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The present study investigated the effects of PCBs on the rat kidneys with attention given to the determination critical effect dose (CED) using the Benchmark dose (BMD) approach. Male albino Wistar rats (7 animals per group) were given by oral gavage Aroclor 1254 dissolved in corn oil at doses of 0.0, 0.5, 1, 2, 4, 8, or 16 mg/kg b.w./day for 28 days. The PCB nephrotoxicity was manifested by a dose-dependent changes in serum urea levels. The study has also revealed PCB-induced oxidative stress induction in kidneys. The observed nephrotoxic effects can be partly explained by oxidative damage of lipids and proteins in the kidneys due to observed reduced CuZnSOD activity and disturbances in antioxidant protection. Аll the renal oxidative stress parameters showed dependence on PCB oral doses as well as internal, measure kidney PCB levels. Calculated BMDL values were lower than estimated no observed adverse effect levels (NOAEL) based on the study, suggesting the importance of BMD approach use in future risk assessment.

Most Pb and Cd neurotoxicity studies investigate exposure to either of the toxic metals alone, while data on co-exposure are scarce. The aim of our study was to fill that gap by investigating acute combined effects of Pb and Cd on redox and essential metal status in the brain of Wistar rats. Animals were randomised in four groups of six to eight rats, which received 15 or 30 mg/kg of Cd, 150 mg/kg of Pb, or 150 mg/kg of Pb + 15 mg/kg of Cd by gavage. The fifth, control, group received distilled water only. Co-treatment with Pb and Cd induced significant increase in malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) compared to control and groups receiving either metal alone. This is of special importance, as MDA presence in the brain has been implicated in many neurodegenerative disorders. The groups did not significantly differ in Zn, Cu, Mn, and Fe brain levels. Our findings highlight the importance of metal mixture studies. Neurotoxicity assessments of single chemicals do not provide a real insight into exposure to mixtures in real life. Further research should look into interactions between these metals to reveal complex molecular mechanisms of their neurotoxicity., Dosadašnji podatci o neurotoksičnosti olova (Pb) i kadmija (Cd) uglavnom su opisani nakon izloženosti pojedinačnim metalima, a podatci o neurotoksičnom djelovanju smjese tih dvaju metala prilično su oskudni. Cilj ovoga rada bio je ispitati učinak akutnoga izlaganja smjesi olova i kadmija na parametre oksidacijskoga stresa i status bioelemenata u mozgu štakora. Životinje su bile podijeljene u pet skupina: Cd15 (15 mg/kg), Cd30 (30 mg/kg), Pb150 (150 mg/kg), Pb150+Cd15 i kontrolna, netretirana skupina. Smjesa olova i kadmija dovela je do značajno viših vrijednosti malondialdehida (MDA) i drugih produkata u mozgu štakora u usporedbi s kontrolnom skupinom i obama pojedinačnim metalima. To je iznimno važno, imajući u vidu da je prisutnost MDA-a u mozgu povezana s mnogim neurodegenerativnim poremećajima. Nije dobivena statistički značajna razlika između ispitivanih skupina u razinama cinka (Zn), bakra (Cu), mangana (Mn) I željeza (Fe). Rezultati ovoga istraživanja važan su doprinos budućim istraživanjima smjesa i upućuju na to da istraživanja toksičnosti u kojima se procjenjuje neurotoksičnost pojedinačnih kemikalija ne pružaju stvarni uvid u neurotoksičnost njihovih smjesa kojima smo izloženi u stvarnom životu. Dobiveni rezultati otvaraju daljnja pitanja o interakciji i mehanizmima toksičnosti smjese tih metala.

The extent of human exposure to chemicals, their endocrine-disrupting mechanisms of action, and the relationship between exposure and various human diseases raise significant scientific and public health concerns. Polychlorinated biphenyls (PCBs) belong to the group of organic compounds known as persistent organic pollutants, characterized by long-range transport, persistence, bioaccumulation, and high toxicity. They have been identified as endocrine-disrupting chemicals. In vivo and in vitro studies have shown that endocrine-disrupting effects of PCBs mainly involve thyroid and reproductive function. In the review presented, these effects were placed in the context of the most recent findings on PCB-induced endocrine-disrupting mechanisms and modes of action.

This paper aims to present the importance of the benchmark dose (BMD) as a point of departure (the lowest dose or concentration in the experiment that deviates from the response that differs from the normal response) in toxicological risk assessment, as well as to present commonly used software for its calculation (BMDS and PROAST). Benchmark dose is defined as a statistical lower confidence limit of a dose that results in a small change in effect (5-10%) in comparison with the control value. The BMD approach is considered a substitution for the NOAEL approach, which uses the highest observed no-effect level (NOAEL) to obtain the reference dose. The BMD approach is a methodically more forward-thinking technique than the NOAEL approach because it has statistical power and provides a wide range of dose-response relationships and allows the determination of their uncertainty and variability. Moreover, the BMD approach contributes to the reduction of experimental animals in toxicity studies. Therefore, the European Food Safety Authority (EFSA) recommends the use of BMDL10values for quantal and BMDL05for continuous data. Cilj ovog rada je da predstavi značaj granične benchmark doze (engl. benchmark dose, BMD) kao polaznog doznog nivoa (najniže doze ili koncentracije u eksperimentu koja odstupa od normalnog odgovora) u toksikološkoj proceni rizika, kao i da prikaže najčešće korišćene softvere za njeno izračunavanje (BMDS i PROAST). Benchmark doza predstavlja statističku donju granicu pouzdanosti doze koja dovodi do malog povećanja efekta (5-10%) u odnosu na kontrolnu vrednost. Benchmark pristup predstavlja alternativu NOAEL (engl. no observed adverse effects level, NOAEL) pristupu, u kome se u svrhu dobijanja referentnih vrednosti koristi najviša doza koja ne izaziva štetan efekat. Benchmark pristup naučno je napredniji metod od tradicionalnog NOAEL pristupa, jer je statistički utemeljen, daje širok opseg podataka o odnosu doza-odgovor i omogućava kvantifikaciju njihove nesigurnosti i varijabilnosti. Takođe, BMD pristup doprinosi smanjenju broja eksperimentalnih životinja u toksikološkim studijama. Samim tim, Evropska agencija za bezbednost hrane (EFSA) preporučuje primenu doza BMDL10 za kvantalne i BMDL05 za kontinuirane podatke.

