Effect of pesticide exposure on total antioxidant capacity and biochemical parameters in Brazilian soybean farmers.

Farmers represent a population highly vulnerable to the toxic effects of pesticide exposure. Antioxidant capacity and biochemical parameters have been used as biomarkers of occupational exposure to pesticides. The aim of this study was to evaluate hepatic and renal parameters as well as butyrylcholinesterase (BChE) activity and ferric-reducing ability of plasma (FRAP) considering high and low exposure periods in soybean farmers in southern Brazil. The exposed group consisted of 50 soybean farmers. Two control groups were used, composed by 35 (Novo Hamburgo control group) and 28 (Sertão control group) subjects not exposed to pesticides. Farmers blood samples were collected during the high and low pesticide exposure periods. BChE, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), urea, and creatinine levels were determined. The FRAP assay was carried out to evaluate the antioxidant potential in the exposed group. Considering the exposed group, significantly lower BChE and increased AST activity were observed during high pesticide exposure period as well as higher FRAP, urea and creatinine levels; however, ALT and GGT did not differ between the two periods. When compared with the control groups, only urea and creatinine were higher in the exposed group. The present results indicate that occupational exposure to mixtures of pesticides might elicit adverse effects at the biochemical level. In addition, the study highlights the importance in considering periods of a same crop season with different degree of pesticide exposure during biologic monitoring of these biochemical parameters.

Assessment of DNA damage and cholinesterase activity in soybean farmers in southern Brazil: High versus low pesticide exposure.

The aim of this study was to evaluate the DNA damage in soybean growers during two agricultural periods of a crop season (high and low exposure) and a control group, as well as butyrylcholinesterase (BChE) activity during these exposure periods in order to estimate the degree of BChE inhibition for the exposed group. DNA damage in peripheral whole blood was evaluated by the comet assay and plasma BChE activity was accessed as a measure of exposure to cholinesterase inhibitors. None of the soybean growers reported using full Personal Protective Equipment (PPE). BChE was lower in high exposure period than in low exposure period and DNA damage index was significantly increased in the high exposure period than in the low exposure period. In addition, DNA damage in both exposure periods was higher than control group. No correlation was found between exposure time and DNA damage and BChE activity. However, negative correlation was observed between DNA damage in high and low exposure periods. The results indicate that soybean growers are exposed to cholinesterase inhibitors and to pesticides mixtures with genotoxic potential.

Occupational exposure to pesticides and thyroid function in Brazilian soybean farmers.

INTRODUCTION: Agriculture production has been supported especially by the use of pesticides for crop protection and pest control. Although the agricultural production has been increased by pesticides use, these substances also reach non-target organisms and may become a risk to the health of farmers. Several epidemiological studies in human have investigated the association between exposure to pesticides and altered serum levels of thyroid hormones, reporting both positive and negative results. Overall, the impact of pesticides on human thyroid function is still limited. OBJECTIVE: The aim of this study was to access serum levels of free thyroxin (FT4), total triiodothyronine (TT3), thyroid-stimulating hormone (TSH), and butyrylcholinesterase (BChE) in soybean farmers in southern Brazil. METHODS: The exposed group was composed by 46 rural workers and 27 subjects not exposed to pesticides composed the control group. All subjects had blood samples collected by venipuncture in order to analyze the serum levels of FT4, TT3, TSH and BChE. RESULTS: The results showed a significant decreasing in TSH and increasing in TT3 and FT4 in rural workers, compared to control group. BChE levels were lower in exposed group than in control group. The results suggest that farmers are exposed to mixtures of pesticides with endocrine disruptor properties.

Micronuclei and other nuclear anomalies in exfoliated buccal cells of urban solid waste collectors and recyclers in southern Brazil.

