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Abstract

Trace elements are a very important factor affecting functions of living organisms. Silicon, the third most abundant trace element in the human body, is present in all healthy tissues of people. It is especially strongly associated with connective tissues, as it has been found to participate in bone development, collagen formation and mineralization of bone matrix. Silicon has also been suggested to be involved in mammalian hormonal control and to protect people from heart diseases. An average dietary intake of silicon is about 20-30 mg/person/day, with higher intakes for men than women. Silicic acid or orthosilicic acid are the bioavailable forms of silicon, found mainly in food rich in fibre and whole grains, in vegetables, fruit and in drinking water. Various alcoholic beverages such as beer or wine also contain considerable amounts of silicon. Silicon provided with food is digested in the gastrointestinal tract to silicic acid, which is then absorbed. With blood, it is distributed into various tissues and organs, where it can exerts its action. The highest amounts of silicon are accumulated in the kidneys, liver, bone, skin, spleen, lungs, while free orthosilicic acid, not bounded to proteins, occurs in blood. The amount of silicon in tissues decreases with age. Depleted levels of silicon have also been observed in some pathological states e.g. atherosclerosis. The aim of the paper has been to present the role of dietary silicon in living organisms. Silicon is necessary for the growth and bone calcification and as a biological crosslinking agent of connective-tissue-based membrane structures. This element is considered to have beneficial effects on several human disorders, including osteoporosis, ageing of skin, hair and nails or atherosclerosis. It has also been suggested that silicon and silicic acid may decrease the bioavailability of aluminium by blocking the uptake of the latter by the gastrointestinal tract and impeding its reabsorption in the kidneys, thus protecting an organism against the toxic (especially neurotoxic) action of aluminium. Anticancer, antiatherosclerotic and antidiabetic effects of silicon have also been suggested. Key words: silicon, silicon metabolism, bone, connective tissue, aluminium toxicity.
489
J. Elem. s. 489–497 DOI: 10.5601/jelem.2011.16.3.13
prof. zw. dr hab. Kazimierz Pasternak, Chair and Department of Medical Chemistry, Medi-
cal University of Lublin, ChodŸki 4a, 20-093 Lublin, Poland, phone: +48 81 535 73 61,
e-mail: kazimierz.pasternak@umlub.pl
REVIEW PAPER
SILICON IN MEDICINE AND THERAPY
Anna Boguszewska-Czubara, Kazimierz Pasternak
Chair and Department of Medical Chemistry
Medical University of Lublin
Abstract
Trace elements are a very important factor affecting functions of living organisms.
Silicon, the third most abundant trace element in the human body, is present in all heal-
thy tissues of people. It is especially strongly associated with connective tissues, as it has
been found to participate in bone development, collagen formation and mineralization of bo-
ne matrix. Silicon has also been suggested to be involved in mammalian hormonal control
and to protect people from heart diseases.
An average dietary intake of silicon is about 20-30 mg/person/day, with higher intakes
for men than women. Silicic acid or orthosilicic acid are the bioavailable forms of silicon,
found mainly in food rich in fibre and whole grains, in vegetables, fruit and in drinking
water. Various alcoholic beverages such as beer or wine also contain considerable amounts
of silicon. Silicon provided with food is digested in the gastrointestinal tract to silicic acid,
which is then absorbed. With blood, it is distributed into various tissues and organs, where
it can exerts its action. The highest amounts of silicon are accumulated in the kidneys,
liver, bone, skin, spleen, lungs, while free orthosilicic acid, not bounded to proteins, occurs
in blood. The amount of silicon in tissues decreases with age. Depleted levels of silicon
have also been observed in some pathological states e.g. atherosclerosis.
The aim of the paper has been to present the role of dietary silicon in living organi-
sms. Silicon is necessary for the growth and bone calcification and as a biological cross-
linking agent of connective-tissue-based membrane structures. This element is considered
to have beneficial effects on several human disorders, including osteoporosis, ageing of
skin, hair and nails or atherosclerosis. It has also been suggested that silicon and silicic
acid may decrease the bioavailability of aluminium by blocking the uptake of the latter by
the gastrointestinal tract and impeding its reabsorption in the kidneys, thus protecting an
organism against the toxic (especially neurotoxic) action of aluminium. Anticancer, antia-
therosclerotic and antidiabetic effects of silicon have also been suggested.
Key words: silicon, silicon metabolism, bone, connective tissue, aluminium toxicity.
490
KRZEM W MEDYCYNIE I LECZNICTWIE
Abstrakt
Pierwiastki œladowe s¹ bardzo wa¿nym czynnikiem warunkuj¹cym prawid³owe funk-
cjonowanie organizmów ¿ywych. Krzem, trzeci pierwiastek œladowy pod wzglêdem rozpo-
wszechnienia w organizmie cz³owieka, jest obecny we wszystkich zdrowych tkankach.
Szczególn¹ rolê odgrywa krzem w tworzeniu i funkcjonowaniu tkanki ³¹cznej, poniewa¿
bierze on udzia³ w rozwoju koœci, tworzeniu kolagenu i mineralizacji macierzy kostnej.
Krzem uczestniczy równie¿ w kontroli hormonalnej u ssaków oraz w ochronie przed cho-
robami serca u ludzi.
