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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.

The genotoxic and antigenotoxic behavior of the interfacial charge transfer (ICT) complex between nano-sized TiO2 particles and caffeic acid (CA) was studied in in vitro experiments. The formation of the ICT complex is indicated by the appearance of absorption in visible-spectral range. The continual variations method indicated bridging coordination between the ligand, caffeic acid, and the surface Ti atoms, while the stability constant of the ICT complex was found to be 1.5×103 mol-1 L. An agreement between the experimental data and the theoretical results, based on the density functional theory, was found. The ICT complex and its components did not display genotoxicity in the broad concentration range 0.4‒8.0 mg mL-1 TiO2 at a mole ratio c(TiO2)/c(CA) = 8. On the other hand, post-treatment of damaged DNA by the ICT complex induced antigenotoxic effect at lower concentrations, but at higher concentrations, 5.125–10.250 mg mL-1 ICT, the ICT complex did not show any beneficial effect on H2O2-induced DNA damaged cells. The experimental data were analyzed using the combinatorial method to determine the effect of component interaction on the genotoxic and antigenotoxic behavior of the ICT complex. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. 45020 and Grant no. 173034]

Does Alzheimer Disease show a decline in cognitive functions that relate to the awareness of external reality? In this paper, we will propose a perspective that patients with increasing symptoms of AD show a change in the awareness of subjective versus objective representative axis of reality thus consequently move to a more internal like perception of reality. This paradigm shift suggests that new insights into the dynamicity of the conscious representation of reality in the AD brain may give us new clues to the very early signs of memory and self-awareness impairment that originates from, in our view the microtubules. Dialog between Adso and William, in Umberto Eco’s The Name of the Rose, Third Day: Vespers. “But how does it happen,” I said with admiration, “that you were able to solve the mystery of the library looking at it from the outside, and you were unable to solve it when you were inside?” “Thus, God knows the world, because He conceived it in His mind, as if it was from the outside, before it was created, and we do not know its rule, because we live inside it, having found it already made.”

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.

Increased levels of oxidative stress and oxidative DNA damage are common features in the pathology of Alzheimer’s disease (AD) found in neurons and peripheral cells like peripheral blood lymphocytes (PBL). Natural products such as strawberry cultivar Alba are an important source of bioactive nutrients that could help in lowering both the oxidative stress and DNA damage levels. The objective was to estimate the effects of Alba extract on DNA damage in peripheral blood lymphocytes of sporadic AD (aged 60–84 years) patients, and healthy elderly (aged 69–83 years) and young (aged 21–30 years) individuals in in vitro conditions. Comet assay was used as a sensitive technique for the evaluation of PBL DNA damage levels. Reduction of basal DNA damage level in PBL was shown in the young group after the incubation with Alba extract ranging from 25 to 200 μg/ml, with 100 μg/ml being the most effective concentration. Selected Alba extract of 100 μg/ml was further used for PBL treatment of AD and healthy elderly age matched group, displaying potential to significantly attenuate DNA damage levels in both groups (p

Normal cellular physiology and biochemical processes require undamaged RNA molecules. However, RNAs are frequently subjected to oxidative damage. Overproduction of reactive oxygen species (ROS) leads to RNA oxidation and disturbs redox (oxidation-reduction reaction) homeostasis. When oxidation damage affects RNA carrying protein-coding information, this may result in the synthesis of aberrant proteins as well as a lower efficiency of translation. Both of these, as well as imbalanced redox homeostasis, may lead to numerous human diseases. The number of studies on the effects of RNA oxidative damage in mammals is increasing by year due to the understanding that this oxidation fundamentally leads to numerous human diseases. To enable researchers in this field to explore information relevant to RNA oxidation and effects on human diseases, we developed DES-ROD, an online knowledgebase that contains processed information from 298,603 relevant documents that consist of PubMed abstracts and PubMed Central full-text articles. The system utilizes concepts/terms from 38 curated thematic dictionaries mapped to the analyzed documents. Researchers can explore enriched concepts, as well as enriched pairs of putatively associated concepts. In this way, one can explore mutual relationships between any combinations of two concepts from used dictionaries. Dictionaries cover a wide range of biomedical topics, such as human genes and proteins, pathways, Gene Ontology categories, mutations, noncoding RNAs, enzymes, toxins, metabolites, and diseases. This makes insights into different facets of the effects of RNA oxidation and the control of this process possible. The usefulness of the DES-ROD system is demonstrated by case studies on some known information, as well as potentially novel information involving RNA oxidation and diseases. DES-ROD is the first knowledgebase based on text and data mining that focused on the exploration of RNA oxidation and human diseases.

