Lemon Flavonoid Extract Eriomin Improves Pro/Antioxidant Status and Interferes with Cholesterol Metabolism without Affecting Serum Cholesterol Levels in Aged Rats.

This study aimed to assess the antioxidant capacity of lemon flavonoid extract Eriomin® (LE) and its impact on cholesterol metabolism in the context of healthy aging. We orally treated 24-month-old male Wistar rats with an LE (40 mg/kg) suspended in 0.3 mL of sunflower oil. At the same time, control groups received an equal volume of sunflower oil (CON) or remained untreated (ICON) daily for 4 weeks. We examined LE's effects on superoxide dismutase and catalase- and glutathione-related enzyme activities, the concentration of lipid peroxides and protein carbonyls, total oxidant status (TOS) and antioxidant status (TAS), and oxidative stress index (OSI) in the liver, jejunum, and ileum. We also measured total cholesterol, its biosynthetic precursors (lanosterol, lathosterol, desmosterol), its degradation products (bile acid precursors) in the serum, liver, jejunum, and ileum, and serum phytosterols (intestinal absorption markers). LE reduced TOS, TAS, and OSI (p < 0.05) compared with control values, indicating its consistent antioxidant action in all examined organs. LE lowered hepatic desmosterol (p < 0.05) while also reducing 7α- and 24-hydroxycholesterol levels in the liver and ileum (p < 0.01). Serum cholesterol, hepatic gene expression, and the immunostaining intensity of CYP7A1 were unchanged. In conclusion, LE exerted non-enzymatic antioxidant effects and reduced cholesterol degradation, reducing its biosynthesis products, thereby maintaining serum cholesterol levels.

Differences in Cholesterol Metabolism, Hepato-Intestinal Aging, and Hepatic Endocrine Milieu in Rats as Affected by the Sex and Age.

Age and sex influence serum cholesterol levels, but the underlying mechanisms remain unclear. To investigate further, we measured cholesterol, precursors (surrogate synthesis markers), degradation products (oxysterols and bile acid precursors) in serum, the liver, jejunum, and ileum, as well as serum plant sterols (intestinal absorption markers) in male and female Wistar rats (4 and 24 months old). The analysis of histomorphometric and oxidative stress parameters (superoxide dismutase, catalase, glutathione-related enzyme activities, lipid peroxide, and protein carbonyl concentrations) in the liver and jejunum offered further insights into the age- and sex-related differences. The hepatic gene expression analysis included AR, ERα, and sex-specific growth hormone-regulated (Cyp2c11 and Cyp2c12) and thyroid-responsive (Dio1, Tbg, and Spot 14) genes by qPCR. We observed age-related changes in both sexes, with greater prominence in females. Aged females had significantly higher serum cholesterol (p < 0.05), jejunum cholesterol (p < 0.05), and serum plant sterols (p < 0.05). They exhibited poorer hepato-intestinal health compared with males, which was characterized by mild liver dysfunction (hydropic degeneration, increased serum ALT, p < 0.05, and decreased activity of some antioxidant defense enzymes, p < 0.05), mononuclear inflammation in the jejunal lamina propria, and age-related decreases in jejunal catalase and glutathione peroxidase activity (p < 0.05). Aged females showed increased levels of 27-hydroxycholesterol (p < 0.05) and upregulated ERα gene expression (p < 0.05) in the liver. Our study suggests that the more significant age-related increase in serum cholesterol in females is associated with poorer hepato-intestinal health and increased jejunal cholesterol absorption. The local increase in 27-hydroxycholesterol during aging might reduce the hepatoprotective effects of endogenous estrogen in the female liver.

Age-related changes in antioxidant defenses of the Mediterranean centipede Scolopendra cingulata (Chilopoda).

