotic Chemistry to Biological Chemistry

The origin of life on Earth is associated with the Precambrian era, in which the existence of a large diversity of microbial fossils has been demonstrated. Notwithstanding, despite existing evidence of the emergence of life many unsolved questions remain. The first question could be as follows: Which was the inorganic structure that allowed isolation and conservation of the first biomolecules in the existing reduced conditions of the primigenial era? Minerals have been postulated as the ones in charge of protecting theses biomolecules against the external environment. There are calcium, barium, or strontium silica-carbonates, called biomorphs, which we propose as being one of the first inorganic structures in which biomolecules were protected from the external medium. Biomorphs are structures with different biological morphologies that are not formed by cells, but by nanocrystals; some of their morphologies resemble the microfossils found in Precambrian cherts. Even though biomorphs are unknown structures in the geological registry, their similarity with some biological forms, including some Apex fossils, could suggest them as the first "inorganic scaffold" where the first biomolecules became concentrated, conserved, aligned, and duplicated to give rise to the pioneering cell. However, it has not been documented whether biomorphs could have been the primary structures that conserved biomolecules in the Precambrian era. To attain a better understanding on whether biomorphs could have been the inorganic scaffold that existed in the primigenial Earth, the aim of this contribution is to synthesize calcium, barium, and strontium biomorphs in the presence of genomic DNA from organisms of the five kingdoms in conditions emulating the atmosphere of the Precambrian era and that CO₂ concentration in conditions emulating current atmospheric conditions. Our results showed, for the first time, the formation of the kerogen signal, which is a marker of biogenicity in fossils, in the biomorphs grown in the presence of DNA. We also found the DNA to be internalized into the structure of biomorphs.

Requirements and Metabolism for Calcium, Phosphorus and Vitamin D3 in the Growing-Furring Blue Foxes

A 3 × 3 factorial experiment was conducted to investigate the influence of dietary calcium, phosphorus, and vitamin D3 (VD3) supplement levels on the growth performance, nutrient digestibility, and serum biochemical indices of growing-furring blue foxes. One hundred and thirty-five 120-day-old male blue foxes were randomly allocated into nine groups. The nine treatment diets were supplemented with 0%, 0.4%, or 0.8% Ca, and 1000, 2000, or 4000 IU·kg−1 VD3. The base diet contained 0.8% Ca and 327 IU·kg−1 VD3. The dietary calcium level had a significant effect on the average daily gain (ADG) of blue foxes at 121 to 135 days of age and 136 to 150 days (p < 0.05). The ADG of blue foxes at 121 to 135 days of age was significantly decreased by VD3 level (p < 0.05). The Ca dosage decreased the nutrient digestibility (p < 0.05). The Ca dosage increased the fecal Ca and P and decreased the P digestibility (p < 0.05). Interactions were found between the Ca and VD3 levels, which affected the digestibility of Ca and P (p < 0.05). In conclusion, this research determined the suitable doses of Ca and VD3 for growing-furring blue foxes.

Peelu (Salvadora oleoides Decne.): An Unexplored Medicinal Fruit with Minerals, Antioxidants, and Phytochemicals

The Peelu (Salvadora oleoides Decne.) fruit is well known for its nutritional and medicinal values. The current study analyzed the chemical composition of Salvadora oleoides fruit. Fresh Peelu fruits were harvested, and physicochemical properties, proximate composition, macro- and micronutrients, and phytochemical properties were determined. Moreover, ethanol and methanol fruit extract was analyzed for physicochemical properties. The Peelu fruit seemed to be a potential source of essential macro- ((nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)) and micronutrients (zinc (Zn), manganese (Mn), iron (Fe), and copper (Cu)). The fruit had significant biochemical properties (total soluble solids (TSS), total acidity (TA), and TSS : TA ratio) with appreciable moisture, crude fiber, and ash contents. The fruit extracts demonstrated significantly higher antioxidants and phenolics, ascorbic acid contents, and carotenoids. Phytochemical screening of fruit revealed the presence of coumarins, flavonoids, phlobatannins, tannins, and terpenoids. Physicochemical and sensory evaluation of extracts indicated its potential for further in vivo study trials. The Peelu fruit was found to be a good source of mineral nutrients, proximate contents, vitamins (ascorbic acid and carotenoid), phytochemicals (total phenolic sand antioxidant contents), and pharmaceutically important metabolites that can be used as functional drink.

