Update on the possible nutritional importance of silicon

Ionic medicine: exploiting metallic ions to stimulate skeletal muscle tissue regeneration

The regeneration of healthy and functional skeletal muscle at sites of injuries and defects remains a challenge. Mimicking the natural environment surrounding skeletal muscle cells and the application of electrical and mechanical stimuli are approaches being investigated to promote muscle tissue regeneration. Likewise, chemical stimulation with therapeutic (biologically active) ions is an emerging attractive alternative in the tissue engineering and regenerative medicine fields, specifically to trigger myoblast proliferation, myogenic differentiation, myofiber formation, and ultimately to promote new muscle tissue growth. The present review covers the specialized literature focusing on the biochemical stimulation of muscle tissue repair by applying inorganic ions (bioinorganics). Extracting information from the literature, different ions and their potential influence as chemical cues on skeletal muscle regeneration are discussed. It is revealed that different ions and their varied doses have an individual effect at different stages of muscle cellular development. The dose-dependent effects of ions, as well as applications of ions alone and in combination with biomaterials, are also summarized. Some ions, such as boron, silicon, magnesium, and zinc, are reported to exhibit a beneficial effect on skeletal muscle cells in carefully controlled doses, while the effects of other ions such as iron and copper appear to be contradictory. In addition, calcium is an essential regulatory ion for the differentiation of myoblasts. On the other hand, some ions such as phosphate have been shown to inhibit muscle cell behaviour. It is expected that this review will provide a complete overview of the application of ionic stimulation for skeletal muscle tissue engineering applications, and will highlight the importance of inorganic ions as an attractive alternative to the application of small molecules and growth factors to stimulate muscle tissue repair. STATEMENT OF SIGNIFICANCE: Ionic medicine (IM) is emerging as a promising and attractive approach in the field of tissue engineering, including muscle tissue regeneration. IM is based on the delivery of biologically active ions to injury sites, acting as stimulants for the repair process. This method offers a potentially simpler and more affordable alternative to conventional biomolecule-based regulators such as growth factors. Different biologically active ions, depending on their specific doping concentrations, can have varying effects on cellular development, which could be either beneficial or inhibitory. This literature review covers the field of IM in muscle regeneration with focus on the impact of various ions on skeletal muscle regeneration. The paper is thus a critical summary for guiding future research in ionic-related regenerative medicine, highlighting the potential and challenges of this approach for muscle regeneration.

Nutritional Value and in vitro Antigiardial Activity of Anise (Pimpinella anisum L.) Seeds

The present study focused on evaluating the proximate analysis, mineral composition, and in vitro anti-giardial activity of Pimpinella anisum seed extracts, which are aromatic plants with a long history of usage in folk and conventional medicine, as well as pharmaceutical manufacturing. Standard methods were used to determine the proximate analysis of the powdered plant sample, including dry matter, ash, fat, protein, fiber, and carbohydrates. The mineral contents of Pimpinella anisum seed were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), revealing that the plant has a high fiber content (42.62%) followed by carbohydrates (38.79%). The seeds were also found to be a rich source of minerals, with notable amounts of Rubidium, Magnesium, and Calcium. The extracts showed a high mortality percentage compared to Metronidazole, with the chloroform extract exhibiting higher anti-giardial activity (78.71%) than the ethanolic extract (75.29%) at a concentration of 500 ppm. These findings support the traditional use of Anise in treating gastrointestinal issues and as a natural supplement. Further studies are needed to isolate the active ingredients and understand their mechanism of action.

Silicon in prevention of atherosclerosis and other age-related diseases

Researchers' interest in silicon as an element important for the functioning of the animal and human body began in the 1970s. Soluble compounds of silicon bioavailable from water and food seem to have important meaning for life processes occurring in the body. So far, researchers have focused on the significance of silicon for the development of bones and connective tissue, and its role in preventing neurodegenerative diseases and atherosclerosis. Despite numerous studies, the role of silicon as an active element in the human body is poorly understood. Since the involvement of lipid oxidation and inflammatory processes in the pathogenesis of atherosclerosis is well known, this article summarizes and discusses the current research and scientific observations regarding silicon, primarily in terms of its beneficial influence on redox and anti-inflammatory reactions and the lipid profile. The association of silicon with the stabilization of the structure of glycosaminoglycans and their protein complexes may also support the anti-atherosclerotic effect. The authors attempted to collect and present existing publications that could confirm the beneficial role of dietary silicon in the prevention of age-related diseases and explain the potential mechanisms of its action.

Silicon Supplementation for Bone Health: An Umbrella Review Attempting to Translate from Animals to Humans

Studies have attempted to demonstrate the benefits of silicon on bone health using a wide range of Si amounts-provided in the diet or through supplementation-and several different animal species. Previous studies in humans have also demonstrated a positive correlation between Si intake and bone health measures. The aim of the current review is to determine the effective levels of Si intake or supplementation that influence bone health to better inform future study designs and guidelines. Articles were identified using one of two search terms: "silicon AND bone" or "sodium zeolite A AND bone". Articles were included if the article was a controlled research study on the effect of Si on bone health and/or mineral metabolism and was in English. Articles were excluded if the article included human subjects, was in vitro, or studied silica grafts for bone injuries. Silicon type, group name, Si intake from diet, Si supplementation amount, animal, and age at the start were extracted when available. Dietary Si intake, Si supplementation amount, and the amount of Si standardized on a kg BW basis were calculated and presented as overall mean ± standard deviations, medians, minimums, and maximums. Studies that left out animal weights, amount of food or water consumed, or nutrient profiles of the basal diet were excluded from these calculations. Standardized Si intakes ranged from 0.003 to 863 mg/kg BW, at times vastly exceeding current human Si intake recommendations (25 mg/d). The lack of data provided by the literature made definitively determining an effective threshold of supplementation for skeletal health difficult. However, it appears that Si consistently positively influences bone and mineral metabolism by around 139 mg Si/kg BW/d, which is likely unfeasible to attain in humans and large animal species. Future studies should examine this proposed threshold more directly and standardize supplemental or dietary Si intakes to kg BW for better study replication and translation.

Iron(III) Monoglycerolate as a New Biocompatible Precursor in the Synthesis of Bioactive Nanocomposite Glycerohydrogels

BACKGROUND

Nanocomposite glycerohydrogels based on biocompatible elementcontaining glycerolates are of practicular interest for biomedical applications.

OBJECTIVE

Using two biocompatible precursors, silicon and iron glycerolates, a new bioactive nanocomposite silicon‒iron glycerolates hydrogel was obtained by sol-gel method.

METHODS

The composition and structural features of the hydrogel were studied using a complex of modern analytical techniques, including TEM, XRD, and AES. On the example of experimental animals hemostatic activity of the hydrogel was studied, as well as primary toxicological studies were carried out.

RESULTS

The composition of dispersed phase and dispersion medium of silicon‒iron glycerolates hydrogel was determined. The structural features of hydrogel were revealed and its structure model was proposed. It was shown that silcon-iron glycerolates hydrogel is nontoxic, and exhibits pronounced hemostatic activity.

CONCLUSION

Silicon-iron glycerolates hydrogel is a potential hemostatic agent for topical application in medical and veterinary practice.

