Search

Oxidative stress and inflammation are DNA instability factors for rheumatoid arthritis (RA) patients. The aims of this study were to evaluate cytogenetic alterations in Peripheral Blood Lymphocytes (PBL) in two groups of RA patients: the early and the long-term RA group; and to examine potential of concomitant treatment with Methotrexate (MTX) and Dry olive leaf extract (DOLE) against cytogenetic damage in RA patients after a 3-weeks treatment. A total of 32 RA patients and 10healthy individuals were included. RA patients were equally divided into four groups: two groups with early phase RA (one treated with MTX alone, the other in combination with DOLE); and two long-term phase RA groups (group with active disease and group with low disease activity)-both treated with MTX and DOLE combination. PBL cultures were screened for chromosome aberrations and micronuclei frequencies. Significantly increased frequencies of micronuclei were shown in active phase RA disease (both early and long-term) but not in the group with low disease activity, as compared to controls. Chromosome aberrations were detected for all 4 RA groups. The highest frequencies of micronuclei and chromosome aberrations were found in the long-termactive RA group. After 3 weeks-treatment, there were no significant decrease of the micronuclei frequencies compared to baseline, although they were reduced in all RA groups, except for the group with the long-term active disease. High level of cytogenetic damage in RA patients was concordant with duration and activity of the RA disease. At 3 weeks of therapy, neither the combined treatment (MTX+DOLE), nor MTX alone did not affect the frequency of micronuclei formation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI 173034]

In cellular physiology and signaling, reactive oxygen species (ROS) play one of the most critical roles. ROS overproduction leads to cellular oxidative stress. This may lead to an irrecoverable imbalance of redox (oxidation-reduction reaction) function that deregulates redox homeostasis, which itself could lead to several diseases including neurodegenerative disease, cardiovascular disease, and cancers. In this study, we focus on the redox effects related to vascular systems in mammals. To support research in this domain, we developed an online knowledge base, DES-RedoxVasc, which enables exploration of information contained in the biomedical scientific literature. The DES-RedoxVasc system analyzed 233399 documents consisting of PubMed abstracts and PubMed Central full-text articles related to different aspects of redox biology in vascular systems. It allows researchers to explore enriched concepts from 28 curated thematic dictionaries, as well as literature-derived potential associations of pairs of such enriched concepts, where associations themselves are statistically enriched. For example, the system allows exploration of associations of pathways, diseases, mutations, genes/proteins, miRNAs, long ncRNAs, toxins, drugs, biological processes, molecular functions, etc. that allow for insights about different aspects of redox effects and control of processes related to the vascular system. Moreover, we deliver case studies about some existing or possibly novel knowledge regarding redox of vascular biology demonstrating the usefulness of DES-RedoxVasc. DES-RedoxVasc is the first compiled knowledge base using text mining for the exploration of this topic.

Strawberry fruit Fragaria × ananassa Duchesne, Rosaceae (cv. Romina), rich in anthocyanin polyphenols, has been demonstrated to have favorable effects on health due to its antioxidant properties. The present study investigated the antigenotoxic potential of anthocyanin-enriched fraction of Romina strawberry methanolic extract (ACY) against DNA damage on human peripheral blood leukocytes, induced by hydrogen peroxidein vitro. Five concentrations of the ACY extract were used in all experiments (2.5, 5, 10, 15, 20 μg/ml). The results of the alkaline comet assay showed no genotoxic effect of the ACY. After the pre-exposureof the leukocytes to the ACY, and subsequent incubation with H2O2, a decreased number of DNA damaged cells was recorded in all the tested concentrations, compared to controls. In the post-treatment, there was a concentration-dependent DNA damage reduction, while a statistically significant decrease was achieved with 15 and 20 μg/ml concentrations. The results indicate that ACY is efficient in oxidative DNA damage reduction, and it is more potent as a post-applicative than a protective agent. Plodovi jagode Fragaria × ananassa Duchesne, Rosaceae (cv. Romina), bogati antocijaninima, pokazali su povoljne efekte na zdravlje zahvaljujući svojim antioksidativnim svojstvima. U ovoj studiji ispitivan je antigenotoksični potencijal frakcije metanolnog ekstrakta jagode Romina koji je obogaćen antocijaninom (ACY) na oštećenja DNK na leukocitima humane periferne krvi, izazvanih vodonik-peroksidom in vitro. U svim eksperimentima je korišćeno i testirano pet koncentracija ekstrakta ACY (2.5, 5, 10, 15, 20 µg /ml). Rezultati ispitivanja alkalnim komet testom nisu pokazali genotoksični efekat ACY. Nakon izloženosti leukocita ACY i potom njihovog tretmana i inkubacije sa H2O2, smanjen je broj ćelija sa oštećenom DNK, u svim ispitivanim koncentracijama u poređenju sa kontrolama. U post-tretmanu, došlo je do smanjenja oštećenja DNK u zavisnosti od koncentracije ekstrakta, dok je statistički značajno smanjenje postignuto sa koncentracijama od 15 i 20 µg/ml. Rezultati ukazuju da je ACY efikasan u smanjenju oksidativnih oštećenja DNK i da pokazuje snažniji efekat kao postaplikativno nego kao zaštitno sredstvo.