The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione S-transferase (GST), as well as the concentrations of sulfhydryl (SH) groups and glutathione (GSH) were analyzed in five age classes of the Mediterranean centipede Scolopendra cingulata as follows: embryo, adolescens, maturus junior, maturus, and maturus senior. The data obtained showed the presence of SOD, CAT, GSH-Px, GR, GST, and SH groups in embryos. The transition from embryo to adolescens was accompanied by an increase in the activities of all studied enzymes, in response to the increased production of ROS due to the increased metabolic activity of the centipede associated with growth and development. Our results show that trends in antioxidant enzyme (AOE) activities were not uniform among adult age classes, suggesting that maturus junior, maturus, and maturus senior differentially respond and/or have different susceptibility to ROS. On the other hand, GSH concentration in embryos was undetectable, highest in adolescens and decreased in the latter part of life. Pearson correlation analysis in embryos showed that the activities of the AOEs were strongly and positively correlated with each other but negatively correlated with GSH and SH groups. At later age classes, SOD, CAT, GSH-Px, GR, GSH, and SH groups were no longer significantly correlated with GST. In the discriminant analysis, the variables that separated the age classes were GR, GST, SH groups, and body length. Body length was directly related to the age of individuals, clearly indicating that development/aging affects the regulation of antioxidant defense in this species.

The Effects of BSA-Stabilized Selenium Nanoparticles and Sodium Selenite Supplementation on the Structure, Oxidative Stress Parameters and Selenium Redox Biology in Rat Placenta.

The chemical element selenium (Se) is a nonmetal that is in trace amounts indispensable for normal cellular functioning. During pregnancy, a low Se status can increase the risk of oxidative stress. However, elevated concentrations of Se in the body can also cause oxidative stress. This study aimed to compare the effects of BSA-stabilized Se nanoparticles (SeNPs, Se0) (BSA-bovine serum albumin) and inorganic sodium selenite (NaSe, Se+4) supplementation on the histological structure of the placenta, oxidative stress parameters and the total placental Se concentration of Wistar rats during pregnancy. Pregnant females were randomized into four groups: (i) intact controls; (ii) controls that were dosed by daily oral gavage with 8.6% bovine serum albumin (BSA) and 0.125 M vit C; (iii) the SeNP group that was administered 0.5 mg of SeNPs stabilized with 8.6% BSA and 0.125 M vit C/kg bw/day by oral gavage dosing; (iv) the NaSe group, gavage dosed with 0.5 mg Na2SeO3/kg bw/day. The treatment of pregnant females started on gestational day one, lasted until day 20, and on day 21 of gestation, the fetuses with the placenta were removed from the uterus. Our findings show that the mode of action of equivalent concentrations of Se in SeNPs and NaSe depended on its redox state and chemical structure. Administration of SeNPs (Se0) increased fetal lethality and induced changes in the antioxidative defense parameters in the placenta. The accumulation of Se in the placenta was highest in SeNP-treated animals. All obtained data indicate an increased bioavailability of Se in its organic nano form and Se0 redox state in comparison to its inorganic sodium selenite form and Se+4 redox state.

Examination of Trace Metals and Their Potential Transplacental Transfer in Pregnancy.

With the ever-growing concern for human health and wellbeing, the prenatal period of development requires special attention since fetuses can be exposed to various metals through the mother. Therefore, this study explored the status of selected toxic (Pb, Cd, Ni, As, Pt, Ce, Rb, Sr, U) and essential trace metals (Mn, Co, Cu, Zn, Se) in the umbilical cord (UC) sera, maternal sera, and placental tissue samples of 92 healthy women with normal pregnancies. A further aim focuses on the potential transplacental transfer of these trace metals. Based on the obtained levels of investigated elements in clinical samples, it was observed that all of the trace metals cross the placental barrier and reach the fetus. Furthermore, statistical analysis revealed significant differences in levels of toxic Ni, As, Cd, U, Sr, Rb, and essential Mn, Cu, and Zn between all three types of analyzed clinical samples. Correlation analysis highlighted As to be an element with levels that differed significantly between all tested samples. Principal component analysis (PCA) was used to enhance these findings. PCA demonstrated that Cd, Mn, Zn, Rb, Ce, U, and Sr were the most influential trace metals in distinguishing placenta from maternal and UC serum samples. As, Co, and Cu were responsible for the clustering of maternal serum samples, and PCA demonstrated that the Pt level in UC sera was responsible for the clustering of these samples. Overall, the findings of this study could contribute to a better understanding of transplacental transfer of these trace metals, and shed a light on overall levels of metal exposure in the population of healthy pregnant women and their fetuses.

The Effects of a Meldonium Pre-Treatment on the Course of the Faecal-Induced Sepsis in Rats.