Microporous Hydroxyapatite-Based Ceramics Alter the Physiology of Endothelial Cells through Physical and Chemical Cues

Incorporation of silicate ions in calcium phosphate ceramics (CPC) and modification of their multiscale architecture are two strategies for improving the vascularization of scaffolds for bone regenerative medicine. The response of endothelial cells, actors for vascularization, to the chemical and physical cues of biomaterial surfaces is little documented, although essential. We aimed to characterize in vitro the response of an endothelial cell line, C166, cultivated on the surface CPCs varying either in terms of their chemistry (pure versus silicon-doped HA) or their microstructure (dense versus microporous). Adhesion, metabolic activity, and proliferation were significantly altered on microporous ceramics, but the secretion of the pro-angiogenic VEGF-A increased from 262 to 386 pg/mL on porous compared to dense silicon-doped HA ceramics after 168 h. A tubulogenesis assay was set up directly on the ceramics. Two configurations were designed for discriminating the influence of the chemistry from that of the surface physical properties. The formation of tubule-like structures was qualitatively more frequent on dense ceramics. Microporous ceramics induced calcium depletion in the culture medium (from 2 down to 0.5 mmol/L), which is deleterious for C166. Importantly, this effect might be associated with the in vitro static cell culture. No influence of silicon doping of HA on C166 behavior was detected.

The Role of Trace Elements and Minerals in Osteoporosis: A Review of Epidemiological and Laboratory Findings

The objective of the present study was to review recent epidemiological and clinical data on the association between selected minerals and trace elements and osteoporosis, as well as to discuss the molecular mechanisms underlying these associations. We have performed a search in the PubMed-Medline and Google Scholar databases using the MeSH terms "osteoporosis", "osteogenesis", "osteoblast", "osteoclast", and "osteocyte" in association with the names of particular trace elements and minerals through 21 March 2023. The data demonstrate that physiological and nutritional levels of trace elements and minerals promote osteogenic differentiation through the up-regulation of BMP-2 and Wnt/β-catenin signaling, as well as other pathways. miRNA and epigenetic effects were also involved in the regulation of the osteogenic effects of trace minerals. The antiresorptive effect of trace elements and minerals was associated with the inhibition of osteoclastogenesis. At the same time, the effect of trace elements and minerals on bone health appeared to be dose-dependent with low doses promoting an osteogenic effect, whereas high doses exerted opposite effects which promoted bone resorption and impaired bone formation. Concomitant with the results of the laboratory studies, several clinical trials and epidemiological studies demonstrated that supplementation with Zn, Mg, F, and Sr may improve bone quality, thus inducing antiosteoporotic effects.

Bismuth release from endodontic materials: in vivo analysis using Wistar rats

Calcium silicate-based materials are used to block the communication between the root canal and the periodontal ligament space. This brings the materials into contact with tissues and the potential for local and systemic elemental release and movement. The aim of the study was to evaluate the elemental release of bismuth from ProRoot MTA in contact with connective tissues after 30 and 180 days as well as any accumulation in peripheral organs using an animal model. Tricalcium silicate and hydroxyapatite containing 20% bismuth oxide (HAp-Bi) were used as controls. The null hypothesis was that bismuth migrates from tricalcium silicate-based materials when associated with silicon. The materials were examined using scanning electron microscopy, energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction prior to implantation as well as using SEM/EDS, micro X-ray fluorescence and Raman spectroscopy after implantation to assess elemental presence in surrounding tissues. Histological analysis was used to evaluate the changes in tissue architecture and inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the elemental deposition. For the systemic investigation, routine blood analysis was performed and organs were obtained to evaluate the presence of bismuth and silicon using ICP-MS after acid digestion. In the histological analysis of the implantation sites, macrophages and multinucleated giant cells could be observed after 30 days which after 180 days became a chronic infiltrate; although, no major differences were identified in red and white blood cell analyses and biochemical tests. Implantation altered the materials as observed in the Raman analysis and bismuth was detected both locally and within kidney samples after both periods of analysis, indicating the potential for accumulation of bismuth in this organ. Smaller amounts of bismuth than observed in the kidney were also detected in blood, liver and brain for the ProRoot MTA and HAp-Bi after 180 days. Bismuth was released from the ProRoot MTA locally and was detected systemically and in samples without silicon; thus, the null hypothesis was rejected. The bismuth release demonstrated that this element accumulated both locally and systemically, mainly in the kidneys in comparison with brain and liver regardless of the material base.

Electrochemical and biological characterization of Ti-Nb-Zr-Si alloy for orthopedic applications

The performance of current biomedical titanium alloys is limited by inflammatory and severe inflammatory conditions after implantation. In this study, a novel Ti-Nb-Zr-Si (TNZS) alloy was developed and compared with commercially pure titanium, and Ti-6Al-4V alloy. Electrochemical parameters of specimens were monitored during 1 h and 12 h immersion in phosphate buffered saline (PBS) as a normal, PBS/hydrogen peroxide (H₂O₂) as an inflammatory, and PBS/H₂O₂/albumin/lactate as a severe inflammatory media. The results showed an effect of the H₂O₂ in inflammatory condition and the synergistic behavior of H₂O₂, albumin, and lactate in severe inflammatory condition towards decreasing the corrosion resistance of titanium biomaterials. Electrochemical tests revealed a superior corrosion resistance of the TNZS in all conditions due to the presence of silicide phases. The developed TNZS was tested for subsequent cell culture investigation to understand its biocompatibility nature. It exhibited favorable cell-materials interactions in vitro compared with Ti-6Al-4V. The results suggest that TNZS alloy might be a competitive biomaterial for orthopedic applications.

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 50 μM 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.

Bone fragility during the COVID-19 pandemic: the role of macro- and micronutrients

Bone fragility is the susceptibility to fracture due to poor bone strength. This condition is usually associated with aging, comorbidities, disability, poor quality of life, and increased mortality. International guidelines for the management of patients with bone fragility include a nutritional approach, mainly aiming at optimal protein, calcium, and vitamin D intakes. Several biomechanical features of the skeleton, such as bone mineral density (BMD), trabecular and cortical microarchitecture, seem to be positively influenced by micro- and macronutrient intake. Patients with major fragility fractures are usually poor consumers of dairy products, fruit, and vegetables as well as of nutrients modulating gut microbiota. The COVID-19 pandemic has further aggravated the health status of patients with skeletal fragility, also in terms of unhealthy dietary patterns that might adversely affect bone health. In this narrative review, we discuss the role of macro- and micronutrients in patients with bone fragility during the COVID-19 pandemic.