More people die from cardiovascular diseases (CVD) than from any other cause. Cardiovascular complications are thought to arise from enhanced levels of free radicals causing impaired “redox homeostasis,” which represents the interplay between oxidative stress (OS) and reductive stress (RS). In this review, we compile several experimental research findings that show sustained shifts towards OS will alter the homeostatic redox mechanism to cause cardiovascular complications, as well as findings that show a prolonged antioxidant state or RS can similarly lead to such cardiovascular complications. This experimental evidence is specifically focused on the role of glutathione, the most abundant antioxidant in the heart, in a redox homeostatic mechanism that has been shifted towards OS or RS. This may lead to impairment of cellular signaling mechanisms and elevated pools of proteotoxicity associated with cardiac dysfunction.

The health benefits of natural products have long been recognized. Consumption of dietary compounds such as supplements provides an alternative source of natural products to those obtained from the diet. There is a growing concern regarding the possible side effects of using different food supplements simultaneously, since their possible interactions are less known. For the first time, we have tested genotoxic and antigenotoxic effects of Biochaga, in combination with dihydroquercetin. No genotoxic effect on whole blood cells was observed within individual treatment of Biochaga (250 μg/mL, 500 μg/mL and 1000 μg/mL) and dihydroquercetin (100 μg/mL, 250 μg/mL and 500 μg/mL), nor in combination. Afterwards, antigenotoxic potency of both supplements against hydrogen peroxide- (H2O2-) induced DNA damage to whole blood cells (WBC) was assessed, using the comet assay. Biochaga and dihydroquercetin displayed a strong potential to attenuate H2O2-induced damage on DNA in cells at all tested concentrations, with a statistical significance (p<0.05), whereas Biochaga at the dose of 500 μg/mL in combination with dihydroquercetin 500 μg/mL was most prominent. Biochaga in combination with dihydroquercetin is able to protect genomic material from oxidative damage induced by hydrogen peroxide in vitro.

Immune Assist (IA) is produced from extract of six species of medical mushrooms: Agaricus blazei - Cordyceps sinensis - Grifola frondosa - Ganoderma lucidum - Coriolus versicolor - Lentinula edodes. The genoprotective potential of IA was evaluated for the first time. Significant antigenotoxic effects were detected in human peripheral blood cells against H2O2 induced DNA damage, in the pretreatment and in the posttreatment. The most efficient concentration of IA in pretreatment was 500 μg/mL, while in posttreatment it was the concentration of 250 μg/mL. Kinetics of attenuation of H2O2 induced DNA damage in posttreatment with the optimal concentration of IA showed significant decrease in the number of damaged cells at all time periods (15–60 min), reaching the greatest reduction after 15 and 45 min. Remarkable ·OH scavenging properties and moderate reducing power, together with the modest DPPH scavenging activity, could be responsible for the great attenuation of DNA damage after 15 min of exposure to IA, while reduction of DNA damage after 45 min could be the result in additional stimulation of the cell’s repair machinery. Our results suggest that IA displayed antigenotoxic and antioxidant properties. A broader investigation of its profile in biological systems is needed. This is peer-reviewed version of the following article: Živković, L.; Bajić, V.; Bruić, M.; Borozan, S.; Popić, K.; Topalović, D.; Santibanez, J.; Spremo-Potparević, B. Antigenotoxic and Antioxidant Potential of Medicinal Mushrooms (Immune Assist) against DNA Damage Induced by Free Radicals-an in Vitro Study. Mutat. Res. Genet. Toxicol. Environ. Mutagen. 2019, 845. [https://doi.org/10.1016/j.mrgentox.2019.06.008]