Workers involved in urban solid waste collection may be exposed to various environmental contaminants, including chemical pollutants, which might be mutagenic and increase the risk of diseases such as cancer. Evaluation of DNA damage in workers in this field are still scarce. This study aims to evaluate mutagenic and cytotoxic effects in workers involved in the collection and segregation of urban solid waste generated in southern Brazil. Municipal solid waste collectors were recruited in two municipalities of the state of Rio Grande do Sul. The control group was composed of workers of the education and commerce areas, with no exposure to known genotoxic agents. Slides of exfoliated buccal cells were analyzed to estimate the frequency of micronuclei (MN) as well as other nuclear abnormalities, such as broken-egg/bud, binucleation and karyorrhexis. The analyses of 44 workers and 45 control subjects have shown that the frequencies of MN, binucleated cells and karyorrhexis in the exposed workers were significantly higher than in the control group. In the exposed group, frequencies of MN and binucleated cells showed a significant positive correlation. The other cytogenetic parameters were not correlated among each other or with age and exposure time. These results indicate that the workers involved in urban solid waste collection are exposed to mutagenic and cytotoxic agents.

Pesticide exposure and health conditions among orange growers in Southern Brazil.

This study aimed to evaluate the exposure to pesticides through the biomarkers analysis, as well as life habits and use of Personal Protective Equipment (PPE) in a group of farmers who grow citrus in the Vale do Caí region, in Rio Grande do Sul, southern Brazil. The study population consisted of 73 volunteer farmers, 45 males and 28 females, aged between 13 and 69 years old. The control group consisted of 30 individuals who were not exposed to pesticides. Measures of urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), plasma cholinesterase (BChE) activity, and hematological parameters were analyzed. The study population also answered a structured questionnaire on life habits and health. The results showed that BChE activity was significantly lower in the exposed group than in the control group. AST, ALT, and creatinine were increased in the group of women exposed to pesticides when compared to the control group. GGT, urea, and hematological parameters did not show statistical differences for both male and female group. The most prevalent symptom reported by farmers after exposure to pesticides was headache. Furthermore, it was verified that the use of complete PPE is only made by 38% of the studied population.

DNA Damage in Wistar Rats Exposed to Organophosphate Pesticide Fenthion.

In the last several decades, exposure to pesticides has become a concern to environmental and human health. Many pesticides are environmentally persistent and are characterized by varying degrees of toxicity and adverse effects, including DNA damage. The present study was undertaken to evaluate the genotoxic potential of organophosphate pesticide fenthion in Wistar rats, as assessed by the comet assay. Adult male Wistar rats were treated with a solution of fenthion at a concentration of 40 mg/kg/day, administered intraperitoneally for 18 consecutive days. Rats were killed 24 hours after the last pesticide administration, and the comet assay was performed in peripheral blood cells. The comet assay results revealed that the damage index (19.29 ± 3.59 vs. 7.80 ± 2.25) and the damage frequency (17.00 ± 3.46 vs. 7.5 ± 2.46) found in fenthion-treated rats were significantly higher than those found in the control group (p = 0.001 and p = 0.0006, respectively). The results show that fenthion affects the DNA integrity of rat cells and may induce DNA damage in exposed organisms.

Evaluation of the pharmacological activity of the Alternanthera brasiliana aqueous extract.

CONTEXT: Alternanthera brasiliana (L.) Kuntze (Amarantaceae) is widely used in Brazilian traditional medicine as an analgesic, anti-inflammatory and antibacterial. OBJECTIVE: To investigate the potential anti-inflammatory, analgesic, anxiolytic, and locomotor effect of the infusions in preclinical models. MATERIALS AND METHODS: Anti-inflammatory activity was evaluated by a carrageenan-induced pleurisy test in Wistar rats (200 and 400 mg/kg, n = 6-7). Analgesic activity was evaluated by the number of abdominal contractions induced by 0.6% acetic acid administered to Swiss mice (25, 50, 100, 200, and 400 mg/kg, n = 10). Effects on the central nervous system (CNS) were evaluated in Wistar rats (100, 200, and 400 mg/kg, n = 10) using open field and plus maze models. RESULTS AND DISCUSSION: Possible anti-inflammatory activity was indicated by the significant reduction of 19.8% for 200 mg/kg (p < 0.05) and 23.9% for 400 mg/kg (p < 0.05) of polymorphonuclear cells in pleural exudate. Analgesic activity was suggested by the significant reduction (p < 0.01) of number of abdominal contractions for all doses under study. No anxiolytic effect was noted, but there was an increase in the number of rearings in the group of rats treated with 100 mg/kg dose (p < 0.05). CONCLUSIONS: Our findings suggest that the aqueous extract of the leaves of A. brasiliana has a potential pharmacological effect on inflammation and pain.