Higher Lead and Lower Calcium Levels Are Associated with Increased Risk of Mortality in Malaysian Older Population: Findings from the LRGS-TUA Longitudinal Study

The main objective of this study is to determine the association of various trace elements’ status with the 5-year mortality rate among community-dwelling older adults in Malaysia. This study was part of the Long-term Research Grant Scheme—Towards Useful Ageing (LRGS-TUA). The participants were followed up for five years, and their mortality status was identified through the Mortality Data Matching Service provided by the National Registration Department, Malaysia. Of the 303 participants included in this study, 34 (11.2%) participants had died within five years after baseline data collection. As compared to the survivors, participants who died earlier were more likely (p < 0.05) to be men, smokers, have a lower intake of total dietary fiber and molybdenum, higher intake of manganese, lower zinc levels in toenail samples, lower calcium and higher lead levels in hair samples during baseline. Following the multivariate Cox proportional hazard analysis, lower total dietary fiber intake (HR: 0.681; 0.532−0.871), lower calcium (HR: 0.999; 95% CI: 0.999−1.000) and higher lead (HR: 1.309; 95% CI: 1.061−1.616) levels in hair samples appeared as the predictors of mortality. In conclusion, higher lead and lower calcium levels are associated with higher risk of mortality among community-dwelling older adults in Malaysia. Our current findings provide a better understanding of how the trace elements’ status may affect older populations’ well-being and mortality rate.

A Short Review on the N,N-Dimethylacrylamide-Based Hydrogels

Scientists have been encouraged to find different methods for removing harmful heavy metal ions and dyes from bodies of water. The adsorption technique offers promising outcomes for heavy metal ion removal and is simple to run on a large scale, making it appropriate for practical applications. Many adsorbent hydrogels have been developed and reported, comprising N,N-dimethylacrylamide (DMAA)-based hydrogels, which have attracted a lot of interest due to their reusability, simplicity of synthesis, and processing. DMAA hydrogels are also a suitable choice for self-healing materials and materials with good mechanical properties. This review work discusses the recent studies of DMAA-based hydrogels such as hydrogels for dye removal and the removal of hazardous heavy metal ions from water. Furthermore, there are also references about their conduct for self-healing materials and for enhancing mechanical properties.

Probiotics and Isoflavones as a Promising Therapeutic for Calcium Status and Bone Health: A Narrative Review

Probiotics have potential clinical effects for treating and preventing osteoporosis. Meanwhile, isoflavones have attracted much attention due to their ability to prevent postmenopausal symptoms. Research has established that probiotics and isoflavones can regulate hormones, immune cells, and the gastrointestinal system, acting as links in the gut-bone axis. However, combining the effects of probiotics and isoflavones on calcium status and bone health is a more novel and a still-evolving research area. Lactobacillus and Bifidobacterium are the foremost strains that influence bone health to a significant extent. Among the isoflavones, daidzein, genistein, and the metabolites of genistein (such as equol) stimulate bone formation. It can be concluded that probiotics and isoflavones promote bone health by regulating calcium uptake, gut microbiota, and various metabolic pathways that are associated with osteoblast activity and bone formation. Nevertheless, further experiments of probiotics and isoflavones are still necessary to confirm the association between calcium bioavailability and bone health.