Exogenous silicon enhances resistance to 1,2,4-trichlorobenzene in rice

Environmental contamination with 1,2,4-trichlorobenzene (TCB) is a threat to rice growth, and ultimately, to human health. Silicon (Si) plays an important role in plants' stress responses. However, little is known about the effects of Si on the TCB tolerance of rice plants. We investigated the effects of Si on the morphological, physiological, and molecular characteristics of rice plants under TCB stress. First, we compared the TCB tolerance of 13 rice cultivars by measuring seven growth-related and 13 physiological indices across four treatments. Then, six cultivars with contrasting TCB tolerance were selected to study the expression of Si transport and detoxification related genes. Compared with the control, the TCB treatment resulted in decreased growth indices, chlorophyll content, and antioxidant enzyme activities, and increased the superoxide anion content and root electrical conductivity. Application of Si improved rice growth, chlorophyll content and alleviated oxidative damage caused by TCB. The alleviating effect of Si ranged from 4.1 % to 56.72 % among the cultivars, with the strongest alleviating effect on Wuyujing 36. The transcript levels of genes encoding Si transporters and detoxification enzymes were higher in tolerant cultivars than in sensitive cultivars. The TCB treatment induced the expression of GST and Lsi2 in roots and HO-1 in leaves; these genes as well as Lsi1 were differentially expressed in roots and/or leaves in the TCB + Si treatment. Lsi1 played a key role in Si-mediated TCB tolerance in Wuyujing 36. The joint analysis of gene transcript levels in TCB and TCB + Si treatments confirmed that all six genes were associated with TCB tolerance, especially Lsi1 and Lsi2 in roots and GST and CuZn-SOD in leaves. Si can increase rice plants' resistance to TCB stress by improving growth and enhancing superoxide dismutase (SOD) activity and chlorophyll content, and by up-regulating genes involved in Si transport and detoxification.

Silicon Resorption from Equisetum arvense Tea - A Randomized, Three-Armed Pilot Study

Equisetum arvense tea (TEA) contains high concentrations of silicon and has been used in folk medicine for the treatment of inflammatory ailments. We examined the resorption of silicon after TEA consumption. Safety and immunological effects were secondary outcomes. A monocentric, randomized, three-armed pilot study was conducted with 12 voluntary, healthy, male subjects. The study is registered in the German register for clinical trials (DRKS-ID: DRKS00016628). After a low silicon diet for 36 hours, 1000 mL TEA1 with approximately 200 000 µg silicon/L, TEA2 with approximately 750 000 µg silicon/L, or Si-low-Water (approximately 10 - 10 000 µg silicon/L as a control) were ingested on three consecutive days. Blood and urine samples were collected at baseline, day 1 examining silicon kinetics, day 3 examining silicon accumulation, and day 8 (safety, immunological parameters). Si-low-Water intake did not change silicon serum (Cmax 294 µg/L) or urine (19 000 µg/24 h) concentrations compared to baseline. Cmax was 2855 µg/L for TEA1 and 2498 µg/L for TEA2; tmax was 60 and 120 min, respectively. Silicon accumulation did not occur. Urine silica within 24 h (E24 h) was higher after TEA2 compared to TEA1 ingestion (142 000 vs. 109 000 µg/24 h). Serum silicon levels at t = 120 min differed significantly after intake of TEA2 or intake of Si-low-Water (p = 0.029). The immunological parameters did not show any significant changes indicating immunosuppressive effects in volunteers. TEA1 was well tolerated, while TEA2 caused diarrhoea in 4 subjects. Our investigations show that intake of TEA1 leads to significant rise in serum silicon concentration.

Effects of Rice-Husk Silica Liquid in Streptozotocin-Induced Diabetic Mice

Type 2 diabetes mellitus is a complex multifactorial disease characterized by poor glucose tolerance and insulin resistance. Rice-husk silica liquid (RHSL) derived from rice husk has the ability to improve the dysfunction of pancreatic β-cells. This study aimed to confirm the potential protective effects of RHSL in streptozotocin (STZ)-induced diabetic mice. Diabetes was induced in male C57BL/6J mice by intraperitoneal administration of STZ (200 mg/kg BW). RHSL, food-grade silica liquid (FDSL), and rosiglitazone (RSG) were administered to diabetic mice for 12 weeks after successful induction of diabetes. During the experiment, fasting blood glucose, serum insulin, and organ weights were measured. The histopathology of liver tissue was evaluated by H&E staining. Western blotting was performed to assess protein expression levels. The results showed that RHSL significantly reversed the serum insulin levels and improved oral glucose tolerance test (OGTT) results (p < 0.05). In addition, liver sections of STZ-induced diabetic mice after RHSL treatment showed neatly arranged and intact hepatocytes. Furthermore, RHSL was more effective than FDSL in increasing the expression of SIRT1 and decreasing the expression of the PPAR-γ and p-NF-κB proteins. Taken together, this study demonstrated that RHSL ameliorated STZ-induced insulin resistance and liver tissue damage in C57BL/6J mice.

Barium Oxide Doped Magnesium Silicate Nanopowders for Bone Fracture Healing: Preparation, Characterization, Antibacterial and In Vivo Animal Studies

Magnesium silicate (MgS) nanopowders doped with barium oxide (BaO) were prepared by sol-gel technique, which were then implanted into a fracture of a tibia bone in rats for studying enhanced in vivo bone regeneration. The produced nanopowders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope with energy-dispersive X-ray spectrometry (SEM-EDX) and transmission electron microscope (TEM). Mechanical and bactericidal properties of the nanopowders were also determined. Increased crystallinity, particle diameter and surface area were found to decrease after the BaO doping without any notable alterations on their chemical integrities. Moreover, elevated mechanical and antibacterial characteristics were recognized for higher BaO doping concentrations. Our animal studies demonstrated that impressive new bone tissues were formed in the fractures while the prepared samples degraded, indicating that the osteogenesis and degradability of the BaO containing MgS samples were better than the control MgS. The results of the animal study indicated that the simultaneous bone formation on magnesium biomaterial silicate and barium MgS with completed bone healing after five weeks of implantations. The findings also demonstrated that the prepared samples with good biocompatibility and degradability could enhance vascularization and osteogenesis, and they have therapeutic potential to heal bone fractures.

Nutrition, Physical Activity, and Dietary Supplementation to Prevent Bone Mineral Density Loss: A Food Pyramid

Bone is a nutritionally modulated tissue. Given this background, aim of this review is to evaluate the latest data regarding ideal dietary approach in order to reduce bone mineral density loss and to construct a food pyramid that allows osteopenia/osteoporosis patients to easily figure out what to eat. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains), together with fruits and vegetables (5 portions; orange-colored fruits and vegetables and green leafy vegetables are to be preferred), light yogurt (125 mL), skim milk (200 mL,) extra virgin olive oil (almost 20 mg/day), and calcium water (almost 1 l/day); weekly portions should include fish (4 portions), white meat (3 portions), legumes (2 portions), eggs (2 portions), cheeses (2 portions), and red or processed meats (once/week). At the top of the pyramid, there are two pennants: one green means that osteopenia/osteoporosis subjects need some personalized supplementation (if daily requirements cannot be satisfied through diet, calcium, vitamin D, boron, omega 3, and isoflavones supplementation could be an effective strategy with a great benefit/cost ratio), and one red means that there are some foods that are banned (salt, sugar, inorganic phosphate additives). Finally, three to four times per week of 30-40 min of aerobic and resistance exercises must be performed.

Nutrient alloying elements in biodegradable metals: a review

As a new generation of biomedical metallic materials, biodegradable metals have become a hot research topic in recent years because they can completely degrade in the human body, thus preventing secondary surgery, and reducing the pain and economic burden for patients. Clinical applications require biodegradable metals with adequate mechanical properties, corrosion resistance, and biocompatibility. Alloying is an important method to create biodegradable metals with required and comprehensive performances. Since nutrient elements already have important effects on various physiological functions of the human body, the alloying of nutrient elements with biodegradable metals has attracted much attention. The present review summarizes and discusses the effects of nutrient alloying elements on the mechanical properties, biodegradation behavior, and biocompatibility of biodegradable metals. Moreover, future research directions of biodegradable metals with nutrient alloying elements are suggested.

