Pharmacokinetics, biodistribution, and in vivo toxicity of 7-nitroindazole loaded in pegylated and non-pegylated nanoemulsions in rats.

Sepsis is a life-threatening condition caused by a dysregulated host response to infection. The development of sepsis is associated with excessive nitric oxide (NO) production, which plays an important role in controlling vascular homeostasis. 7-nitroindazole (7-NI) is a selective inhibitor of neuronal nitric oxide synthase (NOS-1) with potential application for treating NO imbalance conditions. However, 7-NI exhibits a low aqueous solubility and a short plasma half-life. To circumvent these biopharmaceutical limitations, pegylated (NEPEG7NI) and non-pegylated nanoemulsions (NENPEG7NI) containing 7-NI were developed. This study evaluates the pharmacokinetic profiles and toxicological properties of 7-NI loaded into the nanoemulsions. After a single intravenous administration of the free drug and the nanoemulsions at a dose of 10 mg.kg-1 in Wistar rats, 7-NI was widely distributed in the organs. The pharmacokinetic parameters of Cmax, t1/2, and AUC0-t were significantly increased after administration of the NEPEG7NI, compared to both free 7-NI and NENPEG7NI (p < 0.05). No observable adverse effects were observed after administering the free 7-NI, NEPEG7NI, or NENPEG7NI in the animals after a single dose of up to 3.0 mg.kg-1. The results indicated that 7-NI-loaded nanoemulsions are safe, constituting a promising approach to treating sepsis.

Grape Seed Components as Protectors of Inflammation, DNA Damage, and Cancer.

PURPOSE OF REVIEW: Oxidative stress is related to the pathogenesis of several chronic diseases, including inflammatory processes. Free radicals excess increase not only oxidative stress but also genomic instability. Polyphenols are non-enzymatic antioxidants that act as a defense barrier against free radicals and non-radical oxidants. The purpose of this article was to review published articles relating dietary polyphenols contained in grape seed proanthocyanidin extracts with its potential for reversing DNA damage. RECENT FINDINGS: Proanthocyanidin components exert pleiotropic actions having several biological, biochemical, and significant pharmacological effects and showed the ability to reduce cytotoxicity and genotoxicity. Grape seed proanthocyanidin extracts showed the ability to reduce cytotoxicity and genotoxicity through the comet assay and the micronucleus technique.

Iron supplementation does not aggravate impaired glucose tolerance and sugar overload-induced genotoxicity in rats.

High sugar intake is a major risk factor for metabolic disorders. Genotoxicity is an important factor in diabetes onset, and iron (Fe) may be an aggravating element. However, this relationship is still poorly established. Thus, this study evaluated whether Fe supplementation could aggravate obesity, impaired glucose tolerance, and sugar overload-induced genotoxicity in rats. A total of 24 rats were treated with different diets: standard diet (SD, n = 8), invert sugar overload (320 g/L, HSD, n = 8), or Fe plus invert sugar overload (2.56 mg/L of Fe2+, Fe-HSD, n = 8) for four months. After treatment, the Fe-HSD group showed no excessive weight gain or impaired glucose tolerance. DNA damage in blood, as assessed by comet assay, gradually increased in HSD during treatment (p < 0.001), whereas Fe-HSD showed a nonlinear increase in DNA damage. Moreover, Fe-HSD presented 0.6-fold more DNA damage compared with SD (p = 0.0055) in the 1st month of treatment. At months 2 and 3, results show a ≥ 1.4-fold increase in HSD and Fe-HSD DNA damage, respectively, compared with SD (p < 0.01). At the end of the experiment, only HSD DNA damage differed from SD (1.5-fold more, p = 0.0196). Fe supplementation did not aggravate the invert sugar-induced DNA damage (p > 0.05). In the pancreas, results showed no differences in DNA damage. Mutagenicity, evaluated by micronucleus testing, was not observed regardless of treatment (p = 0.428). Fe supplementation, in the evaluated concentration, did not aggravate weight gain, impaired glucose tolerance, and sugar overload-induced genotoxicity in rats.

DNA damage analysis in newborns and their mothers related to pregnancy and delivery characteristics.

