Silicon Intake Research Articles

Avidin-positive mast cells of the liver when exposed to water-soluble silicon for nine months

Mast cells, due to the mediators contained in them, are active participants in various processes occurring in the body. The reaction of avidin-positive mast cells of the liver to the intake of silicon with drinking water at a concentration of 20 mg/L for nine months was studied. The experiment was conducted on laboratory nonlinear male rats, which were divided into two groups: the control group received bottled drinking water with a silicon concentration of 10 mg/L; the experimental group received the same water, but with the addition of sodium metasilicate nine-hydrate, which was used to adjust the total concentration of silicon in drinking water to 20 mg/L. The mass concentration of silicon in the water of the control and experimental groups was determined using an inductively coupled plasma emission spectrometer 5110 ICP-OES. After nine months, the animals were sacrificed, the liver was extracted and fixed in 10% neutral formalin, processed and embedded in paraffin. After deparaffinization, 6-ìm-thick liver sections were incubated for 30 minutes with green fluorescent-labeled avidin (Avidin, Alexa Fluor® 488 conjugate, Invitrogen, Germany). The preparations were analyzed under a fluorescence microscope at an excitation light wavelength of 495 nm. According to the results of the study, an increase in the number of avidin-positive mast cells due to weakly fluorescent ones was found in the liver of rats of the experimental group, as well as an increase in the median of their area and fluorescence intensity. It was revealed that the change in the median of area of avidin-positive mast cells in the liver of rats of the experimental group is due to a decrease in the number of small cells and an increase in the number of medium and large cells. Positive strong and positive average correlations were established between the cell area and its intensity in the control and experimental groups, respectively. Thus, the study made it possible to expand the data on the effect of water-soluble silicon on the liver and indirectly suggest the occurrence of inflammatory processes in the organ under study.

Assessment of the biological effect of natural silicon when entering the body of experimental animals with drinking water. Part 1

Introduction. The biological effect of natural silicon (Si) and its hygienic regulation in drinking water still remain subjects of controversy in the scientific literature and in the practice of providing favourable conditions for water use by the population. In this regard, an assessment was made of the effect of natural silicon contained in drinking water in concentrations close to the maximum permissible concentration on the body of laboratory animals.
 Materials and methods. Drinking waters containing natural Si at MPC levels in water were studied, their effect was assessed in a three-month experiment on 80 white outbred male rats. Observations were made of the general condition, appearance of the animals, body weight dynamics, water consumption. 
 The morphological composition of whole blood was studied. Biochemical indices of the condition of internal organs, including the liver, were determined 
 in serum samples (the ALT and AST activity, the level of total protein and albumin), pancreas (α-amylase activity), kidneys (creatinine content), as well as lactate dehydrogenase activity as a nonspecific indicator of tissue damage.
 Results. In animals received 17±3.4 mg/L silicon with drinking water at a hardness of 2.25±0.47 mg-eq/L, a significant decrease in ALT activity was found on the 30th and 90th days of the experiment, AST – on 90th day, increase in the content of total protein and albumin in the serum on the 30th day of the experiment. Drinking water with silicon concentrations of 20.5±4.1 mg/L and hardness 3.55±0.76 mg-eq/L decreased ALT activity and serum creatinine concentration on the 30th day and increased amylase activity on the 90th day of the experiment. The animals had the highest water consumption and intake of silicon from drinking water over the first month of the experiment.
 Limitations. Limitations of the study are related to the short duration of observation and the small number of points for determining biochemical parameters over time.
 Conclusion. Consumption of drinking water containing natural silicon for 90 days led to changes in biochemical indices, largely indicating the positive effect of the element in concentrations of 17±3.4 mg/L and 20.5±4.1 mg/L on the body of laboratory animals.

Реакция Iba-1+ и CD68+ макрофагов печени лабораторных крыс на двухмесячное поступление водорастворимого кремния

