RESUMO
A priority in the prevention and correction of immune disorders in athletes is the use of products with high nutrient density, fortified with various nutrients or bioactive compounds, as well as probiotic microorganisms. Probiotics help to maintain the gut microbiota, which is actively involved in the absorption of substances and energy and increases the host immune resistance. Dietary fiber, resistant to digestion in the small intestine, is fully or partially fermented in the large intestine and acts as an essential substrate for the growth and regulation of metabolic activity of normal flora, improves peristalsis and digestion. The purpose of the study was to evaluate the impact of a multi-strain probiotic in combination with dietary fiber on the immune status of basketball athletes during the training period. Material and methods. The study was conducted with the participation of 30 male basketball athletes aged 18 to 24 years. The athletes were randomly divided into 2 groups of 15 people. Athletes in the main group received 1 capsule of multi-strain probiotic (≥1.25×1010 CFU of 10 probiotic strains of bifidobacteria and lactobacilli) and 40 g of corn bran (as a source of dietary fiber) for 23 days. Athletes in the control group received 1 placebo capsule containing maltodextrin and breadcrumbs (40 g/day). Subpopulations of peripheral blood lymphocytes were studied by flow cytometry: T lymphocytes, T helper cells, T cytotoxic lymphocytes, NK cells, NKT cells, B lymphocytes, as well as lymphocytes carrying activation markers and apoptosis marker antigen. The content of cytokines in blood serum [FGF, Eotaxin, G-CSF, GM-CSF, IFN-γ, IL-1ra, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12(p70), IL-13, IL-15, IL-17A, MCP-1, MIP-1α, MIP-1ß, PDGF-BB, RANTES, TNF-α, VEGF] was determined using a multiplex immunoassay. Results. Calculation of the absolute number of lymphocytes revealed a tendency (0.05
Assuntos
Atletas , Fibras na Dieta , Probióticos , Humanos , Probióticos/farmacologia , Probióticos/administração & dosagem , Masculino , Fibras na Dieta/farmacologia , Adolescente , Adulto , Basquetebol , Adulto Jovem , Citocinas/sangueRESUMO
Nutrition in sports, as a branch of nutritional science, is a constantly developing field with a growing number of scientific researches and recommendations concerning the justification of the diet composition to ensure the requirements for macro- and micronutrients of the athlete's body at different stages of sports activity and energy value, as well as the use of special dietary supplements of various nature, including protein in forms of specialized dry mixes, drinks, etc. The aim of the research was to present the results of studies conducted abroad, presented in review publications and original articles, on the role of protein and the impact of its various levels of consumption on the maintenance of muscle mass as a criterion for the effectiveness of diets used, including in conditions of their reduced calorie content; on the safety of consuming significantly higher than recommended amounts of protein (>2.0 g/kg of body weight per day); about the relationship between protein dose and the possible increase in lean body mass. Material and methods. For the main source search, the PubMed Internet resource was used, and the websites of the Springer and Elsevier publishers were used to access the full text of the articles. Search depth 10 years. Results. This review presents the official position of the International Society of Sports Nutrition (ISSN) on the role of protein in training optimization, body composition change and improving the performance of athletes. Generalized data on the body's energy costs for the assimilation of nutrients, food thermogenesis and the importance of protein for maintaining resting energy expenditure are presented. Published results based on meta-analyses support the efficacy of higher protein intake in reducing body weight and fat mass while maintaining lean mass in an energy-deficient setting. The anabolic properties of protein under conditions of increased physical exertion will manifest themselves only with sufficient energy and protein supply. The proposed values and boundaries within which increased protein intake effectively affect body composition in the process of adaptation to strength training are given. It has been shown that an increase in protein intake above the average maximum values practically does not lead to an increase in lean body mass without the simultaneous introduction of additional resistance exercises that restores its growth. In accordance with the official position of the ISSN, the recommended protein intake corresponds to values from 1.4 to 2.0 g/kg of body weight per day for individuals performing various special sets of physical exercises. The use of high-protein diets (protein >2.0 g/kg/day) in highly qualified athletes who do not have kidney and liver diseases showed no changes in the biochemical parameters of blood and bone mineral density confirming its safety. Conclusion. Based on the analysis of scientific data, it can be stated that proteins make the main contribution to the thermogenesis of the body compared to other dietary macronutrients. The effect of protein intake on body composition, recovery and muscle building of an athlete has been proven. Athletes require higher amounts of protein to optimal increase of lean body mass under increased training loads and to maintain lean mass under an energy-deficient diet. If necessary, high-protein diets can be used in highly qualified athletes without kidney or liver diseases, but comprehensive researches in this direction should be continued.
Assuntos
Dieta , Hepatopatias , Humanos , Ingestão de Energia , Atletas , Peso Corporal , Composição CorporalRESUMO
Restoring the adaptive potential of an athlete is of paramount importance not only for the implementation of his training and competitive activities, but also for maintaining health. One of the leading place in complex recovery programs in sports is given to full-fledged optimal nutrition, which provides for meeting the body's requirements not only in energy, macro- and micronutrients, but also in minor bioactive compounds. The use of anthocyanin-containing products is a promising strategy for the normalization of metabolic and immune disorders that develop as a result of intense physical and neuro-emotional stress not only in athletes, but also in other groups of people exposed to these factors, including military personnel undergoing training in conditions close to combat. This determines the relevance of this study. The aim of the research was to study the effect of an anthocyanin-enriched diet on hematological profile and cellular immunity in rats after intense physical activity. Material and methods. The experiment was carried out for 4 weeks on 4 groups of male Wistar rats with an initial body weight of ~300 g. The motor activity of the animals of the 1st (control) and 2nd groups was limited by the standard keeping animals in the vivarium, while physically active rats of the 3rd and 4th groups received additional physical activity - training on a treadmill. Before the end of the experiment, the animals of 3rd and 4th groups were given debilitating physical activity on a treadmill (until the rats refused to continue the exercise). Rats of all 4 groups received a standard semi-synthetic diet, water ad libitum. Animals in 2nd and 4th groups were additionally fed blueberry and blackcurrant extract (30% anthocyanins) as part of the diet at a daily dose of 15 mg anthocyanins/kg body weight. Hematological parameters were determined on a Coulter ACT TM 5 diff OV hematological analyzer. Expression of CD45R, CD3, CD4, CD8a, CD161 receptors on rat peripheral blood lymphocytes was determined by direct immunofluorescent staining of whole blood cells using a panel of monoclonal antibodies conjugated with fluorescent dyes: APC, FITC, PE. The measurements were carried out on an FC-500 flow cytometer. Results. Intense physical activity in rats of the 3rd group did not lead to a significant change in erythrocyte parameters compared with the control group. Enrichment of the diet with blueberry and black currant extract (the 2nd and the 4th groups) provided a significant (p<0.05) increase in blood content of hemoglobin (Hb) (150.7±0.9 and 154.4±2.0 vs 145.4±0.9 g/l in control), hematocrit (44.95±0.21 and 46.18±0.64 vs 43.78±0.32%) and the average content of Hb in erythrocytes (18.00±0.20 and 18.03±0.24 vs 17.35±0.24 pg). The absolute content of leukocytes and other cellular elements of the leukocyte formula, as well as leukocyte indices in rats of the experimental groups didn't significantly differ from those of the control rats, which