This work is part of the collaboration between the Labora-tory of Radiobiology and Molecular Genetics, Vinca Insti-tute of Nuclear Sciences, University of Belgrade, Belgrade,Serbia and King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Cen-ter (CBRC), Thuwal, Saudi Arabia. This work has beensupported by grants No. 173033 (E.R.I.) from the Ministryof Education, Science and Technological Development,Republic of Serbia and by the KAUST grant OSR#4129(to E.R.I. and V.B.B.), which also supported M.O., S.Z.,E.S.M., and V.P.B. V.B.B. has been supported by the KingAbdullah University of Science and Technology BaseResearch Fund (BAS/1/1606-01-01), and V.B.B. andM.E. by KAUST Office of Sponsored Research (OSR)Awards No. FCC/1/1976-24-01 and FCC/1/1976-17-01.M.O., S.Z., E.S.M, A.T., J.S., and V.P.B. have beensupported by the grants No. 173033 (E.R.I.) and No. 173034from the Ministry of Education, Science and TechnologicalDevelopment, Republic of Serbia

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.

Phenolic groups of steroidal or nonsteroidal estrogens can redox cycle, leading to oxidative stress, where creation of reactive oxygen species are recognized as the main mechanism of their DNA damage properties. Dry olive (Olea europaea L.) leaf extract is known to contain bioactive and antioxidative components and to have an ability to modulate the effects of various oxidants in cells. The main goal of this study was to investigate antigenotoxic potential of a standardized dry olive leaf extract on DNA damage induced by 17β-estradiol and diethylstilbestrol in human whole blood cells in vitro, using comet assay. Our results indicated that both hormones showed a genotoxic effect at a concentration of 100 μM (P lt 0.05, n = 6). Dry olive leaf extract was efficient in reducing number of cells with estrogen-induced DNA damage at tested concentrations (0.125, 0.5 and 1 mg/mL) (P lt 0.05, n = 6) and under two experimental protocols, pre-treatment and post-treatment, exhibiting antigenotoxic properties. Analysis of antioxidant properties of the extract revealed moderate ABTS radical scavenging properties and reducing power. Overall, our results suggested that the protective potential of dry olive leaf extract could arise from the synergistic effect of its scavenging activity and enhancement of the cells' antioxidant capacity.

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.

Harmful effects of elevated levels of catecholamines are mediated by various mechanisms, including gene transcription and formation of oxidation products. The aim of this study was to see whether the molecular mechanisms underlying the damaging action of adrenaline on DNA are mediated by reactive oxygen species (ROS). To do that, we exposed human whole blood cells to 10 μmol L-1 adrenaline or 50 μmol L-1 H2O2 (used as positive control) that were separately pre-treated or post-treated with 500 μmol L-1 of quercetin, a scavenger of free radicals. Quercetin significantly reduced DNA damage in both pre- and post-treatment protocols, which suggests that adrenaline mainly acts via the production of ROS. This mechanism is also supported by gradual lowering of adrenaline and H2O2-induced DNA damage 15, 30, 45, and 60 min after treatment. Our results clearly show that DNA repair mechanisms are rather effective against ROS-mediated DNA damage induced by adrenaline., Štetni učinci povišenih razina katekolamina posredovani su različitim mehanizmima, uključujući transkripciju gena i formiranje produkata oksidacije. Svrha je ovoga istraživanja bila utvrditi jesu li molekularni mehanizmi koji stoje u osnovi štetnoga djelovanja adrenalina na DNA posredovani reaktivnim vrstama kisika (ROS). Da bismo to postigli, izložili smo humane stanice pune krvi adrenalinu (10 μmol L-1) i vodikovu peroksidu (50 μmol L-1) (pozitivna kontrola), koje su odvojeno predtretirane i post-tretirane kvercetinom (500 μmol L-1), „hvatačem“ slobodnih radikala. Kvercetin je značajno smanjio broj stanica s DNA oštećenjima i u predtretmanu i u post-tretmanu, što je sugeriralo da adrenalin djeluje uglavnom stvaranjem ROSa. Taj je mehanizam podržan i postupnim smanjenjem broja stanica s oštećenjima DNA izazvanim adrenalinom i H2O2 u vremenskim intervalima od 15, 30, 45 i 60 minuta nakon tretmana. Naši rezultati jasno pokazuju da su mehanizmi popravka prilično učinkoviti u odnosu na ROS-posredovana oštećenja DNA izazvana adrenalinom.