Introduction. Silicon compounds are widely used in industrial production; therefore, people are highly likely to have constant contact with this element. Hepatic macrophages are crucial in maintaining homeostasis in the liver; thus, investigating their reaction can provide new information on their possible participation in the inflammation induced by silicon supplied with water. The aim was to explore how Iba1+ and CD68+ liver cells in laboratory rats respond to the intake of silicon with drinking water at a concentration of 10 mg/l during two months. Materials and methods. Laboratory rats were divided into 2 groups: the control group (n=5) received drinking bottled water ad libitum, whereas the experimental one was given the same water with addition of sodium metasilicate nonahydrate (Na2SiO3 × 9 H2O) at a concentration of 10 mg/l in terms of silicon. This corresponded to the maximum allowable concentration, according to SanPiN 2.1.4.1074-01 in force at the time of the experiment. The animals were withdrawn from the experiment 2 months after had begun. The liver was removed and fixed in 10% neutral formalin and embedded in paraffin according to the standard protocol. Iba1+ and CD68+ structures were detected with immunohistochemical and immunofluorescence methods using specific antibodies. Results. We compared the expression patterns of the two macrophage markers and detected that in the experimental group, the median area of Iba1-positive cells in the livers of rats had a 0.87-time decrease compared to that in the control group (p=0.000006). The experimental group showed an increase in the number of Iba1+ and CD68+ cells (p=0.02 and p=0.01, respectively). We revealed that in the experimental group, immunofluorescence in Iba-1+ liver macrophages decreased (p=0.01), whereas that in CD68+ macrophages increased (p=0.27). Conclusion. The intake of water-soluble silicon at a concentration of 10 mg/l activates liver macrophages in a relatively short period of exposure (two months). Therefore, the safety of silicon compounds in the conditions of their constant supply should be studied more thoroughly.

Using the sorption properties of diatomite from the Aktobe deposit in improving the quality of drinking water in Western Kazakhstan

The paper describes the results of monitoring studies of the quality of tap water in the city of Uralsk. A solution was found to use natural reserves of the mineral diatomite in the purification of drinking water. The natural sorbent diatomite was modified with hydrochloric acid before testing. Natural and modified diatomite samples were studied using X-ray fluorescence analysis and electron microscopy. In acid-activated diatomite, the specific surface area and porosity increase by 2.5 times. Xray fluorescence analysis of the elemental composition showed an increase in the silicon content in the sorbent. Organoleptic and physicochemical properties were studied in the original and diatomite-treated water: turbidity, taste, smell, color, hardness, permanganate oxidation, pH, iron and copper ions. The efficiency of sorption with respect to heavy metals was tested using the model toxicant copper sulfate. Determinations of copper and iron ions were carried out using the atomic spectrometry method. Hardness, permanganate oxidation, pH and organoleptic parameters were determined by standard methods. Treatment of water with natural and modified diatomite made it possible to significantly reduce water pollution according to the studied parameters. Filtering water with a modified diatomite sorbent allows you not only to purify water from unwanted impurities, but also to adjust its salt composition due to the intake of silicon. Based on the results of the work, we can conclude that, compared to natural, modified diatomite has higher adsorption properties in relation to copper and iron cations, increases pH, and also contributes to more effective water purification from unwanted impurities.

POSSIBLE CAUSES OF CHANGES IN SEROTONIN CONTENT IN THE LIVER OF RATS IN CONDITIONS OF CHRONIC INTAKE OF SILICON WITH DRINKING WATER

The paper presents data on changes in the intensity of serotonin luminescence in the liver structures of rats who were in an experiment with the intake of silicon with drinking water for two and nine months. The possible causes of identified changes are also considered and discussed. The aim of the study was to correlate the serotonin status of the liver with the number of immunocompetent cells (eosinophils, mast cells, CD68–positive cells) and with peripheral blood indicators in different periods of the experiment with the intake of silicon with drinking water. Material and methods. The rats were divided into two groups: the control group (n = 20) received bottled drinking water, the experimental group (n = 20) received the same water, but supplemented with Na2SiO3*9H2O at the concentration of 10 mg/l in terms of silicon. The animals had free access to a water source. Blood was taken from the caudal vein for analysis before the start of the experiment, as well as in 2 and 9 months after its start. After two and nine months, the rats were withdrawn from the experiment. Fresh frozen slices with a thickness of 10 microns were prepared from one part of the liver to perform the Falk–Hillarp reaction, the other part of the liver was placed in a 10% formalin solution for subsequent paraffin embedding. After deparaffination, the sections were processed by various methods for counting immunocompetent cells: by hematoxylin and eosin (eosinophils), by Unna's toluidine blue (mast cells), by indirect immunohistochemical method (CD68-positive cells). The differences in all cases were considered statistically significant at p < 0.05. Results and their discussion. An increase in the intensity of serotonin luminescence was found in the studied liver structures (hepatocytes, central vein membranes, luminescent granular cells and their microenvironment) in rats of the experimental group. At this, an increase in their intensity by 2-3 times was recorded in the liver of rats who were in the experiment for 9 months. It was revealed that the number of platelets, erythrocytes, hemoglobin, leukocytes, a mixture of monocytes, eosinophils, basophils and immature cells in the blood of rats treated with silicon with drinking water at a concentration of 20 mg/ l is inversely dependent on the duration of the experiment. At both terms, an increase in the number of eosinophils in the portal zones was observed, as well as an increase in the area of mast cells. After 2 months of the experiment, the number of CD68-positive cells and mast cells increased in the liver of rats of the experimental group, and after 9 months their number equalized and decreased, respectively. Attention is drawn to the participation of the above-mentioned immunocompetent cells in serotonin metabolism. Serotonin involvement in the processes of physiological and reparative liver regeneration is discussed. Conclusions. Changes in the number and areas of immunocompetent cells (eosinophils, mast cells, macrophages) in the liver of rats making the experimental groups, as well as a decrease in the platelet content in their blood are associated with an increase in the intensity of serotonin luminescence in the liver structures containing it.

