A New Caco-2 Cell Model of in vitro Intestinal Barrier: Application for the Evaluation of Magnesium Salts Absorption (original) (raw)
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Dose-Dependent Absorption Profile of Different Magnesium Compounds
Biological Trace Element Research, 2019
Magnesium, one of the basic elements for the human body, is necessary for many physiological functions. Magnesium deficiency is widely observed as a result of the reduced nutrient content of foods, over-cooking, diseases, drugs, alcohol, and caffeine consumption. Taking a dietary supplement is necessary magnesium deficiency. It has been demonstrated that absorption of organic magnesium compounds is better than absorption of inorganic compounds. The aim of this study is to investigate transitions to tissues of different organic magnesium compounds in different doses and whether there is a difference in the organic acid-bounded compounds (magnesium citrate and magnesium malate) and the amino acid-bounded compounds (magnesium acetyl taurate and magnesium glycinate), associated with transition and bioavailability. In addition, the effects of split dosages of high doses in a high volume of solvent on tissue magnesium levels are being investigated, because galenic formulation problems are regarded to prepare convenient dosage that can be taken once a day. All magnesium compounds were administered as three different doses, 45, 135, and 405 mg/70 kg elemental magnesium, were given per orally to Balbc mice. In a second set of experiments, 405 mg/70 kg high dose was divided into two doses of 202.5 mg/70 kg each and administered every 12 h. Brain, muscle tissues, and serum magnesium levels measured in all experimental groups and control 24 h later. Brain magnesium levels were found increased in all magnesium acetyl taurate administered subjects. Magnesium citrate increased muscle and brain magnesium levels in a dose-independent manner. We showed that dividing high doses of daily administered magnesium compounds did not sufficiently increase tissue magnesium levels. Although passive paracellular mechanism by solvent drag is the main mechanism of Mg absorption, other factors (electrochemical gradient effects, transcellular transporter mechanisms, magnesium status) should be effective on our results. It is necessary for further research on long-term administration of different magnesium compounds and their effect on other tissues.
Magnesium Absorption: Mechanisms and the Influence of Vitamin D, Calcium and Phosphate
The Journal of Nutrition, 1991
Magnesium absorption has been studied in both humans and animals under diverse experimen tal conditions. As a result, the data often appear confusing and conflicting. In this review we attempt to summarize information concerning Mg absorption and, where possible, to reconcile apparently conflicting ob servations. Most studies suggest that Mg is absorbed predominately in the distal intestine. At usual Mg intakes, Mg absorption occurs primarily by intercellular diffusional and solvent drag mechanisms.
Journal of Nutritional Science and Vitaminology, 2009
This study aimed to clarify the regulatory mechanism of Mg homeostasis on administration of excessive Mg in rats. Six-week-old male Wistar rats (n ϭ 30) were fed a Mgdeficient diet (D) or a control diet (M) in addition to which they received subcutaneous injections of saline (S) or additional Mg (M) for 14 d. Feces and urine were collected from the rats for 4 d every week. Between the MS and MM rats and the DS and DM rats, the injection of additional Mg increased Mg retention, but intestinal Mg absorption did not differ. Urinary Mg excretion in the MM rats was significantly greater than that in the MS rats, but fecal Mg excretion did not increase. Mg retention in the DM rats was approximately 30% of that in the MS rats, and urinary Mg excretion did not differ between the 2 groups, although the serum Mg in DM rats was low. There was no significant difference in the femoral Mg between the MM and MS groups. The physiological Mg pool in the bone appears to be limited. Therefore, there is no physiological Mg pool for the storage of excessive Mg, and there appears to be no negative feedback mechanism on intestinal Mg absorption upon administration of excessive Mg in the rats. In conclusion, it appears that the kidney is the only organ that regulates Mg in the body; apart from this, regulatory mechanisms corresponding to the physiological Mg requirement do not exist or are weak.