Objective. Prooxidants and antioxidants affect the oxidative balance at the intracellular level. Oxidative stress is a consequence of the overproduction of prooxidants and is caused by disturbances in the balance of oxidative reduction processes. Non-enzymatic low molecular weight antioxidants can be introduced into the body through food. Cordyceps sinensis (C. sinensis) is a medicinal fungus used in traditional Chinese medicine, with rich content of vitamins, various polysaccharides, and many nucleosides. The aim of this study is to evaluate the antioxidant capacity of the dietary supplement C. sinensis. Methods. The capacity of the hydroxyl radical scavenger activity, the total antioxidant activity of FRAP (Ferric Reducing Antioxidant Power) and the DPPH (2,2-diphenyl-1- picrylhydrazyl) scavenger activity were measured. Results. C. sinensis at the tested concentrations of 0.0078–2.00 mg/mL had a pronounced ability to remove hydroxyl radicals with IC50 of 0.5 mg/mL, while at concentrations (0.0078–10.00 mg / mL) it showed a moderate reducing ability. C sinensis showed no ability to remove DPPH radicals. Conclusion. C. sinensis effectively removes hydroxyl radicals, for which the body does not have adequate antioxidant protection, so we can include it in the group of free radical scavengers. Cilj. Prooksidansi i antioksidansi utiču na oksidativnu ravnotežu na intracelularnom nivou. Oksidativni stres je posledica prekomerne produkcije prooksidanasa i nastaje usled poremećaja u ravnoteži oksido-redukcionih procesa. Neenzimski antioksidansi male molekulske mase mogu se uneti u organizam preko hrane. Cordyceps sinensis (C. sinensis) lekovita je gljiva koja se koristi u tradicionalnoj kineskoj medicini, ima bogat sadržaj vitamina, raznih polisaharida, kao i mnogih nukleozida. Cilj istraživanja ove studije bila je evaluacija antioksidativnog kapaciteta dijetetskog suplementa C. sinensis. Metode. Mereni su kapacitet „skevindžer“ aktivnosti hidroksil radikala, ukupna antioksidativna aktivnost primenom FRAP (Ferric Reducing Antioxidant Power) metode i DPPH (2,2-difenil-1-pikrilhidrazil) – skevindžer aktivnost. Rezultati. C. sinensis je u ispitivanim koncentracijama 0,0078–2,00 mg/mL imao izraženu sposobnost uklanjanja hidroskil radikala, čija je IC50 iznosila 0,5 mg/mL, dok je u koncentracijama 0,0078–10,00 mg/mL pokazao umerenu redukcionu sposobnost. C. sinensis nije pokazao sposobnost uklanjanja DPPH radikala. Zaključak. C. sinensis efikasno neutrališe hidroksilne radikale, za koje organizam nema adekvatnu antioksidativnu zaštitu pa ga možemo uvrstiti u grupu potencijalnih protektora od slobodnih radikala.

The effects of co-administration of dry olive leaf extract (DOLE) with standard methotrexate (MTX) therapy on the parameters of cell damage and inflammation in patients with early and long-term rheumatoid arthritis (RA) were evaluated at baseline, 3 and 6 weeks. Patients were assigned to groups: the early phase RA group on MTX monotherapy (E MTX), and the two RA groups that received co-treatment with DOLE and MTX: early (E MTX + DOLE) and long-term phase patients (L-t MTX+ DOLE). Baseline values indicated increased parameters of cell damage and disruption of redox balance in all groups. After three weeks the E MTX + DOLE group maintained high catalase activity, exhibited decrease of lipid peroxidation and protein damage indicators-thiols and nitrites, while levels of DNA damage and pro-inflammatory interleukin-6 were significantly reduced. In E MTX group catalase activity remained unaltered while significant lipid peroxidation and DNA damage reductions were seen only after six weeks. L-t MTX + DOLE group showed only modest alterations of cell damage parameters during six weeks. Combined administration of DOLE with MTX contributes to faster reduction of cell damage, restores oxidative balance and improves interleukin-6 suppression during high disease activity in early phase RA, but not in long term patients. Copyright © 2016 John Wiley & Sons, Ltd.

Ganoderma lucidum is traditionally used in Eastern medicine to preserve vitality, promote longevity, and treat disease. It possesses immunomodulatory, antitumor, antimicrobial, and antiaging activities, among others, but one of the most important is its antioxidant property, which is the basis for other effects, because free radicals trigger many diseases. The substrate commonly used for commercial cultivation of G. lucidum is not environmentally friendly nor economically justified, so there is a need to find new alternative substrates. The aim of this study was to analyze the effect of substrate composition on the bioactivity of G. lucidum basidiocarps. G. lucidum was cultivated on 2 different substrates: (1) a mixture of wheat straw, grapevine branches, and wheat bran, and (2) wheat straw. Commercial fruiting bodies, cultivated on oak sawdust, were used as the control. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, total phenols, and flavonoid content were determined spectrophotometrically to define the antioxidative potential of basidiocarp extracts. The comet test was performed to detect the degree of DNA damage in the cells that were exposed to G. lucidum extracts before and after the effect of oxidants. Higher antioxidative potential was observed for the extract of G. lucidum basidiocarps cultivated on wheat straw compared with that from the mixed substrate and especially with commercial ones. The alternatively cultivated basidiocarps also showed stronger antigenotoxic potential compared with commercial ones. The study showed that fruiting bodies produced on wheat straw, one of the most accessible and cheapest crop residues, are more potent antioxidant and antigenotoxic agents than commercially cultivated ones.