Humans are exposed to multiple chemicals on a daily basis instead of to just a single chemical, yet the majority of existing toxicity data comes from single-chemical exposure. Multiple factors must be considered such as the route, concentration, duration, and the timing of exposure when determining toxicity to the organism. The need for adequate model systems (in vivo, in vitro, in silico and mathematical) is paramount for better understanding of chemical mixture toxicity. Currently, shortcomings plague each model system as investigators struggle to find the appropriate balance of rigor, reproducibility and appropriateness in mixture toxicity studies. Significant questions exist when comparing single-to mixture-chemical toxicity concerning additivity, synergism, potentiation, or antagonism. Dose/concentration relevance is a major consideration and should be subthreshold for better accuracy in toxicity assessment. Previous work was limited by the technology and methodology of the time, but recent advances have resulted in significant progress in the study of mixture toxicology. Novel technologies have added insight to data obtained from in vivo studies for predictive toxicity testing. These include new in vitro models: omics-related tools, organs-on-a-chip and 3D cell culture, and in silico methods. Taken together, all these modern methodologies improve the understanding of the multiple toxicity pathways associated with adverse outcomes (e.g., adverse outcome pathways), thus allowing investigators to better predict risks linked to exposure to chemical mixtures. As technology and knowledge advance, our ability to harness and integrate separate streams of evidence regarding outcomes associated with chemical mixture exposure improves. As many national and international organizations are currently stressing, studies on chemical mixture toxicity are of primary importance., The research was partly supported by the Ministry of Education, Science and Technological Development of Serbia (Project III 46009), the Special Research Account of University of Crete (ELKE No 3550, No 3963, No 4920) and the University of Crete Spin- Off ToxPlus S.A., the Oklahoma State University Center for Health Science Pilot Grant Program (#1-54333), Ministry of Research and Innovation in Romania: Program 1—The Improvement of the National System of Research and Development, Subprogram 1.2—Institutional Excellence—Projects of Excellence Funding in RDI, Contract No. 7PFE/16.10.2018.

Although profoundly studied, etiology of pancreatic cancer (PC) is still rather scarce. Some of established risk factors of PC are connected to an increased cadmium (Cd) body burden. Hence, the aim of this study was to investigate the role of this environmental pollutant in PC development by conducting human observational, experimental and in vitro studies.The case-control study included 31 patients with a histologically based diagnosis of exocrine PC subjected to radical surgical intervention as cases and 29 accidental fatalities or subjects who died of a nonmalignant illness as controls. Animal study included two treated groups of Wistar rats (15 and 30 mg Cd/kg b.w) and untreated control group, sacrificed 24 h after single oral exposure. In in vitro study pancreas hTERT-HPNE and AsPC-1 cells were exposed to different Cd concentrations corresponding to levels measured in human cancerous pancreatic tissue.Cd content in cancer tissue significantly differed from the content in healthy controls. Odds ratio levels for PC development were 2.79 (95% CI 0.91–8.50) and 3.44 (95% CI 1.19–9.95) in the third and fourth quartiles of Cd distribution, respectively. Animal study confirmed Cd deposition in pancreatic tissue. In vitro studies revealed that Cd produces disturbances in intrinsic pathway of apoptotic activity and the elevation in oxidative stress in pancreatic cells.This study presents three different lines of evidence pointing towards Cd as an agent responsible for the development of PC. Keywords: Pancreatic cancer, Cadmium, Carcinogenesis, Risk factors

This study aimed to investigate the potential hepatotoxicity, nephrotoxic, and hematotoxic effects of simultaneous occupational low-level exposure of shoe workers to a mixture of organic solvents. The study included 16 male and 55 female workers and non-exposed subjects (

Linkage between bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and bisphenol A (BPA) co-exposure and type 2 diabetes mellitus (T2DM), as well as ability of multi-strained probiotic to reduce DEHP, DBP and BPA mixture-induced oxidative damage in rat pancreas were investigated. The Comparative Toxicogenomics Database, Cytoscape software and ToppGene Suite were used for data-mining. Animals were sorted into seven groups (n = 6): (1) Control group: corn oil, (2) P: probiotic: Saccharomyces boulardii + Lactobacillus rhamnosus + Lactobacillus plantarum LP 6595 + Lactobacillus plantarum HEAL9; (3) DEHP: 50 mg/kg b.w./day, (4) DBP: 50 mg/kg b.w./day, (5) BPA: 25 mg/kg b.w./day, and (6) MIX: 50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA; (7) MIX + P. Rats were sacrificed after 28 days of oral exposure. In silico investigation highlighted 44 DEHP, DBP and BPA mutual genes linked to the T2DM, while apoptosis and oxidative stress were highlighted as the main mechanisms of DEHP, DBP and BPA mixture-linked T2DM. In vivo experiment confirmed the presence of significant changes in redox status parameters (TOS, SOD and SH groups) only in the MIX group, indicating possible additive effects, while probiotic ameliorated mixture-induced redox status changes in rat pancreatic tissue.

The aim of this study was to: (i) determine and compare the capacity of bis (2 –ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), bisphenol A (BPA), and their mixture to produce testicular toxicity after the subacute exposure; (ii) explore the mechanisms behind the observed changes using in silico toxicogenomic approach. Male rats were randomly split into groups (n = 6): (1) Control (corn oil); (2) DEHP (50 mg/kg b.w./day); (3) DBP (50 mg/kg b.w./day); (4) BPA (25 mg/kg b.w./day); and (5) MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA). Animals were sacrificed after 28 days of oral exposure, testes were extracted and prepared for histological assessments under the light microscope (haematoxylin and eosin staining) and redox status analysis. The Comparative Toxicogenomics Database (CTD; http://CTD.mdibl.org ), Cytoscape software ( https://cytoscape.org ) and ToppGene Suite ( https://toppgene.cchmc.org ) were used for data-mining. Present pathohistological study has demonstrated more pronounced testicular toxicity of the MIX group (desquamated germinal epithelium cells, enlarged cells with hyperchromatic nuclei, multinucleated cell forms and intracytoplasmic vacuoles) in comparison with the single substances, while effects on redox status parameters were either more prominent, or present only in the MIX group. In silico investigation revealed 20 genes linked to male reproductive disorders, affected by all three investigated substances. Effects on metabolism, AhR pathway, apoptosis and oxidative stress could be singled out as the most probable mechanisms involved in the subacute DEHP, DBP and BPA mixture testicular toxicity, while the effect on oxidative stress parameters was confirmed by in vivo experiment.

Exposure to lead (Pb) is still rising concern worldwide, having in mind that even low-dose exposure can induce various harmful effects. Thus, in-depth knowledge of the targets of Pb toxicity and corresponding mechanisms is essential. In the presented study, the six groups (male Wistar rats, n = 6) received 0.1; 0.5; 1; 3; 7; 15 mg Pb/kg body weight/day for 28 days, each day by oral gavage, while the control group received distilled water only. All animals were sacrificed 24 h after the treatment, and blood was collected for the analysis of hematological, biochemical, oxidative status and essential elements levels. An external and internal dose-response relationship was performed using PROASTweb 70.1 software. The results showed that low doses of Pb affect hematological parameters and lipid profile after 28 days. The possible mechanisms at examined Pb dose levels were a decrease in SOD, O2•− and Cu and an increase in Zn levels. The dose-dependent nature of changes in cholesterol, HDL cholesterol, O2.-, SOD, AOPP in serum and hemoglobin, Fe, Zn, Cu in blood were obtained in this study. The most sensitive parameters that were alerted are Cu blood levels (BMDL5: 1.4 ng/kg b.w./day) and SOD activity (BMDL5: 0.5 μg/kg b.w./day). The presented results provide information that may be useful in further assessing the health risks of low-level Pb exposure.