Sepsis is a life-threatening condition caused by the dysregulated and overwhelming response to infection, accompanied by an exaggerated pro-inflammatory state and lipid metabolism disturbance leading to sequential organ failure. Meldonium is an anti-ischemic and anti-inflammatory agent which negatively interferes with lipid metabolism by shifting energy production from fatty acid oxidation to glycolysis, as a less oxygen-demanding pathway. Thus, we investigated the effects of a four-week meldonium pre-treatment on faecal-induced sepsis in Sprague-Dawley male rats. Surprisingly, under septic conditions, meldonium increased animal mortality rate compared with the meldonium non-treated group. However, analysis of the tissue oxidative status did not provide support for the detrimental effects of meldonium, nor did the analysis of the tissue inflammatory status showing anti-inflammatory, anti-apoptotic, and anti-necrotic effects of meldonium. After performing tissue lipidomic analysis, we concluded that the potential cause of the meldonium harmful effect is to be found in the overall decreased lipid metabolism. The present study underlines the importance of uninterrupted energy production in sepsis, closely drawing attention to the possible harmful effects of lipid-mobilization impairment caused by certain therapeutics. This could lead to the much-needed revision of the existing guidelines in the clinical treatment of sepsis while paving the way for discovering new therapeutic approaches.

Differences between antioxidant defense parameters and specific trace element concentrations in healthy, benign, and malignant brain tissues.

There are only a few reports examining the impact of oxidative stress in patients with benign and malignant brain tumors. In this study we investigated whether there are changes in antioxidant system (AOS) parameters and key trace elements between control, benign and malignant brain tissues. The study also aimed to examine correlations between the analyzed parameters. The study enrolled both types of brain tumors, benign tumors (BT) and malignant tumors (MT). The results were compared with control tissue (CT) without tumor infiltration collected from patients with BT. The following antioxidant parameters were determined: activities of total, manganese-containing, and copper/zinc-containing superoxide dismutase (TotSOD, MnSOD and CuZnSOD), activities of catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and acetylcholine esterase (AChE), the concentrations of glutathione and sulfhydryl groups and of manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se). BT and MT had altered activities/levels of multiple AOS parameters as compared to CT, indicating that tumor cells had an altered cell metabolism and changes in AOS represent adaptive response to increased oxidative stress. Low MnSOD and AChE and high GST activities were significant for distinguishing between MT and CT. Malignant tissue was also characterized by lower Mn and Cu concentrations relative to CT and BT. Principal Component Analysis clearly discriminated BT from CT and MT (PC1, 66.97%), while PC2 clearly discriminated CT from BT and MT (33.03%). Most correlative relationships were associated with Se in the BT group and Cu in the MT group. The results of this study reveal differences between the AOS parameters and the essential trace elements between the analyzed groups. The observed dysregulations show that oxidative stress could have an important role in disrupting brain homeostasis and its presence in the pathogenesis of benign and malignant brain tumors.

Possible zinc deficiency in the Serbian population: examination of body fluids, whole blood and solid tissues.

Studies indicate that the soil, water and consequently foodstuffs in Serbia are significantly poor in zinc (Zn), and thus, it is likely that there is a Zn deficiency in the Serbian population. This study examined the Zn status in multiple clinical samples, including body fluids (serum, cerebrospinal fluid), whole blood and Zn-rich solid tissues (thyroid and brain tissue). Differences between sex and age were also considered, and comparative analysis of Zn status with other world populations was performed. Serum samples from a large number of Serbian adults approximately had twofold lower Zn amounts when compared to other populations. A similar trend was obtained for whole blood. Males had significantly higher amounts of Zn in serum, whole blood and thyroid tissue samples than females. Higher amounts of Zn were observed in the group older than 50 years. Importantly, in thyroid and brain tissues, Zn was 10- and 20-fold lower, respectively, than reported in the literature. Our results indicate that the population in Serbia could be considered Zn deficient. Therefore, adequate oral Zn supplementation and/or foodstuff fortification should be considered to prevent the deleterious effects caused by Zn deficiency.

The effects of meldonium on the acute ischemia/reperfusion liver injury in rats.