INTRODUCTION: Increased DNA damage is associated with early events in carcinogenesis. The foetus may be more susceptible to effects of environment by transplacental exposure. We aimed to evaluate DNA damage in cells from umbilical cord (arteries and vein) and maternal blood from pregnant women. METHODS: Fifty eight pregnant women and their offspring were included in this study. They were submitted to an interview to obtain information about personal history, clinical history, and lifestyle habits. Other Information was obtained from medical records. The samples were prepared for Single Cell Gel/Comet assay and Cytokinesis-block Micronucleus Cytome (CBMN-Cyt) assay. RESULTS: Correlation between DNA damage frequency by Comet assay from newborns and their mothers was statistically significant and was significantly associated with nulliparity and more than 1 h of second stage of labour (umbilical vein and maternal blood). A positive MNi relationship was noticed for age (mother's blood) and inappropriate birth weight for gestational age (maternal blood). When multivariate statistical analyses were applied to measure the degree of association between variables that influenced DNA damage markers in the first evaluation, inadequate birth weight and pregnant weight gain were associated with MNi frequency in maternal and newborns blood, respectively. DISCUSSION: Significant associations between DNA damage in newborns and pregnant women, and birth and pregnancy events suggest molecular evidence of transplacental genotoxic effects. However, a potentially increased risk of degenerative diseases, such as cancers, in this population should be carefully investigated by further prospective cohort studies.

DNA damage, oxidative stress, and inflammation in children with celiac disease.

The objective of this study was to evaluate the level of genomic instability in patients with celiac disease and to establish a relationship between inflammation, oxidative stress, and DNA damage in these patients. Myeloperoxidase (MPO) activity, adenosine deaminase, nitric oxide (NOx), thiobarbituric acid, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and DNA damage were evaluated in peripheral blood samples from 47 celiac disease patients and 31 controls. Patients with celiac disease presented higher levels of DNA damage in comparison to controls (p=0.023). This difference was also observed for markers of oxidative stress, such as CAT (p=0.011) and SOD (p=0.013), and inflammatory markers such as MPO (p < 0.001) and NOx (p=0.009). Positive correlations were found between DNA damage levels and the values of CAT (r=0.405; p=0.009) and SOD (r=0.516; p < 0.001). Positive correlations were also found between GPx and NOx (r=0.349; p=0.030) and MPO and NOx (r=0.239; p=0.039). CAT and NOx showed a negative correlation (r= -0.315; p=0.042). In conclusion, intestinal inflammation can have systemic effects, causing an imbalance between oxidant and antioxidant markers, which may promote increased levels of DNA damage.

DNA damage and repair in individuals with ataxia-telangiectasia and their parents.

Ataxi A-T elangiectasia (AT) is a multisystem, complex and rare disease inherited in an autosomal recessive manner. Homozygous individuals have a variety of pathological manifestations, however, heterozygotes only present a higher risk of developing cancer. We evaluated the background levels of DNA damage (basal damage) and cell response to bleomycin or ionizing radiation using Comet assay and the cytokinesis-block micronucleus (CBMN) test in individuals with AT, their parents and controls. To evaluate DNA repair, the challenge experiment with ionizing radiation was performed using Comet assay, and different recovery times were evaluated. Results showed that basal MN frequencies differ between patients, parents and controls. Meanwhile, using the Comet assay, the results from the basal analysis do not differ between the groups, but monitoring the kinetics of DNA repair, we verified that the group of patients showed a delay in repair, compared to controls. Another finding was the nuclear bud (NBUD) frequency: spontaneous and induced cell cultures (with bleomycin and radiation) showed clear differences between patients, parents and controls. The CBMN assay and repair measurement with the Comet assay can help in the diagnosis of AT patients and ATM gene carriers, as complementary methods. The use of genomic instability evaluation techniques for the identification of the heterozygotes in families, where at least one member is affected, may be of great clinical importance.

Markers of genotoxicity and oxidative stress in farmers exposed to pesticides.