confirms the absence of an inflammatory process. Intense physical activity and anthocyanin enrichment of the diet didn't have a significant effect on rat platelet parameters. Enrichment of the diet of rats of the 4th group with blueberry and black currant extract led to the activation of cellular immunity, as evidenced by a significant (p<0.01) increase in the percentage (from the total content of T-lymphocytes) of T-helpers (70.13 ±1.34 vs 63.75±0.99%) and a decrease in the relative content of cytotoxic T-lymphocytes (28.65±1.38 vs 34.71±0.95%) in comparison with those in rats of the 3rd group and at the level of the trend (Ñ<0.1) - from the 1st group indexes (66.87±1.20 and 31.87±1.26%, accordingly). Intense physical activity led to a decrease in immunoregulatory index in rats of the 3rd group (1.86±0.07) compared with the control (2.13±0.12) (p<0.1), and in animals of the 4th group this indicator was significantly higher (2.50±0.14, p<0.05). In animals of the 3rd group a statistically significant (p<0.05) decrease in the relative content of NK cells in peripheral blood was found compared to the control. Enrichment of the diet of physically active rats with blueberry and black currant extract led to a significant (p<0.05) increase in the percentage of NK cells compared to this indicator in rats of the 3rd group (4.87±0.75 vs 2.08±0.18%) and had no significant difference with the indicator in rats of the control group (4.32±0.98%). Conclusion. The enrichment of the rats' diet with blueberry and blackcurrant extract containing a daily dose of 15 mg of anthocyanins per kg of body weight provides an increase in blood Hb content, hematocrit and the average content Hb in erythrocytes. It has been established that intense physical activity induces the cellular immunity suppression. The activating effect of anthocyanins on adaptive cellular immunity and NK cells, which are lymphocytes of innate immunity, was revealed. The data obtained indicate the effectiveness of the use of bioactive compounds (anthocyanins) to increase the adaptive potential of the organism.
Assuntos
Adaptação Fisiológica , Antocianinas , Condicionamento Físico Animal , Animais , Masculino , Ratos , Antocianinas/administração & dosagem , Eritrócitos , Leucócitos , Ratos Wistar , Imunidade Celular , Imunidade Adaptativa , DietaRESUMO
Currently, due to the increase in the distribution and accumulation of microplastics and nanoplastics (MP and NP) in the environment, their negative impact on human health has become a global problem. The purpose of this research was to analyze the results of the studies on the effect of MPs and NPs on the body and evaluate their impact as pathogenetic factors of immune status disorders in vitro and in vivo. Material and methods. The search for literary sources was carried out in the PubMed Internet resource, and the Scopus and Web of Science databases were also used. The Springer and Elsevier websites were used to access the full text of the articles. Results. MP and NP enter the human body through ingestion of food, water, as well as through inhalation and contact with the skin. The results of the studies indicate that MP and NP particles, entering the human body, can move along with the blood and accumulate in various organs: the liver, spleen, heart, lungs, thymus, reproductive organs, kidneys and brain, i.e., to overcome the blood-brain barrier. The immune system is the main regulatory and protective system of the body, playing a major role in the recognition and destruction of foreign antigens of a viral, bacterial and chemical nature. Innate immunity is the first line of defense against pathogens. Macrophages, monocytes, natural killer cells (NK cells), and leukocytes (neutrophils) phagocytize antigens and present them to adaptive immune cells. It has been established that the damaging effect of MPs and NPs on immunity (immunotoxicity) is mainly due to the presence of oxidative stress with the formation of reactive oxygen species (ROS) and damage-associated molecular patterns (DAMP). The toxicity of MPs and NPs is realized by reducing the expression of the Nrf2 factor (a redox-sensitive transcription factor that regulates antioxidant protection) and the activation of p38 mitogen-activated protein kinases. In addition, it was found that the inflammatory process after exposure to MP and NPs is mediated by the expression of pro-inflammatory cytokines: IFN-γ, TNF-α, IL-1ß, IL-6 and IL-33 and a decrease in the expression of cytokines: IL-4, IL-5, IL-10, IL-33 and TGF-ß1, which leads to activation of the signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NF-κB) and cGas/STING pathways. Conclusion. Analysis of the data of MP and NP effect on the immune system indicates the presence of aseptic chronic inflammation, which requires studying the causes and mechanisms of the development of inflammatory processes.
Assuntos
Interleucina-33 , Microplásticos , Humanos , Plásticos , Leucócitos , CitocinasRESUMO
Currently, in sports medicine, much attention is paid to the prevention and treatment of delayed muscle soreness syndrome (DOMS), which occurs several hours or days after unusual or intense physical activity, as well as the state of athlete overtraining. One of the main pathogenetic factors in the development of this syndrome is myocyte ultrastructural damage with apoptosis activation. Therefore, using natural antioxidants in sports nutrition for the relief of this pathology is of particular relevance. The aim of the study was to study the effect of an anthocyanin-enriched diet on apoptosis of gastrocnemius muscle myocytes of rats after intense exercise. Material and methods. The experiment was carried out for 4 weeks on 4 groups of male Wistar rats (12 animals in each, initial body weight ~300 g). Animals were divided into groups of rats (groups 1 and 2), whose motor activity was limited by standard conditions for keeping animals in vivarium, and groups of physically active rats (groups 3 and 4), which received additional physical activity - treadmill training. Before the end of the experiment, the animals of groups 3 and 4 were given debilitating (until the rats refused to continue the exercise) physical activity on a treadmill. Rats of all four groups received a standard semi-synthetic diet, water ad libitum. Animals in groups 2 and 4 were additionally given blueberry and blackcurrant extract (30% anthocyanins) as part of the diet at a daily dose of 15 mg anthocyanins/kg body weight. The intensity of apoptosis of gastrocnemius muscle myocytes was studied by flow cytometry. Cells were stained with fluorochrome-conjugated annexin V and vital dye 7-aminoactinomycin. The results are presented as the percentage of intact cells and cells at different stages of apoptosis per 100 000 counted objects in each sample. Results. The enrichment of the diet of control group rats with blueberry and black currant extract did not have a significant effect on the relative content of intact cells and the studied parameters of apoptosis of gastrocnemius muscle myocytes of rats of the 2nd group. Intense physical activity in rats of the 3rd group led to a statistically significant (p<0.05) decrease in the relative content of intact (live) cells compared with this indicator in rats of other groups (85.32±1.44 vs 90.87±0.66% - in the 1st group; 90.16±0.79% - in the 2nd group; 89.01±0.81% - in the 4th group, Ñ<0.05). After intense physical activity in rats of the 3rd group, activation of apoptosis of gastrocnemius muscle myocytes was found, as evidenced by an increase in the relative content of objects in apoptosis compared with other groups (11.61±1.45 vs 7.88±0.60% - in the 1st group, Ñ<0.05; 8.01±0.70% - in the 2nd group, p<0.10; 7.93±0.59% - in the 4th group Ñ<0.05). Enrichment of the diet of exercise rats with blueberry and blackcurrant extract (4th group) had a protective effect on the intensity of the apoptosis process, the studied parameters did not differ significantly from those in rats of the control and the 2nd groups. Conclusion. The results of the study indicate the activation of the process of apoptosis of gastrocnemius muscle myocytes of rats after intense physical activity. Enrichment of rats' diet with anthocyanins from blueberry and black currant extracts ensures the restoration of the studied apoptosis parameters to the level of control group rats. In the control group of rats with normal physical activity, the addition of anthocyanins to the diet does not have a significant effect on the physiological process of apoptosis of gastrocnemius muscle myocytes. In this way, an evidence base for the effectiveness of the use of biologically active substances - anthocyanins - in sports nutrition for the restoration of skeletal muscles has been obtained.