Dzienna dawka krzemu dla doros³ego cz³owieka powinna wynosiæ 20-30 mg, przy czym
zapotrzebowanie na krzem jest wiêksze u mê¿czyzn ni¿ u kobiet. Przyswajaln¹ form¹ krze-
mu jest kwas krzemowy lub kwas ortokrzemowy, którego Ÿród³em w diecie s¹ zbo¿a, wa-
rzywa, owoce oraz woda pitna. Krzemiany z po¿ywienia s¹ w przewodzie pokarmowym hy-
drolizowane do ³atwo przyswajalnego kwasu ortokrzemowego, który wraz z krwi¹ jest
rozprowadzany do wszystkich tkanek i organów. Najbogatsze w krzem s¹ nerki, w¹troba,
koœci, skóra, œledziona oraz p³uca, a we krwi krzem wystêpuje w postaci wolnego kwasu
ortokrzemowego, niezwi¹zanego z bia³kami. Wszystkie tkanki zawieraj¹ du¿o krzemu, gdy
s¹ ca³kowicie zdrowe, natomiast jego poziom zmniejsza siê w nich wraz z wiekiem cz³owie-
ka i tkanki ulegaj¹ wówczas stopniowej degeneracji. Zani¿ony poziom krzemu obserwuje
siê równie¿ w pewnych stanach chorobowych, na przyk³ad w mia¿d¿ycy.
Celem pracy by³a prezentacja zale¿noœci miêdzy krzemem przyswajanym z po¿ywienia
a wp³ywem, jaki wywiera on na organizmy ¿ywe. Krzem jest niezbêdny w procesie wzro-
stu oraz wapnienia i mineralizacji koœci, jest równie¿ czynnikiem sieciuj¹cym struktury
tkanki ³¹cznej. Pierwiastek ten wywiera korzystny wp³yw w pewnych schorzeniach, takich
jak osteoporoza, starzenie siê skóry, w³osów i paznokci, mia¿d¿yca. Krzem ma unikatowe
w³aœciwoœci wi¹zania metali ciê¿kich w nierozpuszczalne kompleksy, ograniczaj¹c ich szko-
dliwe dzia³anie. Dodatkowo, kwas krzemowy hamuje wch³anianie glinu i jest antidotum na
jego toksyczne dzia³anie. Sugeruje siê równie¿ jego dzia³anie przeciwcukrzycowe, przeciw-
mia¿d¿ycowe oraz przeciwnowotworowe.
S³owa kluczowe: krzem, metabolizm krzemu, koœci, tkanka ³¹czna, toksycznoœæ glinu.
INTRODUCTION
Trace elements are a very important factor, affecting functions of living
organisms. Although silicon is the second most abundant element in bio-
sphere after oxygen, due to its very poor bioavailability to the human or-
ganism, its influence on metabolic processes is only fragmentarily known
and poorly understood (BIRCHALL et al. 1996).
The daily recommended intake (DRI) has not been determined yet, al-
though a suggested daily dose of silicon should reach 20-30 mg for an adult,
which corresponds to 0.28-0.43 mg kg–1 b.w. a day for a man weighing 70kg.
Dietary sources of silicon are grains (rice, barley, oat, wheat) and grain
products (breakfast cereals, bread, pasta), root vegetables (carrots, beetroot,
radish, onion, potatoes), bean, corn, fruit (especially bananas) as well as
dried fruit (raisins) and nuts. Silicon is highly available from drinking water
491
and its concentration depends upon the geology of water intake surround-
ings because Si is derived from weathering rocks and soil minerals (JUGDA-
OHSINGH et al. 2002, SRIPANYAKORN et al. 2005). Beer and wine are also rich
sources of dietary silicon, containing quite high amounts of orthosilicic acid,
a Si bioavailable form (THIEL et al. 2004, GONZÁLEZ-MUÑOZ et al. 2008). Drink-
ing infusions of silicon containing herbs (like Common Horsetail, Knotweed,
Red Hemp-nettle, Lungwort) can supplement dietary deficits of that element
as well as to alleviate symptoms of some diseases (ZIELECKA 1996).
Silicates from food are hydrolyzed into readily available orthosilicic acid
in the gastrointestinal tract (BAREL et al. 2005). The exact site where silicic
acid is absorbed from the gastrointestinal canal has not been established,
although it has been suggested that silicon compounds from food in the
presence of hydrochloric acid and other gastric acids in the stomach are
broken down into orthosilicic acid, which easily diffuses through mucous
membranes into the blood circulation system. In the Framingham and Fram-
ingham Offspring studies, values of an average daily silicon availability have
been determined as 12.1-13.5 mg for men and 9.9-10.2 mg for women (JUGD-
AOHSINGH et al. 2002, JUGDAOHSINGH et al. 2004). The peak increase in the
serum silicon concentration was observed 60-84 minutes after orthosilicic
acid consumption (REFFITT et al. 1999) and 100-120 minutes after ingestion of
a silicon-rich meal (13.15 mg) (JUGDAOHSINGH et al. 2002). Kidneys play a key
role in silicon turnover. Silicon is readily filtered by the renal glomerulus
because it does not form any bonds with plasma proteins (SRIPANYAKORN et al.