COMPREHENSIVE ASSESSMENT OF MORPHOLOGICAL CHANGES IN THE LIVER OF RABBITS EXPOSED TO WATER-SOLUBLE SILICON FOR THREE MONTHS

The article presents the results obtained when studying the liver of rabbits who were in an experiment with the intake of silicon with drinking water at a concentration of 20 mg / l expressed in terms of silicon. The aim of the study was a comprehensive assessment of liver changes in laboratory rabbits under the conditions of the experiment with the intake of water-soluble silicon for three months. Material and methods. Rabbits were kept in a vivarium on a standard diet with free access to drinking water for three months. Animals of the control group (n = 3) received bottled drinking water, rabbits of the experimental group (n = 3) received the same water, but with the addition of sodium metasilicate enneahydrate at a concentration of 20 mg /l expressed in terms of silicon. After the animals were removed from the experiment, the liver was extracted. A part of the liver was sent to a cryostat for freezing with further preparation of fresh slices with a thickness of 10 microns and producing a Cross, Evan and Rost reaction to detect histamine luminescent structures, the other part was placed in a 10% formalin solution for subsequent paraffin embedding. Paraffin blocks were made; sections of 5 microns thick after deparaffination were stained with hematoxylin and eosin, methyl green-pyronine by Brachet method, as well as by Van Gieson method to identify connective tissue. The measurement results were considered statistically significant at p < 0.05. Results and their discussion. When stained with hematoxylin and eosin in the liver preparations of rabbits of the experimental group who received silicon with drinking water at a concentration of 20 mg/l ad libitum for three months, statistically significant increases in the average area of hepatocytes, the average area of hepatocyte nuclei, and the average diameter of sinusoidal capillaries were revealed in comparison with the preparations in the control group. An increase in the area of central veins was noted, but these changes were not statistically significant. A change in the shape of hepatocytes' nuclei was observed, which was manifested by a decrease in the shape factor of the nucleus and eccentricity and an increase in the index of the nucleus contour, as well as leukocytic infiltration of the portal tract area, formation of areas of hepatocytes' focal necrosis, proliferation of connective tissue with the formation of portal fibrosis and portoportal septa. In rabbits of the experimental group, a decrease in the DNA optical density was determined in liver histopreparations stained by Brush method in hepatocyte nuclei. We found an increase in the intensity of histamine luminescence in the luminescent granular liver cells of rabbits containing it. Conclusions. The intake of silicon at a concentration of 20 mg/l for three months results in pronounced morphological changes in the liver of rabbits.

CHANGES IN THE HISTAMINE STATUS OF THE INTERNAL ORGANS OF LABORATORY ANIMALS DEPENDING ON THE SILICON CONCENTRATION IN DRINKING WATER