The acute toxicity of surface-modified TiO2 nanoparticles (NPs) with caffeic acid (CA) was compared with those of its separate constituents (free CA and bare TiO2 NPs) upon their oral administration in laboratory mice. Prior to in vivo experiments, the interfacial charge transfer (ICT) complex between surface Ti atoms and CA is thoroughly characterized. Composition and stability constants of ICT complex were determined using Job's method and Banesi-Hildebrand analysis, respectively. The experimental data were supported with quantum chemical calculations based on density functional theory (DFT). Acute toxicity signs, including biochemical alterations and extensive histopathological changes in the liver tissue of mice were detected 14 days after oral administration of bare TiO2 NPs. However, the clinical signs of toxicity, the fractional contribution of organs, biochemical parameters of liver and kidney function, and histopathological changes in liver upon treatment with surface-modified TiO2 NPs with CA were not observed. Also, the genotoxic potential of the ICT complex and its constituents were evaluated in leukocytes of whole blood cells in vivo by comet assay. Both, bare and surface-modified TiO2 NPs did not display DNA damaging effect in time frame of 24 h upon their oral administration in mice.

Homocysteine (Hcy) is a thiol group containing the amino acid, which naturally occurs in all humans. Hcy is degraded in the body through two metabolic pathways, while a minor part is excreted through kidneys. The chemical reactions that are necessary for degradation of Hcy require the presence of folic acid, vitamins B6 and B12. Consequently, the level of the total Hcy in the serum is influenced by the presence or absence of these vitamins. An elevated level of the Hcy, hyperhomocysteinemia (HHcy) and homocystinuria is connected with occlusive artery disease, especially in the brain, the heart, and the kidney, in addition to venous thrombosis, chronic renal failure, megaloblastic anemia, osteoporosis, depression, Alzheimer's disease, pregnancy problems, and others. Elevated Hcy levels are connected with various pathologies both in adult and child population. Causes of HHcy include genetic mutations and enzyme deficiencies in 5, 10-methylenetetrahydrofolate reductase (MTHFR) methionine synthase (MS), and cystathionine β-synthase (CβS). HHcy can be caused by deficiencies in the folate, vitamin B12 and to a lesser extent, deficiency in B6 vitamin what influences methionine metabolism. Additionally, HHcy can be caused by the rich diet and renal impairment. This review presents literature data from recent research related to Hcy metabolism and the etiology of the Hcy blood level disorder. In addition, we also described various pathological mechanisms induced by hereditary disturbances or nutritional influences and their association with HHcy induced pathology in adults and children and treatment of these metabolic disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.

Breast cancer (BC) is a heterogeneous disease in an urgent need for developing novel research, classification, and therapy approaches. Breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) proteins are well described tumor suppressors with great potential to be the subjects of different therapies. MicroRNAs (miRNAs) are genetic elements that might be used to solve the complex BC puzzle. BRCA1 was described to be the target of up to 100 miRNAs. BRCA1 may directly repress miR-155 activity. In addition, miR-15/107/182-mediated downregulation of BRCA1 interrupt DNA repair and may change the course of BC therapy. miR-146a and miR-146-5p silencing BRCA1 may trigger formation of triple-negative and basal-like sporadic BC cases. miR-182 might effect the therapy outcome. miR-21 targeted therapy might be useful for the treatment of BRCA2 mutation carriers. miR-342 overexpression and the absence of functional BRCA1 gene might cause synthetic lethality, which might be used as a base for future therapies. The present review discusses the latest data from studies that focus on the complex network of miRNAs and BRCA1/2 related BCs, which might be important for improving the therapy within the patients with triple-negative BC (TNBC) and basal-like BC, and for understanding the formation of TNBC.

Noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long ncRNAs (lncRNAs), are important players in diseases and emerge as novel drug targets. Thus, unraveling the relationships between ncRNAs and other biomedical entities in cells are critical for better understanding ncRNA roles that may eventually help develop their use in medicine. To support ncRNA research and facilitate retrieval of relevant information regarding miRNAs and lncRNAs from the plethora of published ncRNA-related research, we developed DES-ncRNA (www.cbrc.kaust.edu.sa/des_ncrna). DES-ncRNA is a knowledgebase containing text- and data-mined information from public scientific literature and other public resources. Exploration of mined information is enabled through terms and pairs of terms from 19 topic-specific dictionaries including, for example, antibiotics, toxins, drugs, enzymes, mutations, pathways, human genes and proteins, drug indications and side effects, mutations, diseases, etc. DES-ncRNA contains approximately 878,000 associations of terms from these dictionaries of which 36,222 (5,373) are with regards to miRNAs (lncRNAs). We provide several ways to explore information regarding ncRNAs to users including controlled generation of association networks as well as hypotheses generation. We show an example how DES-ncRNA can aid research on Alzheimer disease and suggest potential therapeutic role for Fasudil. DES-ncRNA is a powerful tool that can be used on its own or as a complement to the existing resources, to support research in human ncRNA. To our knowledge, this is the only knowledgebase dedicated to human miRNAs and lncRNAs derived primarily through literature-mining enabling exploration of a broad spectrum of associated biomedical entities, not paralleled by any other resource.