2005). Hence, about 70-80% of plasma silicon is eliminated by kidneys with-
in 3-8 hours after meal ingestion (POPPLEWELL et al. 1998). Thus, urinary Si
excretion is a good surrogate marker of silicon absorption (WIDNER et al.
1998, REFFITT et al. 1999). Silicon in the form of inorganic silicate occurs in
large quantities in kidneys and is a constant component of urine. Silica also
fulfils a role of protective colloid preventing appearance of urinary stones,
although silicon excess may lead to formation of renal deposits and calculus
(ZIELECKA 1996). Studies on kinetics of silicon absorption and elimination dem-
onstrated that the organs and tissues characterized by the highest concen-
trations of silicon are connective tissues, bone, skin liver, heart, muscle,
kidneys and lungs (POPPLEWELL et al. 1998, JUGDAOHSINGH 2007). The amount
of silicon in tissues decreases with age, probably because the organ respon-
sible for silicon absorption and turnover in an organism is the thymus, which
undergoes atrophy with age.
492
INFLUENCE OF SILICON ON THE DEVELOPMENT
AND FUNCTIONS OF A LIVING ORGANISM
For a long time, silicon has been thought to be an inactive substance,
not participating in biochemical processes due to its overall unavailability to
living organisms. Only recently it has been recognized as one of the most
essential trace elements in human metabolism.
The highest concentrations of silicon have been found in organs consist-
ing of connective tissues such as the aorta, trachea, bones and skin. The
content of silicon in human skin is 49.5 µg g–1 of tissue, in hair 42.0 µg g–1
of tissue and in nails 26.12 µg g–1 of tissue. A high content of silicon in the
connective tissue is attributed to its presence in protein complexes, which
form the structure of the tissue as a cross-linking entity (ZIELECKA 1996). In
animal studies, the aorta, trachea and tendons were found 4 or 5-fold richer
in silicon than the liver, heart and muscles. In blood, silicon occurs in the
form of free orthosilicic acid, not bounded with proteins, reaching a concen-
tration from 50 to 200 µg L–1, depending on its content in a diet (D’HAESE et
al. 1995). The overall silicon content in a man weighing 70 kg is from 140
to 700 mg, which classifies that element as the third most abundant mac-
roelement, after zinc and iron (SRIPANYAKORN et al. 2005). All tissues contain
large amounts of silicon when they are perfectly healthy, but its amount
decreases with age and then the tissues undergo gradual degradation. De-
pleted levels of silicon have also been observed in some pathological states
like atherosclerosis or neoplastic diseases (BISSÉ et al. 2005).
In vitro studies showed that orthosilicic acid in a physiological concen-
tration stimulates collagen synthesis and, through an increase in prolylhy-
droxylase activity in human osteoblasts, it stimulates their differentiation
(REFFITT et al. 2003, JUGDAOHSINGH et al. 2004). Much silicon has also been
found in human osteoblasts, highly metabolically active cells. In the human
organism, silicon is mainly accumulated in sites of active bone growth. Nu-
merous studies have confirmed that silicon actively participates in the proc-
ess of bone calcification and accelerates the rate of bone mineralization. Sili-
con deficiency causes deformations or delay in bones formation as well as
disorders in joint cartilage and connective tissue formation (RICO et al. 2000).
There is evidence that dietary silicon is able to lower the plasma total,
VLDL and LDL cholesterol level (WACHTER et al. 1998) and to significantly
inhibit the atherosclerotic process induced by a cholesterol rich diet (PELUSO,
SCHNEEMAN 1994). According to some authors, silicon exerts antiatherosclerot-
ic action mainly through increasing membrane permeability and the basal
substance of arteries. Studies carried out on animals proved that silicon
administered in the form of silica prevented occurrence of endoxan or strep-
tozotocin-induced diabetes (OSCHILEWSKI et al. 1986). Antineoplastic properties
of silicon, which can be associated with its influence on the connective tis-
493
sue synthesis, thereby reducing progress and propagation cancer, have been
reported. Synthetic silicon compounds, e.g. silitrans derivatives, applied to-
gether with cytostatics, improved manifold the effectiveness of the latter
(JANCZARSKI, JANCZARSKI 1991). Silicon also plays a role in immune functions
influencing lymphocytes proliferation (SEABORN et al. 2002).
Silicon has a unique property of binding heavy metals into insoluble
complexes, thereby limiting their possible harmful effects. Additionally, sil-
icic acid inhibits the gastrointestinal absorption of aluminium, a metal
of neurodegenerative action, whose role in the pathogenesis of Alzheimer’s
disease is stated to be significant. Silicon is reported to be an antidote to
aluminium toxicity as it reduces Al bioavailability (BELLIA et al. 1996, REFFITT
et al. 1999, DOMINGO 2006).
Silicon metabolism is connected with the turnover of numerous macro-
and microelements. With calcium, silicon is involved in the processes of bone
decalcification as well as calcification. Silicon is calcium-antagonist, there-
fore it can regulate calcium and magnesium turnover. It acts synergistically
with copper, thus depressing the zinc concentration in tissues. It also antag-
onises harmful effects of aluminium on osteogenesis. Additionally, silicon
influences the metabolism of such elements as P, Cl, Na, K, S, Mo, Co
(O’CONNOR et al. 2008). This element is required to remove harmful and toxic
heavy metals from the brain (BIRCHALL et al. 1996, PERRY, KEELING-TUCKER 1998,
BOGUSZEWSKA et al. 2003).