Influence of composite flour constituents and extrusion temperature in the production of analog rice

This study was conducted to determine the effect of composite flour (CF) constituents and different extrusion temperatures on the production of analog rice and community perceptions about the produced rice. CF was produced by mixing modified cassava flour (Mocaf) and snakehead fish flour (SF) in the following ratios: 100:0; 97:3; 94:6; 91:9; and 88:12. Analog rice was then extruded from CF at the following temperatures: 50, 70, and 90°C. The analog rice was tested for physical properties (bulk density and cooking time), chemical properties (nutrient content), and organoleptic properties. The results showed that CF and extrusion temperature affect the nutrient content of analog rice. The best analog rice formulation constituted of CF with Mocaf:SF ratio of 91:9 and extrusion temperature of 70°C, and contained 14.34% water, 0.85% ash, 71.83% carbohydrate, 11.24% protein, 1.12%, calcium 1,113 ppm, and 2.43% dietary fiber. This study included 42 respondents aged 20-23 years, including 20 males and 22 females. All the respondents showed acceptance for the analog rice, suggesting that it could substitute ordinary rice as a staple food.

Polymorphisms Contributing to Calcium Status: A Systematic Review

This systematic review assessed genotypes and changes in calcium homeostasis. A literature search was performed in EMBASE, Medline and CENTRAL on 7 August 2020 identifying 1012 references. Studies were included with any human population related to the topic of interest, and genetic variations in genes related to calcium metabolism were considered. Two reviewers independently screened references, extracted relevant data and assessed study quality using the Q-Genie tool. Forty-one studies investigating Single Nucleotide Polymorphisms (SNPs) in relation to calcium status were identified. Almost half of the included studies were of good study quality according to the Q-Genie tool. Seventeen studies were cross-sectional, 14 case-control, seven association and three were Mendelian randomization studies. Included studies were conducted in over 18 countries. Participants were mainly adults, while six studies included children and adolescents. Ethnicity was described in 31 studies and half of these included Caucasian participants. Twenty-six independent studies examined the association between calcium and polymorphism in the calcium-sensing receptor (CASR) gene. Five studies assessed the association between polymorphisms of the Vitamin D receptor (VDR) gene and changes in calcium levels or renal excretion. The remaining ten studies investigated calcium homeostasis and other gene polymorphisms such as the CYP24A1 SNP or CLDN14. This study identified several CASR, VDR and other gene SNPs associated with calcium status. However, to provide evidence to guide dietary recommendations, further research is needed to explore the association between common polymorphisms and calcium requirements.

Physico-chemical and sensory acceptability of no added sugar chocolate spreads fortified with multiple micronutrients

Vitamin D and magnesium-calcium carbonate nanoparticles were used to fortify a newly developed healthy chocolate spread formulated with inulin and maltitol as sugar replacers and alternative to palm oil to reduce the concentration of saturated fatty acid. These samples were compared with well-known commercially available chocolate spreads in terms of rheology, polyphenols content and in vitro digestion, sensory attributes and willingness to buy. The fortified chocolate spreads showed comparable if not better acceptability than the current products on the market and over 80% of the participants were inclined to buy and 66% prepared to spend 10 to 15% more money on the product enriched with the three micronutrients. The results also demonstrate that the incorporation of nanoparticles could affect the rheological and physio-chemical properties of the formulations and an appropriate ratio between the fat phase and particles seems an important factor to consider.

Elemental Impurities in Pediatric Calcium Carbonate Preparations-High Throughput Quantification and Risk Assessment

Calcium carbonate which is extracted from the Earth in combination with other mineral impurities, is largely used in preparations for pediatric supplements. Elemental impurities in drug products pose toxicological concerns without therapeutic benefits. Thus, it is very urgent to assess the safety of chronic exposure to elements that may be present in trace amounts. In the present study, we developed high throughput ICP-MS method for the quantitative determination of 62 elemental impurities in high matric calcium carbonate samples and validated according to USP 233. Calcium carbonate preparations which state clearly used for child (including neonates, infants, toddlers and children) from 9 manufactures and two types of raw materials (light calcium carbonate and ground calcium carbonate) were investigated in terms of the content and variability of 62 elemental impurities. According to the results, ground calcium carbonate was more suitable to be used in pediatric preparations concerning elemental impurities. Parts of elemental impurities in CaCO₃ preparations which are derived from the raw materials and the preparation process, may cause potential risks for children. These results indicate that it is necessary to establish a modern instrumental analysis method to evaluate and control elemental impurities in CaCO₃ raw materials and preparations.

