Gabriela Göethel

Acute and Subchronic Toxicity Evaluation of Poly(ɛ-Caprolactone) Lipid-Core Nanocapsules in Rats

Owing to concerns over the effects of the physicochemical properties of nanoparticles and their interaction with biological systems, further investigation is required. We investigated, for the first time, the toxicity of lipid-core nanocapsules (LNCs) containing a polymeric wall of poly(ε-caprolactone) and a coating of polysorbate 80 used as drug delivery devices (~245nm) in Wistar rats after single- and repeated-dose treatments. The suspensions were prepared by interfacial deposition of the polymer and were physicochemically characterized. Toxicological effects were determined after single doses of 18.03, 36.06, and 72.12 × 10(12) LNC/kg and repeated doses of 6.01, 12.02, and 18.03 × 10(12) LNC/kg for 28 days by ip administration. The results for both the treatments showed no mortality or permanent body weight changes during the experiments. A granulomatous foreign body reaction was observed in the liver and spleen of higher dose groups in acute and subchronic treatments. Most of the hepatotoxicity and nephrotoxicity markers were within the reference values and/or were similar to the control group. However, a slight alteration in the hematologic parameters was observed in both the studies. Thus, to verify a possible methodological influence, we performed an in vitro test to confirm such influence. These findings are in agreement with earlier reports regarding no appreciable toxicity of biodegradable polymeric nanoparticles, indicating that LNC might be a safe candidate for drug delivery system. Furthermore, the results presented in this study are important for health risk assessment and to implement strategies for testing biodegradable polymeric nanoparticles.

Genotoxicity and oxidative stress in gasoline station attendants

We evaluated genotoxic effects of exposure to low levels of benzene, a class I human carcinogen, among gasoline station attendants (GSA). Oxidative stress and the protective effects of antioxidants on DNA damage were also analyzed. Although exposures were below ACGIH (American Conference of Governmental Industrial Hygienists) limits, the GSA group presented higher DNA damage indices and micronucleus frequencies, increased oxidative protein damage, and decreased antioxidant capacity relative to the control group. Duration of benzene exposure was correlated with DNA and protein damage. The biomarkers evaluated in this work may provide early signals of damage in subjects occupationally exposed to benzene.

Evaluation of genotoxicity in workers exposed to benzene and atmospheric pollutants.

Gas station attendants and taxi drivers are occupationally exposed to xenobiotics which may be harmful to their health. Atmospheric pollutants and benzene can lead to DNA damage. Genotoxicity and mutagenicity assays can be used to evaluate the effects of these pollutants. We have evaluated genotoxicity and mutagenicity in workers occupationally exposed to xenobiotics, by application of the 8-hydroxy-2-deoxyguanosine (8-OHdG), comet, and micronucleus (MN) assays. Biomarkers of benzene and carbon monoxyde exposure were also measured: urinary t,t-muconic acid (t,t-MA) and carboxyhaemoglobin (COHb) in whole blood, respectively. The study groups comprised 43 gas station attendants (GSA), 34 taxi drivers (TD), and 22 persons without known occupational exposures (NE). Levels of t,t-MA in the GSA group were significantly elevated compared to the NE group (p<0.001), however these levels were below of levels established by ACGIH (American Conference of Governmental Industrial Hygienists). COHb levels were not significantly different between the TD and NE groups (p>0.05). DNA damage index (DI) and 8-OHdG levels were significantly higher for both the GSA and TD groups, compared to the NE group (p<0.001), but MN frequencies were not elevated. Spearman correlation analysis showed that the frequency of MN was positively correlated with 8-OHdG. A positive correlation between DNA DI levels and 8-OHdG was also observed. In conclusion, our results indicated that low levels of occupational exposure to benzene and atmospheric pollutants may be linked to genotoxicity and oxidative DNA damage.

Cognitive deficits and ALA-D-inhibition in children exposed to multiple metals

Children are especially vulnerable to adverse effects of multiple metals exposure. The aim of this study was to assess some metals concentrations such as lead (Pb), arsenic (As), chromium (Cr), manganese (Mn) and iron (Fe) in whole blood, serum, hair and drinking water samples using inductively coupled plasma-mass spectrometry (ICP-MS) in rural and urban children. In addition, evaluate the adverse effects of multiple metals exposure on cognitive function and δ-aminolevulinate dehydratase (ALA-D) activity. The cognitive ability assessment was performed by the Ravens Colored Progressive Matrices (RCPM) test. The ALA-D activity and ALA-D reactivation index (ALA-RE) activity with DTT and ZnCl2 also were determined. Forty-six rural children and 23 urban children were enrolled in this study. Rural children showed percentile IQ scores in the RCPM test significantly decreased in relation to urban children. According to multiple linear regression analysis, the Mn and Fe in hair may account for the cognitive deficits of children. Manganese and Fe in hair also were positively correlated with Mn and Fe in drinking water, respectively. These results suggest that drinking water is possibly a source of metals exposure in children. ALA-D activity was decreased and ALA-RE with DTT and ZnCl2 was increased in rural children in comparison to urban children. Moreover, ALA-D inhibition was correlated with Cr blood levels and ALA-RE/DDT and ALA-RE/ZnCl2 were correlated with levels of Cr and Hg in blood. Thus, our results indicated some adverse effects of childrens exposure to multiple metals, such as cognitive deficits and ALA-D inhibition, mainly associated to Mn, Fe, Cr and Hg.