Disturbances in silicon turnover have been reported in patients suffer-
ing from different skin problems or tuberculosis and in persons treated with
antibiotics and chemotherapeutics for a long time (O¯AROWSKI 1996, CALOMME,
VANDEN BERGHE 1997).
SILICON AND BONE
In the 1980s, the earliest studies on silicon biochemistry, carried out by
Carlise, suggested strong connection between a proper level of dietary sili-
con intake and normal growth of animals (chickens and rats) (CARLISLE 1980).
Particularly collagenous tissues, like bones, cartilages, skin and hair were
markedly abnormal in Si-deprived animals. Bone health subsequently became
the main subjects for researchers studying the biological role of silicon, main-
ly because osteoporosis, characterized by low bone mass, is a growing health
problem worldwide and leads to marked disability, increased mortality and
raised health care costs (SRIPANYAKORN et al. 2005, JUGDAOHSINGH 2007).
According to recent studies, silicon is co-located with calcium in the
osteoid tissue, thus some interactions between these elements were sus-
pected to occur in processes of bone growth and mineralization (PERRY, KEEL-
ING-TUCKER 1998). In the earliest stage of calcification, in active calcification
494
sites in young bones, there is a direct relationship between silicon and calci-
um when the calcium content of the preosseous tissue is very low. There-
fore, it has been suggested that silicon is associated with calcium in the
early stage of bone formation. It was demonstrated that dietary silicon in-
creased the rate of mineralization, especially in calcium-deficient rats (KIM
et al. 2009). Evidence has been obtained to indicate that when rats are fed
low calcium diets, bone composition is affected by silicon deprivation: the
deprivation depressed concentrations of calcium, magnesium, and phospho-
rus in the tibia and skull (CARLISLE 1980). Additionally, silicon was found to
promote the union of a bone after a fracture, in contrast to calcium, which
can actually slow down the healing process or interfere with it altogether,
especially when calcium levels are very high. All these facts can be inter-
preted as promoting bone mineralization by silicon under the conditions of
a low level of calcium in a diet, but on the other hand in may also indicate
interactions between calcium and silicon in the gut lumen, which can re-
duce the gastrointestinal absorption of silicon (SRIPANYAKORN et al. 2005, JUGD-
AOHSINGH 2007).
SILICON AND SKIN, HAIR AND NAILS
Many studies on silicon influence on bone and cartilage formation con-
firmed, that the element’s primary effect is thought to be on matrix synthe-
sis rather than mineralization (CALOMME, VANDEN BERGHE 1997). Silicon in form
of orthosilicic acid at physiological concentrations was found to stimulate
collagen type 1 synthesis in human osteoblast-like cells and skin fibroblasts.
Silicon treatment also enhanced osteoblastic differentiation. The suggested
mechanism of orthosilicic acid is to modulate activity of prolyl hydroxylase,
an enzyme involved in conversion of hydroxylate proline to hydroxyproline
in the process of collagen formation, rather than alteration in collagen type
1 gene expression (REFFITT et al. 2003). Silicon was also reported to be nec-
essary in formation of glycosaminoglycans in bone and cartilage due to its
structural role in the cross-linking of glycoaminoglycans in connective tis-
sue. As type 1 collagen and its monomer hydroxyproline are major constitu-
ents of skin, the improvement in skin parameters, like hydratation or mi-
crorelief (roughness), after silicon supplementation indicates on potential
regeneration or de novo synthesis of collagen fibers. Treatment with silicon
also might improve the glycosaminoglycan structure in the dermis and the
keratin structure in hair and nails, what was seen through decrease in hair
and nails brittleness (BAREL et al. 2005).
495
SILICON AND ALUMINIUM TOXICITY
Despite the widespread occurrence of aluminium in the environment as
well as its presence in trace amounts in almost all plants and animals, for
a long time Al has been considered to be indifferent to living organisms.
However, aluminium can have deleterious effects on plants, animals as well
as on human beings. In the terrestrial environment, that is in plants, it is
responsible for the development of a stunted and brittle root system;
in animals and human it causes growth disorders and disturbed neurological
functioning (Alzheimer type senile dementia, amyotrophic lateral sclerosis,
a type of Parkinson’s disease) (DOMINGO 2006). Aluminium is even more toxic
in the aquatic environment, where it can be fatal to fish. Acute aluminium
toxicity can be associated to its ability to bind to biologically important lig-
ands, like phosphate groups in membranes, DNA and ATP. Aluminium is
also able to bind to aionic sites on fish gill epithelia, stimulating excessive
mucus production, which causes potentially lethal disturbances in respira-
tion as well as ion transport (PERRY, KEELING-TUCKER 1998). The idea that
silicon may be involved in a mechanism to protect against aluminium poi-
soning, inspired by Si-Al interactions observed in inorganic chemistry, has
been checked in numerous experiments. The most recent research shows
that silicic acid interacts with metal ions that are basic at physiological pH,
such as aluminium. Silicon is involved in relieving Al toxicity in many dif-
ferent biological systems as well as in reducing aluminium bioavailability in
humans by reducing its gastrointestinal absorption and enhancing its renal
excretion (BIRCHALL et al. 1996, REFFITT et al. 1999). Orthosilicic acid from
beer was found to increase the urinary output of aluminium, perhaps by
interacting with filterable Al in renal tubules, forming hydroxyaluminosili-
cates and thus preventing re-absorption of aluminium (BELLIA et al. 1996).