While Alzheimer’s disease (AD) is primarily considered to be a neurodegenerative disorder, there is much evidence supporting the idea that it is also a systematic disease, so the occurrence of genomic instability in cells that are not neurons is equally important. Accordingly, acrocentric chromosomes play an important role in the etiology of AD, especially the presence of trisomy 21. The aim of this work was to assess the relationship between the frequency of acrocentrics included in satellite association (SA) and acrocentrics with premature centromere division (PCD) in the peripheral blood lymphocytes of AD patients and age-matched controls. Since our results showed that there are significant differences in SA frequency, as well as in the frequency of PCD in acrocentrics between AD patients and control group, we may conclude that the occurrence of acrocentric chromosome alterations presented in this study could be related to the etiology of AD. [Projekat Ministarstva nauke Republike Srbije, br. OI 173034] This article has been corrected. Link to the correction 10.2298/ABS150713084E

Subclinical hypothyroidism (SH) is characterized by a mildly elevated concentration of thyroid stimulating hormone (TSH) despite free thyroxine (FT4) and triiodothyronine (FT3) levels within the reference range. Numerous studies revealed SH to be an independent risk factor for cardiovascular disease (CVD), including atherosclerosis, congestive heart failure, coronary heart disease, ischemic heart disease and the associated mortality. The relationship between SH and CVD is well documented, but the molecular mechanism underlying this correlation remain unknown. Endothelial dysfunction has been recognized as an initial step leading to CVD in patients with SH. Changes in lipid profile, inflammation and/or oxidative stress contribute to the endothelial dysfunction in SH. Moreover, the progression of SH is characterized by significantly decreased nitrite and nitrate levels. Recent animal and clinical studies discussed in this review suggest that nitric oxide (NO) levels could be a reliable biomarker for cardiovascular risk in SH. Understanding the regulation of NO production by thyroid hormone may provide novel and useful knowledge regarding how endothelial dysfunction in SH is linked with CVD and help us to uncover new treatments for SH. We suggest that serum NO level may be an indicator for the introduction and dosage of levothyroxine (LT4) replacement therapy in SH patients. Future studies should focus on understanding the molecular mechanisms underlying the effects of NO in physiological as well as in pathophysiological conditions such as hypothyroidism and their clinical relevance.

Alzheimer?s disease (AD), as the most common form of dementia, has for many years attracted the attention of researchers around the world, primarily because of the problems of reliable diagnostic methods that could help in the early detection of this devastating disease. One of the important aspects of genetic research related to AD is the analysis of chromosome instability which includes: aneuploidies of different chromosomes, telomere shortening and the phenomenon of premature centromere division (PCD). The aim of this study was to describe specific biomarkers in different types of cells as potential parameters for the diagnosis of AD in order to promptly recognize pre-symptomatic stages and prevent the development of disease and/or slow down its progression.

8-chloro-cyclic adenosine 3',5'-monophosphate (8-Cl-cAMP) is the most potent cAMP analogue that selectively inhibits a variety of cancer cell lines in vitro and tumors in vivo. Its action toward a variety of tumors, especially when coupled with other antitumor agents, have lead to phase I clinical investigations and recently phase II clinical investigations. Until today very little was done to evaluate its genotoxic potential. In order to evaluate its genotoxic potential we used the cytogenetic and cytokinesis block micronucleus assay in vitro on peripheral blood lymphocytes of healthy individuals. Using three concentrations (1 microM, 5 microM and 15 microM), 8-Cl-cAMP in normal human peripheral blood lymphocytes did not induce any cytogenetic aberrations of the structural type [chromatid breakage, isochromatid breakage and gaps], but did induce premature centromere separation (PCS) in all respective doses and increased the frequency of micronuclei (p0.05) only in the highest dose (15 microM). Antiproliferative action of 8-Cl-cAMP was estimated by using the cytokinesis block nuclear division index (NDI). The results showed a decrease in the NDI of cells exposed to all doses of 8-Cl-cAMP when compared to control. Therefore, the overall results show a genotoxic potential of 8-Cl-cAMP in peripheral blood lymphocytes in vitro.