The thyroid hormones change the rate of basal metabolism, modulating the consumption of oxygen and causing production of reactive oxygen species, which leads to the development of oxidative stress and DNA strand breaks. Olive (Olea europaeaL.) leaf contains many potentially bioactive compounds, making it one of the most potent natural antioxidants. The objective of this study was to evaluate the genotoxicity of L-thyroxine and to investigate antioxidative and antigenotoxic potential of the standardized oleuropein-rich dry olive leaf extract (DOLE) against hydrogen peroxide and L-thyroxine-induced DNA damage in human peripheral blood leukocytes by using the comet assay. Various concentrations of the extract were tested with both DNA damage inducers, under two different experimental conditions, pretreatment and posttreatment. Results indicate that L-thyroxine exhibited genotoxic effect and that DOLE displayed protective effect against thyroxine-induced genotoxicity. The number of cells with DNA damage, was significantly reduced, in both pretreated and posttreated samples (P< 0.05). Comparing the beneficial effect of all tested concentrations of DOLE, in both experimental protocols, it appears that extract was more effective in reducing DNA damage in the pretreatment, exhibiting protective role against L-thyroxine effect. This feature of DOLE can be explained by its capacity to act as potent free radical scavenger.

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.

The ability ofAgaricus blazeimushroom in its dried and powdered mycelial form was evaluated for its antigenotoxic properties for the first time. Antigenotoxic effects in human peripheral blood cells against H2O2-induced DNA damage were examined in pretreatment and posttreatment protocol by comet assay. The results showed better antigenotoxic properties ofAgaricus blazeion the interventional level, respectively, after treatment.Agaricus blazeiin concentration of 250 μg/mL after treatment was most efficient in regard to its action against DNA damage. The evaluation of repair kinetics showed decrease in H2O2induced DNA damage 15 min after the application ofA. blazei, reaching the maximum potency after 30 min. Analysis of antioxidant properties ofAgaricus blazeirevealed strongOH•scavenging properties and moderate reducing power, while its DPPH scavenging ability was weak. In regard to our findings, we can conclude that our preliminary results demonstrated antigenotoxic properties ofAgaricus blazeiand its strongOH•scavenging ability. Mechanisms underlying its properties should be further evaluated in in vivo studies.

The CaNa(2)EDTA chelation therapy is often practiced with antioxidant supplementation. Dry olive leaf extract (DOLE) is natural product with antioxidant and DNA protective properties. The effects of DOLE on the levels of DNA damage were investigated ex vivo in peripheral blood lymphocytes (PBLs) of 19 workers occupationally exposed to lead (Pb), before and after CaNa(2)EDTA chelation therapy. POLE demonstrated pronounced radical scavenging activity in concentrations GT = 1 mg/mL, and showed no genotoxicity per se, in concentrations 0.125-1 mg/mL. The level of DNA damage in PBLs of workers before chelation therapy was elevated (24.21 +/- 14.26) compared to controls (6.0 +/- 3.37). The incubation of PBLs before chelation therapy with selected concentration of DOLE lead to a severe increase of DNA damage (64.03 +/- 20.96), exhibiting prooxidant rather than antioxidant effect. After the five-day CaNa2EDTA chelation regimen, DNA damage in PBLs of workers decreased (8.26 +/- 4.62) significantly compared to baseline. Treatment of PBLs with DOLE after chelation, again produced high level of damage (41.82 +/- 23.17) and the acute prooxidant effects of DOLE remained, but, DNA damage was less severe than before chelation. The DOLE exhibits prooxidant effect in presence of Pb in lymphocytes of exposed workers, and its effect is less pronounced following the removal of Pb after standard chelation therapy. (C) 2016 Elsevier Ltd. All rights reserved.