These findings may benefit transplant patients in clearing the accumulated
aluminium as well as other patients, protecting them from harmful effects
of aluminium excess.
The role of silicon in human biology is poorly understood, although the
above findings and studies may suggest beneficial influence of silicon on the
human organism in some diseases, like osteoporosis, atherosclerosis,
progress of diabetes, propagation of neoplastic process as well as occurrence
of heart diseases (TURNER et al. 2008). Silicon was also found to reduce nega-
tive effects of some processes as skin, hair and nails ageing (JUGDAOHSINGH et
al. 2002). It is very important for regenerating tissues, activating vital proc-
esses of cells and improving the general immunity of organism. Therefore,
further studies on silicon biology, biochemistry as well as silicon homeosta-
sis and its interactions with essential mineral elements as well as with oth-
er biologically important molecules are necessary.
496
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... The University of Memphis (2018) reported that the mineral (silica) can support the immune response and also help to control body inflammation, thereby keeping the heart in good working conditions [12]. Also another studies carried out on some animals have proved that silicon ingested in form of silica helps to prevent the occurrence of streptozotocininduced diabetes [13]. ...
... This significant risk is associated to eating the seeds raw. Besides, GN is also known to contain anti nutrients factors such as phytic acid, tryps in inhibitor, tannin, saponin, which inhibit absorption of some nutrients in diet [13][14][15]. However, we have seen the nutritional, biological and therapeutic effects of silica; it's depletion level in our body system via kidney and skin flushing needs to be replenished by eating the right meal that contain relative amount of silica. ...
... However, we have seen the nutritional, biological and therapeutic effects of silica; it's depletion level in our body system via kidney and skin flushing needs to be replenished by eating the right meal that contain relative amount of silica. Though many literatures had reported food sources that contain silica [3,13,[16][17][18], but published literatures on comparing the amount of silica in edible food is rare. Hence the purpose of this paper has been aimed at comparative analysis of dietary silica in Vigna subterranean and Arachis hypogea, respectively. ...
... The specific mechanism is not yet well understood but is likely related to collagen synthesis and stabilization in bone matrix. Silicone's importance in bone regeneration and maintaining proper bone mineral density has also been underlined by scientists [1]. ...
... Consequently, in countries such as China or India, where a plant-based diet is prevalent, silicone intake is much higher than in the West. Interestingly, it has been shown that the incidence of hip fracture is lower in countries where silicone intake is higher [1]. Besides its role in connective tissue formation, stabilization, and bone formation [4], silicone's role in the processes of immune or inflammatory response and influence on cognitive functions and copper and magnesium absorption have been described [4]. ...
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This article introduces an algorithm for detecting glucose and silicon levels in solution. The research focuses on addressing the critical need for accurate and efficient glucose monitoring, particularly in the context of diabetic management. Understanding and monitoring silicon levels in the body is crucial due to its significant role in various physiological processes. Silicon, while often overshadowed by other minerals, plays a vital role in bone health, collagen formation, and connective tissue integrity. Moreover, recent research suggests its potential involvement in neurological health and the prevention of certain degenerative diseases. Investigating silicon levels becomes essential for a comprehensive understanding of its impact on overall health and well-being and paves the way for targeted interventions and personalized healthcare strategies. The approach presented in this paper is based on the integration of hyperspectral data and artificial intelligence techniques. The algorithm investigates the effectiveness of two distinct models utilizing SVMR and a perceptron independently. SVMR is employed to establish a robust regression model that maps input features to continuous glucose and silicon values. The study outlines the methodology, including feature selection, model training, and evaluation metrics. Experimental results demonstrate the algorithm’s effectiveness at accurately predicting glucose and silicon concentrations and showcases its potential for real-world application in continuous glucose and silicon monitoring systems.
... The silicon compound in the blood is a free orthosilicic acid, which is not bound to proteins. The concentration of this acid can range from 50 to 200 µg/L and depends on the silicon content in the diet [2,3]. In our body, the repositories of silicon are the thyroid gland, adrenal glands, pituitary gland, and lymph nodes. ...
... The green area (2) is the area of biological activity of class B, in which the corresponding biologically active glasses are osteoconductive (bind only to bone tissue). The formation of the HAp layer is observed from 24 to 96 h after integration into a body; • ...
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Calcium phosphate materials and materials based on silicon dioxide have been actively studied for more than 50 years due to their high biocompatibility and bioactivity. Hydroxyapatite and tricalcium phosphate are the most known among calcium phosphate materials, and Bioglass 45S5 is the most known material in the Na2O–CaO–SiO2–P2O5 system. Each of these materials has its application limits; however, some of them can be eliminated by obtaining composites based on calcium phosphate and bioglass. In this article, we provide an overview of the role of silicon and its compounds, including Bioglass 45S5, consider calcium phosphate materials, talk about the limits of each material, demonstrate the potential of the composites based on them, and show the other ways of obtaining composite ceramics in the Na2O–CaO–SiO2–P2O5 system.