The results of a study of the histamine status of the internal organs of Djungarian hamsters when silicon was taken with drinking water are presented. The aim of the study was to assess the histamine status of the liver, spleen and testicles of Djungarian hamsters when silicon was ingested with drinking water for three months at various concentrations. Material and methods. The hamsters were kept in the vivarium on a standard diet with free access to drinking water for three months. Hamsters of the control group (n = 3) received bottled drinking water, hamsters of the experimental groups received the same bottled water with the addition of sodium metasilicate 9-hydrate at a concentration of 10 mg/l in terms of silicon (the first experimental group, n = 3) and 20 mg/l in terms of silicon (the second experimental group, n = 3). To detect and quantify histamine in organs and tissues in cryostat sections of the liver, spleen and testicles, the fluorescent-histochemical Cross method was used. A general blood test and a blood test for glucose and cholesterol were also performed. Results and their discussion. A general blood test of hamsters that received drinking water with different concentrations of silicon did not reflect the effect of microelement intaked into the organism, while, depending on the concentration of silicon in water, the average blood glucose level tended to increase, and the cholesterol level tended to decrease. The obtained results do not contradict our previous studies in that direction. It has been shown that the concentration of silicon in drinking water from 10 mg/l hardly noticeably affects the histamine status of such organs as the liver, spleen and testes: only the intensity of histamine luminescence in macrophages of the red pulp increases statistically significantly. When silicon enters the body with drinking water at a concentration of 20 mg/l, the histamine status of organs changes more noticeably, the cells surrounding the central veins and the interstitial histamine-containing testes cells are “involved” into the reaction, which is visually reflected in the luminescent morphology of the investigated organs. Conclusions. The intake of silicon at a concentration of 10 mg/l and 20 mg/l for three months affects the histamine status of the liver, spleen and testes of Djungarian hamsters, while the indicators of the general blood test do not change.

THE EFFECT OF SILICON NANOPARTICLES AND WATER-SOLUBLE SILICATES ON THE LIVER (COMPARISON OF OUR OWN RESEARCH RESULTS WITH THE LITERATURE DATA)

This literature review combines data on the effect of silicon compounds on the body – silicon nanoparticles and water-soluble silicates, obtained by domestic and foreign researchers over the past decade. a widespread use of amorphous silicon dioxide in modern industry, as well as revision of regulatory documents on silicon content in drinking water in the Russian Federation give this aspect special relevance. Increased attention is paid to comparing our own results of long-term experiments on silicon intake with drinking water by laboratory animals and the literature data. It has been shown that morphological changes in the liver caused by exposure to water-soluble silicates and nanoparticles are similar. Thus, questions about the biological inertness of silicon, monitoring the use of silicon in industry, and adjustment of its maximum permissible concentration in drinking water require further study.

Experimental silicon intake with drinking water affects the serotonin supply in the digestive tract of laboratory rats

Serotonin plays an important role in the function of the gastrointestinal tract. Currently, the dietary supplementation containing silicon becomes very popular trend, even for the long‐time reception. The effect of dietary silicon intake on serotonin level in small intestine (SI) and liver are not well understood. In this study we checked the impact of water‐soluble silicon compounds intake on the serotonin supply in structures of SI and liver.The study was curry out on 2‐months‐old male rats, which were divided on two groups: control group (n=10) received ad libitum drinking water; experimental group (n=10) received ad libitum the same water containing sodium metasilicate (Na2SiO3x9H2O, 10 mg/liter) for 2 and 9 months. Five animals from each group were sacrificed 2 months after beginning of the experiment, the rest – 9 months later. All manipulations with experimental animals were performed in accordance with the Regulations on Animal Experiments and in Compliance with European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes. The liver and pieces of small intestine (10 sm below the hepatoduodenal ligament) were isolated after decapitation and immediately frozen for the luminescence‐histochemical study. The presence of serotonin was detected on 10 µm cryosections using Falck‐Hillarp method modified by Krokhina (1982). The sections were examined under the Leica D1000 fluorescent microscope (360 nm of exciting light length, 525 nm of emission wavelength). Spectrofluorimetry was used to identify and quantify the serotonin levels in cytoplasm of follow structures: epithelial cells of mucous membrane, in the macrophages of the lamina propria of SI, in hepatocytes and luminescent granular cells (LGC) of liver.There are no significant differences in intensity of serotonin fluorescence in investigates structures of SI between control and experimental groups were detected after 2 months from the beginning of experiments. However, in liver the value of serotonin fluorescence intensity in the wall of the central veins and hepatocytes of rats in experimental group was elevated in 1.2 times, in LGC and their microenvironment – 1.5 times (р < 0,05) compared to the control group.The 9‐months silicon supplementation leads to the up‐regulation of serotonin fluorescence intensity in structures of SI: in cytoplasm of epithelial cells of the mucous membrane, in macrophages of the lamina propria and in their microenvironment, by 1.2 and 1.4 times, respectively (p < 0.05). The intensity of serotonin value in cytoplasm of hepatocytes and in the wall of the central veins of liver increased by 1.2 and 1.1 times, respectively (p < 0.05), in LGC and their microenvironment – by 1.3 and 1.7 times, respectively (p < 0.05).We concluded that (i) the liver is a little more sensitive to the intake of silicon with drinking water than the structures of SI; (ii) the silicon supplementation generally increases the intensity of serotonin content in structures of liver and SI, which can be explained by age‐related changes in these organs.