Poly (lactic-co-glycolic acid) (PLGA)-based materials are widely investigated for drug delivery and tissue engineering applications. Despite their popularity the genotoxic potential of PLGA has not been investigated. In this study, the comet assay, a sensitive assay for DNA damage, was used to evaluate potential genotoxicity in model cell types exposed to PLGA microspheres. Human umbilical vein endothelial cells (HUVECs) and mesenchymal stem cells (MSCs) cells were exposed to PLGA microspheres (0.4-6 mg/mL) and DNA damage assessed at 24 h, 4 days, and 7 days. DNA damage was not identified after 24 h. However, after 4 and 7 days of exposure to 2 and 6 mg/mL of PLGA microspheres a significant elevation of DNA damage in both cell types was observed. The PLGA microspheres did not exhibit any cytotoxic effects on the cells under the conditions tested. Our results suggest that PLGA may have a genotoxic effect on cells. A broader investigation of the PLGA genotoxic profile in biological systems is needed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 284-291, 2017.

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 disease (AD) is considered a neurodegenerative disorder, the importance of chromosome instability in non-neuronal cells is equally important, not only for shedding light on the etiology of the disease, but also for possible diagnostic purposes and monitoring the progress of the disease. Here, we evaluated the frequency of DNA damage and expression of premature centromere division (PCD) in peripheral blood lymphocytes of sporadic AD patients, age-matched and young controls. The results show that in male patients with AD, the frequencies of PCD and DNA damage were significantly greater (88%, p < 0.01 and 38%, p < 0.05, respectively) than in age-matched control group. AD females had significantly increased frequency of PCD (134%, p < 0.01) as well as a higher frequency of DNA damage (37%, p < 0.05). Ageing per se, both in males and females, shows significant increase of percentages of PCD (2.3 times, p < 0.01 and 2.8 times, p < 0.01, respectively) and DNA damage (63%, p < 0.01 and 50%, p < 0.01, respectively) comparing with young controls. In addition, a strong (R2 = 0.873, n = 6) and significant (p < 0.01) correlation between the frequencies of PCD and DNA damage was found in all examined groups. We may conclude that the increases in both parameters evaluated in this study are not only associated with normal ageing processes, but are markedly and significantly intensified in AD pathogenesis. Thus, our data support the view that AD is a generalized systemic disease, at least as for the increased DNA damage and PCD incidence in peripheral blood cells.

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.

The essential oils of genus Seseli are known for their beneficial biological activities and could present novel targets in the development of safe and effective preparations of plant products. The objective was to test the essential oils of different parts of Seseli rigidum from two natural habitats for potential genotoxic and antigenotoxic activities against H202-induced DNA damage in human whole blood cells in vitro, by the comet assay. The essential oil analysis showed a high falcarinol content in oil from the root, while oils of the fruit and aerial parts contained α-pinene as the main compound. Genotoxicity was not detected at any of the concentrations of the essential oils from the three parts of the plant from localities I and II. Although the antioxidant activity (established by the FRAP and DPPH tests) of the investigated oils was low, all oils demonstrated a strong antigenotoxic effect against H2O2-induced damage post-treatment, when the oils were applied after the oxidant. Based on the lack of pretreatment activity and the post-treatment reduction in DNA damage, the antigenotoxic effect of S. rigidum essential oils was probably based on the stimulation of DNA repair mechanisms. Environmental conditions did not affect the antigenotoxic properties of the oils. In conclusion, our results revealed the antigenotoxic properties of S. rigidum essential oils and appropriate and safe doses with beneficial effects under the described conditions. [Projekat Ministarstva nauke Republike Srbije, br. OI 173034, 173021]

Author thanks the Fulbright Association , German DAAD Association and the Ministry of Education, Science and Technological Development of the Republic of Serbia for financial support (Project No: 173034).

Aging is the common denominator and the highest risk factor for macular degeneration and Alzheimers Disease (AD). Important pathological hallmarks common to both diseases are the presence of amyloid β (Aβ) in the senile plaques of the AD brain and in the drusen of age-related macular degeneration (AMD) patients, oxidative stress, and apoptotic cell death. Data suggest that a common pathogenic mechanism might exist between AMD and AD. Brain and eye depend on redox electrons from pyridinic and flavinic nucleotides to produce ATP, and reactive oxygen intermediates (ROI). Disorganization of mitochondrial structure and decline in mitochondrial oxidative phosphorylation (OXPHOS) functioning, as well as hypometabolism and alterations in mitochondrial DNA are aging features. Because ROI damage and mitochondrial dysregulation are prominent in AMD and AD and their relationship to the redox state is unclear we addressed a new hypothesis according to which the interaction of melatonin vs Aβ are intertwined to balance of the intra- and extra-mitochondrial energy production. This balance would be impaired by the ageing process and environmental/genetic factors, ultimately leading to AD and /or AMD.