... In humans and animals, silicon as a chemical compound helps to remove toxic substances from cells, strengthens the protective functions of tissues, and helps reduce inflammation in cells, which determines its choice as a penetrant. The ability of silicon to concentrate in certain organs is known, as well as to stimulate the growth of connective and epithelial tissue (Boguszewska-Czubara, 2011;Keith, 2013;Farooq and Dietz, 2015;Vapirov et al., 2017;Sunita et al., 2022). Boron is a conditionally essential trace element, its compounds have an anti-inflammatory effect, and normalize metabolic processes in cells and tissues (Khaliq et al., 2018;Abdelnour et al., 2018). ...
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Background: Antibiotic resistance is a global health problem related to the transmission of bacteria and genes between human and animals. The development of new drugs with antimicrobial activity research is an urgent task of modern science. Aim: The article presents data of in vitro and in vivo experiments new pharmaceutical composition based on nisin. Methods: The antimicrobial activity was studied on the mastitis pathogens. To identify microorganisms the MALDI-TOF (mass spectrometry) method was performed using. To determine sensitivity, the serial dilution method and the diffusion method were used. On laboratory animals, biochemical, hematological and histological research methods were used. Female nonlinear white laboratory rats were used, which were divided into one control group and three experimental ones. Results: “Duration” factor was statistically significant for the following indicators: hemoglobin, hematocrit, leukocytes, lymphocytes, erythrocyte sedimentation rate (ESR) and eosinophils. The “Dose” factor did not show significance for any indicator, which means that the effect was similar regardless of the dose chosen. When analyzing the biochemical indicators, significant differences were found in the “Duration” and “Dose” factors, in the direction of a decrease in the indicators of total protein, globulins, urea and an increase in the concentration of alkaline phosphatase. When conducting histological studies in the first experimental group, it was established that there were no changes in the structural and functional units of the organs. In animals of the second experimental group, the presence of reversible pathological processes of a compensatory nature was noted. More profound changes in the structure of the studied organs were recorded in the third experimental group. Conclusion: An in vitro study on cell cultures showed that the pharmacological composition has high antimicrobial activity against isolates from the mammary gland secretion of cows with mastitis. An in vivo study on laboratory animals showed that the developed composition belongs to the IV class of substances "low-hazard substances". Histological examination made it possible to select the safest dose of the pharmacological composition of no more than 500 mg / kg.
... Indeed, ortho-silicic acid is known as the primary bioavailable form of silicon (Si) within the body [14,15]. It was reported that silicate, a group of polyatomic anions composed of silicon and oxygen in tetrahedral SiO 4 4− units, undergoes decomposition into bioavailable ortho-silicic acid under acidic conditions, such as gastric juice, and is absorbed into the body in this form [14][15][16]. To date, clear information regarding the excretion fate of SiO 2 following oral intake and intracellular fates after cellular internalization remains unavailable. ...
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A food additive, silicon dioxide (SiO2) is commonly used in the food industry as an anti-caking agent. The presence of nanoparticles (NPs) in commercial food-grade SiO2 has raised concerns regarding their potential toxicity related to nano size. While recent studies have demonstrated the oral absorption and tissue distribution of food-additive SiO2 particles, limited information is available about their excretion behaviors and potential impact on macrophage activation. In this study, the excretion kinetics of two differently manufactured (fumed and precipitated) SiO2 particles were evaluated following repeated oral administration to rats for 28 d. The excretion fate of their intact particles, decomposed forms, or ionic forms was investigated in feces and urine, respectively. Monocyte uptake, Kupffer cell activation, and cytokine release were assessed after the oral administration of SiO2 particles. Additionally, their intracellular fates were determined in Raw 264.7 cells. The results revealed that the majority of SiO2 particles were not absorbed but directly excreted via feces in intact particle forms. Only a small portion of SiO2 was eliminated via urine, predominantly in the form of bioconverted silicic acid and slightly decomposed ionic forms. SiO2 particles were mainly present in particle forms inside cells, followed by ionic and silicic acid forms, indicating their slow conversion into silicic acid after cellular uptake. No effects of the manufacturing method were observed on excretion and fates. Moreover, no in vivo monocyte uptake, Kupffer cell polarization, or cytokine release were induced by orally administered SiO2 particles. These finding contribute to understanding the oral toxicokinetics of food-additive SiO2 and provide valuable insights into its potential toxicity.
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The growing number of viral infections and viral strains from year to year requires the creation of new, more effective antiviral drugs. One of the cost-effective ways to increase drug efficiency is the development of delivery systems for already known and clinically used drugs in order to overcome the challenges currently limiting their efficiency. This review presents the current status of silicon-based particles in this area. Silicon-based materials consist mainly of silicon and its compounds and can contain other inorganic oxides, i.e. are inorganic in nature. Their inorganic nature provides a number of advantages over organic materials (e.g. polymers, lipids, micelles, etc.) which are widely proposed and already used for the indicated purpose. This review provides information about the structural features of the silicon-based materials, methods of their preparation. It contains studies showing why and how the particles themselves can serve as antiviral agents or, as carriers, can help overcome the disadvantages of active drugs and increase their antiviral efficacy. The review highlights the enormous potential of silicon-based inorganic particles (pristine or modified with various inorganic and organic species) in the fight against widespread viral infections.