The effects of chronic exposure to pesticides can lead to the development of several diseases, including different types of cancer, since the genotoxic and mutagenic capacity of these substances can be observed. The objective of this study is to investigate the relation between the occupational exposure to various pesticides and the presence of DNA damage and oxidative stress. Blood samples from 50 rural workers (41 men and 9 women) exposed to pesticides, 46 controls (20 men and 26 women) from the same city (Antônio Carlos, Santa Catarina state, Brazil) and 29 controls (15 men and 14 women) from another city (Florianópolis, Santa Catarina state, Brazil), were evaluated using the comet assay and the cytokinesis-block micronucleus (CBMN) technique for genetic damage, and the test of thiobarbituric acid reactive substances (TBARS) and catalase (CAT) activity for the oxidative stress. Cholinesterase activities were also determined, but there was no statistical difference among exposed workers and controls. Significant differences were found in DNA damage among groups. The comet assay performed on peripheral blood lymphocytes of these individuals had a significantly higher DNA damage index in the exposed group comparing to controls (p < 0.0001). MNi (p < 0.001), NBUDs (p < 0.005) and NPBs (p < 0.0001) were also found to be significantly higher in the exposed group. The TBARS values were significantly higher comparing to the Florianopolis control group (p < 0.0001). Even though CAT values were higher than controls, there was no statistical difference. Thus, it is concluded that the exposed individuals, participants of this study, are more subject to suffer genetic damage and, consequently, more susceptible to diseases resulting from such damages.

Occupational and life-style factors-acquired mutagenicity in agric-workers of northeastern Brazil.

Pesticides are a complex mixture of chemicals used to protect crops from a number of pests and diseases. They have been considered as potential mutagenic agents. This study aims at evaluation of the mutagenic effect of pesticide exposure to agricultural workers through chromosomal aberrations (CA) and micronucleus (MN) assay in peripheral blood lymphocytes and oral mucosal cells, respectively. The exposed group was consisted with 97 farmers, while the control (un-exposed) group consisted of 55. The results showed a significant (p < 0.05) increase in frequency of CA and MN in the exposed group. Both CA and MN profiles were linked to a significant (p < 0.05) co-relation with the confounding factors such as smoking habits, alcohol, vegetables, tea/coffee, vitamins, and sweetener consumptions. More cytogenetic events were denoted in smoking and alcohol consumption as well as non-personal protective equipment (non-PPE) and low/no vegetables user farmers. In conclusion, a deficiency of dietary and medicaments-derived antioxidants, while consumption of alcohol and tobacco, as well as effects of radiation, heavy metal poisoning (especially from sweeteners), and non-PPE using habits, may contribute cytogenetic damage to the workers.

DNA damage response in patients with pediatric Acute Lymphoid Leukemia during induction therapy.

Predicting the individual response to chemotherapy is a crucial challenge in cancer treatment. DNA damage caused by antitumor therapies evokes different repair mechanisms responses, such as Nucleotide Excision Repair (NER), whose components are being studied as prognosis biomarkers and target therapies. However, few reports have addressed DNA damages in pediatric Acute Lymphoid Leukemia (ALL). Hence, we conducted an observational follow-up study with pediatric patients to assess DNA damage (by Comet Assay) and gene expression from NER pathway during chemotherapy induction. Bone marrow samples from diagnosis, 15th(D15) and 35th (D35) days of the treatment were collected from 28 patients with ALL. There was no increase in damage index. However, there was a reduction of cells with low damages on D35 compared with diagnosis. NER pathway expression remained the same, however, in a single patient, a significant decrease was observed, maybe due to silencing or downregulation of repair pathways. DNA damage levels and repair may influence the clinical outcome, being involved in drug resistance and risk of relapse. In pediatric ALL, we analyzed for the first time DNA damage and repair behavior in BM samples. Monitoring patient's outcomes will help to access the implication of our findings in survival and relapse rates.

Intellectual Disability in a Birth Cohort: Prevalence, Etiology, and Determinants at the Age of 4 Years.

BACKGROUND: Intellectual disability (ID), characterized by impairments in intellectual function and adaptive behavior, affects 1-3% of the population. Many studies investigated its etiology, but few are cohort studies in middle-income countries. AIMS: To estimate prevalence, etiology, and factors related to ID among children prospectively followed since birth in a Southern Brazilian city (Pelotas). METHODS: In 2004, maternity hospitals were visited daily and births were identified. Live-born infants (n = 4,231) whose family lived in the urban area have been followed for several years. At the age of 2 and 4 years, performances in development and intelligence tests were evaluated using the Battelle Developmental Inventory and Wechsler Intelligence Scale, respectively. Children considered as having developmental delay were invited to attend a genetic evaluation. RESULTS: At 4 years of age, the prevalence of ID was 4.5%, and the etiology was classified into 5 groups: environmental (44.4%), genetic (20.5%), idiopathic (12.6%), neonatal sequelae (13.2%), other diseases (9.3%). Most children presented impairment in two or more areas of adaptive behavior. There was no difference in prenatal care attendance or maternal schooling among the groups. CONCLUSION: For about 40% of children, ID was attributed to nonbiological factors, suggesting that the rate may be reduced with appropriate interventions early in life.