Viral load and epidemiological profile of patients infected by pandemic influenza a (H1N1) 2009 and seasonal influenza a virus in Southern Brazil.

Correlation between virologic profile and clinical features of patients infected by influenza virus provides important information for epidemiological control and clinical management of future disease outbreaks. Samples from patients in Southern Brazil, from June to December 2009, were examined and the viral load was correlated with epidemiological data. All samples were analyzed by qRT-PCR for detection of the 2009-pandemic Influenza A (H1N1). Relative viral loads were assessed based on the 2(-ΔCT) method and epidemiological data were obtained for each patient, following ethical policies. A total of 933 samples were positive for pH1N1 (2009) influenza; 172 were positive for seasonal influenza A; 13 were undetermined; 1992 samples were negative for influenza A. Combined molecular and epidemiological data were available for 38 seasonal and 198 pandemic samples. The median viral load was higher in pandemic than in seasonal influenza samples; in patients infected with pH1N1 (2009), viral load associated positively with chills, myalgia and rhinorrhea, and negatively with dyspnea, but no association was observed with other symptoms, nor with clinical conditions such as pregnancy, smoking, immunodepression and co-morbidities. Regarding patients infected with seasonal influenza, viral loads did not show statistically significant association with any of the symptoms. This is the first study in Brazil that examines epidemiological and molecular data from the 2009 influenza pandemic. The results may serve as a basis for developing strategies to control human-to-human infection and viral dissemination, and for implementing effective measures and public health policies against future novel disease outbreaks.

Effect of rosmarinic and caffeic acids on inflammatory and nociception process in rats.

Rosmarinic acid is commonly found in species of the Boraginaceae and the subfamily Nepetoideae (Lamiaceae). It has a number of interesting biological activities, for example, antiviral, antibacterial, anti-inflammatory, and antioxidant. The aim of the present study was to investigate the effect of the i.p. administration of caffeic and rosmarinic acid (5 and 10 mg/kg) on anti-inflammatory and nociceptive response using carrageenan-induced pleurisy model and tail-flick assay in rats. The analysis of cells in the pleural exudates revealed a reduction of 66% of the number of leukocytes that migrated to the pleural cavity in the animals treated with 5 mg/kg caffeic acid, and of 92.9% for the animals treated with 10 mg/kg in comparison with the control group. These exudates showed a balanced distribution of polymorphonuclear (PMN) and mononuclear (MN) cells, differently from the control group, in which PMN cells were predominant. The analysis to tail-flick latency was increased in the group treated with 10 mg/kg caffeic acid characterizing a nociceptive response. While there was no difference between control group and animals treated with rosmarinic.

Pharmacological evaluation of Copaifera multijuga oil in rats.

CONTEXT: Copaiba oil is an oleoresin made up of resin acids and volatile compounds, and it is obtained by tapping the trunks of trees that are members of the Copaifera L. (Leguminoseae) genus and are found in tropical parts of Latin America. OBJECTIVE: This study analyzed the chemical composition of Copaifera multijuga Hayne oil and conducted preclinical trials to investigate anti-inflammatory effects and any action it may have on the central nervous system (CNS) of rats. MATERIALS AND METHODS: The chemical analysis was carried out using gas chromatography with mass spectroscopy. Anti-inflammatory activity was measured by leucocytes mobilization, by chemotaxis assay in Boyden's chamber, and by pleurisy model in rats. CNS effect was determined by plus maze and open-field assays. The statistical test applied was analysis of variance (ANOVA) followed by Tukey's test or ANOVA followed by Duncan's test. RESULTS: The oil was composed of sesquiterpenes with the predominance of ß-caryophyllene (36.0%), followed by α-copaene (18.8%), ß-bisabolene (8.5%), and α-trans-bergamotene (7.0%). Data demonstrated that at 100 and 200 mg/kg doses and at a concentration of 200 µl/ml copaiba essential oil presented anti-inflammatory effects both in vivo and in vitro based on reduced leukocyte migration to the rats' pleural cavity and to the chemotactic agent lipopolysaccharide solution, respectively. During the experiments investigating CNS effects, locomotive and exploratory activities were reduced and the animals' anxiety increased at 100 and 200 mg/kg. CONCLUSION: The results obtained suggest that copaiba oil has an interesting anti-inflammatory effect and important effect on the CNS.