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Silicon dioxide, commonly referred to as silica, is present in plant cell walls and interstitial spaces, and is often found as a component of dietary fibers that have exhibited hypocholesterolemic activity in animals. The primary objective of this study was to determine the cholesterolemic effects of two different morphological forms of silicon in the diet of cholesterol-fed rats. Male Wistar rats were provided diets containing 1 g cholesterol/100 g diet, and 0.65 g Si/100 g diet as either a sodium salt (silicate group) or silicon dioxide, a synthetic silica polymer (silica group). Cellulose was used as a control (control group). The in vitro bile acid binding capacity of the SiO2 was also measured. After 44 d of diet administration, animals were deprived of food for 24 h and then killed. Plasma total, VLDL, and LDL cholesterol concentrations were 18%, 29%, and 26% lower, respectively, in the silica group than in the control group. However, liver cholesterol concentrations were not different among dietary treatments. During the initial 15 d of the study, average daily total fecal bile acids were 38% higher in the silica group than in the control group, but fecal bile acid outputs were not different for the remainder of the experiment. The silica polymer used in the feeding trial was found to adsorb 5 times more cholate than chenodeoxycholate, at pH 7.5 in vitro. In vivo, the potential for silica to enhance fecal cholic acid excretion, relative to chenodeoxycholic acid during the initial stage of the study, may have contributed to the hypocholesterolemic response to the silica diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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Although silicon is considered as an essential element, little is known about the basic effects and clinical significance of increased concentrations of the element in dialysis patients. In a multicentre study we found silicon levels in haemodialysis (HD) patients to be markedly increased. In these patients silicon concentrations were significantly higher than those noted in subjects with normal renal function as well as in patients with chronic renal failure not yet in dialysis and patients treated by continuous ambulatory peritoneal dialysis (CAPD). Moreover we noted that in both HD and CAPD patients mean silicon levels differed from one centre to another. Also, was there in the HD population a significant difference in serum silicon levels among patients from different countries. In HD patients differences in serum silicon levels were either due to the use of silicon contaminated dialysis fluids or an increased oral intake of the element mainly originating from the high silicon content of the drinking water. Silicon contamination of the dialysis fluid was found to be due to either the use of reverse osmosis membranes that insufficiently retain the element during water treatment or by the addition of concentrates containing high amounts of silicon. Using a recently developed high-performance liquid chromatographic/atomic absorption spectrophotometric (HPLC/ETAAS) hybrid technique, we found silicon in serum to be present as a low-molecular-weight non-protein-bound component, which in the presence of a low silicon dialysate is adequately removed during treatment. The clinical relevance of increased serum silicon levels is not yet known and as such deserves further investigation. In view of the controversy that exists on the element's assumed protective as well as toxic role in the development of some (aluminium-related) neurodegenerative diseases and its vital role in bone formation, monitoring of the silicon levels in serum, tap water, and dialysis fluids might become important.
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Summary Silicon (Si) is the third most abundant trace element of the human body and is especially associated with connective tissues such as in bone, skin and blood vessels. Dietary Si is predominately derived from plant-foods and, generally, is readily broken down and absorbed in the gastrointestinal tract in the form of orthosilicic acid. Cereals and cereal products (especially beer), green beans and some mineral water are examples of major dietary sources of Si. The majority of absorbed Si is then excreted in urine although some is taken up into tissues. Average Si intakes are around 25 mg/day in the Western World. In this review, dietary sources of Si, its metabolism and evidence for its biological role in bone health are presented.
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Silicon was confirmed as an essential element in experiments (1972) in which rats and chicks fed on a silicon-depleted diet showed reduced weight gains and pathological changes in the formation and structures of collagenous connective tissue and bone. The biochemical mechanisms underlying the effects of silicon deficiency have until recently been obscure, with no evidence for any organic binding of silicon.Recent studies have shown that silicic acid, Si(OH)4, the form in which silicon exists in physiology, interacts with aqueous aluminium species to form hydroxyaluminosilicates that can have low bio-availability and toxicity. It is now established that the gastro-intestinal absorption of aluminium is greatly reduced in the presence of silicic acid. More recent studies indicate that the intake of dietary silicic acid also influences the excretion of aluminium via the kidneys so that silicon appears to be profoundly involved in aluminium homeostasis. There are strong indications that silicic acid promotes copper utilization. The observed effects of silicon deficiency on collagen and osteogenesis may thus be due to low copper utilization. Whether reduced copper utilization is caused by aluminium so that it is enhanced by silicic acid via the latter's interaction with Al is uncertain. Future research should include the interactions between Si, Al and Cu.