Assuntos
Antocianinas , Ribes , Animais , Anexina A5 , Antocianinas/farmacologia , Apoptose , Peso Corporal , Corantes Fluorescentes , Humanos , Masculino , Células Musculares , Músculo Esquelético , Extratos Vegetais , Ratos , Ratos Wistar , ÁguaRESUMO
The study of the relationship between hematopoiesis and metabolism is now particularly relevant in view of the high incidence of alimentary dependent diseases, including non-alcoholic fatty liver disease. In this regard, pathogenetic factors of this disease development are studied actively in order to choose adequate drug therapy and usage of bioactive substances with antioxidant properties. The aim of the study was to study the pathogenetic relationship of hematological disorders and imbalance of growth factors, leptin and ghrelin in male Wistar rats in the model of the initial stage of non-alcoholic fatty liver disease development and to assess the regulatory effect of minor bioactive substances - carnosine and α-lipoic acid. Material and methods. The studies were performed on male Wistar rats with initial body weight 150±10 g within 8 weeks. Animals were divided into 5 groups (n=8 in each). Rats of the control group received a complete modified diet AIN93M, in which soybean oil was replaced with sunflower oil and lard (1:1). Rats of the experimental groups consumed high-calorie choline-deficient diet (HCCDD), in which fat content was 45%, fructose content - 20% of the energy value of the diet. Rats of the 2nd group were fed HCCDD without any supplements, the 3rd group - with the addition of carnosine (75 mg/kg body weight), the 4th group - with the addition of α-lipoic acid (75 mg/kg body weight), the 5th group - with the combined addition of carnosine and α-lipoic acid in a total dose of 150 mg/kg body weight. Hematological values were determined on a hematological analyzer. The content of ghrelin and leptin, as well as growth factors GM-CSF and M-CSF in blood plasma and adipose tissue lysates, was determined by multiplex immunoassay using xMAP technology. Results. Rat intake of HCCDD resulted in decreased hemoglobin levels and red blood cell scores compared to controls. Diet enrichment with carnosine and α-lipoic acid did not have a reliable effect on these indicators. Carnosine intake had a protective effect on erythrocyte volume, a decrease of which was recorded in other experimental groups. HCCDD stimulated the growth of the absolute number of leukocytes in peripheral blood due to granulocytes and mononuclears. The enrichment of HCCDD with carnosine and α-lipoic acid led to a further increase in leukocytosis, the maximum level of which was observed in the group of rats fed HCCDD, simultaneously enriched with carnosine and α-lipoic acid (14.86±1.48×109/l compared to 8.67±1.23×109/l in control). All diets used in the research had no effect on the number of erythrocytes and platelets in the peripheral blood of rats. The use of both HCCDD alone and in combination with carnosine or α-lipoic acid intake had a negative effect on the level of growth factors GM-CSF and M-CSF in blood plasma and adipose tissue. The consumption of HCCDD caused an increase in leptin blood level (8.54±0.69 compared to 2.58±0.37 pg/ml in control, Ñ<0.05), which was normalized by enriching the diet with carnosine and α-lipoic acid. Ghrelin blood level significantly decreased in all experimental groups compared to the control: by 30% in rats fed and by almost 50% when carnosine and α-lipoic acid were added to HCCDD. The intake of α-lipoic acid led to hormone level changes in adipose tissue lysates, leptin content decreased (2.31±0.11 vs 2.77±0.15 pg/ml), while ghrelin level significantly increased (0.35±0.14 vs 0.20±0.06 pg/ml), compared with the control group (Ñ<0.05). Conclusion. The revealed interrelation of parameters of the cellular composition of peripheral blood and hemoglobin content with the changes in the content of GM-CSF, M-CSF, leptin and ghrelin in blood plasma and adipose tissue indicates the mutual influence of the studied CSF, leptin, ghrelin and added antioxidants (carnosine and α-lipoic acid) on the regulatory mechanisms of hematopoiesis in rats fed HCCDD.