While experimental animal investigation has historically been the most conventional approach conducted to assess drug safety and is currently considered the main method for determining drug toxicity, these studies are constricted by cost, time, and ethical approvals. Over the last 20 years, there have been significant advances in computational sciences and computer data processing, while knowledge of alternative techniques and their application has developed into a valuable skill in toxicology. Thus, the application of in silico methods in drug safety assessment is constantly increasing. They are very complex and are grounded on accumulated knowledge from toxicology, bioinformatics, biochemistry, statistics, mathematics, as well as molecular biology. This review will summarize current state-of-the-art scientific data on the use of in silico methods in toxicity testing, taking into account their shortcomings, and highlighting the strategies that should deliver consistent results, while covering the applications of in silico methods in preclinical trials and drug impurities toxicity testing. Ispitivanja na eksperimentalnim životinjama ne samo da su u prošlosti bila smatrana najkonvencionalnijim pristupom za procenu bezbednosti lekova, već su i trenutno osnovna metoda za utvrđivanje njihove toksičnosti. Međutim, ova ispitivanja su skupa, vremenski zahtevna i za njihovo sprovođenje neophodne su etičke dozvole. Tokom poslednjih 20 godina došlo je do napretka u računarskoj nauci i kompjuterskoj obradi podataka, dok se znanje o alternativnim tehnikama i njihovoj primeni razvilo u dragocenu veštinu u toksikologiji. Stoga, primena in silico metoda u proceni bezbednosti lekova neprestano raste. Ove metode su veoma složene i zasnivaju se na saznanjima iz toksikologije, bioinformatike, biohemije, statistike, matematike i molekularne biologije. Ovaj pregledni rad će rezimirati trenutna naučna saznanja koja se tiču upotrebe in silico metoda u ispitivanju toksičnosti lekova, uzimajući u obzir njihova ograničenja i ističući strategije pomoću kojih se mogu dobiti konzistentni rezultati, sa posebnim osvrtom na primenu in silico metoda u pretkliničkim ispitivanjima i ispitivanjima toksičnosti nečistoća u lekovima.

The aims of this study were to: (i) examine the toxic effects of sodium fluoride (NaF) in blood, liver, spleen, and brain cells of Wistar rats after the subacute exposure; (ii) explore the potential protective properties of selenium (Se) against fluoride toxicity after the simultaneous administration. Twenty male Wistar rats, eight weeks old, weighing approximately 140–190 g, were divided into four experimental groups (n = 5) as follows: I control-tap water; II NaF 150 ppm; III NaF 150 ppm and Se 1.5 mg/L; IV Se 1.5 mg/L, and had available water with solutions ad libitum for 28 days. DNA damage detected by comet assay was confirmed in the liver, spleen, and brain cells, but not in blood. Selenium supplementation together with NaF decreased DNA damage in liver and spleen cells. According to the histological findings, no changes were observed in spleen and brain tissues after NaF administration. Unlike the observed Se protective effect on the DNA level, no significant reduction of liver tissue injury was observed after the NaF and Se treatment, resulting in mild inflammation. Data of this study suggest that DNA damage after NaF subacute exposure at moderately high concentration was reduced in liver and spleen cells due to Se supplementation, but a similar change was not seen in the brain.

Recent research has helped clarify the role of cadmium (Cd) in various pathological states. We have demonstrated Cd involvement in pancreatic cancer, as well as the bioaccumulation of Cd in the pancreas. Bioaccumulation and increased toxicity suggest that Cd may also be involved in other pancreas-mediated diseases, like diabetes. Cd falls into the category of “hyperglycemic” metals, i.e., metals that increase blood glucose levels, which could be due to increased gluconeogenesis, damage to β-cells leading to reduced insulin production, or insulin resistance at target tissue resulting in a lack of glucose uptake. This review addresses the current evidence for the role of Cd, leading to insulin resistance from human, animal, and in vitro studies. Available data have shown that Cd may affect normal insulin function through multiple pathways. There is evidence that Cd exposure results in the perturbation of the enzymes and modulatory proteins involved in insulin signal transduction at the target tissue and mutations of the insulin receptor. Cd, through well-described mechanisms of oxidative stress, inflammation, and mitochondrial damage, may also alter insulin production in β-cells. More work is necessary to elucidate the mechanisms associated with Cd-mediated insulin resistance.

Phthalates and bisphenol A, to which people are mainly exposed through food, interfere with the body's endocrine system, along with various other toxic effects. Literature data suggest that probiotic cultures might be able to decrease the adverse effects of toxic substances by various mechanisms. The aim of this study was to investigate if treatment with multi-strained probiotic could reduce the toxicity of phthalates and bisphenol A mixture in Wistar rats. Animals were divided into four experimental groups (n = 6): (1) Control (corn oil); (2) P (probiotic (8.78 * 108 CFU/kg/day): Saccharomyces boulardii + Lactobacillus rhamnosus + Lactobacillus planarum LP 6595+ Lactobacillus planarum HEAL9); (3) MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA); (4) MIX + P. Animals were euthanized after 28 days of daily oral gavage treatment; blood and organs were collected for further analysis. Probiotic reduced systemic inflammation and had protective effects on liver, kidneys, spleen, lipid status and serum glucose level. It almost completely annulled the changes in biochemical, hematological and hormonal parameters and mitigated changes in relative liver size, food consumption and organ histology. These results suggest considering multi-strained probiotics as a dietary therapeutic strategy against toxicity of the investigated mixture.

For over a century, one of the main toxicologists’ goals was finding the relationship between the chemical structure and toxicity. The development of computer technologies has lead to the production of software models that could be applied for this purpose. However, use of in silico methodology in toxicology is very complex. Having in mind that toxic effect occurs through multiple mechanisms on different tissues and organs, creating software that can make reliable toxicity predictions is very complicated. In silico methods found the application in toxicity assessment of substances for which data obtained from traditional toxicity tests is lacking (metabolites, drug impurities, etc.). Also, in silico methods can be used in the process of chemical synthesis, with the aim of designing safer chemicals. Currently, in silico methods for toxicity predictions are most commonly used along with standard toxicological tests, with a tendency to replace in vitro and in vivo toxicity tests in the future. This paper will present the strengths and limitations of commonly used software in in silico toxicology (OECD QSAR Toolbox, Derek Nexus, ToxTree i MultiCASE). Već više od sto godina jedan od glavnih ciljeva toksikologa je povezivanje hemijske strukture supstanci sa njihovom toksičnošću. Progres u razvoju kompjuterskih tehnologija omogućio je kreiranje softverskih modela za ovu namenu. Međutim, primena in silicometodologije u toksikologiji je veoma složena. Kako se toksični efekat može ostvariti preko više mehanizama na različitim tkivima i organima, veoma je kompleksno kreirati softvere kojima se može dovoljno pouzdano predvideti toksičnost ispitivane supstance. Upotreba in silico metoda našla je primenu u proceni toksičnosti onih supstanci za koje ne postoji dovoljno podataka dobijenih tradicionalnim testovima toksičnosti (metaboliti, nečistoće u lekovima, itd.). Takođe, in silico metode se mogu koristiti u procesu sinteze hemikalija, sa ciljem dobijanja bezbednijih hemikalija, dajući uvid u strukturne karakteristike odgovorne za toksičnost. In silicometode za predviđanje toksičnosti trenutno se najčešće koriste uz standardna toksikološka ispitivanja, dok je tendencija da u budućnosti zamene deo in vitro i in vivo testova toksičnosti. U ovom radu biće prikazane mogućnosti i ograničenja najčešće korišćenih softvera u in silico toksikologiji (OECD QSAR Toolbox, Derek Nexus, ToxTree i MultiCASE).