Current chemotherapeutic drugs act for the most part by killing cancer cells directly. Treatment with these drugs often can be harmful to normal cells and may cause incomplete elimination of the target cells, resulting in the recurrence of the disease. To coop with current treatments the path of biomodulation rather than cytotoxicity, has been seen in the role of cAMP in normal versus malignant cells. It has been found that an increase of cAMP levels in normal cells stimulates proliferation, and that in the same time cancerous cells are inhibited to proliferate. This inverted reaction has given the momentum for synthesis of various cAMP analogues and investigation of there antitumor activity. A number of analogues, such as 8-PIP-cAMP, 8-Br-CAMP or 8-HA-cAMP showed efficacy only in millimolar concentrations. Only one of them, 8-Cl-cAMP as specific analogue has achieved inhibition of proliferation and stimulation of apoptosis of malignant cells in low or micromole concentrations. Still, 25 years later the mechanism of action of 8-clcAMP has not been fully elucidated or defined. This review is to challenge these mechanisms of action and to set a view of the nature of 8-Cl-cAMP action.

C-reactive protein (CRP) is a marker of inflammation. Atherosclerosis is now recognized as inflammatory disease, and it seems that CRP directly contributes to atherogenesis. Oxidation of low-density lipoprotein (LDL) molecule increases the uptake of lipid products by macrophages leading to cholesterol accumulation and subsequent foam cell formation. The elevated levels of high sensitivity CRP (hsCRP) and oxidized LDL (OxLDL) in the blood were found to be associated with cardiovascular diseases (CVD). In this review, we highlighted the evidence that CRP and OxLDL are involved in interrelated (patho) physiological pathways. The findings on association between hsCRP and OxLDL in the clinical setting will be also summarized.

The aim of this study was to determine oxidative alterations leading to cellular dysfunctions in Pb-exposed subjects by evaluating damage to all major classes of biomolecules in the cell, lipid peroxidation, protein and DNA damage and determine relationships between parameters of Pb toxicity and specific biomarkers of oxidative damage.Analysis was conducted of smelter workers with high blood Pb and urine aminolevulinic acid levels and slightly elevated values of coproporphyrin and erythrocyte protoporphyrin IX. Significant decreases of thiol groups and increases in carbonyl groups as protein degradation end products, and of nitrite were detected. Elevated rates of lipid peroxidation and rises in the activities of the antioxidant enzymes Cu-Zn superoxide dismutase and catalase were also observed. Both enzymes showed positive correlations with the blood lead levels and urine coproporphyrin, while thiol groups correlated negatively with the same indices. The genotoxic potential of lead was manifested through an increased number of DNA-damaged cells. Increased activities of serum lactate dehydrogenase isoenzymes indicated cellular damage in the lungs, kidneys, and liver. These lead-induced impairments should be taken into consideration in the assessment of Pb-related health hazards. This is peer-reviewed version of the following article: Čabarkapa, A.; Borozan, S.; Živković, L.; Milanović-Čabarkapa, M.; Stojanović, S.; Bajić, V.; Spremo-Potparević, B. Implications of Oxidative Stress in Occupational Exposure to Lead on a Cellular Level. Toxicol. Environ. Chem. 2015, 97 (6), 799–813. [https://doi.org/10.1080/02772248.2015.1060973] Published version: [http://cer.ihtm.bg.ac.rs/handle/123456789/1706]

Thyroid hormones enhance the metabolic rate and the aerobic metabolism favoring oxidative stress, which is accompanied by induction of damage to cellular macromolecules including the DNA. The aim of the present study was to investigate the ability of thyroxine to induce sister chromatid exchange and micronuclei, and to modulate cell-cycle kinetics in cultured human lymphocytes. Eight experimental concentrations of thyroxine were used, ranging from 2 x 10(-9) to 0.5 x 10(-4) M. Treatment with thyroxine increased the frequency of SCE per cell at the higher concentrations (1.5 x 10(-6), 0.5 10(-5), 1.5 x 10(-5) and 0.5 x 10(-4) M). On the other hand, there were no significant aneugenic and/or clastogenic effects observed in the cytokinesis-block micronucleus assay. The results show that thyroxine acted as a relatively weak clastogen compared with the positive control N-methyl-N '-nitro-N-nitrosoguanidine (MNNG). In addition to the genotoxic effects, two high concentrations of thyroxine decreased the mitotic index and caused cell-cycle delay. In conclusion, thyroxine exhibited weak clastogenic effects only at high concentrations. Therefore, effects in humans might appear in cases of acute thyroxine overdose.