Acute ischemia/reperfusion (I/R) liver injury is a clinical condition challenging to treat. Meldonium is an anti-ischemic agent that shifts energy production from fatty acid oxidation to less oxygen-consuming glycolysis. Thus, we investigated the effects of a 4-week meldonium pre-treatment (300 mg/kg b.m./day) on the acute I/R liver injury in Wistar strain male rats. Our results showed that meldonium ameliorates I/R-induced liver inflammation and injury, as confirmed by liver histology, and by attenuation of serum alanine- and aspartate aminotransferase activity, serum and liver high mobility group box 1 protein expression, and liver expression of Bax/Bcl2, haptoglobin, and the phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells. Through the increased hepatic activation of the nuclear factor erythroid 2-related factor 2, meldonium improves the antioxidative defence in the liver of animals subjected to I/R, as proved by an increase in serum and liver ascorbic/dehydroascorbic acid ratio, hepatic haem oxygenase 1 expression, glutathione and free thiol groups content, and hepatic copper-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activity. Based on our results, it can be concluded that meldonium represent a protective agent against I/R-induced liver injury, with a clinical significance in surgical procedures.

Association between oxidative stress biomarkers and concentrations of some metal ions in the blood of patients with brain tumors and hydrocephalus.

INTRODUCTION: Any substance that induces production of free radicals can be a potential cause of brain damage. The aim of our study was to investigate the relationship between some metal ions and oxidative stress biomarkers in the blood of patients with brain tumor and hydrocephalus. MATERIAL AND METHODS: Our study included 27 control subjects, 24 patients with brain tumor and 21 patients with hydrocephalus. The activities of superoxide dismutase (CuZn SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione S-transferase (GST) and acetyl cholinesterase (AChE), as well as concentrations of reduced glutathione (GSH), lipid peroxides (TBARS) and sulfhydryl groups (SH) were analyzed in the plasma and red blood cells (RBCs) of patients. We also determined the concentrations of Mn, Ni, Co, Cu, Zn, As, Se, Cd, Hg and Fe. RESULTS: The higher activity of SOD and concentration of GSH in both investigated groups could indicate higher oxidative stress. We also observed decreased levels of SH groups in both groups of patients. In both groups of patients we detected decreased concentrations of Ni, Co, Zn and Fe (and Mn in brain tumor patients) and increased concentrations of As, Se and Cd in the blood. Interestingly, we observed a higher concentration of Cd in both plasma and RBCs of hydrocephalus patients compared to the patients with brain tumor. CONCLUSIONS: There are strong correlations between some metal ion concentrations and certain oxidative stress biomarkers in the blood of patients, which supports our hypothesis, but the observed trend needs to be further investigated.

Assessment of trace metal alterations in the blood, cerebrospinal fluid and tissue samples of patients with malignant brain tumors.

The pathogenesis of malignant brain tumors (MBTs) should be better understood due to the evident association between prolonged exposure to metals and increased risk of MBTs. The present research aimed to find trace metals that could contribute to the pathogenesis of MBTs. Essential trace elements (Mn, Co, Zn, Cu, Se) and relevant toxic metals (Al, Ni, As, Sr, Cd, Ce, Pt, Pb, U) in the serum, cell fraction (CF), cerebrospinal fluid (CSF) and cancerous tissue (CT) samples of MBT patients were analyzed. The results were compared with sex- and age-matched control groups. For the first time, this research showed that elemental profiles of serum, CF, CSF and CT samples in MBT patients were significantly altered compared to the appropriate controls, as well as that higher contents of trace elements (particularly Mn, Se, and Pb) could be involved in the pathogenesis of MBTs. However, the most noticeable change found was the elevated U content, indicating its considerable role as a major cerebral discriminator of the presence/absence of MBTs. The U/Se ratio could be considered as an appropriate blood marker in diagnostic MBT evaluation. The reported results could contribute to better understanding of the poorly understood pathogenesis of MBTs. Furthermore, the reported results could highlight a molecular basis for the pathophysiological changes caused by the hazardous effects of trace metals on brain homeostasis.

Reference values for trace essential elements in the whole blood and serum samples of the adult Serbian population: significance of selenium deficiency.

This study was aimed to determine reference values (RVs) for the manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se) in the whole blood (B) and serum (S) samples of the Serbian population. Blood specimens were collected from healthy persons (n = 295; women/men ratio = 149/146; mean age: 42 ± 2 years). The RVs were calculated as lower limit (LL) and upper limit (UL) of the 95% confidence interval (CI) and were expressed as percentiles (P) in the range from P2.5 to P97.5. The influences of sex, age, and smoking habits on element profiles were considered. It was found that the contents of B-Cu and S-Cu were higher in women, while the contents of B-Zn and S-Zn were higher in men. Both trace elements were significantly increased in a group of persons above 40 when compared to a younger persons (≤ 40 years). According to smoking habits, increased content was found only for S-Mn in the nonsmoker's group (p < 0.05). Comparing our results to the results reported in other population groups worldwide, the Serbian population had significantly reduced content of Se in both types of samples. This finding could highlight the deficiency of Se in the investigated Serbian population and could contribute to the better understanding of the molecular basis for the increased incidence of thyroid and other diseases in which selenium plays a key role.