Combined effect of silicon and non-thermal plasma treatments on yield, mineral content, and nutraceutical proprieties of edible flowers of Begonia cucullata

Edible flowers are becoming popular as a nutraceutical and functional food that can contribute to human nutrition with high antioxidant molecules and mineral elements. While comparative studies between different flower species have been performed, less is known about the best agronomical practices to increase yield and nutraceutical proprieties of blooms. Silicon stimulates plant resistance against stress and promotes plant growth while non-thermal plasma (NTP) technology has been applied for the disinfection and decontamination of water, as well as for increasing plant production and quality. The application of silicon and NTP technology through nutrient solution and spraying was investigated in edible flowers given that the combination of these treatments may play a role in promoting their nutritional and nutraceutical proprieties. The treatments were applied on two varieties of Begonia cucullata Willd. (white and red flowers) to explore their effects on different flower pigmentations. Plants with red flowers showed higher nutraceutical proprieties than the white ones but yielded a lower flower number. While the NTP treatment did not improve flower yield and quality, the silicon treatment increased anthocyanins and dry weight percentage in red flowers. NTP treatment increased zinc concentration, while it decreased potassium, magnesium, and manganese, and increased silicon concentration in white flowers. The combination of silicon and NTP showed negative effects on some nutraceutical proprieties of red flowers thus highlighting that the two treatments cannot be combined in edible flower production. In conclusion, the positive effect of silicon use in edible flower production has been demonstrated while the NTP technology showed contrasting results and its use should be explored in greater depth, including a consideration of its role in biotic attack prevention and reduced chemical input.

Relative absorption of silicon from different formulations of dietary supplements: a pilot randomized, double-blind, crossover post-prandial study

The purpose of the present study was to compare the relative absorption of a new powder presentation of silicon (Si) as orthosilicic acid with maltodextrin (Orgono Powder) compared to usual Si liquid presentations as orthosilicic acid with Equisetum arvense and Rosmarinus officinalis (G5 Siliplant) and orthosilicic acid with aloe vera (G7 Aloe). All dietary supplements were administered at the same Si oral dose (21.6 mg) in a randomized, double-blind, crossover post-prandial study conducted in 5 healthy men. Urine was collected at baseline and over the 6-h post-dose period in 2 separate 3-h collections for the analysis of Si concentration, which was conducted by inductively coupled plasma optical emission spectrometry as the gold standard method. No significant differences in total urinary Si excretion were found after the intake of these 3 dietary supplements; 34.6%, 32.4% and 27.2% of the ingested Si from G7 Aloe, G5 Siliplant and Orgono Powder, respectively, was excreted in urine over the 6-h follow-up period. The 3 different oral Si formulations tested, in powder and liquid presentations, provide highly bioavailable Si and present an equivalent relative absorption in healthy humans.

Versatile role of silicon in cereals: Health benefits, uptake mechanism, and evolution

Silicon (Si) is an omnipresent and second most abundant element in the soil lithosphere after oxygen. Silicon being a beneficial element imparts several benefits to the plants and animals. In many plant species, including the cereals the uptake of Si from the soil even exceeds the uptake of essential nutrients. Cereals are the monocots which are known to accumulate a high amount of Si, and reaping maximum benefits associated with it. Cereals contribute a high amount of Si to the human diet compared to other food crops. In the present review, we have summarized distribution of the dietary Si in cereals and its role in the animal and human health. The Si derived benefits in cereals, specifically with respect to biotic and abiotic stress tolerance has been described. We have also discussed the molecular mechanism involved in the Si uptake in cereals, evolution of the Si transport mechanism and genetic variation in the Si concentration among different cultivars of the same species. Various genetic mutants deficient in the Si uptake have been developed and many QTLs governing the Si accumulation have been identified in cereals. The existing knowledge about the Si biology and available resources needs to be explored to understand and improve the Si accumulation in crop plants to achieve sustainability in agriculture.

Rice Husk Silica Liquid Protects Pancreatic β Cells from Streptozotocin-Induced Oxidative Damage

Type 2 diabetes mellitus is a complex multifactorial disease characterized by insulin resistance and dysfunction of pancreatic β-cells. Rice husk silica liquid (RHSL) is derived from rice husks and has not been explored in diabetes mellitus until now. Previous studies showed that rice husk is enriched with silica, and its silica nanoparticles are higher more biocompatible. To investigate the potential protective role of RHSL on pancreatic β cells, we utilized RIN-m5F pancreatic β cells and explored RHSL effect after streptozotocin (STZ)-stimulation. The recovery effects of RHSL were evaluated using flow cytometry, Western blotting, and immunofluorescence analysis. Results of our study showed that RHSL reversed the cell viability, insulin secretion, reactive oxygen species (ROS) production, and the change of mitochondria membrane potential (ΔΨm) in STZ-treated RIN-m5F cells. Moreover, the expression of phospho-receptor-interacting protein 3 (p-RIP3) and cleaved-poly (ADP-ribose) polymerase (PARP), phospho-mammalian target of rapamycin (p-mTOR), and sequestosome-1 (p62/SQSTM1) were significantly decreased, while the transition of light chain (LC)3-I to LC3-II was markedly increased after RHSL treatment in STZ-induced RIN-m5F cells. Interestingly, using autophagy inhibitors such as 3-methyladenine (3-MA) and chloroquine (CQ) both showed an increase in cleaved-PARP protein level, indicating apoptosis induction. Taken together, this study demonstrated that RHSL induced autophagy and alleviated STZ-induced ROS-mediated apoptosis in RIN-m5F cells.

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.

Preferential uptake of antibody targeted calcium phosphosilicate nanoparticles by metastatic triple negative breast cancer cells in co-cultures of human metastatic breast cancer cells plus bone osteoblasts

Calcium phosphosilicate nanoparticles (CPSNPs) are bioresorbable nanoparticles that can be bioconjugated with targeting molecules and encapsulate active agents and deliver them to tumor cells without causing damage to adjacent healthy tissue. Data obtained in this study demonstrated that an anti-CD71 antibody on CPSNPs targets these nanoparticles and enhances their internalization by triple negative breast cancer cells in-vitro. Caspase 3,7 activation, DNA damage, and fluorescent microscopy confirmed the apoptotic breast cancer response caused by targeted anti-CD71-CPSNPs encapsulated with gemcitabine monophosphate, the active metabolite of the chemotherapeutic gemcitabine used to treat cancers including breast and ovarian. Targeted anti-CD71-CPSNPs encapsulated with the fluorophore, Rhodamine WT, were preferentially internalized by breast cancer cells in co-cultures with osteoblasts. While osteoblasts partially internalized anti-CD71-GemMP-CPSNPs, their cell growth was not affected. These results suggest that CPSNPs may be used as imaging tools and selective drug delivery systems for breast cancer that has metastasized to bone.