Alzheimer’s disease (AD) is the most frequent progressive neurodegenerative disorder in elderly associated with irreversible cognitive impairment and dementia. The vast majority of AD patients are sporadic (SAD) in which the disease develops after age of 65. Despite of century of research, we lack understanding of the SAD etiology and pathogenesis. Several hypotheses try to explain the main causes of brain degeneration in SAD, one of them assuming that genomic instability and the reentry of certain neurons into the incomplete cell cycle may be the pathogenic basis of the disease. Although the brain is the most affected organ in AD, numerous studies showed structural and functional alterations in peripheral tissues, suggesting that AD is a generalized systemic disorder. Diverse changes in peripheral cells from AD patients are described in literature including cell cycle aberration and chromosome instability, alterations in cell viability, proliferation and apoptosis, oxidative metabolism, amyloid precursor protein and amyloid β protein metabolism, and other cellular processes. The aim of this paper was to summarize and review the results of our investigations and the growing literature data concerning the multiple chromosomal alterations in peripheral cells of AD patients and to consider their possible role in the disease pathogenesis as well as the importance of such investigations. [Projekat Ministarstva nauke Republike Srbije, br. 173034]

In breast carcinoma, disruption of the p53 pathway is one of the most common genetic alterations. The observation that the p53 can express multiple protein isoforms adds a novel level of complexity to the outcome of p53 mutations. p53 expression was analysed by Western immunoblotting and immunohistochemistry using monoclonal antibodies DO-7, Pab240, and polyclonal antiserum CM-1. The more frequently p53-positive nuclear staining has been found in the invasive breast tumors. One of the most intriguing findings is that mutant p53 appears as discrete dot-shaped regions within the nucleus of breast cancer cells. In many malignant cells, the nucleolar sequestration of p53 is evident. These observations support the view that the nucleolus is involved directly in the mediation of p53 function or indirectly by the control of the localization of p53 interplayers. p53 expressed in the nuclear fraction of breast cancer cells revealed a wide spectrum of isoforms. p53 isoforms ΔNp53 (47 kDa) and Δ133p53β(35 kDa), known as dominant-negative repressors of p53 function, were detected as the most predominant variants in nuclei of invasive breast carcinoma cells. The isoforms expressed also varied between individual tumors, indicating potential roles of these p53 variants in human breast cancer.

The cell cycle consists of four main phases: G(1), S, G(2), and M. Most cells undergo these cycles up to 40-60 times in their life. However, neurons remain in a nondividing, nonreplicating phase, G(0). Neurons initiate but do not complete cell division, eventually entering apoptosis. Research has suggested that like cancer, Alzheimer's disease (AD) involves dysfunction in neuronal cell cycle reentry, leading to the development of the two-hit hypothesis of AD. The first hit is abnormal cell cycle reentry, which typically results in neuronal apoptosis and prevention of AD. However, with the second hit of chronic oxidative damage preventing apoptosis, neurons gain "immortality" analogous to tumor cells. Once both of these hits are activated, AD can develop and produce senile plaques and neurofibrillary tangles throughout brain tissue. In this review, we propose a mechanism for neuronal cell cycle reentry and the development of AD.

There have been a number of attempts to reduce the oxidative radical burden of tobacco. A recently patented technology, pulse electromagnetic technology, has been shown to induce differential action of treated tobacco products versus untreated products on the production of reactive oxygen species (ROS) in vivo. In a 90-day respiratory toxicity study, Wistar rats were exposed to cigarette smoke from processed and unprocessed tobacco and biomarkers of oxidative stress were compared with pathohistological analysis of rat lungs. Superoxide dismutase (SOD) activity was decreased in a dose-dependent manner to 81% in rats exposed to smoke from normal cigarettes compared to rats exposed to treated smoke or the control group. These results correspond to pathohistological analysis of rat lungs, in which those rats exposed to untreated smoke developed initial signs of emphysema, while rats exposed to treated smoke showed no pathology, as in the control group. The promise of inducing an improved health status in humans exposed to smoke from treated cigarettes merits further investigation.

summary Premature centromere division, or premature centromere separation (PCS), occurs when chromatid separation is dysfunctional, occurring earlier than usual during the interphase stage of mitosis. This phenomenon, seen in Robert’s syndrome and various cancers, has also been documented in peripheral as well as neuronal cells of Alzheimer’s disease (AD). In the latter instances, fluorescent in situ hybridization (FISH), applied to the centromere region of the X-chromosome in interphase nuclei of lymphocytes from peripheral blood in AD patients, demonstrated premature chromosomal separation before mitotic metaphase directly after completion of DNA replication in G2 phase of the cell cycle. Furthermore, and perhaps unexpectedly given the presumptive post-mitotic status of terminally differentiated neurons, neurons in AD patients also showed significantly increased levels of PCS of the X-chromosome. Taken together with other phenomena such as cell cycle re-activation and ectopic re-expression of cyclins and cyclin dependent proteins, we propose that AD is an oncogenic phenotype leading to accelarated aging of the affected brain.