Ortho-silicic Acid Plays a Protective Role in Glucocorticoid-Induced Osteoporosis via the Akt/Bad Signal Pathway In Vitro and In Vivo.

Glucocorticoid-induced osteoporosis (GIOP) has been the most common form of secondary osteoporosis. Glucocorticoids (GCs) can induce osteocyte and osteoblast apoptosis. Plenty of research has verified that silicon intake would positively affect bone. However, the effects of silicon on GIOP are not investigated. In this study, we assessed the impact of ortho-silicic acid (OSA) on Dex-induced apoptosis of osteocytes by cell apoptosis assays. The apoptosis-related genes, cleaved-caspase-3, Bcl-2, and Bax, were detected by western blotting. Then, we evaluated the possible role of OSA on osteogenesis and osteoclastogenesis with Dex using Alizarin red staining and tartrate-resistant acid phosphatase (TRAP) staining. We also detected the related genes by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and western blotting. We then established the GIOP mouse model to evaluate the potential role of OSA in vivo. We found that OSA showed no cytotoxic on osteocytes below 50μM and prevented MLO-Y4 from Dex-induced apoptosis. We also found that OSA promoted osteogenesis and inhibited osteoclastogenesis with Dex. OSA had a protective effect on GIOP mice via the Akt signal pathway in vivo. In the end, we verified the Akt/Bad signal pathway in vitro, which showed the same results. Our finding demonstrated that OSA could protect osteocytes from apoptosis induced by GCs both in vitro and in vivo. Also, it promoted osteogenesis and inhibited osteoclastogenesis with the exitance of Dex. In conclusion, OSA has the potential value as a therapeutic agent for GIOP.

Silicon-containing water intake confers antioxidant effect, gastrointestinal protection, and gut microbiota modulation in the rodents.

We explored the effects of silicon-containing water (BT) intake on gastrointestinal function and gut microbiota. BT was obtained by pressuring tap water through silicon minerals (mullite, Al6Si2O13) column. BT decreased H2O2 chemiluminescence counts, indicating its antioxidant activity. Four weeks of BT drinking increased H2O2 scavenging activity and glutathione peroxidase activity of plasma. BT drinking did not affect the body weight but significantly reduced the weight of feces and gastrointestinal motility. BT drinking significantly suppressed pylorus ligation enhanced gastric juice secretion, gastric reactive oxygen species amount, erythrocyte extravasation, IL-1β production by infiltrating leukocyte, and lipid peroxidation within gastric mucosa. Data from 16S rRNA sequencing revealed BT drinking significantly increased beneficial flora including Ruminococcaceae UCG-005, Prevotellaceae NK3B31, Weissella paramesenteroides, Lactobacillus reuteri, and Lactobacillus murinus and decreased harmful flora including Mucispirillum, Rodentibacter, and Staphylococcus aureus. This study pioneerly provided scientific evidences for the potential effects of water-soluble forms of silicon intake on antioxidant activity, gastrointestinal function, and gut microbiota modulation.

Silicon: A neglected micronutrient essential for bone health.

Bone matrix is predominantly made up of collagen, and in vitro and in animal models studies have shown that silicon is linked to glycosaminoglycans and plays an important role in the formation of cross-links between collagen and proteoglycans, determining the beneficial effects on strength, composition, and mechanical properties of bone. However, there are still no precise indications regarding a possible role of silicon on bone health in humans. Given this background, the aim of this narrative review was to consider the effectiveness of silicon dietary intake and silicon dietary supplementation (alone or with other micronutrients), in order to suggest a daily dosage of Si supplementation, on bone mineral density in humans. This review included eight eligible studies: four regarding dietary intake and four considering supplementation with silicon alone or with other nutrients. Despite the number of studies considered being low, the number of subjects studied is high (10012) and the results are interesting. Although to date the available scientific evidences are not considered valid enough to allow to establish an adequate level of Silicon intake, based on extrapolations from the data obtained with studies on animal and human models, it has been suggested that an adequate intake in order to promote beneficial effects for bone could be considered to be around 25 mg silicon/day. As for silicon dietary supplements, it has been shown that the combined treatment with orthosilicic acid (6 mg), calcium, and vitamin D has a potentially beneficial effect on femoral BMD compared to only use of calcium and vitamin D.