Biomonitoring of gasoline station attendants exposed to benzene: Effect of gender

Women are employed in increasing numbers as gasoline station attendants, a work category with risk of exposure to benzene. We have assessed the effect of gender on biomarkers of occupational benzene exposure. Gasoline station attendants (20 men and 20 women) and 40 control individuals (20 men and 20 women) with no history of occupational benzene exposure were evaluated. Benzene exposure was monitoring by environmental and biological measurements. Urinary trans,trans-muconic acid levels, well-known genetic and hematological alterations linked to benzene exposure, and non-cancer effects on the immune, hepatic, and renal systems were investigated. Our results suggest a potential effect of gender on some effects of occupational benzene exposure, particularly the hematological parameters and trans,trans-muconic acid levels. Despite limitations of our study, our findings provide important considerations about occupational exposure of women to benzene and may contribute to the development of occupational protection standards.

Protective effects of melatonin-loaded lipid-core nanocapsules on paraquat-induced cytotoxicity and genotoxicity in a pulmonary cell line

Many acute poisonings lack effective and specific antidotes. Due to both intentional and accidental exposures, paraquat (PQ) causes thousands of deaths annually, especially by pulmonary fibrosis. Melatonin (Mel), when incorporated into lipid-core nanocapsules (Mel-LNC), has enhanced antioxidant properties. The effects of such a formulation have not yet been studied with respect to mitigation of PQ- induced cytotoxicity and DNA damage. Here, we have tested whether Mel-LNC can ameliorate PQ-induced toxicity in the A549 alveolar epithelial cell line. Physicochemical characterization of the formulations was performed. Cellular uptake was measured using nanocapsules marked with rhodamine B. Cell viability was determined by the MTT assay and DNA damage was assessed by the comet assay. The enzyme-modified comet assay with endonuclease III (Endo III) and formamidopyrimidine glycosylase (FPG) were used to investigate oxidative DNA damage. Incubation with culture medium for 24h did not alter the granulometric profile of Mel-LNC formulations. Following treatment (3 and 24h), red fluorescence was detected around the cell nucleus, indicating internalization of the formulation. Melatonin solution (Mel), Mel-LNC, and LNC did not have significant effects on cell viability or DNA damage. Pre-treatment with Mel-LNC enhanced cell viability and showed a remarkable reduction in % DNA in tail compared to the PQ group; this was not observed in cells pre-treated with Mel. PQ induces oxidative DNA damage detected with the enzyme-modified comet assay. Mel-LNC reduced this damage more effectively than did Mel. In summary, Mel-LNC is better than Mel at protecting A549 cells from the cytotoxic and genotoxic effects of PQ.

Relationship between blood metals and inflammation in taxi drivers.

BACKGROUND Cardiovascular disease is a cause of concern in public health worldwide, reinforcing the need for studies related to the identification of potential agents that contribute to the inflammation process and atherosclerosis. This study aimed to evaluate whether metals are associated with inflammatory and kidney damage and could contribute to the atherosclerosis process. METHODS Blood metals, inflammatory markers, homocysteine, antioxidants and renal markers were measured in 42 taxi drivers and 27 controls (non-occupationally exposed). RESULTS Taxi drivers had increased Hg, As, Pb and Cd levels, however Cu and Zn levels were decreased compared to controls (p<0.05). Hg, As and Pb levels were positively associated with pro-inflammatory cytokines, nitric oxide and negatively associated with glutathione peroxidase. Moreover, Hg, As and Pb presented positive associations with homocysteine, an independent risk factor for atherosclerosis. Regarding markers of kidney function, N-acetyl-beta-d-glucosaminidase levels were increased in taxi drivers and correlated to inflammation markers. CONCLUSION Hg levels were found above the recommended limits in taxi drivers and both Hg and As levels showed associations with inflammatory process, oxidative status and homocysteine. Thus, chemical substances as Hg and As can be considered as additional contributors to the development of cardiovascular diseases.

Are Delta-Aminolevulinate Dehydratase Inhibition and Metal Concentrations Additional Factors for the Age-Related Cognitive Decline?