Low dietary silicon supplementation may not affect bone and cartilage in mature, sedentary horses

As osteoarthritis is a major cause of lameness in horses in the United States, improving collagen health prior to onset and increasing collagen turnover within affected joints could improve health- and welfare-related outcomes. Through its positive effects on bone mineral content and density and its role in increasing collagen synthesis, silicon (Si) may slow the development and progression of osteoarthritis, thereby reducing lameness. This study evaluated the hypothesis that Si supplementation would increase cartilage turnover through increased collagen degradation and formation markers, as well as bone formation markers, resulting in reduced lameness severity when compared with controls. Ten mature Standardbred geldings were assigned to either a Si-treated (SIL) or control (CON) group and group-housed on pasture for 84 d. Horses were individually fed to ensure no cross-contamination of Si other than what was present in the environment. For the duration of the study, SIL horses received a Si-collagen supplement at the rate of 0.3 g supplement/(100 kg body weight day). Serum samples were taken weekly for osteocalcin, and plasma samples were taken on days 0, 42, and 84 for plasma minerals. On days 0, 42, and 84, subjective and objective lameness exams were performed, and radiographs and synovial fluid samples were taken from reference and osteoarthritic joints. Plasma minerals were similar in both groups and were lower on day 84 than on day 0 (P < 0.05). Si supplementation, fed at the manufacturer's recommended rate, did not improve lameness or radiographs when compared with controls, and supplemented horses did not show greater collagen degradation and/or synthesis markers in synovial fluid than controls, indicating that cartilage turnover remained unaffected. However, a minimum beneficial threshold and range for Si supplementation standardized to body weight need to be established.

Adsorption of titanium dioxide nanoparticles onto zebrafish eggs affects colonizing microbiota

Teleost fish embryos are protected by two acellular membranes against particulate pollutants that are present in the water column. These membranes provide an effective barrier preventing particle uptake. In this study, we tested the hypothesis that the adsorption of antimicrobial titanium dioxide nanoparticles onto zebrafish eggs nevertheless harms the developing embryo by disturbing early microbial colonization. Zebrafish eggs were exposed during their first day of development to 2, 5 and 10 mg TiO2 L-1 (NM-105). Additionally, eggs were exposed to gold nanorods to assess the effectiveness of the eggs' membranes in preventing particle uptake, localizing these particles by way of two-photon microscopy. This confirmed that particles accumulate onto zebrafish eggs, without any detectable amounts of particles crossing the protective membranes. By way of particle-induced X-ray emission analysis, we inferred that the titanium dioxide particles could cover 25-45 % of the zebrafish egg surface, where the concentrations of sorbed titanium correlated positively with concentrations of potassium and correlated negatively with concentrations of silicon. A combination of imaging and culture-based microbial identification techniques revealed that the adsorbed particles exerted antimicrobial effects, but resulted in an overall increase of microbial abundance, without any change in heterotrophic microbial activity, as inferred based on carbon substrate utilization. This effect persisted upon hatching, since larvae from particle-exposed eggs still comprised higher microbial abundance than larvae that hatched from control eggs. Notably, pathogenic aeromonads tolerated the antimicrobial properties of the nanoparticles. Overall, our results show that the adsorption of suspended antimicrobial nanoparticles on aquatic eggs can have cascading effects across different life stages of oviparous animals. Our study furthermore suggests that aggregation dynamics may occur that could facilitate the dispersal of pathogenic bacteria through aquatic ecosystems.

Effect of Silicon Supplementation in Diets with Different Calcium Levels on Balance of Calcium, Silicon and Magnesium, and Bone Status in Growing Female Rats

Silicon (Si) is important for the growth and development of bone and connective tissues. This study aimed to evaluate the effect of Si supplementation on the balance of calcium (Ca), Si, magnesium (Mg), and bone status in growing female rats fed diets with different Ca levels. Sixty 6-week-old female Wistar rats were divided into 6 groups and fed diets with different levels of Ca (0.1, 0.5, 1.5%) and Si (5, 500 ppm) for 10 weeks. Experimental groups were as follows: Low-Ca group (LCa; 0.1% Ca), Low-Ca with Si supplementation group (LCaSi), adequate-Ca group (ACa; 0.5% Ca), adequate-Ca with Si supplementation group (ACaSi), high-Ca group (HCa; 1.5% Ca), and high-Ca with Si supplementation group (HCaSi). Si retention significantly increased by Si supplementation and significantly decreased by high-Ca diet (1.5%). Mg retention significantly decreased by high-Ca diet. Serum Ca and Si contents were not significantly different among the 6 groups. Low-Ca diet significantly increased serum osteoclain and C-telopeptide cross-link of type 1 collagen (CTx) levels, and Si supplementation significantly decreased CTx levels in the low-Ca diet group. Bone mineral density was significantly increased along with Ca increase in the diet, but was decreased by Si supplementation in the high-Ca diet. Rats in the adequate-Ca diet group had a significant increase in strength of tibia after Si supplementation. These findings indicate that the effect of Si supplementation on bone metabolism may differ according to the Ca-intake level in growing females. Although further research is needed, when supplementing Si to improve bone health in growing females, Ca-intake level should be considered.

Silicon supplementation affects mineral metabolism but not bone density or strength in male broilers

Because leg injuries produce welfare concerns and impact production for broilers, numerous interventions have been suggested as potential solutions. One mineral which may affect bone quality is silicon. The objective of this study was to determine if supplementing bioavailable silicon could affect bone morphology, mineralization, and strength without negatively influencing welfare and meat quality. Male broilers were raised from d 1 after hatching until 42 d of age and randomly assigned to treatment groups for silicon supplementation in water: Control (no supplement, C; n = 125), Normal (0.011 ml supplement/kg bodyweight, N; n = 125) and High (0.063 ml supplement/kg bodyweight, H; n = 125). Toe damage, footpad dermatitis, hock burn, and keel blisters were assessed on d 42. Blood samples were collected from wing veins for serum osteocalcin, pyridinoline cross-links, and mineral analysis. Clinical QCT scans and analysis were conducted immediately before four-point bending tests of tibias. Texture analysis was performed on cooked fillets. Silicon supplementation tended to increase daily water consumption in N and H as compared to C (P = 0.07). Footpad dermatitis and hock burn scores were higher in H than in N or C (P < 0.05 for both comparisons). Supplementation altered serum minerals (P < 0.001), but bone density, morphology, and strength measures were similar among groups. The highest level of supplementation in the current study on a kg bodyweight basis was above recommended intakes but below previous amounts demonstrating silicon’s positive influence on bone, indicating that previously suggested minimum thresholds need to be reevaluated. Factors such as growth rate and mechanical loading likely play a greater role in developing bone quality than trying to supplement on top of good basic nutrition alone.