Biodegradable magnesium-based biomaterials: An overview of challenges and opportunities

As promising biodegradable materials with nontoxic degradation products, magnesium (Mg) and its alloys have received more and more attention in the biomedical field very recently. Having excellent biocompatibility and unique mechanical properties, magnesium-based alloys currently cover a broad range of applications in the biomedical field. The use of Mg-based biomedical devices eliminates the need for biomaterial removal surgery after the healing process and reduces adverse effects induced by the implantation of permanent biomaterials. However, the high corrosion rate of Mg-based implants leads to unexpected degradation, structural failure, hydrogen evolution, alkalization, and cytotoxicity. To overcome these limitations, alloying Mg with suitable alloying elements and surface treatment come highly recommended. In this area, open questions remain on the behavior of Mg-based biomaterials in the human body and the effects of different factors that have resulted in these challenges. In addition to that, many techniques are yet to be verified to turn these challenges into opportunities. Accordingly, this article aims to review major challenges and opportunities for Mg-based biomaterials to minimize the challenges for the development of novel biomaterials made of Mg and its alloys.

The effect of high-dose, short-term caffeine intake on the renal clearance of calcium, sodium and creatinine in healthy adults

The consumption of caffeine has been linked to osteoporosis, believed to be due to enhanced bone resorption as a result of increased calcium excretion in the urine. However, the amount of calcium in the urine may not necessarily reflect the true effect of caffeine on calcium clearance. This study therefore examined the impact of high-dose, short-term caffeine intake on renal clearance of calcium, sodium and creatinine in healthy adults. In a double-blind clinical study, participants chewed caffeine (n = 12) or placebo (n = 12) gum for 5 minutes at 2-hour intervals over a 6-hour treatment period (800 mg total caffeine). Caffeine increased renal calcium clearance by 77%. Furthermore, the effect was positively correlated with sodium clearance and urine volume, suggesting that caffeine may act through inhibition of sodium reabsorption in the proximal convoluted tubule. This study confirmed that caffeine does increase renal calcium clearance and fosters further investigation into safe consumption of caffeine.

Evaluation of serum parameters to predict the dietary intake of calcium and available phosphorus in growing pigs

Adequate provision of calcium (Ca) and phosphorus (P) is essential for bone formation and high growth performance in pigs. Nevertheless, reliable serum biomarkers for pig's Ca and P intake are still missing. Here, we used phytase supplementation to alter the dietary available P (aP) level in order to investigate the effect of differences in dietary aP levels on serum parameters related to the Ca and P homeostasis in pigs. Moreover, we assessed whether serum parameters can be used to predict the Ca, total P (tP), and aP intake in barrows and gilts throughout the fattening period. In total, 216 pigs (115 gilts and 101 barrows) were randomly allotted to one of the two diets in three replicate batches, each lasting 56 d (n = 108/diet). Pigs had free access to the diets without (Con) or with phytase (Phy; 650 phytase units/kg) via a transponder-based feeding system. Blood samples were collected on days 2, 23, and 52, and serum parameters were correlated with the daily Ca, tP, and aP intake. The intake of tP, aP, and Ca was overall 14.2%, 13.8%, and 14.2% higher in barrows compared with gilts, respectively (P < 0.001). Concurrently, phytase decreased the intake of tP and Ca by 8.4% and 6.7%, respectively, whereas it raised the intake of aP by 16.3% compared with the Con diet (P < 0.001). Serum levels of fibroblast growth factor 23, alkaline phosphatase (ALP), vitamin D (VitD), and osteocalcin (OCN) decreased with age (P < 0.05). The higher aP intake of pigs fed the Phy diet increased serum P on days 2 and 23 but decreased it on day 52 compared with the Con diet (P = 0.004). Pigs fed the Phy diet had higher serum ALP compared with pigs fed the Con diet on days 23 and 52 (P < 0.05). Correlation analysis between serum parameters and Ca, tP, and aP intake showed age- and sex-related associations. With 12 wk of age, serum P in both sexes, serum VitD in barrows, and serum OCN and ALP in gilts correlated with aP intake (|r| > 0.38), whereas serum OCN correlated with Ca in both sexes' intake (r > 0.50). At 20 wk, serum Ca and ALP in gilts correlated with aP intake, whereas serum P, Ca, and VitD correlated with Ca intake in both sexes (|r| > 0.39). In conclusion, the present results showed that the daily Ca and aP intake could be most reliably estimated from serum parameters for an approximate age of 12 and 20 wk. Serum P and the Ca:P ratio at 12 wk of age and serum VitD at 20 wk of age may be used to predict pig's daily aP intake in both sexes.