Aging is often accompanied by cognitive impairments and influenced by oxidative status and chemical imbalances. Thus, this study was conducted to examine whether age-related cognitive deficit is associated with oxidative damage, especially with inhibition of the enzyme delta-aminolevulinate dehydratase (ALA-D), as well as to verify the influence of some metals in the enzyme activity and cognitive performance. Blood ALA-D activity, essential (Fe, Zn, Cu, Se) and non-essential metals (Pb, Cd, Hg, As, Cr, Ni, V) were measured in 50 elderly and 20 healthy young subjects. Cognitive function was assessed by tests from Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) battery and other. The elderly group presented decreased ALA-D activity compared to the young group. The index of ALA-D reactivation was similar to both study groups, but negatively associated with metals. The mean levels of essential metals were within the reference values, while the most toxic metals were above them in both groups. Cognitive function impairments were observed in elderly group and were associated with decreased ALA-D activity, with lower levels of Se and higher levels of toxic metals (Hg and V). Results suggest that the reduced ALA-D activity in elderly can be an additional factor involved in cognitive decline, since its inhibition throughout life could lead to accumulation of the neurotoxic compound ALA. Toxic metals were found to contribute to cognitive decline and also to influence ALA-D reactivation.

Energy drink and alcohol combination leads to kidney and liver alterations in rats

ABSTRACT The aim of this study was to evaluate the acute toxicity of the association of energy drink and alcohol in male Wistar rats. Animals were treated by oral gavage with 10ml/kg distilled water (control); 10ml/kg energy drink (ED10); 3.2mg/kg caffeine+40mg/kg taurine; 2g/kg alcohol 20%; 2g/kg alcohol 20%+ED10; and 2g/kg alcohol 20%+3.2mg/kg caffeine+40mg/kg taurine. Behavioral alterations were observed for 6h after treatment. Animals presented significant differences in the frequency of rearing, ambulation, grooming, wakefulness and tachypnea along time. Caffeine+taurine increased the levels of TBARS and total thiols in kidneys. ED10 increased lipoperoxidation in liver. The association of ED10+alcohol induced nephrotoxicity observed by the increase of urinary N‐acetyl‐&bgr;‐d‐glucosaminidase (NAG) activity. Histopathological analysis showed the presence of congestion and hydropic and hyaline degenerations in the livers of ED10+alcohol treated rats, and hemorrhage in the liver of alcohol+caffeine+taurine group. In kidneys, hyaline degeneration was observed in ED10; ED10+alcohol; caffeine+taurine; and alcohol+caffeine+taurine. Hemorrhage was present in the kidneys of all groups. The combination of energy drinks and alcohol is not safe for the consumers. Therefore, precautionary measures should be disseminated among risk populations, especially the teenagers. HIGHLIGHTSThe consumption of energy drinks associated with alcohol could be harmful.Behavioral effects after the association of alcohol and energy drink are distinct.Energy drinks and their constituents induce oxidative damage in the kidney of rats.The combined consumption of energy drink and alcohol induced nephrotoxicity to rats.

Exposure to environment chemicals and its possible role in endocrine disruption of children from a rural area

ABSTRACT Endocrine disrupting chemicals (EDCs), including pesticides and metals, are present in rural areas, endangering the health of exposed populations. This work aimed to investigate the possible association between the exposure to these xenobiotics and thyroid dysfunction in children living in a rural community of Southern Brazil. Fifty‐four children aged 5–16 years participated in this study. Peripheral biomarker evaluations were performed in periods of low and high exposure to pesticides. Thyroid ultrasonography was evaluated in the high exposure period. Blood levels of chromium (Cr), manganese (Mn), mercury (Hg), and lead (Pb), as well as hair Pb levels were positively correlated with thyroid stimulating hormone (TSH) concentrations and negatively associated with free thyroxine (fT4) levels in the low exposure period. Prolactin was positively associated with hair Mn in both periods. In the ultrasound tests, the majority of children presented a normal echogenicity of thyroid. Glucose was inversely associated with the biomarker of exposure to cholinesterase inhibitor insecticides, butyrylcholinesterase (BuChE). Lipid profile was above the recommended levels in both periods. In summary, our results show that children environmentally exposed to a mixture of xenobiotics in an agricultural community may have health impairments, especially on thyroid function, dyslipidemia, and glucose homeostasis disruption. HighlightsRural children had elevated blood and hair Mn and Cr levels.Disruption on thyroid function can be related to metals exposure in rural areas.Dyslipidemia is associated to thyroid dysfunction in children exposed to metals.Cholinesterase inhibitors insecticides affect the glucose homeostasis of children.Children exposed to high levels of Mn can be evaluated through the prolactin.