Materials Science and Engineering: C, 2016
Magnesium and its alloys have considerable potential for orthopaedic applications. During the degradation process the interface between material and tissue is continuously changing. Moreover, too fast or uncontrolled degradation is detrimental for the outcome in vivo. Therefore in vitro setups utilizing physiological conditions are promising for the material / degradation analysis prior to animal experiments. The aim of this study is to elucidate the influence of inorganic salts contributing to the blood buffering capacity on degradation. Extruded pure magnesium samples were immersed under cell culture conditions for 3 and 10 days. Hank's balanced salt solution without calcium and magnesium (HBSS) plus 10% of fetal bovine serum (FBS) was used as the basic immersion medium. Additionally, different inorganic salts were added with respect to concentration in Dulbecco's modified Eagle's medium (DMEM, in vitro model) and human plasma (in vivo model) to form 12 different immersion media. Influences on the surrounding environment were observed by measuring pH and osmolality. The degradation interface was analysed by electron-induced X-ray emission (EIXE) spectroscopy, including chemical-element mappings and electron microprobe analysis, as well as Fourier transform infrared reflection micro-spectroscopy (FTIR).
Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?
Biological trace element research, 2018
Magnesium is an element of great importance functioning because of its association with many cellular physiological functions. The magnesium content of foods is gradually decreasing due to food processing, and magnesium supplementation for healthy living has become increasingly popular. However, data is very limited on the bioavailability of various magnesium preparations. The aim of this study is to investigate the bioavailability of five different magnesium compounds (magnesium sulfate, magnesium oxide, magnesium acetyl taurate, magnesium citrate, and magnesium malate) in different tissues. Following a single dose 400 mg/70 kg magnesium administration to Sprague Dawley rats, bioavailability was evaluated by examining time-dependent absorption, tissue penetration, and the effects on the behavior of the animals. Pharmacokinetically, the area under the curve calculation is highest in the magnesium malate. The magnesium acetyl taurate was found to have the second highest area under th...
European Journal of Nutrition, 2003
s Summary Magnesium (Mg) intake is below the recommended daily allowances in many developed countries. Mg-rich mineral waters can provide significant amounts of energy-free Mg and thus help to meet Mg requirements. We assessed the effects of different Mg-rich mineral waters on overall intestinal Mg absorption and urinary Mg excretion in 40 rats split into four groups: one received distilled water, another a solution of MgCl 2 and the others two different mineral waters, sulphated water (Hépar) and carbonated water (Badoit) mixed with the diet and as drinking water, for four weeks. The rats were given 3 mg of 26 Mg orally and 0.5 mg of 25 Mg intravenously. They were placed in metabolic cages, and diet consumption, and faeces and urine excretion were monitored during the last four days of the experiment. The rats were then sacrificed and blood was sampled. Mg levels in the diet, faeces, urine and biological samples were measured by atomic absorption spectrometry. Mg stable isotope measurements were performed by ICP/MS. Mg-rich mineral waters significantly increased net intestinal absorption of Mg by more than 30 %, but the proportions of both apparent and true intestinal absorption of Mg were similar in all four groups. Thus, net and fractional retention of Mg were similar in the three Mg-supplemented groups. In conclusion, both types of Mg-rich mineral waters studied similarly increased both absorption and urinary excretion of Mg with no positive effect on the overall retention of Mg, probably because the Mg status of the rats was already satisfactory.