Extra-skeletal effects of dietary calcium: Impact on the cardiovascular system, obesity, and cancer

Calcium is well known to be integral to bone and muscle health, with deleterious effects such as osteoporosis associated with inadequate calcium intake. Recent studies have also highlighted the significant effects of calcium in extra-musculoskeletal functioning, including the cardiovascular system, obesity, and cancer. Calcium impacts the cardiovascular system as an antagonist associated with a reduction in hypertension, increase vasodilation, and improvement in blood vessel function when obtained in the diet as an organic source, through food. However, the inorganic source of calcium, found in supplements, may be negatively associated with the cardiovascular system due to plaque deposits and atherogenesis when taken in excess. Some studies suggest that calcium intake may impact obesity by regulation of adipogenesis and reducing fat deposits with resulting weight loss. The pathogenesis of calcium for reducing obesity is thought to be related in part to its impact on gut microbiota profile, with the suggestion that calcium may have prebiotic properties. Animal and some human studies propose that calcium may also have a role in cancer prevention and/or treatment due to its function in the cell proliferation process and the impact on hormonal regulation, and thus warrants more investigations in the human population. Some prospective and small clinical studies suggest that calcium may be beneficial for colorectal cancer. Overall, emerging research in various areas continues to highlight the essentiality of dietary calcium for functioning at the molecular and biochemical level toward improvement in health and some chronic disease conditions.

New Insights on the Role of TRP Channels in Calcium Signalling and Immunomodulation: Review of Pathways and Implications for Clinical Practice

Calcium is the most abundant mineral in the human body and is central to many physiological processes, including immune system activation and maintenance. Studies continue to reveal the intricacies of calcium signalling within the immune system. Perhaps the most well-understood mechanism of calcium influx into cells is store-operated calcium entry (SOCE), which occurs via calcium release-activated channels (CRACs). SOCE is central to the activation of immune system cells; however, more recent studies have demonstrated the crucial role of other calcium channels, including transient receptor potential (TRP) channels. In this review, we describe the expression and function of TRP channels within the immune system and outline associations with murine models of disease and human conditions. Therefore, highlighting the importance of TRP channels in disease and reviewing potential. The TRP channel family is significant, and its members have a continually growing number of cellular processes. Within the immune system, TRP channels are involved in a diverse range of functions including T and B cell receptor signalling and activation, antigen presentation by dendritic cells, neutrophil and macrophage bactericidal activity, and mast cell degranulation. Not surprisingly, these channels have been linked to many pathological conditions such as inflammatory bowel disease, chronic fatigue syndrome and myalgic encephalomyelitis, atherosclerosis, hypertension and atopy.

Calcium homeostasis

Calcium and phosphorus are the most abundant minerals in the body. An adult body contains over 1 kg of calcium and it has various functions throughout the body. The average plasma concentration of calcium is about 2.5 mmol/l. The intracellular concentration of calcium is approximately 100 nmol/ml. The control of both intracellular and extracellular calcium concentrations is vital.