Ortho-silicic Acid Inhibits RANKL-Induced Osteoclastogenesis and Reverses Ovariectomy-Induced Bone Loss In Vivo.

Numerous experiments in vitro and in vivo have shown that an appropriate increase intake of silicon can facilitate the synthesis of collagen and its stabilization and promote the differentiation and mineralization of osteoblasts. In this study, we examined whether ortho-silicic acid restrains the differentiation of osteoclast through the receptor activator of nuclear factor κB ligand (RANKL)/receptor activator of nuclear factor κB (RANK)/osteoprotegerin (OPG) signaling pathway by investigating its effect in vitro and in vivo. Bone marrow macrophage (BMM) cells were isolated and cultured with or without ortho-silicic acid, and then TRAP staining and immunofluorescence were performed to detect the differentiation of osteoclast. The RANKL-induced osteoclast marker gene and protein expression including c-Fos, nuclear factor of activated T cells cl (NFATcl), tumor necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor kappa B P50 (NF-κB P50), NF-κB P52, RANK, integrin β3, cathepsin K (CTSK), DC-STAMP, and TRAP were quantitatively detected by western blot and RT-PCR. Ovariectomized (OVX) rats were injected with ortho-silicic acid (OVX+Si group) and normal saline (OVX group), and sham-operated rats were injected with normal saline (Sham group). And micro-CT, H&E, and TRAP staining, ELISA, and western blot were performed. Ortho-silicic acid could inhibit the differentiation of osteoclast, and the marker genes and proteins were decreased. The OVX-induced bone loss could be reversed by ortho-silicic acid. Our finding demonstrated that ortho-silicic acid suppresses RANKL-induced osteoclastogenesis and has potential value as a therapeutic agent for OVX-induced bone loss.

Dietary Silicon and Its Impact on Plasma Silicon Levels in the Polish Population.

Silicon in nutritional amounts provides benefits for bone health and cognitive function. The relationship between silicon intake from a common daily diet and silicon blood level has been scarcely elucidated, so far. The aim of this study was to analyze the associations between plasma silicon levels and the total and bioavailable silicon intake—along with the contribution of silicon made by food groups—in a healthy adult Polish population. Si intake was evaluated in 185 healthy adults (94 females and 91 males, aged 20–70) using a 3-day dietary recall and a database on the silicon content in foods, which was based on both previously published data and our own research. Fasting plasma silicon levels were measured in 126 consenting subjects, using graphite furnace atomic absorption spectrometry. The silicon intake in the Polish population differed significantly according to sex, amounting to 24.0 mg/day in women and 27.7 mg/day in men. The median plasma silicon level was 152.3 µg/L having no gender dependency but with a negative correlation with age. Significant correlations were found between plasma silicon level and total and bioavailable silicon intake, as well as water intake in the diet (r = 0.18, p = 0.044; r = 0.23, p = 0.011; r = 0.28, p = 0.002, respectively). Silicon intakes from non-alcoholic beverages, cereal foods, and carotene-rich vegetables were also positively associated with plasma silicon levels. These results may help establish dietary silicon recommendations and formulate practical advice on dietary choices to ensure an appropriate supply of silicon. The outcome of this study, however, needs to be confirmed by large-scale epidemiological investigations.

Silicon intake and plasma level and their relationships with systemic redox and inflammatory markers in rheumatoid arthritis patients

The nutritional significance of silicon for the human body is highlighted by a continually growing body of evidence. In conditions of excessive reactive oxygen species and upregulated immune response, silicon has been observed to provide benefits, but its role in redox and inflammatory status has not yet been examined in rheumatoid arthritis (RA). The aim of this study was to assess the relationship of silicon intake and plasma level to systemic indices of redox status and inflammation in patients with RA. Silicon intake and plasma levels were measured in 115 RA subjects and 129 control subjects. Serum antioxidant and oxidant levels, antioxidant enzyme activity, and albumin, uric acid, TBARS, hs-CRP, and IL-6 levels were measured and compared to the intake and plasma levels of silicon. Silicon intake and plasma silicon levels were higher in RA subjects than in the controls. In the RA group, a generally favorable correlation to redox and inflammatory markers was found for silicon in diet and in plasma; however, albumin level, smoking status, and gender interfered with these results. In the control subjects, a significant relationship was observed only between plasma silicon and non-enzymatic markers of redox status. There are suggestions of silicon's involvement in managing redox and inflammatory status in RA, though further studies are warranted.