Oxidative stress and DNA damage in older adults that do exercises regularly.

OBJECTIVES: Free radicals may damage lipids, proteins and DNA, which may lead to critical diseases in the aging. This work evaluated levels of malondialdehyde (MDA), glutathione peroxidase (GPx) and DNA damage by comet assay (SCGE) in older adults that do exercises regularly. DESIGN AND METHODS: 110 females, aged 66.3+/-8 years were divided into sedentary (n=54), walking (n=36) and muscle building (n=20) groups. Levels of MDA, GPx and SCGE were measured in venous blood before and after exercise. RESULTS: MDA levels were higher (P<0.005) and GPx levels were lower (P<0.005) in active groups than in sedentary group. SCGE index after physical activity was greater than at baseline (muscle building: P=0.004; walking: P=0.002). CONCLUSIONS: Exercise reduces the diseases risk, but may promote the production of free radicals. It remains unclear whether cell adaptations responsible for health benefits are associated with such events. However we may suggest the existence of a different biochemical pattern for older adults that do exercise regularly.

Effect of radicicol infusion on the Src tyrosine kinase activity of rat hippocampus before and after training in an inhibitory avoidance task.

The participation of protein serine/threonine kinases in memory formation and retrieval is well established. In contrast, relatively little is known on the role of protein tyrosine kinases (PTKs). Previous work showed that intra-hippocampal infusion of the Src-PTK inhibitor radicicol inhibits memory acquisition, consolidation, and retrieval of one-trial step-down inhibitory avoidance task. In this study, we investigated the possible interaction between levels of Src-PTK activity in hippocampus and memory acquisition, formation, and retrieval of this task. Radicicol (0.5 microg/ml) was infused into the CA1 region of the hippocampus of rats trained in a one-trial step-down inhibitory avoidance task. Radicicol infused 15 min before training decreased Src-PTK activity, as measured 0, 1.5, and 24 h after training, and impaired memory acquisition of the task. When given immediately after training, there was a decrease in Src-PTK activity 1.5 h, but not 0 or 24 h after training. This treatment depressed memory consolidation. Radicicol infused into CA1 10 min prior to retrieval testing inhibited hippocampal Src-PTK activity, as measured immediately after the test session. The results suggest that Src-PTKs participate in memory acquisition, consolidation, and retrieval processes, but the timing of the role of the enzyme is different in each case.

Neuropharmacological analysis of caffeic acid in rats.

The aim of the present study was to investigate the effect of intraperitoneal administration of caffeic acid (0.5, 1, 2, 4 or 8 mg/kg) on elevated plus-maze and open field tasks in rats and its possible neuroprotection/neurotoxicity using the comet assay. Caffeic acid at 1 mg/kg increased the number of entries and the time spent in the open arms on plus-maze, suggesting an anxiolytic-like effect when used in lower doses without affecting locomotion and exploration on the open field. Furthermore, a protective effect against hydrogen peroxide-induced oxidative damage on brain tissue was observed through the treatment with caffeic acid at 1 and 8 mg/kg. However, in the highest dose, caffeic acid induced DNA damage in brain tissue.

Neurobehavioral and genotoxic aspects of rosmarinic acid.

Rosmarinic acid is a naturally occurring hydroxylated compound. It is present in many plants, for example, it occurs in Artemisia capillaris, Calendulla officinalis, Melissa officinalis, Salvia officinalis and in other several plant families. It also shows a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The aim of the present study was to investigate the effect of the i.p. administration of rosmarinic acid (1, 2, 4 or 8 mg kg(-1)) on elevated plus-maze, step-down inhibitory avoidance and open field task in rats. In addition, we evaluated its genotoxic effect on brain tissue using the comet assay. Rosmarinic acid (2 and 4 mg kg(-1)) increased the number of entries in the open arms, suggesting an anxiolytic-like activity when used in lower doses, without affecting the short-term memory (STM) and long-term memory (LTM) retention on inhibitory avoidance task. Eight milligrams per kilograms of this acid was enough to increase the locomotion and motivation of the animals, but not 1, 2 or 4 mg kg(-1), suggesting that in lower doses, this compound can produce anxiolytic-like effect without exerting locomotor alterations or DNA damage in brain tissue.