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Carnosina , Hepatopatia Gordurosa não Alcoólica , Ácido Tióctico , Animais , Antioxidantes/farmacologia , Carnosina/farmacologia , Fígado , Masculino , Ratos , Ratos Wistar , Ácido Tióctico/farmacologiaRESUMO
The introduction of methods for food production using microbial synthesis, including those obtained with the help of genetically modified (GM) microorganisms, at the present stage, allows to increase production volumes and reduce the cost of food. At the same time, such products in accordance with TR CU 021/2011 "On food safety" are classified as a "novel food"¼ and can be placed on the market only after its risk estimation for health. The emergence of new data and research methods in the last years has made it necessary to improve the risk assessment system for this category of food. The aim of the research is to develope risk assessment approaches of food obtained by microbial synthesis on the example of the GM strain Aspergillus awamori Xyl T-15 and the enzyme preparation (EP) (a complex of glucoamylase and xylanase) produced by it. Material and methods. Outbred ICR mice (CD-1) and Wistar rats (males and females) were used in the experimental studies. Investigations of GM strain A. awamori Xyl T-15 virulence and its ability to disseminate internal organs have been carried out. Acute and subacute (during 80 days) toxicity of EP (a complex of glucoamylase and xylanase) have been studied. Results. The presented experimental data allow us to make a conclusion about the avirulence of the A. awamori Xyl T-15 strain, the lack of ability to disseminate internal organs (invasiveness). At the same time, the strain is characterized by the ability to produce mycotoxins (ochratoxin, fumonisin B2, T-2 and HT-2 toxins). The EP, a complex of glucoamylase and xylanase from A. awamori Xyl T-15, has a low oral acute toxicity for rats (LD50>5000 mg/kg). I ntragastric EP administration at doses of 10, 100 and 1000 mg/kg of body weight during 80 days had not revealed adversely affect on the rate of weight gain in animals, indicators of anxiety and cognitive function, and some studied biochemical indicators. At a dose of 100 mg/kg b.w. or more, there were changes in the relative mass of organs (lungs, kidneys, adrenal glands), small shifts in the parameters of erythropoiesis and leukocyte formula, at a dose of 1000 mg/kg b.w. - an increase in oxidative DNA destruction. T he most pronounced and dose-dependent was the effect of the EP on hepatocyte apoptosis. According to this indicator, the not observed adverse effect level (NOAEL) for EP is not more than 100 mg/kg b.w. in terms of protein. The main target organ for the toxic effect of EP is the liver. Conclusion. The data obtained demonstrate the necessity to conduct an additional analysis of the risks of possible negative effects of EP, namely, to study its impact on the gut microbiocenosis and the immune status of experimental animals, to analyze the presence of determinants of pathogenicity and antibiotic resistance, DNA of selective marker genes of A. awamori Xyl T-15 strain by PCR analysis and DNA sequencing methods.
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Glucana 1,4-alfa-Glucosidase , Animais , Aspergillus , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Ratos , Ratos Wistar , Medição de RiscoRESUMO
Non-alcoholic fatty liver disease (NAFLD) is now a common liver disease affecting about a third of the world's population. In this regard, the issue of studying the pathogenetic factors of the development of this disease in order to select adequate drug therapy and biologically active substances with antioxidant properties regulating the balance of pro- and anti-inflammatory cytokines is of particular relevance. The aim of the study was to assess the effect of minor biologically active substances - carnosine and α-lipoic acid on hepatocyte apoptosis and the cytokine profile in the experimental model of the initial stage of NAFLD. Material and methods. The studies were performed on male Wistar rats with initial body weight of 150±10 g. Animals were divided into 5 groups of 8 rats each. Within 8 weeks, rats of the 1st group (control) received a complete modified diet AIN93M, in which soybean oil was replaced with sunflower oil and lard (1:1). Rats of the experimental groups consumed high-calorie choline-deficient diet (HCCDD), in which fat content was 45%, fructose content - 20% of the energy value of the diet. Rats of the 2nd group were fed HCCDD without any supplements, the 3rd group - with the addition of carnosine (75 mg/kg body weight), the 4th group - with the addition of α-lipoic acid (75 mg/kg body weight), the 5th group - with the addition of carnosine and α-lipoic acid in a total dose of 150 mg/kg body weight. The study of rat hepatocyte apoptosis was performed by flow cytometry. Hepatocytes were stained with annexin V and vital dye 7-aminoactinomycin, followed by detection on an flow cytometer. The content of cytokines and chemokines (IL-1α, IL-10, IL-17Ð, M-CSF, MIP-1α, MIP-3α, RANTES) in the cytoplasmic fraction of liver tissue was determined by multiplex immunoassay. Results and discussion. On the model of the initial stage of development of NAFLD in male Wistar rats the еnrichment of HCCDD with carnosine and α-lipoic acid had demonstrated a protective effect on hepatocytes with a decrease in apoptosis intensity to the level in control rats. Under the influence of HCCDD, an increase in the content of M-CSF and MIP-1α and a decrease in the levels of MIP-3α and RANTES, stimulating the migration and differentiation of various immunoregulatory populations to the parenchyma at an early stage of the formation of fatty hepatosis, in the cytoplasmic fraction of liver tissue were detected. Moreover, a decrease in the level of proinflammatory cytokines IL-17A and IL-1α and an increase in IL-10 produced mainly by Treg-populations indicate the absence of pronounced inflammatory changes in the liver of male Wistar rats at the initial stages of development of fatty dystrophy. Conclusion. Enrichment of HCCDD with both carnosine and α-lipoic acid in Wistar rats had a protective effect on hepatocytes with a decrease in apoptosis to a level in control rats. The increase in the IL-10/IL-17A ratio indicates the activation of anti-inflammatory mechanisms due to the functional predominance of Treg-cells over Th1/Th17 lymphocytes.
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Apoptose/efeitos dos fármacos , Carnosina/farmacologia , Citocinas/metabolismo , Hepatócitos/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ácido Tióctico/farmacologia , Animais , Hepatócitos/patologia , Fígado/patologia , Masculino , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos , Ratos WistarRESUMO
Bentonite nanoclay (NC) manufactured from the natural sedimentary mineral bentonite contains more than 90% montmorillonite. Currently, it is widely used in food industry as processed aids - adsorbents for the purification of vegetable oils and beverages. Clay minerals have also applications as food additives and components in composite package materials. In vitro studies have shown that various forms of NC exerted cytotoxicity in many cell lines, whereas in vivo evidence of NC oral toxicity is contradictory. Therefore, this study aimed to assess the acute oral toxicity of NC and to evaluate its toxicological characteristics in a subacute 92-day experiment on Wistar rats with a daily oral administration in doses of 1, 10, and 100 mg/kg body weight (bw). Material and methods. The NC acute toxicity was evaluated in 8 male and 8 female rats with the initial bw 236±10 and 203± 10 g, respectively. NC was administered as an aqueous dispersion intragastrically at a dose of 5 g/kg bw. On the 14th day (end of the experiment), an autopsy of the chest and abdominal organs was performed. The subacute experiment was carried out on 64 male rats with an average initial bw of 117±7 g. During the experiment the levels of anxiety and memory function were evaluated using the test "Conditional reflex of passive avoidance". On the 90th day of the experiment, diurnal urinary excretion of creatinine and selenium was evaluated. At the end of the experiment, the integral parameters, the state of the intestinal wall permeability were assessed. Hematological and biochemical parameters were examined in blood, the content of non-protein thiols and the number of cells in apoptosis were determined in liver, and the state of cultivated microbiome populations was studied in cecum. Results. The results of the determination of NC acute toxicity showed the absence of rat's mortality and specific pathological changes in the internal organs at a dose as large as 5000 mg/kg bw, which allowed attributing NC to the V hazard class. Nevertheless, under the conditions of the 92-day experiment, NC caused some adverse biological effects on rat's organism. So, even at an NC dose of 1 mg/kg bw, there was a sharp inhibition of the symbiotic bifidobacterium growth, an increase in platelet count, in LDL and the LDL/HDL ratio, together with the presence of hypertriglyceridemia. At a dose of 10 mg/kg bw, an increase in spleen mass and a decrease in the de Ritis coefficient (AsAT/AlAT) were established. At a dose of 100 mg/kg bw there were shifts in the leukocyte blood count, an excessive enterococci growth in the cecum, significantly increased animal bw, along with the decrease of AsAT/AlAT and the level of serum nitrogen metabolites, indirectly indicating inhibition of catabolic processes. However, at the highest dose of NC, intestinal absorption of the protein antigen - ovalbumin, was apparently completely blocked. Conclusion. The data obtained have shown that NC has potentially adverse effects on the rats mainly at a dose of 100 mg/kg bw, nevertheless, its NOAEL in the 92-day daily oral exposure experiment is probably less than 1 mg/kg bw.