SILICON: ITS BIOLOGICAL IMPACT UNDER DIETARY INTAKE AND HYGIENIC STANDARDIZATION OF ITS CONTENT IN DRINKING WATER. A REVIEW

By the prevalence in the earth’s crust, silicon occupies the second place after oxygen. In different quantities silicon always presents in water and food products.The average daily dietary intake of silicon in Western world is about 20-50 mg/day. The biological role of silicon in human organism is still not clear, but it assumed to be necessary for processes of bone mineralization, collagen synthesis, it has a positive effect on the state of skin, hair, and nails, contributes to the prevention of atherosclerosis and Alzheimer disease. A number of scientific research is devoted to biological effects of silicon in animals and human subjects under intake with food and water, and substantiation of silicon (maximum admissible concentrations (MAC) in drinking water. In Chuvashia there was investigated the regional (geographical) pathology, which may be related with an increased silicon intake in association with the sharp imbalances of trace and macro elements in drinking water. Some measures were implemented to identify the possible role of silicon in etiology of Balkan endemic nephropathy. Organization for Economic Co-operation and Development (OECD) report summarized materials for the experimental evaluation of the toxicity and harmless levels of silicon intake with food and water in animals. A series of studies was executed to simulate the development of silicon urolithiasis and for the elucidation of the role of macro- and microelements accompanying the intake of silicon into the body in stone formation. There are studied potential therapeutic effects of water soluble silicon compounds on human health. The standards of silicon in drinking water are regulated only in Russia and Australia. At the same time in our country there were formed two opposing points of view in relation to the hygienic standardization of silicon. The first is one - MAC of silicon in drinking water needs to be cancelled, the second - MAC of silicon in the water needs to be tightened. To resolve the contradictions it is advisable to use both the experience of harmonization of standards with international requirements, and the principle of silicon regional standardization, taking into consideration the biogeochemical characteristics of geographic areas. When searching the literature databases PubMed and CyberLeninka were used.

Relationship Between Dietary Intake and Urinary Excretion of Silicon in Free-Living Korean Adult Men and Women.

Previous studies have reported that silicon (Si) has a positive effect on bone health, immune response, and cognitive health. However, basic and important studies on evaluating dietary intake and urinary excretion of Si are limited. The aim of this study was to evaluate dietary Si intake and urinary excretion according to gender and age in healthy and free-living Korean adults and to investigate the relationship between them with gender. In this cross-sectional study, anthropometric measurements, dietary assessment using a food record, and a 24-h urine collection were conducted in 80 healthy Korean adults (40 males and 40 females; groups of 8 subjects representing each decade of life [20s to 60s]) with self-selected diet. The dietary assessment and 24-h urine collection were performed twice at intervals of 3days. Daily intake of Si was estimated using a Si database of food composition. Urinary excretion of Si was analyzed using ICP-OES. The mean dietary Si intake was 22.8mg/day for men and 19.3mg/day for women without significant difference according to their gender and age. Si intake was the highest from vegetables both in men and women, followed by grains, beverages, and fruits in men and by grains, fruits, and milks in women. Urinary Si excretion was significantly higher in men (9.8mg/day) than women (9.3mg/day), and significantly increased with age only in women. Regarding the relationship between dietary Si intake and urinary Si excretion, a significantly positive correlation was found in men, but not in women. Longitudinal and balance studies to elucidate gender differences in Si nutrition are needed.

Orthosilicic Acid Accelerates Bone Formation in Human Osteoblast-Like Cells Through the PI3K-Akt-mTOR Pathway.

Silicon is one of the essential trace elements in the human body; the deficiency of which may lead to bone diseases. Numerous animal experiments have shown that an appropriate increase in the intake of silicon is beneficial to enhancing bone density and toughness to prevent osteoporosis. However, the molecular mechanisms of the silicon-mediated osteogenesis process have not been sufficiently clarified. In this study, we determined the possible osteogenesis-related mechanisms of orthosilicic acid at a molecular level. We detected the relevant pathway and osteogenic indicators by immunofluorescence (IF), Western blot, alkaline phosphatase (ALP) staining (using 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium [BCIP/NBT]), ALP enzyme labeling method, osteocalcin (OCN), and N-terminal propeptide of type 1 procollagen (P1NP) enzyme-linked immunosorbent assay (ELISA). We found that orthosilicic acid is capable of enhancing the expression of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), phospho-protein kinase B (P-Akt), phospho-mammalian target of rapamycin (P-mTOR), and related osteogenic markers (runt-related transcription factor 2 [RUNX2], type I collagen [COL1], ALP, OCN, and P1NP). However, with the addition of PI3K-Akt-mTOR pathway-specific inhibitor LY294002, the expression of PI3K, P-Akt, P-mTOR, RUNX2, COL1, ALP, OCN, and P1NP decreased. The results indicated that the PI3K-Akt-mTOR pathway played a positive regulatory role in the process of orthosilicic acid-mediated osteogenesis in vitro.