Sources, Bioavailability, and Safety of Silicon Derived from Foods and Other Sources Added for Nutritional Purposes in Food Supplements and Functional Foods

Silicon is a microelement that performs a number of important functions in the human body, being involved in the formation and maintenance of normal osteocartilaginous connective tissue, such as skin, hair, and nails, and having beneficial effects in the prevention of cardiovascular and neurodegenerative diseases. Natural sources of silicon include fruits, vegetables, cereals, and mineral water. European and North American diets are generally low in silicon, which correlates with a diet high in processed foods. Dietary silicon deficiency can be overcome by the consumption of high bioavailability silicon-rich foods and the use of silicon supplements. A good form of supplementation is orthosilicic acid (OSA), usually stabilized by the introduction of a methyl group, choline, or vanillin. OSA is naturally found in diatomaceous earth in the form of amorphous silica and extracts from silicon-rich plants, e.g., horsetail (Eguiseti herba L.) and nettles (Urtica dioica L.). This article presents the characteristics of the various sources of silicon and their bioavailability and safety of use, with particular reference to the sources used in functional foods and dietary supplements. There is a great need to produce functional foods containing dietary silicon, together with other scarce mineral components.

ICP-MS Assessment of Hair Essential Trace Elements and Minerals in Russian Preschool and Primary School Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

The objective of the present study was to investigate the relationship between hair essential trace element and mineral content and ADHD in preschool (4-6 years old) and primary school children (6-10 years old) in relation to age and gender. Hair essential trace element and mineral content in 90 Russian children with ADHD and 90 age- and gender-matched neurotypical controls were assessed using inductively coupled plasma mass-spectrometry after microwave digestion. The obtained data demonstrate that hair Co, Cu, Mn, Si, and Zn contents in ADHD children was significantly reduced by 18%, 10%, 27%, 16%, and 19% as compared to the control values, respectively. The most significant decrease in children with ADHD was observed for hair Mg levels, being 29% lower than those in neurotypical children. After adjustment for age and gender, the observed difference in hair element content was more characteristic for preschool children and girls, respectively. Multiple linear regression analysis demonstrated that in a crude model (hair element levels as predictors), only hair Zn content was significantly inversely associated with ADHD (β = - 0.169; p = 0.025). Adjustment for anthropometric parameters (model 2) did not increase the predictive ability of the model, although it improved the association between hair Zn and ADHD in children (β = - 0.194; p = 0.014). Hypothetically, the observed alterations may at least partially contribute to neurobehavioral disturbances in children with ADHD. Moreover, the results of the present study raise the question about the potential benefits of Zn and Mg supplementation in children with ADHD. However, further detailed studies are required to investigate micronutrient deficiencies in ADHD.

In vitro evaluation of different organic matrices used to modulate silicon bioavailability

Silicon (Si) has numerous health properties. It is an element of the extracellular matrix; it is involved in collagen synthesis, bone mineralization, and immune system modulation; and it reduces metal accumulation in Alzheimer's disease and the risk of atherosclerosis. Given its poor intestinal absorption, Si is ingested in the form of orthosilicic acid (OSA) to promote its bioavailability. The aim of this work was to compare different commercial dietary supplements containing stabilized OSA to ascertain their bioaccessibility, bioavailability, and safety in a model of human intestinal epithelium. Biocompatibility with the glycocalyx was also investigated. Supplements containing collagen, maltodextrins, and choline as OSA stabilizers were analyzed. Bioaccessibility was explored by means of an in vitro digestive process. Bioavailability was investigated using a Caco2 cell line alone, or co-culturing with a HT29-MTX cell line. The safety of the compounds tested (in terms of intestinal epithelium integrity) was judged on the grounds of MTS assay, transepithelial electrical resistance, and apparent permeability. The three formulations were also tested in a Caco2 cell model of intestinal glycocalyx Si retention. The choline-formulated OSA formulation outperformed the maltodextrin-stabilized supplement, with a Si bioavailability about 14 times higher (P < .05). The choline-formulated OSA formulation increased cell permeability, with consequent intestinal epithelium disruption. The supplements' absorption and bioavailability (and harmfulness) differed considerably, depending on the OSA stabilizer involved. Of the three formulations tested, the collagen-formulated OSA represents the best Si dietary supplement.

Soluble silica stimulates osteogenic differentiation and gap junction communication in human dental follicle cells

Several studies have indicated that dietary silicon (Si) is beneficial for bone homeostasis and skeletal health. Furthermore, Si-containing bioactive glass biomaterials have positive effects on bone regeneration when used for repair of bone defects. Si has been demonstrated to stimulate osteoblast differentiation and bone mineralisation in vitro. However, the mechanisms underlying these effects of Si are not well understood. The aim of the present study was to investigate the effects of soluble Si on osteogenic differentiation and connexin 43 (CX43) gap junction communication in cultured pluripotent cells from human dental follicles (hDFC). Neutral Red uptake assay demonstrated that 25 μg/ml of Si significantly stimulated hDFC cell proliferation. Dosages of Si above 100 μg/ml decreased cell proliferation. Alizarin Red staining showed that osteogenic induction medium (OIM) by itself and in combination with Si (25 μg/ml) significantly increased mineralisation in hDFC cultures, although Si alone had no such effect. The expression of osteoblast-related markers in hDFC was analysed with RT-qPCR. OSX, RUNX2, BMP2, ALP, OCN, BSP and CX43 genes were expressed in hDFC cultured for 1, 7, 14 and 21 days. Expression levels of BMP-2 and BSP were significantly upregulated by OIM and Si (25 μg/ml) and were also induced by Si alone. Notably, the expression levels of OCN and CX43 on Day 21 were significantly increased only in the Si group. Flow cytometric measurements revealed that Si (50 μg/ml) significantly increased CX43 protein expression and gap junction communication in hDFC. Next-generation sequencing (NGS) and bioinformatics processing were used for the identification of differentially regulated genes and pathways. The influence of OIM over the cell differentiation profile was more prominent than the influence of Si alone. However, Si in combination with OIM increased the magnitude of expression (up or down) of the differentially regulated genes. The gene for cartilage oligomeric matrix protein (COMP) was the most significantly upregulated. Genes for the regulator of G protein signalling 4 (RGS4), regulator of G protein signalling 2 (RGS2), and matrix metalloproteinases (MMPs) 1, 8, and 10 were also strongly upregulated. Our findings reveal that soluble Si stimulates Cx43 gap junction communication in hDFC and induces gene expression patterns associated with osteogenic differentiation. Taken together, the results support the conclusion that Si is beneficial for bone health.

Silicon Forms a Rich Diversity of Aliphatic Polyol Complexes in Aqueous Solution

A detailed examination of aqueous Si complexation by alditols and aldonic acids was conducted using high-sensitivity ²⁹Si NMR spectroscopy of isotopically enriched solutions combined with theoretical modeling. Contrary to previous thinking, we have established that aliphatic polyols do not require a threo pair of hydroxy groups to form hypercoordinated Si complexes, although formation constants may be orders of magnitude higher if they are present. Thirteen distinctly different molecular assemblages containing 4-, 5-, or 6-coordinate Si centers have been identified, with significant concentrations of 5-coordinate Si bis-ligand complex being detected even under biologically relevant solution conditions.