Assuntos
Bentonita/efeitos adversos , Indústria Alimentícia , Nanoestruturas/efeitos adversos , Administração Oral , Animais , Bentonita/farmacologia , Ratos , Ratos WistarRESUMO
Balanced nutrition of athletes involves the usage of both ordinary products and complexes of functional food ingredients that contribute to improving the performance of athletes, strengthening the immune system. One of the main components of specialized foods that are widely used in sports' nutrition and food supplements are branched chain aminoacids (BCAA): valine, leucine, isoleucine. The aim of the work was to study the effect of the BCAA intake on the parameters of body composition and the immune status of combat sport athletes during the training period. Material and methods. The object of the study was 20 athletes (masters of sports and candidates for masters of sports in combat sports: sambo, judo) at the age of 17-18 years. Athletes were distributed into 2 groups. Athletes of the main group (n=10) for 4 weeks in addition to the main diet were supplemented with BCAA at a dosage of 5 g per day. The athletes of the control group (n=10) received the main diet without BCAA inclusion. Examination of athletes of both groups was carried out at the beginning of the research and after 4 weeks of the observation period. The actual nutrition of athletes and daily energy consumption have been studied, body composition, the quantitative composition of subpopulations of peripheral blood lymphocytes, cytokine profile and hematological parameters have been determined. Results and discussion. As a result of a comprehensive survey of athletes, the positive effect of BCAA intake on the phase angle value (7.35±0.28 vs 6.41±0.32 at the beginning of the study, p<0.05) and muscle mass (25.1±0.8 vs 23.4±0.6 kg, p<0.10) has been demonstrated. In the control group these parameters did not change statistically significantly (7.05±0.25 vs 6.78±0.42 and 24.1±1.7 vs 23.8±1.5 kg). The athletes of the main group showed an increase in erythrocyte hemoglobin content (30.0±0.3 vs 29.0±0.2 pg, p<0.05). The relative content of basophilic leukocytes in athletes of the main group decreased by the end of the observation period - from 0.69±0.05 to 0.54±0.05% (p<0.05), that indicated an increase of immune resistance. The biomarker of the immunotropic effect of BCAA was the suppression of IL-4 production (1.6±0.1 to 1.3±0.1 pg/ml, p<0.05) synthesized by Th2 lymphocytes, with switching response to cellular immunity. Conclusion. The results of this study provide evidence of the effectiveness of BCAA usage in sports' nutrition for maintaining sport performance, immunity, and the adaptive potential of combat sport athletes.
Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Atletas , Dieta , Suplementos Nutricionais , Estado Nutricional , Resistência Física/efeitos dos fármacos , Esportes , Adolescente , Humanos , MasculinoRESUMO
Nowdays, much attention is paid to the study of disorders of immune regulation and methods of effective immune correction in athletes. In this regard, the use of specialized sport foods (SSF), containing nutrients with immunomodulatory properties, is of particular relevance in youth sports. The aim of the work is to study the immunomodulating activity of L-carnitine and coenzyme Q10 in junior athletes during the training period. Material and methods. The object of the study were 30 junior athletes (masters of sports and candidates for masters of sports in swimming) aged 14-18 years, including 9 girls and 21 boys. Athletes were divided into 3 groups of 10 people each. Athletes of the 1st and 2nd main groups received L-carnitine (600 mg per day) and coenzyme Q10 (60 mg/day), respectively, for 4 weeks in addition to the basic diet. The dosage of SSF used in the study was 200% of the adequate level of consumption and did not exceed the upper permissible level of consumption. Athletes of the 3rd group (control) received only basic diet without sports' nutrition. Examination of athletes of all groups was performed at the beginning and after 4 weeks of the observation period. Results and discussion. As a result of a comprehensive survey of junior athletes, the positive effect of L-carnitine intake on erythrocyte hemoglobin content (30.2±0.4 vs 28.3±0.3 pg at the beginning) was observed. The relative content of basophilic leukocytes in athletes of the main groups statistically significantly decreased by the end of the observation period: in the L-carnitine group, from 0.64±0.05 to 0.45±0.04%, in the coenzyme Q10 group, from 0.66±0.07 to 0.50±0.04%, which indicated an increase in the body's resistance to allergic reactions. Conclusion. The biomarkers of the immunotropic effect of L-carnitine and coenzyme Q10 are a decrease in the expression of the apoptotic marker CD95/Fas on peripheral blood lymphocytes and suppression of the production of pro-inflammatory cytokines synthesized by Th1-lymphocytes with switching the response to humoral immunity. An evidence base for the effectiveness of the use of L-carnitine and coenzyme Q10 in sports nutrition for restoring immune dysfunction and adaptive potential of junior athletes has been provided.
Assuntos
Atletas , Carnitina/administração & dosagem , Imunidade Humoral/efeitos dos fármacos , Imunomodulação/efeitos dos fármacos , Células Th1 , Ubiquinona/análogos & derivados , Receptor fas , Adolescente , Feminino , Hemoglobinas/imunologia , Hemoglobinas/metabolismo , Humanos , Contagem de Leucócitos , Masculino , Estado Nutricional , Natação , Células Th1/imunologia , Células Th1/metabolismo , Ubiquinona/administração & dosagem , Receptor fas/sangue , Receptor fas/imunologiaRESUMO
Activity of apoptosis in the thymus, liver, and kidneys on days 20, 22, 35, 50, 80, 110, and 140 of ontogeny was studied in the experiments on rats using the alkaline gel electrophoresis and flow cytofluorometry. Changes in apoptosis intensity depended on animal age. The maximum level of this parameter was observed on day 20 of ontogeny with the following reduction in this parameter to the minimum value on days 35-50. Then it gradually increased up to relatively high levels on day 110 and significantly reduced by day 140.