Genistein and Silicon Synergistically Protects Against Ovariectomy-Induced Bone Loss Through Upregulating OPG/RANKL Ratio.

We have reported that genistein (Gen) and silicon (Si) have synergistic effects on ovariectomy-induced bone loss in rat; however, the potential mechanisms behind this effect were not fully clarified yet. This study was performed to evaluate the bone protective mechanisms of concomitant intake of genistein and silicon in ovariectomized rat by OPG/RANKL axis. Three-month-old Sprague-Dawley female rats were subjected to ovariectomy (OVX) or sham surgery; after surgery, the OVX rats were randomly divided into five groups: OVX-Gen, OVX-Si, OVX-Gen-Si, OVX-E, and OVX. Genistein, silicon, and 17β-estradiol supplementation were started after ovariectomy and continued for 10weeks. The results showed that genistein and silicon treatment increased the bone mineral density (BMD) of ovariectomized rats. In addition, the BMD of the tibia and femur were highest in the OVX-Gen-Si group compared with OVX-Gen and OVX-Si group (p < 0.05). After 10weeks treatment with genistein and silicon, the bone structure of ovariectomized rats was recovered, there was no difference of bone histomorphometric parameters between OVX-Gen-Si, OVX-E, and SHAM group (p > 0.05), and there was no difference in the concentration of serum ALP, Ca, P, OPG, and RANKL between OVX-Gen-Si, SHAM, and OVX-E groups (p > 0.05). RT-PCR showed that genistein and silicon treatment could effectively increase the OPG mRNA expression and decreased the RANKL mRNA expression compared to that of the OVX group (p < 0.05), the OPG/RANKL mRNA ratios were significantly decreased in the OVX group (p < 0.05), and it was nearly to normal in the OVX-Gen-Si group. Immunohistochemical staining results showed that genistein and silicon supplementation could effectively increase the protein expression of OPG and decrease the protein expression of RANKL in bone tissues; there were no significant differences in OPG and RANKL positive expression areas between OVX-Gen-Si, SHAM, and OVX-E group (p > 0.05). The results above indicate that genistein and silicon supplementation can effectively reduce RANKL, increase OPG levels, and OPG/RANKL ratios in the serum and bone tissue of ovariectomized rats; this is the main mechanism by which genistein and silicon play a bone protective role in ovariectomized rats.

Effect of silicon-rich water intake on the systemic and peritoneal inflammation of rats with chronic low levels of aluminum ingestion

Background and ObjectivesStudy evaluated effect of silicon-rich water intake on systemic inflammation and functional characteristics of peritoneal macrophages (PMs) of rats that were chronically exposed to dietary aluminum. MethodsOne month-old female Wistar Albino rats were administered aluminum chloride dissolved in distilled water (1.6 mg/kg body weight in 0.5 mL) by gavage for 90 days. The rats were then given standard (6 mg/L) or silicon-rich water (19 mg/L silicon) (n = 7/group). Control rats underwent sham gavage and received standard or silicon-rich water (n = 7/group). Blood was assessed for cytokine levels. Unstimulated and lipopolysaccharide (LPS)-stimulated PMs were assessed in terms of phagocytic activity and cytokine secretion in vitro. ResultsChronic exposition to dietary aluminum and silicon-rich drinking water did not change serum TNF-α levels. Aluminum increased serum IL-2 and this was reversed by silicon-rich water. The aluminum-exposed rats had higher serum sICAM-1 than sham-gavaged, unrelated to type of water. LPS-stimulated PMs from aluminum-intoxicated animals exhibited low phagocytic activity and release of TNF-α, this was significantly improved by silicon-rich water intake. In the presence of silicon-rich water, LPS-stimulated and unstimulated PMs from aluminum-exposed rats produced significantly more IL-10. ConclusionsChronic ingestion of aluminum, increases systemic and peritoneal inflammation and PM dysfunction. The presence of high levels of the natural aluminum antagonist silicon in the drinking water restored IL-10 and TNF-α PM secretion, preventing prolonged inflammation. Thus, silicon intake can decrease the immunotoxicity of aluminum.