The Effects of Meldonium on the Renal Acute Ischemia/Reperfusion Injury in Rats.

Acute renal ischemia/reperfusion (I/R) injury is a clinical condition that is challenging to treat. Meldonium is an anti-ischemic agent that shifts energy production from fatty acid oxidation to less oxygen-consuming glycolysis. Thus, in this study we investigated the effects of a four-week meldonium pre-treatment (300 mg/kg b.m./day) on acute renal I/R in male rats (Wistar strain). Our results showed that meldonium decreased animal body mass gain, food and water intake, and carnitine, glucose, and lactic acid kidney content. In kidneys of animals subjected to I/R, meldonium increased phosphorylation of mitogen-activated protein kinase p38 and protein kinase B, and increased the expression of nuclear factor erythroid 2-related factor 2 and haeme oxygenase 1, causing manganese superoxide dismutase expression and activity to increase, as well as lipid peroxidation, cooper-zinc superoxide dismutase, glutathione peroxidase, and glutathione reductase activities to decrease. By decreasing the kidney Bax/Bcl2 expression ratio and kidney and serum high mobility group box 1 protein content, meldonium reduced apoptotic and necrotic events in I/R, as confirmed by kidney histology. Meldonium increased adrenal noradrenaline content and serum, adrenal, hepatic, and renal ascorbic/dehydroascorbic acid ratio, which caused complex changes in renal lipidomics. Taken together, our results have confirmed that meldonium pre-treatment protects against I/R-induced oxidative stress and apoptosis/necrosis.

Evaluation of trace metals in thyroid tissues: Comparative analysis with benign and malignant thyroid diseases.

Evaluation of trace metals at level of solid tissue can provide better information than blood or urine and, therefore, could highlight the role of metals in the etiology of organ-specific disease. The current study aimed to establish the baseline content of four essential (Mn, Cu, Zn, Se) and four toxic metals (As, Cd, Pb, U) in the healthy thyroid tissues (HTTs) by considering sex, age and smoking habits. A further aim was to examine whether differences in the content of metals exist in regard to the thyroid diseases, such as benign tumor (BT), Hashimoto's thyroiditis (HT), multinodular goiter (MNG) and thyroid cancer (TC). A total number of investigated tissue samples were 423. All metals were quantified by inductively coupled plasma-mass spectrometry (ICP-MS). It was found that the content of Cu and U was higher in HTTs of women, while the content of Zn was higher in HTTs of men. Increased content of Zn and decreased content of U was found in the group of HTTs above 50 years compared to a younger group (<50 years). Increased content of Cd, Pb and U distinguish smokers from the non-smokers. In comparison with other population groups worldwide, investigated Serbian population had up to 15 times reduced content of Se. Despite the difference in metal's profile according to biological variables, this study also demonstrated, for the first time, that each thyroid disease has its unique metal's profile. The most altered metal's content was found in tissues with HT. Contrarily, the greatest similarity in metal's content with HTTs was found in BT tissues. Based on the increased content, metal's that dominantly discriminated HTTs from the HT, MNG and TC was As, Pb and Cd, respectively. Reported results could highlight the role of toxic and essential trace metals in the not very well clarified etiology of thyroid diseases and, moreover, could provide a molecular basis for pathophysiological changes of metal's hazardous effects on thyroid health at the tissue level.

Cadmium as main endocrine disruptor in papillary thyroid carcinoma and the significance of Cd/Se ratio for thyroid tissue pathophysiology.