Assuntos
Envelhecimento/fisiologia , Apoptose/fisiologia , Células Eucarióticas/fisiologia , Rim/fisiologia , Fígado/fisiologia , Timo/fisiologia , Animais , Animais Recém-Nascidos , Peso Corporal , Células Eucarióticas/citologia , Feminino , Feto , Rim/citologia , Cinética , Fígado/citologia , Masculino , Gravidez , Ratos , Ratos Wistar , Fatores Sexuais , Maturidade Sexual/fisiologia , Timo/citologiaRESUMO
Multiwall carbon nanotubes (MWCNTs) are regarded as environmental pollutants with increased risk. Recently MWCNTs have attracted attention as a promising component of packaging materials for food products, as carriers for agricultural plant growth stimulants, agrochemicals components and advanced pesticides, which creates the possibility of their exposure through the gastrointestinal tract. Objective of the research is assessment of sub-acute oral toxicity to rats of MWСNTs in an experiment lasting 100 days. MWCNTs preparation «Taunit-M®¼ was preliminary characterized by electron microscopy and Raman light scattering. Nanomaterial was administered to animals as sonicated dispersion in water with 1% by weight of nonionic surfactant Tween 20. The experiment was performed on 80 growing male Wistar rats with initial body weight (b.w.) 86±2 g. Rats of experimental groups (from 2nd to 5th) received MWCNTs dispersion instead of drinking water, the animals of the 1st control group - a carrier solution (Tween 20). Doses of MWCNTs consumed were, respectively, in groups 1-5: 0; 0.01; 0.1; 1.0 and 10 mg/kg b.w. Hematological and biochemical indices of blood were determined together with the activity of glutathione peroxidase of erythrocytes, the content of non-protein thiols in the liver, excretion of 8-hydroxy-2'-deoxyguanosine (8-oxo-G) and content of the main and transient components of gastrointestinal microbiocenosis in the cecum contents. Apoptosis of hepatocytes was studied by flow cytometry. As a result MWCNTs led to increase of blood glucose and creatinine in rats in group 2, a significant decrease in the number of neutrophils and monocytes by increasing the number of lymphocytes, decreased platelet volume, the most pronounced also in group 2, receiving the lowest dose of MWCNTs. There were no signs of oxidative DNA damage identified. At the lowest dose MWCNTs caused a significant decrease in the number of bifidobacteria, increase - citrate-assimilating Enterobacteriaceae, hemolytic aerobic microorganisms and yeast. These changes in the microbiota should be considered as adverse, apparently leading to disturbances in the immune function.
RESUMO
Nano-sized colloidal silver (NCS) stabilized with polyvinylpyrrolidone (PVP) containing nanoparticles (NPs) of silver with a diameter of 10-80 nm was administered to growing male rats (body weight 80±10 g) during the first 30 days by intragastric gavage and then for 62 days with diet consumed in doses of 0.1, 1.0 and 10 mg/kg of body weight per day based on silver (Ag). The control animals received deionized water and PVP. The composition of microbiota from the cecum was studied using standard microbiological methods with determination of the main and transient components, together with antagonistic activity of symbiotic bifidobacteria. Expression of antigens CD45RA, CD3, CD4, CD8, CD161a on lymphocytes (Ly) of peripheral blood was determined by flow cytometry; blood serum levels of cytokines IL10, IL13, TNFα were examined by ELISA. It was shown that subacute administration of colloidal Ag in all studied doses did not lead to significant changes in the composition of the main components of normal microbiota, providing, however, the inhibitory effect on the growth of some transitory components probably including opportunistic species of microorganisms. Among the studied immunological parameters decreased amount of B-Ly was noticed at the highest dose of the NCS, while changes in the other parameters of the immune system were depended ambiguously on the dose of the product. The results were analyzed in conjunction with the data of previous publications concerning the impact on the NCS on integrated, morphological, hematological, biochemical and enzymological indexes of animals in the 92-day experiment. It was concluded that significant symptoms of NCS sub-acute oral toxicity manifested starting from a dose of 1 mg/kg body weight of Ag, and the maximum not observed adverse effect dose (NOAEL) can be estimated as 0.1 mg/kg body weight.
RESUMO
In this paper we studied the effect of aluminum oxide (Al2O3) nanoparticles (NPs) on the accumulation and biomarkers of toxic action of lead (Pb) when co-administered to rats in subacute experiment. 36 Wistar rats with initial body weight 120-140 g were divided into 4 groups. Animal of group 1 (control group) were given distilled water by gavage. Rats in group 2 received Pb acetate solution in a dose of 20 mg/kg body weight (based on Pb), animal in the 3rd and 4th groups additionally to this received suspension of Al2O3 NPs in doses of 1 and 100 mg/kg body weight, respectively. The experiment lasted 22 days. Body and organ weight, standard haematologic parameters, protein, creatinine, uric acid level, aminotransferase activity (ALT and AST) in serum, urinary 5-aminolevulinic acid (5-ALA) concentration were measured. Apoptosis of hepatocytes was studied by flow cytometry. Pb content was determined by atomic absorption spectrometry. It has been shown that the administration of Al2O3 NPs together with Pb resulted in a significant dose-dependent increase in the relative weight of the kidneys (0.88 ± 0.03% and 0.94 ± 0.06% vs. 0.74 ± 0.02% and 0.85 ± 0.01% in control and group 1). The excretion of 5-ALA in the urine of animals treated with lead acetate significantly (p < 0.001) increased compared to the animals of group 1 (0.80 ± 0.08/µmol/l); while any dependence of this parameter on the dose of Al2O3 NPs was absent (p > 0.05) (group 2: 4.54 ± 0.56 µmol/l; group 3: 7.34 ± 1.35 µmol/l; group 4: 5.71 ± 1.74 µmol/l). The hemoglobin content was significantly reduced in animals of groups 2-4 (134.0 ± 2.9; 133.6 ± 1.8 and 129.9 ± 2.9 g/l) compared to the animals of the control group (144.6 ± 1.5 g/l), the dependence of this parameter on the dose of Al2O3 NPs was also absent. A marked and significant increase of the level of glucose has been noticed on the background of the Al2O3 and NPs (7.46 ± 0.49 u 8.24 ± 0.80 vs. 6.28 ± 0.34 mmol/l in group 2), and its level went beyond physiological norms in the 4th group and ANOVA indicated the influence of Al2O3 NPs administration. The toxic effects of lead on hematological parameters of blood on the background of the Al2O3 and NPs weren't weakened, and in the case of hematocrit even enhanced, as evidenced by one-way analysis of variance (p < 0.05). When administered together with the Al2O3 Pd accumulated in increased amounts in the liver [up to 1.96 ± 0.25 (group 3) and 2.16 ± 0.23 (group 4) vs. 1.17 ± 0.19 (group 2) mg/kg] (p < 0.05). Thus, Al2O3 NPs possibly presented as a contaminant in food can enhance the bioavailability of lead and some indices of its toxic action.