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Silicon (Si), as silicic acid, is suggested to be the natural antidote to aluminium (Al) toxicity, and was recently shown to promote the urinary excretion of Al from body stores. The metabolism of Si in man, however, remains poorly investigated. Here we report on the pharmacokinetics and metabolism of Si in healthy volunteers following ingestion of orthosilicic acid (27-55 mg/l Si) in water. We also investigated whether orthosilicic acid promotes the urinary excretion of endogenous Al. Minimum, median uptake of Si from the ingested dose was 50.3% (range: 21.9-74.7%, n = 8) based on urinary analysis following dosing. Significant correlations were observed between creatinine clearance and Si levels in serum or urine (r = 0.95 and 0.99, respectively). Renal clearance of Si was 82-96 ml/min suggesting high renal filterability. These results suggest that orthosilicic acid is readily absorbed from the gastrointestinal tract of man and then readily excreted in urine. There was no significant increase in Al excretion, over 32 h, following ingestion of the orthosilicic acid dose (P = 0.5; n = 5).
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In this study a potential influence of diatomaceus earth to lower blood cholesterol was investigated. During 12 weeks we monitored serum lipid concentrations in 19 healthy individuals with a history of moderate hypercholesterinemia (9 females, 10 males, aged 35 - 67 years). Individuals administered orally 250 mg diatomaceous earth three-times daily during an 8 weeks observation period. Serum concentrations of cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides levels were measured before study entry, every second week during the period of diatomaceous earth intake and 4 weeks after stop of intake. Compared to baseline (285.8 +/- 37.5 mg/dl = 7.40 +/- 0.97 mM) diatomaceous earth intake was associated with a significant reduction of serum cholesterol at any time point, reaching a minimum on week 6 (248.1 mg/dl = 6.43 mM, -13.2% from baseline; p<0.001). Also low-density lipoprotein cholesterol (week 4: p<0.05) and triglycerides levels decreased (week 2: p<0.05, week 4: p<0.01). Four weeks after intake of diatomaceous earth was stopped, serum cholesterol, low-density lipoprotein cholesterol and triglycerides still remained low and also the increase of high-density lipoprotein cholesterol became significant (p<0.05). Diatomaceous earth, a bioproduct, is capable of reducing blood cholesterol and positively influencing lipid metabolism in humans. Placebo-controlled studies will be necessary to confirm our findings.
Article
The purpose of this study was to investigate the effect of silicon (Si) supplementation on bone mineral density (BMD) and bone metabolism parameters relative to calcium (Ca) intake levels in ovariectomized rats. A total of 72 female Wistar rats (6 weeks) were ovariectomized (OVX) and divided into six groups, and Si (500 mg of Si per kilogram of feed) was or was not administered with diets containing various levels of Ca (0.1%, 0.5%, and 1.5%) for 10 weeks. The groups were as follows: (1) Ca-deficient group (0.1% Ca), (2) Ca-deficient with Si supplementation group, (3) adequate Ca group (0.5% Ca), (4) adequate Ca with Si supplementation group, (5) high Ca group (1.5% Ca), and (6) high Ca with Si supplementation group. Si supplementation significantly increased the BMD of the femur and tibia in Ca-deficient OVX rats, while no change was observed with Si supplementation in the BMD of the spine, femur, and tibia in the adequate and high Ca groups. Serum alkaline phosphatase and osteocalcin levels were not affected by Si supplementation or Ca intake levels. C-telopeptide type I collagen levels were significantly decreased as a result of Si supplementation in Ca-deficient OVX rats. In summary, Si supplementation produced positive effects on bone mineral density in Ca-deficient OVX rats by reducing bone resorption. Therefore, Si supplementation may also prove to be helpful in preventing osteoporosis in postmenopausal women whose calcium intake is insufficient.
Article
Multiple injections of low doses of streptozotocin induce an experimental diabetes in mice. We have analyzed in two inbred strains whether the development of hyperglycaemia can be influenced by administration of macrophage-toxic silica particles or by a monoclonal antibody to Thy-1.2. Mice received streptozotocin (30 or 40 mg/kg) on five consecutive days (day 0-day 4) and in addition either silica particles (starting at day 0) or anti-Thy-1.2 (starting at day -2 or -3). In both strains mice receiving streptozotocin alone became hyperglycaemic within two weeks. Additional treatment with silica almost fully prevented diabetes development. Anti-Thy-1.2 administration was similarly effective in C57B1/Ks and partially protective in C57BL/6 mice. Histological analysis of pancreatic islets showed that a large fraction of beta cells had been spared from destruction by this treatment. The data indicate a role for both macrophages and Thy-1 positive cells in the pathogenesis of low-dose streptozotocin-induced diabetes.
Article
The chemical affinity of silicic acid for aluminium (AI) has been shown to reduce the bioavailability of AI in studies of human gastrointestinal (GI) absorption. Investigations were carried out to ascertain whether or not similar interactions may also enhance the renal excretion of AI by assessing the urinary output of both elements. Healthy individuals given monosilicic acid as naturally found in beer, excreted the majority of the silicic acid content (mean 56 percent) within 8 hours, concomitant with a significant increase in AI excretion (P < 0.05). Ingestion of increasing doses of silicic acid resulted in dose related increases in excretion of Si. Excretion of AI reached a maximum and then declined, consistent with depletion of AI body stores. This was confirmed using the 26AI isotope. The low serum but high urine concentration of Si suggests that if AI and Si interact to form an excretable species they do so in the kidney lumen such that Si limits the reabsorption of AI. Silicic acid's effect on the depletion of aluminium stores and reduced GI absorption suggest its addition to municipal water supplies may be a low risk public health measure to reduce the AI burden in the general population.