To understand the effects of endocrine-disrupting chemicals (EDCs), the mechanism(s) by which EDCs exert their harmful effects on humans and their offspring needs careful examination and clarification. Epigenetic modification, including DNA methylation, expression of aberrant microRNA (miRNA), and histone modification, is one mechanism assumed to be a primary pathway leading to the untoward effects of endocrine disruptors. However, it remains unclear whether such epigenetic changes caused by EDCs are truly predicting adverse outcomes. Therefore, it is important to understand the relationship between epigenetic changes and various endocrine endpoints or markers. This paper highlights the possibility that certain chemicals (Cd, As, Pb, bisphenol A, phthalate, polychlorinated biphenyls) reported having ED properties may adversely affect the epigenome. Electronic database sources PubMed, SCOPUS, JSTOR, and the Google Scholar web browser were used to search the literature. The search was based on keywords from existing theories and basic knowledge of endocrine disorders and epigenetic effects, well-known EDCs, and previous search results. Unclear and often conflicting results regarding the effects of EDCs indicate the need for further research to support better risk assessments and management of these chemicals.

The aim of this study was to explore the mechanisms of bis(2- ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and bisphenol A (BPA) mixture-induced asthma development and test probiotic as a potential positive intervention. Comparative Toxicogenomics Database (CTD) and ToppGene Suite were used as the main tools for in silico analysis. In vivo 28-day experiment was conducted on rats - seven groups (n = 6): (1) Control: corn oil, (2) P: probiotic (8.78 * 108 CFU/kg/day); (3) DEHP: 50 mg/kg b.w./day, (4) DBP: 50 mg/kg b.w./day, (5) BPA: 25 mg/kg b.w./day; (6) MIX: DEHP + DBP + BPA; (7) MIX + P. Lungs, thymus and kidneys were extracted and prepared for redox status and essential metals analysis. By conducting additional in vitro experiment, probiotic phthalate and BPA binding ability was explored. There were 24 DEHP, DBP and BPA asthma-related genes, indicating the three most probable mechanisms - apoptosis, inflammation and oxidative stress. In vivo experiment confirmed that significant changes in redox status/essential metal parameters were either prominent, or only present in the MIX group, indicating possible additive effects. In vitro experiment confirmed the ability of the multy-strain probiotic to bind DEHP/DBP/BPA mixture, while probiotic administration ameliorated mixture-induced changes in rat tissue.

Soil contamination by heavy metals is a serious global environmental problem, especially for developing countries. A large number of industrial plants, which continually pollute the environment, characterize Tuzla Canton, Bosnia and Herzegovina. The aim of this study was to assess the level of soil pollution by heavy metals and to estimate cytotoxicity and genotoxicity of soil leachates from this area. Lead (Pb), cadmium (Cd) and mercury (Hg) were analyzed by ICP-AES and AAS. Soil contamination was assessed using contamination factor, degree of contamination, geoaccumulation index and pollution load index. To determine the connection of variables and understanding their origin in soils, principal component analysis (PCA) and cluster analysis (CA) were used. The results indicate that Cd and Hg originated from natural and anthropogenic activities, while Pb is of anthropogenic origin. For toxicity evaluation, CaCo-2 and HaCaT cells were used. PrestoBlue assay was used for cytotoxicity testing, and cH2A. X for genotoxicity evaluation. Concerning cytotoxicity, Cd and Hg had a positive correlation with cytotoxicity in HaCaT cells, but only Hg induced cytotoxicity in CaCo-2 cells. We also demonstrate that soil leachates contaminated by heavy metals can induce genotoxicity in both used cell lines. According to these results, combining bioassays with standard physicochemical analysis can be useful for evaluating environmental and health risks more accurately. These results are important for developing proper management strategies to decrease pollution. This is one of the first studies from this area and an important indication of soil quality in Southeast Europe.

Breast cancer is at the forefront of female malignancy and the leading cause of cancer death among women. Gender, age, hormone therapy, smoking, exposure to endocrine disruptors and family history are significant breast cancer risk factors according to epidemiological data. Considering metalloestrogenic Cd property and a plethora of research work on hormone involvement in breast cancer the study aimed to determine Cd concentration in three compartments of breast cancer patients in relation to their blood hormone status. Further, as oxidative stress is a critical mechanism of Cd toxicity, the objective of this study was to determine potential changes in oxidative status homeostasis. The study enrolled 55 patients with breast cancer diagnosis and 41 healthy women with benign breast changes. Concentration of Cd was determined using graphite furnace atomic absorption spectrometry. Cadmium concentration in tumor tissue was significantly higher than control and almost four times higher than Cd concentration in the healthy surrounding tissue. Strong positive correlation was observed between Cd concentrations in changed breast tissue and FSH and LH levels, while the correlation was negative with estradiol level. Cancer patients had significantly increased blood total antioxidative status while total oxidative status did not significantly differ between study groups. The study revealed Cd implication in breast cancer onset following a significant odd ratio for Cd levels in changed tissue samples. Moreover, presented data confirmed sex hormone and oxidative status imbalance caused by Cd presence, closely related to cancer development.

Beside the key inhibition of acetylcholinesterase (AChE), involvement of oxidative stress in organophosphate (OP)-induced toxicity has been supported by experimental and human studies. On the other hand, according to our best knowledge, possible antioxidant properties of oximes, the only causal antidotes to OP-inhibited AChE, have been examined only by a few studies. Thus, we have determined the effect of four conventional (obidoxime, trimedoxime, pralidoxime, asoxime) and two promising experimental oximes (K027, K203) on dichlorvos (DDVP)-induced oxidative changes in vivo. Wistar rats (5/group) were treated with oxime (5% LD50 i.m) immediately after DDVP challenge (75% LD50 s.c). Oxidative stress biomarkers were determined in plasma and brain 60 min after the treatment: prooxidative-superoxide anion (O-2 (center dot-)) and total oxidative status (TOS); antioxidative-superoxide dismutase (SOD), total thiol (SH) groups, total antioxidant status (TAS) and paraoxonase (PON1); tissue oxidative stress burden-prooxidative-antioxidative balance (PAB) and oxidative stress index (OSI); oxidative tissue damage-malondialdehyde (MDA) and advanced oxidation protein products (AOPP). All oximes were able to attenuate DDVP-induced oxidative stress in rat plasma and brain. Changes of determined parameters in brain were not as prominent as it was seen in plasma. Based on OSI, better abilities of oxime K027, K203 and obidoxime to maintain DDVP-induced oxidative stress in rat brain were shown as compared to trimedoxime, pralidoxime and asoxime. Oximes can influence the complex in vivo redox processes that might contribute to their overall therapeutic efficacy. Further research is needed to understand the underlying molecular mechanisms involved in this phenomenon.