Electrochemical Analysis and In Vitro Assay of Mg-0.5Ca-xY Biodegradable Alloys

In recent years, biodegradable Mg-based materials have been increasingly studied to be used in the medical industry and beyond. A way to improve biodegradability rate in sync with the healing process of the natural human bone is to alloy Mg with other biocompatible elements. The aim of this research was to improve biodegradability rate and biocompatibility of Mg-0.5Ca alloy through addition of Y in 0.5/1.0/1.5/2.0/3.0wt.%. To characterize the chemical composition and microstructure of experimental Mg alloys, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), light microscopy (LM), and X-ray diffraction (XRD) were used. The linear polarization resistance (LPR) method was used to calculate corrosion rate as a measure of biodegradability rate. The cytocompatibility was evaluated by MTT assay (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) and fluorescence microscopy. Depending on chemical composition, the dendritic α-Mg solid solution, as well as lamellar Mg₂Ca and Mg₂₄Y₅ intermetallic compounds were found. The lower biodegradability rates were found for Mg-0.5Ca-2.0Y and Mg-0.5Ca-3.0Y which have correlated with values of cell viability. The addition of 2-3 wt.%Y in the Mg-0.5Ca alloy improved both the biodegradability rate and cytocompatibility behavior.

Inulin and milk mineral fortification of a pork sausage exhibits distinct effects on the microbiome and biochemical activity in the gut of healthy rats

This study investigated inulin and calcium-rich milk mineral incorporation into a pork sausage in order to examine the effects on microbiome and biochemical activity in the gastrointestinal tract upon ingestion. Rats (n = 48) were fed one of four sausages; a pork sausage enriched with 1) inulin (6.0%) and milk mineral (3%), 2) inulin (6.0%), 3) milk mineral (3%) or 4) control sausages without enrichment. NMR-based metabolomics revealed that inulin-enrichment increased the fecal concentration of short-chain fatty acids (SCFAs). Milk mineral-enrichment also increased SCFA concentrations, although less pronounced. In addition, milk mineral reduced the concentration of nitroso compounds in feces and small intestinal content. Combined enrichment with both inulin and milk mineral showed no cumulative effect on SCFA formation and seemed to oppose the milk mineral-induced reduction of nitroso compound formation. 16S rRNA gene amplicon sequencing indicated that alterations of the gut microbiome contributed to the observed effects.

Dietary Phytase and Lactic Acid-Treated CerealGrains Differently Affected Calcium and PhosphorusHomeostasis from Intestinal Uptake to SystemicMetabolism in a Pig Model

High intestinal availability of dietary phosphorus (P) may impair calcium (Ca)homeostasis and bone integrity. In the present study, we investigated the effect of phytasesupplementation in comparison to the soaking of cereal grains in 2.5% lactic acid (LA) on intestinalCa and P absorption; intestinal, renal, and bone gene expression regarding Ca and P homeostasis;bone parameters; and serum levels of regulatory hormones in growing pigs. Thirty-two pigs wererandomly assigned to one of four diets in a 2 × 2 factorial design in four replicate batches for 19days. The diets comprised either untreated or LA-treated wheat and maize without and withphytase supplementation (500 phytase units/kg). Although both treatments improved the Pbalance, phytase and LA-treated cereals differently modulated gene expression related to intestinalabsorption, and renal and bone metabolism of Ca and P, thereby altering homeostatic regulatorymechanisms as indicated by serum Ca, P, vitamin D, and fibroblast growth factor 23 levels.Moreover, phytase increased the gene expression related to reabsorption of Ca in the kidney,whereas LA-treated cereals decreased the expression of genes for osteoclastogenesis in bones,indicating an unbalanced systemic availability of minerals. In conclusion, high intestinalavailability of dietary P may impair Ca homeostasis and bone integrity.