BACKGROUND: The etiology of papillary thyroid carcinoma (PTC) is unknown and some literature data support the hypothesis that heavy metals, as endocrine disrupters, could play a major role in the pathogenesis of thyroid cancer. This study aimed to estimate the content of selected toxic and essential trace metals (Mn, Co, Ni, Cu, Zn, As, Se, Cd, Pb, Th, and U), as well as the selected ratio's (Cu/Zn and Cd/Se) in the malignant thyroid tissues according to sex, age, smoking habits, familial history of any thyroid disease, pathohistological (PH) types of PTC, tumor size, the existence of a thyroid capsular invasion, intrathyroid tumor dissemination, retrosternal thyroid growth, and TNM progress of PTC. METHODS: The study included 66 patients with PTC (women/men ratio = 46/20, mean age: 54 ± 14 years). A comparative analysis was made by collecting the healthy thyroid tissues (HTTs) of the same patients, making the total number of samples 132. All trace metals were quantified by inductively coupled plasma-mass spectrometry (ICP-MS). RESULTS: Metals that significantly separated papillary thyroid tissues (PTTs) from the HTTs were Cd, U and Se (p < 0.05). The obtained negative correlation between Cd and Se in the PTTs could explain extrusion of essential Se caused by increased content of Cd. Only Cd had an influence on the retrosternal thyroid growth, while the essential metals (Mn, Co, and Zn) had an influence on thyroid capsular invasion. CONCLUSION: It was found that Cd act as the main endocrine disrupter, which could highlight its role in the etiology of PTC. Considering that the Cd/Se ratio significantly separated two studied groups and had an influence on the retrosternal thyroid growth, its altered content could contribute to the better understanding of the molecular basis for pathophysiological changes in the PTC.

Do different diets affect oxidative stress biomarkers and metal bioaccumulation in two snake species?

In this study we examined possible differences in heavy metal accumulation and oxidative stress parameters in the liver and muscle of two semi-aquatic snakes: grass snake (Natrix natrix) and dice snake (N. tessellata), that inhabit the same environment but differ in prey diversity. The obtained results revealed some interspecies, inter-tissue, prey-snake and prey-prey differences in heavy metal concentrations. Grass snakes pray contained significantly higher concentrations of Al, Cr and Fe as compared to food of dice snakes. Both investigated snakes accumulated generally lower concentrations of metals than their prey, indicating that they are not at risk of contaminant biomagnification. A significant interspecies difference in accumulation was observed only for Cu and Mn concentrations. On the other hand, analysis of oxidative stress biomarkers showed clear differences between the investigated snake species and the two investigated tissues. The liver of grass snake had increased superoxide dismutase, glutathione reductase and glutathione-S-transferase activities in comparison to dice snake. In muscle, a reverse trend was observed for the activities of these three enzymes, as well as for glutathione peroxidase activity. The higher number of significant correlations observed between oxidative stress biomarkers and heavy metal concentrations in grass snake points to upregulation of the antioxidative system (AOS), which resulted in a lower TBARS concentration. Results show that while the investigated snake species did not differ significantly in the accumulated metals, their defense mechanisms were different. This reveals the complexity of the AOS and points to the cooperation of different AOS components in individuals from natural populations.

The content of toxic and essential elements in trabecular and cortical femoral neck: a correlation with whole blood samples.

Pollution caused by heavy metals affects all forms of life. The aim of the study was to determine the content of toxic (Sr, Ni, Pb, V, Cd, U, Rb, As) and essential (Na, K, Ca, Mg, Zn, Cu, Se, Mn, Cr, Mo, Co) metals in the bone and whole blood samples, in regard to clinical means of long- and short-term exposure, respectively. For this purpose, the cortical and trabecular parts of femoral neck, as well as the blood samples, were collected to quantify bone-important metals by inductively coupled plasma (ICP)-based techniques. According to principal component analysis (PCA), the most influential metal discriminating blood samples was Cu, while all other quantified elements were present in higher amounts in the bones. Additionally, trabecular bones (TBs) could be characterized by higher content of Mo, Cr, V, Mn, Co, As, and Ni compared to cortical bones (CBs). Linear discrimination analysis (LDA) was successfully applied to distinguish trabecular bone from the cortical bone. Significant correlation between essential Ca and toxic Sr with other elements was found and discussed. This study provides novel data on the effects of metal pollutants on bone health hazards. The results obtained for investigating metals may serve as a baseline for further clinical investigations in the orthopedic fields.

The human biomonitoring study in Serbia: Background levels for arsenic, cadmium, lead, thorium and uranium in the whole blood of adult Serbian population.