The study was designed to investigate the influence of zinc (Zn) supplementation on cadmium-induced alterations in zinc, copper (Cu), and magnesium (Mg) status in rabbits. For this purpose, the concentrations of cadmium (Cd), Zn, Cu, and Mg were estimated in the blood, liver, kidney, and bone. The rabbits were divided in a control group, a Cd group-animals intoxicated orally with Cd (10 mg kg-1 bw, as aqueous solution of Cd-chloride), and a Cd+Zn group-animals intoxicated with the same dose of Cd and co-treated with Zn (20 mg kg-1 bw, as aqueous solution of Zn-sulphate). Solutions were administered orally, every day for 28 days. Sample mineralisation was performed with concentrated nitric acid (HNO3) and perchloric acid (HClO4) (4:1) and metal concentrations were determined by atomic absorption spectrophotometry (AAS). Zinc supplementation improved some of Cd-induced disturbances in bioelement levels in the investigated tissues. Beneficial effects of Zn on Zn and Cu levels were observed in blood, as well as on the Cu kidney level. The calculated values for Cu/Zn, Mg/Zn, and Mg/Cu ratios in blood suggest that Zn co-treatment reduces Cd-induced changes in bioelement ratios in blood.

Phthalates and bisphenol A, classified as endocrine disruptors, have weak estrogenic, anti-androgenic properties, and affect thyroid hormone regulation. The aim of this study on male rats was to compare the subacute toxic effects of low doses of single compounds (bis (2 &ndash, ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and bisphenol A (BPA)) with the effects of their mixture through different biochemical, hormonal, and hematological parameters. Rats were divided into five experimental groups: Control (corn oil), DEHP (50 mg/kg b.w./day), DBP (50 mg/kg b.w./day), BPA (25 mg/kg b.w./day), and MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA). Animals were sacrificed after 28 days of oral treatment and blood was collected for further analysis. The results demonstrated that the mixture produced significant changes in lipid profile, liver-related biochemical parameters, and glucose level. Furthermore, the opposite effects of single substances on the thyroxine level have been shown in comparison with the mixture, as well as a more pronounced effect of the mixture on testosterone level. This study contributes to the body of knowledge on the toxicology of mixtures and gives one more evidence of the paramount importance of mixture toxicity studies, especially in assessing the endocrine disruptive effects of chemicals.

According to the World Health Organization, in 2015, the Serbian population ranked among the highest ones in Europe in terms of smoking habit: 44.3% males and 36.2% females aged 18–64 smoked tobacco. In the last 7 years, 25% of total mortality in men and 9% in women from Serbia were associated with smoking. Tobacco smoking is one of the most important sources of exposure to many toxic substances in general population. Our study confirmed higher blood levels of two toxic metals, cadmium and lead, in the blood of smokers (3.5 and 1.5 times higher than in non-smokers, respectively). Furthermore, smoking habits, such as number of smoked cigarettes per day, smoking period and cigarette type, along with age, were shown to influence these metals’ blood concentration. Higher blood levels of Cd and Pb were found in smokers consuming more than 10 cigarettes per day for more than 10 years. The present study also highlighted the importance of the controlled tobacco production, since it was shown that consumption of illicit tobacco could manifold the exposure to toxic metals that can subsequently increase the frequency of related diseases as well.

This in silico toxicogenomic analysis aims to: (i) testify the hypothesis about the influence of the environmentally relevant toxic metals (lead, methylmercury (organic form of mercury), cadmium and arsenic) on molecular mechanisms involved in amyotrophic lateral sclerosis (ALS), Parkinson's Disease (PD) and Alzheimer's disease (AD) development; and (ii) demonstrate the capability of in silico toxicogenomic data-mining for distinguishing the probable mechanisms of mixture-induced toxic effects. The Comparative Toxicogenomics Database (CTD; http://ctd. mdibl.org) and Cytoscape software were used as the main data-mining tools in this analysis. The results have shown that there were 7, 13 and 14 common genes for all the metals present in the mixture for each of the selected neurodegenerative disease (ND), respectively: ALS, PD and AD. Physical interactions (68.18%) were the most prominent interactions between the genes extracted for ALS, co-expression (60.85%) for PD and interactions predicted by the server (44.30%) for AD. SOD2 gene was noted as the mutual gene for all the selected ND. Oxidative stress, folate metabolism, vitamin B12, AGE-RAGE, apoptosis were noted as the key disrupted molecular pathways that contribute to the neurodegenerative disease's development. Gene ontology analysis revealed biological processes affected by the investigated mixture (glutathione metabolic process was listed as the most important for ALS, cellular response to toxic substance for PD, and neuron death for AD). Our results emphasize the role of oxidative stress, particularly SOD2, in neurodegeneration triggered by environmental toxic metal mixture and give a new insight into common molecular mechanisms involved in ALS, PD and AD pathology.

As oxime-based structures are the only causal antidotes to organophosphate (OP)-inhibited acetylcholinesterase (AChE), the majority of studies on these have been directed towards their synthesis and testing. In this study, experimental bispyridinium oximes K027 and K203, which have shown promising results in the last decade of research, were examined in vivo for their therapeutic and reactivating ability in acute poisoning by the direct AChE-inhibitor dichlorvos (DDVP), used as a dimethyl OP structural model. Additionally, the efficacy of oximes K027 and K203 was compared with the efficacy of four oximes (pralidoxime, trimedoxime, obidoxime and HI-6), already used in efficacy experiments and human medicine. To evaluate therapeutic efficacy, groups of Wistar rats were treated with equitoxic doses of oximes (5% LD50, i.m.) and/or atropine (10 mg/kg, i.m.) immediately after s.c. DDVP challenge (4-6 doses). Using the same antidotal protocol, AChE activity was measured in erythrocytes, diaphragm and brain 60 min after s.c. DDVP exposure (75% LD50). The oxime K027 was the most efficacious in reducing the DDVP induced lethal effect in rats, while the oxime K203 was more efficacious than trimedoxime, pralidoxime and HI-6. Significant reactivation of DDVP inhibited AChE was achieved only with oxime K027 or its combination with atropine in erythocytes and the diaphragm. Moreover, the acute i.m. toxicity of oxime K027 in rats was lower than all other tested oximes. The results of this study support previous studies considering the oxime K027 as a promising experimental oxime structure for further testing against structurally-different OP compounds.

Improvement of COVID-19 clinical condition was seen in studies where combination of antiretroviral drugs, lopinavir and ritonavir, as well as immunomodulant antimalaric, chloroquine/hydroxychloroquine together with the macrolide-type antibiotic, azithromycin, was used for patient's treatment. Although these drugs are “old”, their pharmacological and toxicological profile in SARS-CoV-2 – infected patients are still unknown. Thus, by using in silico toxicogenomic data-mining approach, we aimed to assess both risks and benefits of the COVID-19 treatment with the most promising candidate drugs combinations: lopinavir/ritonavir and chloroquine/hydroxychloroquine + azithromycin. The Comparative Toxicogenomics Database (CTD; http://CTD.mdibl.org), Cytoscape software (https://cytoscape.org) and ToppGene Suite portal (https://toppgene.cchmc.org) served as a foundation in our research. Our results have demonstrated that lopinavir/ritonavir increased the expression of the genes involved in immune response and lipid metabolism (IL6, ICAM1, CCL2, TNF, APOA1, etc.). Chloroquine/hydroxychloroquine + azithromycin interacted with 6 genes (CCL2, CTSB, CXCL8, IL1B, IL6 and TNF), whereas chloroquine and azithromycin affected two additional genes (BCL2L1 and CYP3A4), which might be a reason behind a greater number of consequential diseases. In contrast to lopinavir/ritonavir, chloroquine/hydroxychloroquine + azithromycin downregulated the expression of TNF and IL6. As expected, inflammation, cardiotoxicity, and dyslipidaemias were revealed as the main risks of lopinavir/ritonavir treatment, while chloroquine/hydroxychloroquine + azithromycin therapy was additionally linked to gastrointestinal and skin diseases. According to our results, these drug combinations should be administrated with caution to patients suffering from cardiovascular problems, autoimmune diseases, or acquired and hereditary lipid disorders., Graphical abstract Unlabelled Image, Highlights • Lopinavir/ritonavir affect genes involved in immune system and lipid metabolism • Cardiotoxicity, inflammation, dyslipidemias – lopinavir/ritonavir therapy main risk • Chloroquine/azithromycin interact with genes linked to cytokine regulation • Chloroquine affects two genes more than hydroxychloroquine (BCL2L1 and CYP3A4) • CVD, GIT, skin diseases-(hydroxy)chloroquine/azithromycin therapy main risk