Frequencies of polymorphisms of the Rh, Kell, Kidd, Duffy and Diego systems of Santa Catarina, Southern Brazil.

BACKGROUND: Red blood cell genes are highly polymorphic with the distribution of alleles varying between different populations and ethnic groups. The objective of this study was to investigate gene polymorphisms of blood groups in the state of Santa Catarina, Southern Brazil. METHODS: Three hundred and seventy-three unrelated blood donors and 31 transfusion-dependent patients were evaluated to investigate polymorphisms of the Rh, Kell, Duffy, Kidd, and Diego blood group systems in a population from the state of Santa Catarina. The subjects, from seven regions that comprise the blood-banking network of the state, were assessed between August 2011 and March 2014. The genotypes of the Rh, Kell, Duffy, Kidd, and Diego systems were determined using the restriction fragment length polymorphism-polymerase chain reaction and allele-specific polymerase chain reaction techniques. RESULTS: The genotype frequencies in this study were significantly different when populations from different regions of Santa Catarina were compared. Furthermore, there were also significant differences in the genetic frequencies compared to other Brazilian states. The genotype frequencies of the Kell and Kidd blood groups are similar to European populations from Naples, Italy and Zurich, Switzerland. CONCLUSION: This article reports for the first time the frequency of polymorphisms of blood group systems in blood donors from Santa Catarina, Southern Brazil.

Novel synthetic chalcones induces apoptosis in human glioblastoma cells.

Glioblastoma multiforme is the main and most frequent tumor in adults' central nervous system. With a survival average of 5% two years after diagnosis, this type of cancer is a main health problem. Substances like the chalcones have been tested in order to develop new treatments. Here, we studied the effects of three synthetic chalcones (A23, C31 and J11) on A172 and surgery obtained-glioma cells. All chalcones showed a decrease in cell viability, mainly C31. An increase in apoptosis levels with no further increase of necrosis was observed. This augmentation may be linked to the high oxidative effect found, caused by the increased presence of reactive oxygen species and nitric oxide production. Cell cycle distribution showed an arrest at G0/G1 and S phases, suggesting that C31 interferes in cell cycle control. Our results shall aid in directing future research with this substance and its antitumor effect.

Genomic instability in human lymphocytes from male users of crack cocaine.

Recent research suggests that crack cocaine use alters systemic biochemical markers, like oxidative damage and inflammation markers, but very few studies have assessed the potential effects of crack cocaine at the cellular level. We assessed genome instability by means of the comet assay and the cytokinesis-block micronucleus technique in crack cocaine users at the time of admission to a rehabilitation clinic and at two times after the beginning of withdrawal. Thirty one active users of crack cocaine and forty control subjects were evaluated. Comparison between controls and crack cocaine users at the first analysis showed significant differences in the rates of DNA damage (p = 0.037). The frequency of micronuclei (MN) (p < 0.001) and nuclear buds (NBUDs) (p < 0.001) was increased, but not the frequency of nucleoplasmic bridges (NPBs) (p = 0.089). DNA damage decreased only after the end of treatment (p < 0.001). Micronuclei frequency did not decrease after treatment, and nuclear buds increased substantially. The results of this study reveal the genotoxic and mutagenic effects of crack cocaine use in human lymphocytes and pave the way for further research on cellular responses and the possible consequences of DNA damage, such as induction of irreversible neurological disease and cancer.

Genotoxic potential and physicochemical parameters of Sinos River, southern Brazil.

The present study aimed to evaluate the physicochemical parameters and the genotoxic potential of water samples collected in the upper, middle, and lower courses of the Sinos River, southern Brazil. The comet assay was performed in the peripheral blood of fish Hyphessobrycon luetkenii exposed under laboratory conditions to water samples collected in summer and winter in three sampling sites of Sinos River. Water quality analysis demonstrated values above those described in Brazilian legislation in Parobé and Sapucaia do Sul sites, located in the middle and in the lower courses of the Sinos River, respectively. The Caraá site, located in the upper river reach, presented all the physicochemical parameters in accordance with the allowed limits in both sampling periods. Comet assay in fish revealed genotoxicity in water samples collected in the middle course site in summer and in the three sites in winter when compared to control group. Thus, the physicochemical parameters indicated that the water quality of the upper course complies with the limits set by the national guidelines, and the ecotoxicological assessment, however, indicated the presence of genotoxic agents. The present study highlights the importance of combining water physicochemical analysis and bioassays to river monitoring.