The impact of humic acid additives on mineral metabolism of rabbits in the postnatal period of ontogenesis

Humic acids are characterized by chelating properties due to which they are able to influence the mineral metabolism in animals. Rabbits have species-specific characteristics of mineral metabolism, which distinguishes them from most species of mammals. For the experiment, 16 rabbits of 45-day-old of Hyplus breed were divided into the experimental and control group of 8 rabbits in each. The animals were 15 days in the preparatory period. The rabbits of the experimental group received humic acid additive individually with water in the amount of 5 mg/kg, the rabbits of the control group received pure water in the same amount. The ability of humic acid additive to increase the content of calcium, ionized calcium, iron, to correct the content of copper and zinc, and also to increase the activity of alkaline phosphatase in the blood serum of rabbits of the experimental group has been proved. We observed the early effect of the humic acid additive on increasing the content of iron and calcium ionized and a later effect on the activity of alkaline phosphatase and an increase in the content of copper in the blood serum. The influence of humic acid additive on the distribution of calcium, phosphorus, manganese, copper and zinc in bone tissue is determined. According to a histological study, there was a significant increase in the number of layers of osteons and osteoblasts in the bone tissue of the femur, an increase in the number of osteons and osteoblasts in the bone tissue of the sternum and an increase in the number of columns of chondrocytes and an increase in the number of chondrocytes in the column in the cartilaginous tissue of the sternum. The results of a histological study of bone tissue, together with an increase in structural macroelements in it and redistribution of osteotropic trace elements in the blood and bone tissue suggest the possibility of using a humic acid additive to intensify the growth and mineralization of bone tissue, which can improve the state of bone tissue of rabbits in the postnatal period ontogenesis.

Relative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate

Adequate calcium intake is important for the prevention of bone loss and osteoporosis. For some populations such as those of Southeast Asia where calcium intake is very low, supplements represent a suitable dietary source of calcium. The objective of this study was to compare the relative oral bioavailability of calcium from calcium glucoheptonate, a highly soluble calcium salt containing 8.2% of elemental calcium, to that of calcium carbonate. A single-dose, randomized-sequence, open-label, two-period crossover study, with a 7-day washout period, was conducted in 24 Indonesian healthy adult volunteers. After a 12-hour (overnight) fast, subjects received either two oral ampoules of 250 mg/10 mL of calcium glucoheptonate each or one effervescent tablet of calcium carbonate containing 500 mg of elemental calcium. The relative oral bioavailability of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration. The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120.31% and 60.58%-122.30%, respectively. Five subjects experienced a total of eight adverse events which were all mild and transient; no serious adverse events or deaths were reported. These results indicate that calcium glucoheptonate is associated with a high relative bioavailability of calcium compared to calcium carbonate, and is well-tolerated. Calcium glucoheptonate might thus be a potential choice for calcium supplementation in Southeast Asian populations.

Probiotic Lactobacillus strains from Mongolia improve calcium transport and uptake by intestinal cells in vitro

The aim of this study was to investigate the probiotic properties of 174 Lactobacillus strains isolated from Mongolian dairy products, and particularly their impact on intestinal calcium uptake and absorption. All isolates underwent a first screening based on cell surface hydrophobicity, acid tolerance, tolerance to gastro-intestinal digestion, autoaggregation, adhesion and cytotoxicity against intestinal cells. Six Lactobacillus strains from different species (L. casei, L. kefiranofaciens, L. plantarum, L. fermentum, L. helveticus and L. delbrueckii) were selected, and their impact on intestinal calcium uptake and transport was investigated using Caco-2. Five strains were able to improve total calcium transport after 24 h contact with a differentiated Caco-2 cell monolayer. Concomitantly the L. plantarum strain was able to increase cellular calcium uptake in Caco-2 cells by 10% in comparison to control conditions. To determine which pathway(s) of calcium absorption was modulated by the strains, a qPCR-based study on 4 genes related to calcium/vitamin D metabolism or tight junction integrity was conducted on mucus-secreting intestinal HT-29 MTX cells. The L. plantarum strain modulates the transcellular pathway by regulating the expression of vitamin D receptor (1.79 fold of control) and calcium transporter (4.77 fold of control) while the L. delbrueckii strain acts on the paracellular pathway by modulating claudin-2 expression (2.83 fold of control). This work highlights the impact of Lactobacillus probiotic strains on intestinal calcium absorption and for the first time give some evidence about the cellular pathways involved.