Background/Aim. Fluoride has beneficial effect on dental caries prevention and enables high hardness of enamel. However, fluoride intake above optimal levels can have adverse effects on teeth and bones, especially in young children during the period of intense growth and teeth development. The aim of this study was to assess fluoride intake from water and toothpaste among 3-year-old children in Belgrade, Serbia, in the municipalities of Vračar and Novi Beograd. Methods. A questionnaire for the parents (n = 40) was used to provide information on the water consumption (tap and/or bottled water) and the brand of toothpaste used by children as well as the frequency of tooth brushing and the amount of toothpaste during brushing. Fluoride concentrations in water and toothpaste samples were determined electrochemically by using fluoride-selective electrode. Fluoride intake was estimated through a mathematical model commonly used by the U.S. Environmental Protection Agency. Results. The obtained results indicate no significant difference in daily fluoride intake through drinking water and toothpaste in 3-year-old children in Vračar (n = 19) compared to Novi Beograd (n = 21) (p > 0.05). However, all estimated fluoride levels (0.089-0.625 mg/day) are significantly lower than the optimal daily intake level for caries protection (0.7 mg/day for children up to 4 years, FNB-USA National Institute of Medicine) and two to six times lower than tolerable upper fluoride level for the children of same age (1.3 mg/day, FNB-USA National Institute of Medicine). Furthermore, calculated daily fluoride intake per kilogram body weight confirm very low fluoride intake by water and toothpaste in children of investigated municipalities in Belgrade, being significantly below the recommended an adequate intake (0.05 mg/kg/day, EFSA). Conclusion. This preliminary study has shown that daily fluoride intake in 3-year-olds is lower than tolerable upper fluoride level, even not sufficient for the prevention of dental caries. Uvod/Cilj. Fluoridi imaju pozitivan efekat na prevenciju karijesa zuba kao i povećanje čvrstine zubnog emajla. Međutim, njihov unos iznad optimalnog može imati štetne efekte na zube i kosti, posebno kod male dece tokom intenzivnog rasta i razvoja zuba. Cilj ovog rada bio je da se proceni unos fluorida putem vode za piće i paste za zube kod dece uzrasta od tri godine u Beogradu, na teritoriji dve opštine, Vračar i Novi Beograd. Metode. Anketnim upitnicima (n = 40) za roditelje dobijeni su podaci o vrsti vode koju deca piju (česmenska i/ili flaširana), proizvodima koje koriste za čišćenje i negu zuba, učestalosti pranja zuba kao i količini paste za zube koja se koristi po jednom pranju. Sadržaj fluorida u vodi za piće i pastama za zube određen je elektrohemijski sa fluoridnom jonselektivnom elektrodom. Unos fluorida procenjen je korišćenjem matematičkog modela datog od strane Američke agencije za zaštitu životne sredine. Rezultati. Dobijeni rezultati pokazuju da nema statistički značajne razlike u dnevnom unosu fluorida putem vode za piće i paste za zube između dece uzrasta od tri godine na Vračaru i Novom Beogradu (p > 0,05). Međutim, sve procenjene vrednosti unosa fluorida (0,089-0,625 mg/dan) značajno su niže od optimalnog dnevnog unosa za prevenciju karijesa (0,7 mg/dan za decu uzrasta do 4 godine, FNB-Nacionalnog instituta medicine, SAD) i dva do šest puta niže od tolerišućeg gornjeg nivoa unosa fluorida za decu istog uzrasta (1,3 mg/dan, FNBNacionalnog instituta medicine, SAD). Štaviše, izračunati dnevni unosi fluorida izraženi po kilogramu telesne mase potvrđuju veoma nizak unos fluorida kod dece ispitivanih opština u Beogradu, čak značajno niže od preporučenog optimalnog unosa (0,05 mg/kg/dan, EFSA). Zaključak. Ovim preliminarnim istraživanjem pokazano je da je dnevni unos fluorida kod trogodišnjaka u Beogradu značajno niži od tolerišućeg gornjeg nivoa unosa fluorida, čak niži od optimalnog unosa za prevenciju karijesa.

Background: Cadmium and lead are widespread and non-biodegradable pollutants of great concern to human health. In real life scenarios, we are exposed to mixtures of chemicals rather than single chemicals, and it is therefore of paramount importance to assess their toxicity. In this study, we investigated the toxicity of Cd and Pb alone and as a mixture in an animal model of acute exposure. Methods: Experimental groups received a single treatment of aqueous solution of Cd-chloride (15 and 30 mg/kg body weight (b.w.) and Pb-acetate (150 mg/kg b.w.), while the mixture group received 15 mg Cd/kg b.w. and 150 mg Pb/kg b.w. Toxic effects of individual metals and their mixture were investigated on hematological and biochemical parameters, and the redox status in the plasma, liver, and kidneys of treated Wistar rats. Results: Tissue-specific changes were recorded in various parameters of oxidative damage, while the accumulation of metals in tissues accompanied the disturbances of both hematological and biochemical parameters. It was observed that the level of toxic metals in tissues had a different distribution pattern after mixture and single exposure. Conclusions: Comprehensive observations suggest that exposure to Cd and Pb mixtures produces more pronounced effects compared to the response observed after exposure to single metal solutions. However, further research is needed to confirm toxicokinetic or toxicodynamic interactions between these two toxic metals in the organisms.

Toxic metals are extensively found in the environment, households, and workplaces and contaminate food and drinking water. The crosstalk between environmental exposure to toxic metals and human diseases has been frequently described. The toxic mechanism of action was classically viewed as the ability to dysregulate the redox status, production of inflammatory mediators and alteration of mitochondrial function. Recently, growing evidence showed that heavy metals might exert their toxicity through microRNAs (miRNA)—short, single-stranded, noncoding molecules that function as positive/negative regulators of gene expression. Aberrant alteration of the endogenous miRNA has been directly implicated in various pathophysiological conditions and signaling pathways, consequently leading to different types of cancer and human diseases. Additionally, the gene-regulatory capacity of miRNAs is particularly valuable in the brain—a complex organ with neurons demonstrating a significant ability to adapt following environmental stimuli. Accordingly, dysregulated miRNAs identified in patients suffering from neurological diseases might serve as biomarkers for the earlier diagnosis and monitoring of disease progression. This review will greatly emphasize the effect of the toxic metals on human miRNA activities and how this contributes to progression of diseases such as cancer and neurodegenerative disorders (NDDs).