The purpose of this study was to establish reference values (RVs) for the occupationally- and environmentally-important toxic elements in the whole blood of adult Serbian population for the first time. Contaminated drinking water with arsenic, high share of smokers in the country, removing tetraethyl lead from the gasoline and war attack at the end of the twentieth century were some of the reasons to provide background information for arsenic (As), cadmium (Cd), lead (Pb), thorium (Th), and uranium (U) in the blood of the Serbian population. The whole blood samples were collected from the healthy respondents living in the Belgrade and surrounding areas of the capital (n = 305; w/m ratio = 154/151; mean age: 41 ±â€¯2). The concentrations of toxic metals were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Reference values were estimated as the lower limit (LL) and upper limit (UL) of the 95% confidence interval (CI), together with the selected percentiles (P2.5-P97.5). The obtained geometric mean (GM) for As, Cd, Pb, Th, and U were: 0.50 ng/g, 0.32 ng/g, 20.94 ng/g, 0.30 ng/g, and 0.06 ng/g, respectively. The influences of age, sex and lifestyle on results were considered. Women have significantly higher levels of Cd and Th than men. The increased level of Th was observed in the aged group below 40 years, while smokers had significantly higher levels of Pb and double higher level of Cd in the blood than non-smokers (p < 0.05). In comparison with other population groups worldwide, the Serbian population had significantly higher levels of Th and U (up to 100 times higher). These findings could contribute to better understanding of the molecular basis for the development of various health hazards, including the increased incidence of cancer among the Serbian population which need be confirmed by clinical studies.

Prooxidant effects of chronic exposure to deltamethrin in green toad Bufotes viridis.

Pesticide-induced oxidative stress, as one of mechanism of toxicity, has been a focus of toxicological research. However, there is a lack of data for certain pesticides-oxidative stress effects especially on terrestrial amphibians. This study evaluates the prooxidative effects of orally administered insecticide deltamethrin (DM) in some tissues of the terrestrial toad Bufotes viridis. Toads were randomly divided and assigned to a control group and a test group that was orally exposed to the pesticide (5 mg/kg of body weight/daily) for 21 days. Animals were euthanized from each group on days 7, 14, and 21, and the liver, leg muscle, ventral skin, and gastrointestinal tissue (GIT) were dissected and used for analysis. From battery of investigated antioxidant components, superoxide dismutase (SOD) was the most differentiate parameter in all examined tissues. For the period of prolonged exposure to pesticide, antioxidative strategy of Bufotes viridis was based on SOD utilization in attempt to maintain the oxidative disbalance at acceptable level. The integrated biomarker response (IBR) as the measure of the overall biochemical response to DM exposure revealed that the group exposed for 21 days had the highest response. Our work has offered valuable data ensuring evidence that toads exposed to deltamethrin developed adaptive reactions that were tissue-specific and that DM-generated systemic toxicity was time-dependent. The present work showed that oxidative stress has significant role in pesticide-induced toxicity and contributes to better understanding of ecotoxicological risk in the terrestrial amphibians exposed to DM.

Oxidative stress parameters in two Pelophylax esculentus complex frogs during pre- and post-hibernation: Arousal vs heavy metals.

In spring, frogs from temperate regions are faced with arousal-induced oxidative stress and exposure to various xenobiotics from the environment. The question is whether pollutants can significantly modify the antioxidative defense system (AOS) response of hibernators during recovery from hibernation. If this assumption is true, we would then expect different patterns of seasonal variations in the AOS between individuals exposed to different levels of pollution. To examine this assumption, we determined the relationship between seasonal variations of accumulated metals and AOS parameters in the skin and muscle of two frog species from the Pelophylax esculentus complex (P. ridibundus and P. esculentus) inhabiting two localities (the Danube-Tisza-Danube canal and the Ponjavica River) with different levels of pollution during pre- and post-hibernation periods, respectively autumn and spring. Our results showed that even though there were differences in the concentrations of accumulated metals and AOS parameters between localities and species, the frogs displayed almost the same patterns of AOS variations during seasons, with a higher AOS response observed in spring. The parameters SH groups, GSH, GR and SOD had been contributed most rather than others. Our findings indicate that oxidative stress during the post-hibernation period was mainly caused by the organisms' recovery from hibernation, as the result of natural selection acting on the AOS, and that the accumulated metals did not significantly modify the AOS response. The present study provides new insight into the biological and physiological cellular responses of frogs to arousal stress.