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.

CD3ζ is a subunit of the CD3 molecule that, until recently, appeared restricted to T-cells and natural killer cells. However, experimental studies have demonstrated a role of CD3ζ in dendritic outgrowth in the visual system as well as in synaptic plasticity. Given the increasing evidence for uncharacteristic recapitulation of neurodevelopmental processes in neurodegenerative diseases, in this study, we evaluated brains from subjects with Parkinson's disease and Lewy body dementia for evidence of aberrant CD3 expression. Our data shows marked CD3ζ in association with the α-synuclein containing pathological lesions, i.e., Lewy bodies and Lewy neurites, in the brains of subjects with Parkinson's disease and Lewy body dementia. This finding raises the novel concept of CD3 dysregulation in these disorders as a pathogenic factor and also furthers the increasing evidence that the recall of aberrant neurodevelopmental processes underlies the pathogenesis of neurodegenerative diseases.

As one of the earliest pathologic changes, the aberrant re-expression of many cell cycle-related proteins and inappropriate cell cycle control in specific vulnerable neuronal populations in Alzheimer's disease (AD) is emerging as an important component in the pathogenesis leading to AD and other neurodegenerative diseases. These events are clearly representative of a true cell cycle, rather than epiphenomena of other processes since, in AD and other neurodegenerative diseases, there is a true mitotic alteration that leads to DNA replication. While the exact role of cell cycle re-entry is unclear, recent studies using cell culture and animal models strongly support the notion that the dysregulation of cell cycle in neurons leads to the development of AD-related pathology such as hyperphosphorylation of tau and amyloid-beta deposition and ultimately causes neuronal cell death. Importantly, cell cycle re-entry is also evident in mutant amyloid-beta precursor protein and tau transgenic mice and, as in human disease, occurs prior to the development of the pathological hallmarks, neurofibrillary tangles and amyloid-beta plaques. Therefore, the study of aberrant cell cycle regulation in model systems, both cellular and animal, may provide extremely important insights into the pathogenesis of AD and also serve as a means to test novel therapeutic approaches.

Premature centromere division (PCD) represents a loss of control over the sequential separation and segregation of chromosome centromeres. Although first described in aging women, PCD on the X chromosome (PCD,X) is markedly elevated in peripheral blood lymphocytes of individuals suffering from Alzheimer disease (AD). The present study evaluated PCD,X, using a fluorescent in situ hybridization method, in interphase nuclei of frontal cerebral cortex neurons from sporadic AD patients and age-matched controls. The average frequency of PCD,X in AD patients (8.60 +/- 1.20%) was almost three times higher (p lt 0.01) than in the control group (2.96 +/- 1.20). However, consistent with previous studies, no mitotic cells were found in neurons in either AD or control brain, suggesting an intrinsic inability of post-mitotic neurons to divide. In view of the fact that it has been well-documented that neurons in AD can re-enter into the cell division cycle, the findings presented here of increased PCD advance the hypothesis that deregulation of the cell cycle may contribute to neuronal degeneration and subsequent cognitive deficits in AD.

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]

Lead induced oxidative cellular damage and long-term persistence of associated adverse effects increases risk of late-onset diseases. CaNa(2)EDTA chelation is known to remove contaminating metals and to reduce free radical production. The objective was to investigate the impact of chelation therapy on modulation of lead induced cellular damage, restoration of altered enzyme activities and lipid homeostasis in peripheral blood of workers exposed to lead, by comparing the selected biomarkers obtained prior and after five-day CaNa(2)EDTA chelation intervention. The group of smelting factory workers diagnosed with lead intoxication and current lead exposure 5.8 +/- 1.2 years were administered five-day CaNa(2)EDTA chelation. Elevated baseline activity of antioxidant enzymes Cu, Zn-SOD and CAT as well as depleted thiols and increased protein degradation products-carbonyl groups and nitrites, pointing to Pb induced oxidative damage, were restored toward normal values following the treatment. Lead showed inhibitor potency on both RBC AChE and BChE in exposed workers, and chelation re-established the activity of BChE, while RBC AChE remained unaffected. Also, genotoxic effect of lead detected in peripheral blood lymphocytes was significantly decreased after therapy, exhibiting 18.9% DNA damage reduction. Administration of chelation reversed the depressed activity of serum PON 1 and significantly decreased lipid peroxidation detected by the post-chelation reduction of MDA levels. Lactate dehydrogenase LDF1-5 isoenzymes levels showed evident but no significant trend of restoring toward normal control values following chelation. CaNa(2)EDTA chelation ameliorates the alterations linked with Pb mediated oxidative stress, indicating possible benefits in reducing health risks associated with increased oxidative damage in lead exposed populations. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