Assuntos
Óxido de Alumínio/toxicidade , Artropatias , Articulações/metabolismo , Chumbo/toxicidade , Nanopartículas/efeitos adversos , Animais , Artropatias/sangue , Artropatias/induzido quimicamente , Artropatias/patologia , Articulações/patologia , Masculino , Ratos , Ratos WistarRESUMO
This paper is the third in a series of publications on the experimental study of subacute oral toxicity of nanostructured silicon dioxide (SiO2). We used commercial nanostructured SiO2, obtained by hydrolysis of tetrachlorosilane in the gaseous phase, with the size of the primary nanoparticles (NPs) of 5-30 nm. The aqueous dispersion of SiO2 after treatment with ultrasound was administered to rats with initial weight of 80 +/- 5 g for the first 30 days by intragastric gavage and further for 60 days with diets in doses of 0.1; 1.0; 10 and 100 mg/kg body weight per day. Animals of the control group were treated with deionized water. The amount of basic and transient populations of gut microbiocenosis, hematological indexes were measured using standard methods. Specific content of the B-lymphocytes (CD45RA+), total T-lymphocytes (CD3+), T-helper cells (CD4+), T-cytotoxic cells (CD8+), NK-cells (CD161a+) in general population of lymphocytes was evaluated byflow cytometry; serum cytokine levels of TNF-alpha, IL-6, IL-10 were determined by ELISA. No significant changes in the qualitative and quantitative composition of the intestinal microbiota populations regardless of the dose of administered nanomaterial have been found. This gave reason to believe that the postulated mechanism of the toxic effects of the NPs of SiO2, mediated by modification of the composition of the intestinal microflora and the corresponding changes in its functional activity, apparently, is not realized. The main target of nanostructured SiO2 was the T-cellular system of the immune system of animals, that was manifested in the significant decrease of the number of leukocytes (33%), number of T-helper cells (13%), CD4/CD8 ratio (27%) and increasing the number of cytotoxic lymphocytes (19%) and the level of TNF-alpha (590%). The value of the maximum dose (NOAEL) of nanostructured SiO2, has no effect on T-cell immunity was not more than 100 mg/kg body weight per day.
Assuntos
Antígenos CD/imunologia , Citocinas/imunologia , Imunidade Celular/efeitos dos fármacos , Linfócitos/imunologia , Nanoestruturas/efeitos adversos , Dióxido de Silício , Animais , Relação Dose-Resposta a Droga , Linfócitos/patologia , Masculino , Ratos , Ratos Wistar , Dióxido de Silício/efeitos adversos , Dióxido de Silício/farmacologiaRESUMO
This paper is the final in a series of publications on the assessment of subacute oral toxicity of nanostructured silica (SiO2). Preparation studied was a commercial nanopowder of SiO2, obtained by hydrolysis of tetrachlorosilane in the gaseous phase with the size of primary nanoparticles (NPs) of 530 nm. The experiment was conducted in 95 male Wistar rats weighing 150180 g, divided into 6 groups numbering 25 (group 1), 26 (group 2), 11 (groups 36) of animals. The aqueous dispersion of SiO2 after sonication was administered to animals of groups 2, 4 and 6 for 28 days by intragastric gavage at a dose of 100 mg/kg of body weight per day. Animals of groups 1, 3, and 5 were treated with deionized water. On the 1st, 3d, 5th and 21st day of experiment the rats of groups 1, 2, 3 and 4 were sensitized intraperitoneally with hen's egg ovalbumin (OVA) adsorbed to aluminum hydroxide. Intravenous administration of the challenge dose OVA to rats in groups 1 and 2 was carried out on the 29th day. In the same period animals of groups 36 were bled for analysis of cellular immunity. There were evaluated the severity of systemic anaphylaxis reaction, the level of specific IgG antibodies to OVA in sensitized animals, state of erythrocytes, platelets and leukocytes of peripheral blood using standard methods. Using flow cytometry there were measured contents of lymphocyte populations of B-lymphocytes (CD45RA+), total T-lymphocytes (CD3+), T-helper cells (CD4+), T-cytotoxic cells (CD8+), NKcells (CD161a+), phagocytic activity of polymorphonuclear leukocytes in respect of latex particles. Serum levels of TNFα and IL-10 cytokines were determined by ELISA. The result showed that NPs SiO2, at dose of 100 mg/kg body weight had no any marked effect on severity of active anaphylactic shock and level of specific antibodies. The changes in cellular immunity under the influence of nanomaterial had similar direction in sensitized and non-sensitized animals and were more pronounced in the latter. Based on the discussion of the results, together with data from previous publications it was concluded that oral maximum level without observable adverse effect (NOAEL) of nanostructured SiO2 is located below 100 mg/kg body weight.
Assuntos
Anafilaxia/sangue , Hipersensibilidade Alimentar/sangue , Nanopartículas/efeitos adversos , Dióxido de Silício/efeitos adversos , Anafilaxia/patologia , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Hipersensibilidade Alimentar/patologia , Imunoglobulina G/sangue , Interleucina-10/sangue , Masculino , Ratos , Ratos Wistar , Dióxido de Silício/farmacologia , Fator de Necrose Tumoral alfa/sangueRESUMO
Nano-sized colloidal silver (NCS) is currently one of the most widely used nanomaterials in medicine and consumer's products. Nanoparticles (NPs) of silver, in addition to the direct exposition through products may expose human via various environmental objects. The aim of the study is to assess the safe doses of silver NP received orally. The investigated NCS contained silver NPs with diameter of 1060 nm, predominantly with a nearly spherical form stabilized with polyvinylpyrrolidone (PVP). The experiment was performed during 92 days in 5 groups of male Wistar rats (n=15 in each group), receiving a balanced semisynthetic diet. Animal of group 1 (control) received vehicle (deionized water) intragastrically for 30 days and then with food, groups from 2nd to 4th PVP and groups from 3rd to 5th NCS, in doses respectively, 0.1; 1.0 and 10 mg/kg body weight (b.w.) in terms of silver. The dose of PVP in groups from 2nd to 5th did not differ, amounting to 200 mg/kg b.w. During the experiment, the weight gain, skin condition, activity, stool, cognitive function were assessed. At the end of the feeding period weight of internal organs, intestinal wall permeability to protein macromolecules, liver thiols, standard values of blood erythrocytes, leukocytes and platelets, hepatocyte apoptosis by flow cytometry were studied. These results suggest that in terms of weight gain, lung relative mass, average erythrocyte volume, hemoglobin content and concentration in erythrocytes, the relative proportion of lymphocytes and neutrophils adverse changes have been observed at a dose of 10 mg NPs per kg of b.w. At lower levels of exposure (0.1 and 1.0 mg/kg b.w.) some specific changes were also observed (in terms of thiols pool in liver, cognitive function, relative abundance of monocytes, the number of dead hepatocytes), which, however, did not possess an unambiguous dependence on the dose. Possible mechanisms of the toxic action of the NCS have been discussed.