Vitamin C intake reduces the cytotoxicity associated with hyperglycemia in prediabetes and type 2 diabetes.

Hyperglycemia leads to the formation of free radicals and advanced glycation end-products (AGEs). Antioxidants can reduce the level of protein glycation and DNA damage. In this study, we compared the levels of vitamin C intake, which is among the most abundant antioxidants obtained from diet, with the levels of fasting plasma glucose (FPG), glycated hemoglobin (A1C), DNA damage, and cytotoxicity in prediabetic subjects and type 2 diabetic subjects. Our results indicated that there was no significant correlation between FPG or A1C and DNA damage parameters (micronuclei, nucleoplasmic bridges, and nuclear buds). FPG and A1C correlated with necrosis (r = 0.294; P = 0.013 and r = 0.401; P = 0.001, resp.). Vitamin C intake correlated negatively with necrosis and apoptosis (r = -0.246; P = 0.040, and r = -0.276; P = 0.021, resp.). The lack of a correlation between the FPG and A1C and DNA damage could be explained, at least in part, by the elimination of cells with DNA damage by either necrosis or apoptosis (cytotoxicity). Vitamin C appeared to improve cell survival by reducing cytotoxicity. Therefore, the present results indicate the need for clinical studies to evaluate the effect of low-dose vitamin C supplementation in type 2 diabetes.

Chromosome instability and oxidative stress markers in patients with ataxia telangiectasia and their parents.

Ataxia telangiectasia (AT) is a rare neurodegenerative disorder, inherited in an autosomal recessive manner. Total blood samples were collected from 20 patients with AT, 13 parents of patients, and 17 healthy volunteers. This study aimed at evaluating the frequency of chromosomal breaks in spontaneous cultures, induced by bleomycin and ionizing radiation, and further evaluated the rates of oxidative stress in AT patients and in their parents, compared to a control group. Three cell cultures were performed to each individual: the first culture did not receive induction to chromosomal instability, the second was exposed to bleomycin, and the last culture was exposed to ionizing radiation. To evaluate the rates of oxidative stress, the markers superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid (TBARS) were utilized. Significant differences were observed between the three kinds of culture treatments (spontaneous, bleomycin, and radiation induced) and the breaks and chromosomal aberrations in the different groups. The oxidative stress showed no significant differences between the markers. This study showed that techniques of chromosomal instability after the induction of ionizing radiation and bleomycin are efficient in the identification of syndrome patients, with the ionizing radiation being the most effective.

The influence on DNA damage of glycaemic parameters, oral antidiabetic drugs and polymorphisms of genes involved in the DNA repair system.

The hyperglycaemia seen in type 2 diabetes mellitus (DM2) is associated with increased oxidative stress and production of reactive oxygen species, both of which are factors that can provoke DNA damage. Notwithstanding, other factors, including medications and individual susceptibility, can also induce this type of DNA lesion. The objective of this study was, therefore, to investigate the influence of glycaemic control, oral antidiabetic drugs (metformin and glibenclamide) and polymorphisms of the XRCC1 and XRCC3 genes on the frequency of DNA damage in DM2 patients, which was accessed by the cytokinesis-block micronucleus cytome and the comet assays on the ex vivo mitogenically stimulated lymphocytes. The 53 people recruited to take part in the study were already on treatment with metformin and were followed for 5 months. Ten of these patients were put on combined treatment with the addition of glibenclamide. It was observed that the greater the plasma metformin concentration, the lower the frequency of micronuclei (MN) in the sample total (P = 0.009) and also that the subset of patients using combined treatment including glibenclamide had a significantly higher MN rate 90 days after starting combined treatment (P = 0.024). In the subset who only took metformin, the rate of MN was significantly higher among carriers of the 399Gln allele on the XRCC1 gene (P = 0.008). In addition, homozygotes for the 241Thr allele exhibited a significant increase in MN in the combined treatment group (P = 0.008). Our results suggest that different combinations of oral antidiabetic drugs and polymorphisms on genes involved in the DNA damage repair system could influence the frequency of this type of chromosome lesion, which can be a useful biomarker for assessing the risk of developing cancer.