Kada određena supstacija uđe u organizam, njeno toksično delovanje se klinički može manifestovati na razne načine, zavisno od vrste poremećaja prouzrokovanog na nivou ćelije. Vezivanjem za određene endogene molekule, toksična jedinjenja mogu prouzrokovati poremećaj genske ekspresije (neoplazija, teratogeneza), poremećaj tekućih ili trenutnih aktivnosti ćelije (tremor, konvulzije, spazam, aritmija), poremećaj integriteta ćelije (poremećaj sinteze proteina, poremećaj funkcije ćelijske membrane, smrt ćelije) i poremećaj odnosa sa drugim ćelijama (poremećaj u hemostazi – krvarenje). Najteži poremećaji, koji nastaju usled vezivanja hemijskih supstancija sa takozvanim „kritičnim proteinima” (DNK, RNK), klinički se mogu manifestovati kao: mutageneza, karcinogeneza, teratogeneza i imunotoksičnost. When chemical compound enter the body, its toxic effect may clinical to demonstrate in different way, depend from kind of disturbance, what that substance induced in the cell. Binding for endogenous molecules toxic substances can induced disturbance of gens expression (neoplasia, teratogenesis), disturbance of curently activities of cell (tremor, convulsions, spasm, aritmia), disturbance of integrity of cell (disturbance of sinthesis of proteins, disturbance of function of cell membrane, death of cell) and disturbance of relation with other cells (disorders of hemostasis – bleeding). The most serious disturbances which may to begin because of binding chemical substances for so-called “critical proteins” (DNA, RNA) clinical may to demonstrate as: mutagenesis, carcinogenesis, teratogenesis and as immunotoxicity.

Inhibition of acethylcholinesterase (AChE) as a key molecular event induced by organophosphate (OP) pesticides and nerve agents presents a human health concern. In efficacy testing of experimental oximes, potential antidotes in OP poisoning, reactivation of OP-inhibited AChE is used as specific endpoint. However, according to our best knowledge, so far oximes have not been quantitatively evaluated by comprehensive benchmark dose (BMD) approach, that would improve both identification and quantification of the effect and allow more rigorous comparison of efficacies. Thus, we have examined in vivo dose-response relationship for two promising experimental oximes, K203 and K027, concerning reactivation of erythrocyte AChE inhibited by dichlorvos (DDVP). Groups of Wistar rats were treated with six different doses of oximes (i.m) immediately after DDVP challenge (s.c) and AChE was measured 60 min later. Dose-response modeling was done by PROAST software 65.5 (RIVM, The Nederlands). BMD-covariate method resulted in four-parameter model from both exponential and Hill model families as the best estimate of relationship between AChE activity and oxime dose, with potency parameter being oxime-dependent. Oxime K027 was shown to be 1.929-fold more potent considering that 58% increase in AChE activity was achived with the dose BMD58-K027 = 52 μmol/kg in contrast to BMD58-K203 = 100 μmol/kg.

This study explores relation between dental fluorosis occurrence in schoolchildren, residents of Ritopek, a small local community near Belgrade, and fluoride exposure via drinking water. Additionally, fluoride levels were determined in children's urine and hair samples, and efforts were made to correlate them with dental fluorosis. Dental fluorosis and caries prevalence were examined in a total of 52 schoolchildren aged 7-15 years (29 boys and 23 girls). Fluoride levels in three types of samples were analyzed using composite fluoride ion-selective electrode. Results showed high prevalence of dental fluorosis (34.6 %) and low prevalence of dental caries (23.1 %, mean DMFT 0.96) among children exposed to wide range of water fluoride levels (0.11-4.14 mg/L, n = 27). About 11 % of water samples exceeded 1.5 mg/L, a drinking-water quality guideline value for fluoride given by the World Health Organization (2006). Fluoride levels in urine and hair samples ranged between 0.07-2.59 (n = 48) and 1.07-19.83 mg/L (n = 33), respectively. Severity of dental fluorosis was positively and linearly correlated with fluoride levels in drinking water (r = 0.79). Fluoride levels in urine and hair were strongly and positively correlated with levels in drinking water (r = 0.92 and 0.94, respectively). Fluoride levels in hair samples appeared to be a potentially promising biomarker of fluoride intake via drinking water on one hand, and severity of dental fluorosis on the other hand. Based on community fluorosis index value of 0.58, dental fluorosis revealed in Ritopek can be considered as "borderline" public health issue.

A rising number of patients are being treated for overdosing with new psychoactive substances (NPS) available at the illegal drug market in Serbia. The aim of this study was to report clinical and analytical experience of the National Poison Control Centre of Serbia (NPCC) with synthetic cannabinoids (SCs) and point to the NPS available at the illegal drug market in our country. From January 2013 to December 2016, 58 patients (aged between 14 and 25) were treated for the effects of synthetic cannabinoids at the NPCC. Tachycardia was established in 53, mydriasis in 31, somnolence, nausea, vomiting, and agitation in 16, dizziness in 10, disorientation in 9, dyspnoea and chest pain in 4, and loss of consciousness, pallor, paraesthesia, muscle twitches, and short-term memory impairment in 2 patients. After receiving symptomatic and supportive treatment in the emergency ward, all patients had fully recovered within 8 h and were discharged shortly afterwards. Another part of the study was focused on the analysis of the products known under their local street names as “Biljni tamjan” (herbal incense), “Beli slez”, and “Rainbow Special” and the analysis of urine sampled from the patients with gas chromatography - mass spectrometry and high performance liquid chromatography. The detected synthetic cannabinoids were AB-PINACA, JWH-018, JWH-122, JWH-210, 5F-AKB48, and MDMB-CHMICA in herbal products and AB-FUBINACA, AB-CHMINACA, and MDMB-CHMICA in the urine samples. Our findings have shown the great capacity of NPCC to I) monitor NPS abuse in Serbia, II) reliably detect SCs in illicit products and biological samples, and III) clinically manage the adverse effects in their users. Future commitments of the NPCC will include systematic collection of relevant data on SCs and their adverse effects, detection of changes in purity and composition of the controlled NPS-based products, and raising the public awareness of NPS to improve the effectiveness of the national Early Warning System., U porastu je broj pacijenata koji se zbrinjava zbog predoziranja novim psihoaktivnim supstancijama (NPS), dostupnima na ilegalnom tržištu droga u Srbiji. Cilj je ovog rada prikazati klinička i analitička iskustva Nacionalnog centra za kontrolu trovanja (NCKT) sa sintetičkim kanabinoidima (SC) i upozoriti na NPS-ove dostupne na ilegalnom tržištu droga u Srbiji. Od siječnja 2013. do prosinca 2016. u NCKT-u je zbog učinaka sintetičkih kanabinoida zbrinuto 58 pacijenata u dobi od 14 do 25 godina. Njihova je klinička slika uključivala: tahikardiju (53 od 58 pacijenata), midrijazu (31), pospanost, mučninu, povraćanje i agitaciju (16), nesvjesticu (10), dezorijentaciju (9), dispneju i bol u prsima (4) te gubitak svijesti, bljedilo, parestezije, grčeve u mišićima i kratkotrajni gubitak pamćenja (2). Nakon odgovarajuće simptomatske i suportivne terapije u hitnoj službi, svi su se pacijenti potpuno oporavili u roku od osam sati i ubrzo nakon toga otpušteni. Drugi dio rada fokusiran je na analizu preparata poznatih pod nazivima “Biljni tamjan”, “Bijeli sljez”, “Rainbow Special”, “Herbal incense” itd., i na analizu uzorka urina pacijenata metodom plinske kromatografije s masenom spektrometrijom i tekućinske kromatografije visoke djelotvornosti s masenom spektrometrijom. Detektirani su sljedeći sintetički kanabinoidi: ABPINACA, JWH-018, JWH-122, JWH-210, 5F-AKB48 i MDMB-CHMICA u biljnim proizvodima i AB-FUBINACA, AB-CHMINACA i MDMB-CHMICA u uzorcima urina. Rezultati tih analiza pokazali su da NCKT ima veliki kapacitet za I) praćenje zloporabe NPS-a u Srbiji, II) njihovu učinkovitu detekciju u biljnim proizvodima i biološkim uzorcima i III) kliničko liječenje toksičnih učinaka u korisnika tih supstancija. Kako bi pridonio učinkovitosti nacionalnog sustava ranog upozoravanja, NCKT će u budućnosti sustavno prikupljati relevantne podatke o sintetičkim kanabinoidima i njihovim štetnim učincima, detektirati promjenu čistoće i sastava kontroliranih psihoaktivnih supstancija i preparata na bazi NPSova, istodobno podižući svijest javnosti o tim supstancijama