Adult stem cell response to doped bioactive borate glass

Bioactive glasses have transformed healthcare due to their versatility. Bioactive borate glass, in particular, has shown remarkable healing properties for both hard and soft tissues. Incorporating dopants into the composition of bioactive glass helps to control mechanical properties, and it increases their usefulness for clinical applications. Using a bioactive borate glass, 13-93B3 (B3), we investigated eleven dopants on the viability and migration potential of adipose stem cells (ASCs), a therapeutic source of cells used in tissue engineering and cell therapy. Our results show that under standard cell culture conditions, only Cu-doped B3 decreased cell viability, while only Y-doped B3 attracted ASCs as it dissolved in cell culture media. Using a transwell invasion assay, priming ASCs with Co, Fe, Ga, I, Sr, or Zn-doped B3 increased their homing capacity. Because there is widespread interest in optimizing and enhancing the homing efficiency of ASCs and other therapeutic cells, we then tested if priming bone marrow mesenchymal stem cells (BMSCs) with dopants also increased their homing capacity. In the case of BMSCs, there was a significant increase in invasion when cells were primed with any of the doped-B3 glasses. This work shows that incorporating dopants into borate glasses can provide a platform for a safe and efficient method that stimulates endogenous cells and healing mechanisms.

Beer and its non-alcoholic compounds in health and disease

Moderate alcohol consumption has been associated with beneficial effects on human health. Specifically, consumption of red wine and beer has shown a J-shape relation with many important diseases. While a role of ethanol cannot be excluded, the high content of polyphenols in both beverages has been proposed to contribute to these effects, with beer having the advantage over wine that it is lower in alcohol. In addition to ethanol, beer contains a wide variety of compounds with known medicinal potential such as kaempferol, quercetin, tyrosol and phenolic acids, and it is the main dietary source for the flavones xanthohumol and 8-prenylnaringenin, and bitter acids such as humulones and lupulones. Clinical and pre-clinical evidence for the protective effects of moderate beer consumption against cardiovascular disease and other diseases has been accumulating since the 1990s, and the non-alcoholic compounds of beer likely exert most of the observed beneficial effects. In this review, we summarize and discuss the effects of beer consumption in health and disease as well as the clinical potential of its non-alcoholic compounds which may be promising candidates for new therapies against common chronic diseases.

Dietary Supplementation with Silicon-Enriched Spirulina Improves Arterial Remodeling and Function in Hypertensive Rats

Vascular aging is characterized by increase in arterial stiffness and remodeling of the arterial wall with a loss of elastic properties. Silicon is an essential trace element highly present in arteries. It is involved in the constitution and stabilization of elastin fibers. The nutritional supply and bioavailability of silicon are often inadequate. Spirulina (Sp), micro algae have recognized nutritional properties and are able to incorporate minerals in a bioavailable form. We evaluated the effects of nutritional supplementation with silicon-enriched spirulina (SpSi) on arterial system structure and function in hypertension. Experiments were performed on hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats supplemented with SpSi or Sp over a period of three months. Arterial pressure, vascular function and morphometric parameters of thoracic aorta were analyzed. SpSi supplementation lowered arterial pressure in SHR and minimized morphometric alterations induced by hypertension. Aortic wall thickness and elastic fibers fragmentation were partially reversed. Collagen and elastin levels were increased in association with extracellular matrix degradation decrease. Vascular reactivity was improved with better contractile and vasorelaxant responses to various agonists. No changes were observed in SHR supplemented with Sp. The beneficial effects of SpSi supplementation evidenced here, may be attributable to Si enrichment and offer interesting opportunities to prevent cardiovascular risks.

Silicic acid: The omniscient molecule

We contend that silicic acid is a much under-valued molecule and specifically in the context of its role in establishing and maintaining life on Earth. Silicic acid can also be an ill-understood molecule with its chemistry all too often confused with that of either silicates or silica. Herein we (i) provide a working definition for silicic acid; (ii) identify its omnipresent role in biochemical evolution in excluding aluminium from biota and providing adventitious benefits through biological silicification and (iii) explain how the silicic acid cycle is intrinsic to climate change.

Effects of biochar amendment on the soil silicon cycle in a soil-rice ecosystem

For the soil-plant ecosystem, knowledge about the effects of biochars on the soil silicon (Si) cycle is still tenuous. In this study, the effect of biochars on the yield, Si uptake and Si distribution within different tissues of rice plants and the soil Si cycles in a soil-plant system were investigated. Si-rich (RH300-700) and Si-deficient (WB300-700) biochars prepared from rice husk and wood sawdust were applied to high-Si soil (HSS) and low-Si soil (LSS). Biochar addition increased the yield of grain and straw and had no effect on the yield of root, and the increase in the yield with Si-rich biochars was obvious; this effect had a high response to LSS. Si-rich biochars increased the plant Si content of grain and root and had no effect on straw. RH300 amendment increased the Si concentration in grains, compared to RH500 and RH700. The addition of Si-deficient biochar to HSS had little effect on the Si content, while Si-deficient biochar-amended LSS had a great impact on the reduced Si content in rice straw and root, and WB700 decreased the Si concentration in grains, compared to WB300 and WB500. Finally, the Si-rich biochars increased the total Si uptake within rice, while Si-deficient biochars decreased the total Si uptake in LSS. According to the FTIR and SEM-EDX spectra of biochars before and after rice harvest, a new band of SiOSi at 471 cm^-1 was found after aged WB700, and the minerals of iron and Si were found on the surface of aged WB700; biochars can fix the dissolved Si on its surface as a temporary store to prevent Si loss. Therefore, biochars can be considered reservoirs of soil Si, which is a slow release source of available Si, to impact the speed of biogeochemical cycling of soil Si in agricultural paddy soil.

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.

Spirulina platensis and silicon-enriched spirulina equally improve glucose tolerance and decrease the enzymatic activity of hepatic NADPH oxidase in obesogenic diet-fed rats

The prevalence of metabolic syndrome components, such as obesity, glucose intolerance and hepatic steatosis, is rapidly increasing and becoming a major issue of public health. The present work was designed to determine the effects of Spirulina platensis (Sp) algae and silicon-enriched Sp on major metabolic syndrome components in obesogenic diet-fed rats. Forty male Wistar rats were divided into 4 groups. Ten rats were fed a control diet and 30 rats were fed a high fat (HF) diet. The HF groups were divided into three groups and supplemented with placebo or Sp or Si-enriched Sp for 12 weeks. Dietary intake and body weight were recorded. Oral glucose tolerance test and surrogate metabolic syndrome (insulin, leptin, adiponectin and lipids), mitochondrial function (enzymatic activity of respiratory chain complexes and β-hydroxyacyl-CoA dehydrogenase), NADPH oxidase activity and several long-established oxidative stress markers were measured in the blood and liver. The HF diet induced obesity, glucose intolerance, hepatic steatosis and huge metabolic alterations, associated with higher NADPH oxidase activity and lower hepatic sulfhydryl group and glutathione contents. Otherwise, the Sp and Sp + Si supplements showed some interesting effects on rat characteristics and particularly on blood and hepatic metabolic parameters. Indeed, the intake of Sp or Sp + Si mainly improved glucose tolerance and decreased the enzymatic activity of hepatic NADPH oxidase. Overall, Si supplementation of spirulina does not appear to have more beneficial effects than spirulina alone. Other experiments with different species of rats/mice, different diets or different durations of diet intake should be undertaken to confirm or invalidate these results.