Catechol groups can be involved in redox cycling accompanied by generation of reactive oxygen species (ROS) which may lead to oxidative damage of cellular macromolecules including DNA. The objective of this investigation was to evaluate possible genotoxic effects of a natural catecholamine adrenaline in cultured human lymphocytes using cytogenetic (sister chromatid exchange and micronuclei) and the single cell gel electrophoresis (Comet) assay. In cytogenetic tests, six experimental concentrations of adrenaline were used in a range from 0.01-500 mu M. There were no indications of genotoxic effects of adrenaline in sister chromatid exchange and micronucleus tests. However, at four highest concentrations of adrenaline (5 mu M, 50 mu M, 150 mu M and 300 mu M) we observed a decreased mitotic index and cell-cycle delay. In addition, in the Comet assay we used adrenaline in a range from 0.0005-500 mu M, at two treatment times: 15 min or 60 min. In contrast to cytogenetic analysis, there was a dose-dependent increase of DNA damage detected in the Comet assay. These effects were significantly reduced by concomitant treatment with quercetin or catalase. Therefore, the obtained results indicate that adrenaline may exhibit genotoxic effects in cultured human lymphocytes, most likely due to production of reactive oxygen species.

Hormones are cellular products involved in the regulation of a large number of processes in living systems, and which by their actions affect the growth, function and metabo­lism of cells. Considering that hormones are compounds normally present in the organism, it is important to determine if they can, under certain circumstances, lead to genetic changes in the hereditary material. Numerous experimental studies in vitro and in vivo in different systems, from bacteria to mammals, dealt with the mutagenic and genotoxic effects of hormones. This work presents an overview of the research on genotoxic effects of non­steroidal hormones, although possible changes of genetic material under their influence have not still been known enough, and moreover, investigations on their genotoxic influ­ence have given conflicting results. The study results show that mechanisms of genotoxic effect of nonsteroidal hormones are manifested through the increase of oxidative stress by arising reactive oxygen species. A common mechanism of ROS occurence in thyroid hormones and catecholamines is through metabolic oxidation of their phenolic groups. Mani­festation of insulin genotoxic effect is based on production of ROS by activation of NADPH isophorms, while testing oxytocin showed absence of genotoxic effect. Considering that the investigations on genotoxicity of nonsteroidal hormones demonstrated both positive and negative results, the explanation of this discordance involve limitations of test systems themselves, different cell types or biological species used in the experiments, different lev­el of reactivity in vitro and in vivo, as well as possible variations in a tissue-specific expres­sion. Integrated, the provided data contribute to better understanding of genotoxic effect of nonsteroidal hormones and point out to the role and mode of action of these hormones in the process of occurring of effects caused by oxidative stress. Hormoni su ćelijski proizvodi uključeni u regulaciju velikog broja procesa u živim sistemima koji svojim dejstvom utiču na rast, funkciju ili metabolizam ćelija. Obzirom da su hormoni jedinjenja koja su uobičajeno prisutna u organizmu, značajno je utvrditi da li oni mogu pod izvesnim okolnostima dovesti do genetičkih promena na naslednom materijalu. Eksperimentalna ispitivanja u in vitro i in vivo uslovima u različitim sistemima, od bakterija do sisara, bavila su se istraživanjem mutagenih i genotoksičnih efekata hormona. U ovom radu je dat pregled istraživanja genotoksičnih efekata nesteroidnih hormona, pošto još uvek nisu dovoljno poznate moguće promene naslednog materijala pod njihovim uticajem, a i ispitivanja njihovog genotoksičnog dejstva su dala oprečne rezultate. Rezultati studija pokazuju da se mehanizmi genotoksičnog dejstva nesteroidnih hormona ispoljavaju kroz povećanje oksidativnog stresa nastankom reaktivnih vrsta kiseonika (reactive oxygen species - ROS). Uobičajeni mehanizam nastanka ROS kod tireoidnih hormona i kateholamina je putem metaboličke oksidacije njihovih fenolnih grupa. Ispoljavanje genotoksičnog efekta insulina se zasniva na produkciji ROS putem aktivacije NADPH izoformi, dok je ispitivanje oksitocina pokazalo odsustvo genotoksičnog efekta. Uzimajući u obzir da su ispitivanja genotoksičnosti nesteroidnih hormona pokazala i pozitivne i negativne rezultate, objašnjenja ovog neslaganja obuhvataju ograničenja samih test sistema, različite tipove ćelije ili bioloških vrsta upotrebljenih u eksperimentima, različiti nivo reaktivnosti u in vitro i in vivo uslovima, kao i moguće razlike u tkivno specifičnoj ekspresiji. Objedinjeni, navedeni podaci doprinose boljem razumevanju genotoksičnih efekata nesteroidnih hormona i ukazuju na ulogu i načine delovanja ovih hormona u procesu nastanka efekata izazvanih oksidativnim stresom.