Humans are exposed to a significant number of chemicals that are suspected to produce disturbances in hormone homeostasis. Hence, in recent decades, there has been a growing interest in endocrine disruptive chemicals. One of the alleged thyroid disrupting substances is cadmium (Cd), a ubiquitous toxic metal shown to act as a thyroid disruptor and carcinogen in both animals and humans. Multiple PubMed searches with core keywords were performed to identify and evaluate appropriate studies which revealed literature suggesting evidence for the link between exposure to Cd and histological and metabolic changes in the thyroid gland. Furthermore, Cd influence on thyroid homeostasis at the peripheral level has also been hypothesized. Both in vivo and in vitro studies revealed that a Cd exposure at environmentally relevant concentrations results in biphasic Cd dose-thyroid response relationships. Development of thyroid tumors following exposure to Cd has been studied mainly using in vitro methodologies. In the thyroid, Cd has been shown to activate or stimulate the activity of various factors, leading to increased cell proliferation and a reduction in normal apoptotic activity. Evidence establishing the association between Cd and thyroid disruption remains ambiguous, with further studies needed to elucidate the issue and improve our understanding of Cd-mediated effects on the thyroid gland.

S of the 54th Congress of the European Societies of Toxicology (EUROTOX 2018) TOXICOLOGY OUT OF THE BOX Brussels, Belgium, 2nd – 5th of September, 2018

Hepatotoxicity is one of the well-documented adverse health effects of polychlorinated biphenyls (PCBs)-persistent organic pollutants widely present in the environment. Although previous studies suggest possible role of oxidative stress, the precise mechanisms of PCB-induced ROS production in liver still remain to be fully assessed. The aim of this study was to evaluate the effects of different doses of PCBs on the parameters of oxidative stress and to investigate whether these effects are dose dependent. Furthermore, a comparison between calculated benchmark doses (BMD) and estimated NOAEL values for investigated parameters, was made. Six groups of male albino Wistar rats (7 animals per group) were receiving Aroclor 1254 dissolved in corn oil in the doses of 0.5, 1, 2, 4, 8, 16 mg PCBs/kg b.w./day by oral gavage during 28 days while control animals were receiving corn oil only. The following parameters of oxidative stress were analyzed in liver homogenates: superoxide dismutase activity, glutathione, malondialdehyde (MDA) and total protein thiol levels. Hepatic enzymes AST, ALT, ALP and protein albumin were also determined in serum as clinical parameters of liver function. Collected data on the investigated parameters were analyzed by the BMD method. The results of this study demonstrate that subacute exposure to PCBs causes induction of oxidative stress in liver with dose-dependent changes of the investigated parameters, although more pronounced adverse effects were observed on enzymatic than on non-enzymatic components of antioxidant protection. The obtained values for BMD and NOAEL support the use of BMD concept in the prediction of health risks associated with PCBs exposure. Furthermore, our results implicate possible use of MDA in PCBs risk assessment, since MDA was the most sensitive investigated parameter with calculated low critical effect dose of 0.07 mg/kg b.w.

In order to look into the combined effects of Cd and BDE-209 in vitro, this study was aimed at examining cytotoxic and genotoxic effects using the human colon carcinoma cell line (SW 480) as a biological test system as well as to determine if ROS production was one of the possible mechanisms of their mixture action. This cell line was chosen since ingestion of contaminated food/water represents an important route of exposure to both Cd and BDE-209, which is why intestinal cells are a common target for the contaminants present in food and water. Cells were treated with single Cd in concentrations of 2.5, 7.5 or 15 mu g Cd/mL (corresponding to 22, 67 or 134 mu M), single BDE-209 in concentrations of 2.5, 5 or 10 mu g BDE209/mL (corresponding to 2.5, 5 or 10 mu M), and their mixtures (design 3 x 3). Mixture of Cd and BDE-209 has shown clear potential to reduce the viability of SW 480 cells, as evidenced by cytotoxicity associated with ROS generation. Factorial regression models used to identify type of interaction revealed synergism related to mixture citotoxicity and additive interaction for the effect on ROS production. The results from this introductory study could contribute to the issue of possible adverse effects associated with co-exposure and body burden with two persistent environmental pollutants, Cd and BDE-209.

S of the 54th Congress of the European Societies of Toxicology (EUROTOX 2018) TOXICOLOGY OUT OF THE BOX Brussels, Belgium, 2nd – 5th of September, 2018

Endocrine-disrupting chemicals currently represent one of the major concerns and this study was aimed to investigate the effects of different doses of cadmium, widespread toxic metal, on the levels of thyroid hormones and to calculate Benchmark doses for these effects. Furthermore, the effects of co-exposure to cadmium and polychlorinated biphenyls on thyroid function were investigated. Six orally-treated groups of rats were receiving 0.3, 0.6, 1.25, 2.5, 5 and 10 mg Cd/kg b.w./day, five groups were orally treated with 0.5, 1, 2, 4 and 8 mg PCBs/kgb.w./day, while nine groups of rats were orally-treated with different dose combinations of Cd and PCBs (0.6, 1.25 and 2.5 mg Cd/kgb.w. and 2,4 and 8 mg PCBs/kg b.w./day), during 28 days. Thyroid hormones were adversely affected by cadmium, with most prominent effect observed on triiodothyroxine levels indicating Cd interference with thyroid function at extrathyroidal level. Calculated Benchmark doses for Cd effects on thyroid hormones indicate triiodothyroxine as the most sensitive one that can be used as a basis for risk assessment. This study also implicates possible synergistic effects of Cd and PCBs on thyroid function as a consequence of their interference at different levels of thyroid homeostasis.

s of the 53rd Congress of the European Societies of Toxicology (EUROTOX)Bratislava, Slovakia, 10th–13th September, 2017