Assuntos
Apoptose/efeitos dos fármacos , Hepatócitos/metabolismo , Fígado/metabolismo , Nanopartículas Metálicas/toxicidade , Povidona/análogos & derivados , Prata/toxicidade , Compostos de Sulfidrila/metabolismo , Animais , Coloides , Hepatócitos/patologia , Fígado/patologia , Masculino , Nanopartículas Metálicas/química , Povidona/química , Povidona/toxicidade , Ratos , Ratos Wistar , Prata/químicaRESUMO
Nanoparticles (NPs) are present in the composition of the objects in the environment and foods together with contaminants of conventional nature, and may enhance their toxicity in certain conditions. The aim of this work was to study the effect of nanostructured silicon dioxide (SiO2), widely used as a food additive, on the accumulation and manifestation of the toxic effect of lead (Pb) when co-administered to rats in the subacute experiment. Rats were divided into 6 groups. Animals of the 1st group (control) received distilled water intragatrically by gavage. Rats of the 2nd and 3rd groups received dispersion of SiO2 NPs with primary particle size of 5-30 nm in the doses of 1 and 100 mg/kg body weight, respectively, of Group 4--lead acetate in the dose of 20 mg of lead/kg body weight, group 5 and 6--Pb acetate and SiO2 NPs dispersion in doses, respectively 1 and 100 mg/kg body weight, for 22 days by intragastric gavage. The weight of the body and organs, standard haematological parameters, serum protein, creatinine, uric acid, albumin, glucose level, and -alkiline phosphatase, ALT and AST activity, urinary 5-aminolevulinic acid (ALA) were determined. Hepatocyte apoptosis was studied by flow-cytometry. The content of Pb, cadmium (Cd), arsenic (As), selenium (Se), iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mg), aluminum (Al) and cobalt (Co) in organs (liver, kidney, brain) was determined by ICP-MS. The result showed that the introduction of Pb, but not NPs resulted in a significant increase in the mass of the kidneys and testes. Urinary excretion of 5-ALA in animals from groups 4-6 significantly (p < 0.001) increased, compared with animals 1-3 groups, not influenced by SiO2 NPs administration (p > 0.05). Introduction of SiO2 NPs resulted in a dose-dependent increase in blood hemoglobin, the effect of lead on this index had the opposite direction. Marked changes were noticed in the levels of glucose and serum albumin in combined exposure of Pb and NPs. No additional adverse effect was noticed in Pb co-administration with NPs on haematological parameters and hepatocyte apoptosis. Pb accumulation was revealed in the liver, kidneys and brain in animals of groups 4-6, which was not enhanced by the combined effects of NPs (p > 0.05). The average biosubstrates content of Cd, As, Se, Zn, Cu, Al, Cr, Mn, Co was similar in animals treated and untreated with Pb, and demonstrated no dependence on NPs dose. The only alleged adverse impact on the trace element profile was almost twofold significant increase in the content of Al in the liver in animals treated with lead and SiO2 NPs in the highest dose (0.859 ± 0.085 mg/kg vs 0.468 ± 0.065 mg/kg in the 4th group, p < 0.05). In the absence of lead exposure, this effect was not observed. Thus, there wasn't obtained any unequivocal evidence of lead adverse effects potentiation in the case of a joint income with SiO2 NPs. Moreover, for some indicators, such as weight gain, serum AST activity, hemoglobin concentration, erythrocyte parameters, the introduction of the SiO2 NPs "abolished" to a certain extent some of the adverse effects of lead, which may be due to the effects of its enterosorption. Investigation of the influence of different types of NPs on the intestinal absorption and toxicity of various chemical contaminants should be continued.
Assuntos
Poluentes Ambientais/toxicidade , Chumbo/toxicidade , Nanopartículas/toxicidade , Dióxido de Silício/toxicidade , Administração Oral , Animais , Transporte Biológico , Suplementos Nutricionais , Sinergismo Farmacológico , Poluentes Ambientais/farmacocinética , Chumbo/farmacocinética , Masculino , Nanopartículas/química , Especificidade de Órgãos , Ratos Wistar , Dióxido de Silício/química , Dióxido de Silício/farmacocinéticaRESUMO
Nanostructured amorphous silica (SiO2) is widely used in food additives, pharmaceuticals and cosmetics. Available data on the oral toxicity of this nanomaterial (NM) in vivo, obtained in acute and subacute experiments are contradictory. The purpose of this study is evaluation of some parameters of toxicity of nanostructured SiO2 when orally administered to rats for 3 months. We used commercial SiO2 preparation, obtained by gas-phase hydrolysis of tetrachlorosilane with a size of the primary nanoparticles close to 5-30 nm, which was characterized as NM by several independent methods. SiO2 in the form of sonicated aqueous dispersion was administered to male rats with initial weight of 80 +/- 4 g for the first 30 days by intragastric gavage and then for 62 days with consumed diets in daily dose of 0,1; 1,0; 10 and 100 mg/kg body weight. The control animals received vehicle--deionized water. Weight gain, relative mass of internal organs, intestinal permeability to protein macromolecules (determination of ovalbumin level in blood serum by solid-phase bivalent immunoassay), urinary excretion of oxidative degradation product of DNA 8-oxo-2-deoxyguanosine (8-oxo-G) (by reversed phase HPLC), the level of thiol compounds in liver (spectrophotometrically), liver cell apoptosis (flow cytometer), fixing efficiency of passive avoidance (CRPA) have been measured. It has been shown that three-month administration of nanostructured SiO2 in all doses resulted in animal body weight decrease by 10-15%; a significant increase in adrenal weight was noticed under doses of 1 and 10 mg/kg and urinary 8-oxo-G excretion was significantly reduced at the dose 10 mg/kg. At the maximum dose of NM, 100 mg/kg, after 2 months of administration the number of animals decreased that entered the dark compartment of the experimental setup at initial testing of CRPA. The rest of the studied indices did not experience any significant changes depending on the dose of NM. It is concluded that no toxic effect were expressed in indices studied under the influence of nanostructured SiO2 in rats at daily doses up to 100 mg per kg body weight for 3 months.