Aging is the main risk factor for Alzheimer’s disease (AD). With aging, inflammation has been recognized as potential trigger for starting the neurodegenerative cascade leading to neuronal death. Before Aβ and tau accumulation, evidence has put alterations of the cell cycle at the core of these processes. Still, a number of features of the cell cycle re-entry phenotype have remained elusive to the role of ectopic protein expression in the process of neuroinflammation and consequently neuronal cell death. Recently, a novel cyclin dependent kinase CDK11 has been found to be involved in astrocyte mediated inflammatory response and Alzheimer’s disease. In this review, we aim to establish the missing part of the puzzle between neuroinflammation and APP / Aβ deregulation in AD by evaluating the role of a cyclin, CDK11. CDK11 may play a vital role in cell cycle re-entry in AD neurons in an APP-dependent manner, thus presenting an intriguing novel function of the APP signaling pathway in AD.

X-chromosome instability has been a long established feature in Alzheimer's disease (AD). Premature centromere division and aneuploidy of the X-chromosome has been found in peripheral blood lymphocytes and neuronal tissue in female AD patients. Interestingly, only one chromosome of the X pair has been affected. These results raised a question, "Is the X-chromosome inactivation pattern altered in peripheral blood lymphocytes of women affected by AD?" To address this question, we analyzed the methylation status of androgen receptor promoter which may show us any deviation from the 50 : 50% X inactivation status in peripheral blood lymphocytes of women with AD. Our results showed skewed inactivation patterns (>90%). These findings suggest that an epigenetic alteration on the inactivation centers of the X-chromosome (or skewing) relates not only to aging, by might be a novel property that could account for the higher incidence of AD in women.

Premature centromere division (PCD) of the chromosome 18 was analyzed by using fluorescent in situ hybridization (FISH) on interphase peripheral blood lymphocytes isolated from six sporadic Alzheimer disease (AD) patients and six healthy elderly controls. Results of FISH analysis revealed that chromosome 18 expressed PCD in 5.18% interphase nuclei of AD patients, and in 2.59% interphase nuclei of age-matched controls (p lt 0.05). Our study also showed that hypoploidy and hyperploidy frequency for chromosome 18 exhibited a statistically significant increase in the AD group compared to the control one. The increase in spontaneous aneuploidy of chromosome 18 in AD patients which is correlated with PCD shows that deregulation of the time of centromere separation can be considered as a manifestation of chromosome instability leading to aneuploidy.

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.

Chromosomal alterations as a sign of genetic instability are a feature of Alzheimer's disease (AD). Assessment of the genetic instability of non-neuronal cells of AD patients may provide a method to diagnose or monitor prognosis of the disease. Considering the importance of X chromosome alterations in the possible etiology of AD females, we used fluorescent in situ hybridization (FISH) for the centromere region of the X chromosome to determine aneuploidy, for a possible correlation with premature centromere division (PCD, X) in lymphocytes of AD females and age-matched controls. In AD patients, our results showed a marked and significant increase in the frequency of the X chromosome aneuploidy comparing with age matched controls (p lt 0.001). Also, a significant difference was detected in the PCD, X frequency between AD females when compared with age matched controls (p lt 0.001). In addition, a strong (R2=0.97, n=20) and significant (p lt 0.001) correlation was found between the frequency of aneuploidy and PCD, X in the AD group. Our results support the view that AD is a generalized systematic disease where PCD is to be considered as a stable sign of disease leading to aneuploidy.