Fumagillin is a naturally secreted antibiotic of the fungus Aspergillus fumigates. It is used in veterinary medicine against microsporidiosis of bees and fish. In this study, the genotoxicity of fumagillin (in the form of fumagillin dicyclohexylamine) was evaluated in mouse bone-marrow cells using the mitotic index (MI), the chromosome aberration (CA) assay, and the micronucleus (MN) test. Fumagillin was administered to BALB/c mice by gavage, at doses of 25, 50, 75 mg/kg body weight (bw), repeated for 7 days at 24-h intervals, with water-sugar syrup as a negative control and cyclophosphamide (40 mg/kg bw) as a positive control. All experimental doses of fumagillin induced a significant decrease (p < 0.001) in MI (3.47 +/- 0.04%, 3.17 +/- 0.01%, and 2.27 +/- 0.02%, respectively) in comparison with the negative control (6.00 +/- 0.01%). Fumagillin significantly (p < 0.001) increased the frequency of MN (4.98 +/- 0.35, 8.45 +/- 0.57, and 12.02 +/- 0.37, respectively) over negative control (1.04 +/- 0.28). Significantly increased frequencies (p < 0.01 or p < 0.001) of numerical chromosomal aberrations (aneuploidies and polyploidies) and structural chromosomal aberrations such as gaps, breaks, and centric rings were observed at the highest experimental dose of fumagillin (75 mg/kg bw) compared with the negative control. However, with respect to the induction of Robertsonian translocations, both the intermediate (50 mg/kg bw) and highest (75 mg/kg bw) experimental dose caused a significant (p < 0.001) increase (7.12 +/- 0.26 and 9.00 +/- 0.10, respectively) in comparison with the negative control (0.00 +/- 0.00). Chromosomes 4 and 19 participated in these Robertsonian translocations. Regarding total cytogenetic changes, a significant increase (p < 0.001) was observed in both the intermediate dose group (17.36 +/- 1.83) and the highest dose group (59.49 +/- 1.92) compared with the negative control (7.00 +/- 1.35). These results suggest that fumagillin has genotoxic (clastogenic) potential in mammals in vivo.

Background Growth-modulating noncytotoxic activity of 8-chloro-adenosine 3′,5′-cyclic monophosphate (8-Cl-cAMP) showed inhibitory effect on growth of a wide variety of cancer cell lines in vitro and in vivo . To assess possible genotoxic effects of 8-Cl-cAMP, we conducted a study in vivo using male BALB/c mice. Methods Clastogenic effects were estimated by bone marrow micronucleus assay and cytogenetic test in adult mice BALB/c strain. 8-Cl-cAMP was administered intraperitoneally (i.p.) to three dose groups including 10 mg/kg body weight (b.w.), 90 mg/kg b.w., and 160 mg/kg b.w., with saline solution as negative control and cyclophosphamide, a known mutagen, and clastogen as positive control during a 7-day period in 24-h intervals. Results Micronucleus test in vivo results showed consistently increasing dose-dependent pattern increase of dose regime (10 mg/kg body weight [b.w.], 90 mg/kg b.w., and 160 mg/kg b.w.), and increase in frequency of micronuclei in polychromatic erythrocytes (4.88 ± 0.35, 8.32 ± 0.57, and 11.74 ± 0.37) compared to negative control (2.04 ± 0.28). Quantitative effects are paralleled by structural changes in chromosome morphology. 8-Cl-cAMP induced structural (breaks, gaps, centric rings, acentrics, and Robertsonian translocations) and numerical-type chromosomal aberrations (aneuploidy and polyploidy). Conclusions Results of this study demonstrate that 8-Cl-cAMP has genotoxic potential in vivo .

Alzheimer's disease (AD) is a multi factorial disease, related to the loss of neurons and synapses in cerebral cortex and subcortical structures, leading to degenerative changes and atrophy. Despite abundance of facts related to AD and its pathology, the only drugs used in the prevention and treatment are those from the cholinesterase inhibitors group. However, there is growing evidence that a non-classical therapeutic approach in the treatment of AD has beneficial effects. In this review we summarized recent literature data related to the non-classical drugs for the treatment of AD predominantly used in clinical testing, such as amyloid aggregation inhibitors, beta-sheet breakers, antioxidants, estrogens and immunotherapeutics.

Alzheimer's disease (AD) is a complex and progressive neurodegenerative disorder, and represents the most common form of dementia. The number of people affected by AD is estimated to be doubled by the year of 2050, and more than 100 million people worldwide will be affected by this disease. Still, there is no reliable diagnostic test which would indicate pre-symptomatic conditions or an increased risk of developing AD. The only drugs approved by the FDA belong to the cholinesterase inhibitors (ChEI) group, such as donepezil, rivastigmine, galantamine and memantine that belongs to a class of drugs named receptor NMDA antagonists. Most mainstream pharmacotherapeutic approaches act by slowing the progression of the condition rather than to treat or prevent the cause of AD. In this review we are presenting literature data from recent research related to new avenues in the classical approach to prevention and treatment of AD.