Journal of Nutrition and Food Sciences, 2020
Magnesium (Mg 2+), an essential mineral and cofactor of more than 300 enzymatic processes, has a regulating role in energy metabolism, protein synthesis, muscle and nerve function, blood glucose and blood pressure control. The European Food Safety Authority (EFSA) proposes an Adequate Intake of 350 and 300 mg/day for men and women, respectively. Given deficiencies present in over 50% of the normal population, magnesium is currently a popular nutritional supplement. Based on the source of elemental magnesium, the supplements currently available on the market can be divided into 2 different categories: inorganic or organic salts of magnesium. Inorganic magnesium compounds are generally perceived as not as easily absorbable as organic magnesium compounds. The aim of this study was to compare the efficacy of magnesium glycerophosphate and magnesium bisglycinate with different magnesium formulations previously tested by specific in vitro approaches that previously proved to provide a valid methodology to predict in vivo outcomes and effectiveness of magnesium supplements. Both in fasted and fed state the in vitro bioaccessibility, being a measure for the solubilization of the formulation during gastric incubation, was clearly higher for the organic salts of interest. Nevertheless it should be noted that poor solubility of a magnesium supplement, translating into poor dissolution, was a determining factor in bioaccessibility. Also in in vitro bioavailability, representing the absorption efficiency in the small intestine, the bisglycinate and glycerophosphate salts outperformed the inorganic magnesium oxide. Therefore we conclude that magnesium glycerophosphate and bisglycinate have a higher bioavailability compared to inorganic salts, when formulated in a highly soluble magnesium supplement.
Biological and Pharmaceutical Bulletin
Magnesium (Mg 2) is an endogenous cation that is involved in many essential biological reactions. Abnormal Mg 2 metabolisms in the body affect important physiological and pathological processes. However, most endogenous Mg 2 markers fail to represent body Mg 2 status; they are disadvantageous in terms of representational capacity, applied range, operational convenience, etc. In this article, we evaluated some of the most popular Mg 2 marker candidates. A logical model of the blood Mg 2 compartments was established, which consisted of unstable Mg 2 pools, representative Mg 2 pools, and conserved Mg 2 pools. These pools were based on the metabolic efficiency of Mg 2 in an acute Mg 2 intake test. The results of this study showed that only the erythrocyte intracellular ionized Mg 2 (RBC [Mg 2 ] i), a representative Mg 2 pool, could effectively represent abnormal body Mg 2 metabolisms in various conditions, including dietary Mg 2 adjustments, aging and metabolic syndrome. These results suggest that RBC [Mg 2 ] i might be a widely applicable marker of body Mg 2 levels. On unified technology platform and evaluation system, this research compared the representative capacities of RBC [Mg 2 ] i , plasma Mg 2 concentration (plasma [Mg 2 ]), erythrocyte intracellular total Mg (RBC [Mg] total) and Mg retention in rats and mice under various Mg 2-metabolism-related physiological and pathological conditions. Our technique for the direct quantitative analysis of RBC [Mg 2 ] i may prove valuable for basic physiological research, dietary Mg 2 regulation, as well as clinical monitoring/ intervention of Mg 2-metabolism-related pathology.
British Journal of Nutrition, 2004
We have evaluated urinary monitoring and erythrocyte analysis to determine Mg absorption in human subjects as alternatives to the conventional technique of faecal monitoring by stable-isotope techniques. Ten healthy adults received 2·2 mmol 25 Mg in water, together with wheat bread, followed 15 min later by intravenous injection of 0·6 mmol 26 Mg (day 1). Brilliant blue and Yb (given on day 0 and day 1 respectively) served as qualitative and quantitative faecal markers. Urine was collected for 6 d after test meal intake. Complete collections of faeces were made until excretion of the second brilliant blue marker (given on day 7). Mg isotope ratios were determined by thermal ionisation-MS in urine and faeces and by inductively coupled plasma-MS in erythrocytes. Absorption was determined based on: (1) 6 d urine pools; (2) 24 h urine pools (collected 22 -46 h after test meal intake); (3) erythrocytes from a blood sample drawn on day 14; (4) complete 6 d faecal pools; (5) faecal pools based on the first three consecutive stools after excretion of the first brilliant blue marker. Differences in mean Mg absorption (42 44 %) were statistically insignificant between techniques, except when based on 6 d urine pools for which the value was significantly lower (33 (SD 7) %, P¼0·0003, ANOVA). The results indicate that Mg absorption can be determined from 24 h urine pools or erythrocytes obtained 14 d after test meal intake, an alternative method to the more time-consuming and labourintense faecal monitoring. The choice of technique depends on practical and financial considerations.