Effects of Silicon Compounds on Biomineralization, Osteogenesis, and Hard Tissue Formation

Bioinspired stem cell-based hard tissue engineering includes numerous aspects: The synthesis and fabrication of appropriate scaffold materials, their analytical characterization, and guided osteogenesis using the sustained release of osteoinducing and/or osteoconducting drugs for mesenchymal stem cell differentiation, growth, and proliferation. Here, the effect of silicon- and silicate-containing materials on osteogenesis at the molecular level has been a particular focus within the last decade. This review summarizes recently published scientific results, including material developments and analysis, with a special focus on silicon hybrid bone composites. First, the sources, bioavailability, and functions of silicon on various tissues are discussed. The second focus is on the effects of calcium-silicate biomineralization and corresponding analytical methods in investigating osteogenesis and bone formation. Finally, recent developments in the manufacturing of Si-containing scaffolds are discussed, including in vitro and in vivo studies, as well as recently filed patents that focus on the influence of silicon on hard tissue formation.

Bioactive effects of silica nanoparticles on bone cells are size, surface, and composition dependent

Silica based nanoparticles have been demonstrated to have intrinsic biologic activity towards the skeleton and to function by promoting the differentiation of bone forming osteoblasts while inhibiting the differentiation of bone resorbing osteoclasts. The excitement surrounding nanomedicine in part revolves around the almost unlimited possibilities for varying the physicochemical properties including size, composition, and surface charge. To date few studies have attempted to manipulate these characteristics in concert to optimize a complex biologic outcome. Towards this end, spherical silica nanoparticles of various sizes (50-450 nm), of different surface properties (OH, CO₂H, NR₄+, mNH₂), and of different composition (silica, gold, and polystyrene) were synthesized and evaluated for biological activity toward skeletal cells. Osteoblast activity was most influenced by composition and size variables, whereas osteoclasts were most affected by surface property variation. The study also establishes nanoparticle mediated suppression of Nfatc1, a key transcriptional regulator for osteoclast differentiation, identifying a novel mechanism of action. Collectively, the study highlights how during the design of bioactive nanoparticles, it is vital to consider not only the myriad of physical properties that can be manipulated, but also that the characteristics of the target cell plays an equally integral role in determining biological outcome. STATEMENT OF SIGNIFICANCE: Silica nanomaterials represent a promising biomaterial for beneficial effects on bone mass and quality as well as regenerative tissue engineering and are currently being investigated for intrinsic bioactivity towards the primary cells responsible for skeletal homeostasis; osteoblasts and osteoclasts. The goal of the current study was to assess the physical properties of silica nanoparticles that impart intrinsic bioactivity by evaluating size, surface charge, and composition. Results reveal differential influences of the physical properties of nanoparticles towards osteoblasts and osteoclasts. This study provides new insights into the design of nanoparticles to specifically target different aspects of bone metabolism and highlights the opportunities provided by nanotechnology to modulate a range of cell specific biological responses for therapeutic benefit.

Metallomics: The Science of Biometals and Biometalloids

Metallomics, a discipline integrating sciences that address the biometals and biometalloids, provides new opportunities for discoveries. As part of a systems biology approach, it draws attention to the importance of many chemical elements in biochemistry. Traditionally, biochemistry has treated life as organic chemistry, separating it from inorganic chemistry, considered a field reserved for investigating the inanimate world. However, inorganic chemistry is part of the chemistry of life, and metallomics contributes by showing the importance of a neglected fifth branch of building blocks in biochemistry. Metallomics adds chemical elements/metals to the four building blocks of biomolecules and the fields of their studies: carbohydrates (glycome), lipids (lipidome), proteins (proteome), and nucleotides (genome). The realization that non-essential elements are present in organisms in addition to essential elements represents a certain paradigm shift in our thinking, as it stipulates inquiries into the functional implications of virtually all the natural elements. This article discusses opportunities arising from metallomics for a better understanding of human biology and health. It looks at a biological periodic system of the elements as a sum of metallomes and focuses on the major roles of metals in about 30-40% of all proteins, the metalloproteomes. It emphasizes the importance of zinc and iron biology and discusses why it is important to investigate non-essential metal ions, what bioinformatics approaches can contribute to understanding metalloproteins, and why metallomics has a bright future in the many dimensions it covers.

Bee Collected Pollen with Enhanced Health Benefits, Produced by Fermentation with a Kombucha Consortium

The bioavailability of pollen bioactive compounds for humans is limited. In this study, our aim was to enhance the health-related benefits of pollen by fermentation with a Kombucha/SCOBY (symbiotic culture of bacteria and yeasts) consortium. We performed the fermentation of pollen suspended from the beginning with SCOBY on sweetened green tea or on Kombucha vinegar, by adding pollen after 20 days of Kombucha fermentation. We analyzed: formation of bioactive compounds (anti-oxidant polyphenols, soluble silicon, hydroxy-acids, short chain fatty acids-SCFA); parameters related to Kombucha fermentation (dynamics of lactic acid bacteria-LAB, formation of organic acids, soluble sugar evolution on Kombucha vinegar); the influence of Kombucha fermentation on pollen morphology and ultrastructure; in vitro cytotoxic and antitumoral effects of the Kombucha fermented pollen. The pollen addition increases LAB proportion in the total number of SCOBY microbial strains. SEM images highlight the adhesion of the SCOBY bacteria to pollen. Ultrastructural analysis reveals the release of the pollen content. The content of bioactive compounds (polyphenols, soluble silicon species and SCFA) is higher in the fermented pollen and the product shows a moderate antitumoral effect on Caco-2 cells. The health benefits of pollen are enhanced by fermentation with a Kombucha consortium.

In vitro study of RRS® Silisorg CE Class III medical device composed of silanol: effect on human skin fibroblasts and its clinical use

Introduction

Silanol (organic silicon) has been used for decades in the treatment of skin photoaging as it stabilizes and maintains skin structures through hydrogen bonding electrostatic interaction with extracellular matrix (ECM) proteins or glycosaminoglycans. Organic silicon-based products are often presented as silanol derivatives which are currently associated to other structural molecules such as orthohydroxybenzoate, carboxymethyl theophylline alginate, ascorbate, acetyltyrosine, sodium lactate or mannuronate. Consequently, organic silicon formulations may differ substantially between the medical devices available on the market, which may result in additional effect on the skin. Therefore, there is a real need for a better characterization of the products in terms of their action on human skin and in vitro skin model.

Materials and methods

In this in vitro study, the effect of RRS® Silisorg was analyzed. RRS® Silisorg is a dermal implant (CE Class III medical device) containing monomethylsilanol mannuronate associated to an antioxidant resveratrol. Skin fibroblast viability and capacity to induce the production of key ECM genes were evaluated in the presence of different concentrations of RRS® Silisorg. The key ECM genes selected were collagen type I, elastin and hyaluronan synthase type 2 (HAS2), which is the cellular enzyme responsible for high-molecular weight hyaluronic acid (HA) production. Viability was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and expression was quantified by quantitative polymerase chain reaction.

Results

RRS® Silisorg increased fibroblast gene expression of HAS2 in the first 24 hours, 25 times in the presence of 1 mg/mL of solution, followed by a collagen type I gene expression (4.7 times) and elastin expression (2.5 times) increase after 48 hours.

Conclusion

These results demonstrate that the silanol-based medical device RRS® Silisorg sustains HA, collagen and elastin production in human skin fibroblasts in vitro.