Evaluation of immunological, inflammatory, and oxidative stress biomarkers in gasoline station attendants.

BACKGROUND: Gasoline is a complex mixture of saturated and unsaturated hydrocarbons, in which aromatic compounds, such as BTX (benzene, toluene, and xylene) feature as the main constituents. Simultaneous exposure to these aromatic hydrocarbons causes a significant impact on benzene toxicity. In order to detect early alterations caused in gasoline station attendants exposed to BTX compounds, immunological, inflammatory, and oxidative stress biomarkers were evaluated. METHODS: A total of 66 male subjects participated in this study. The gasoline station attendants (GSA) group consisted of 38 gasoline station attendants from Rio Grande do Sul, Brazil. The non-exposed group consisted of 28 subjects who were non-smokers and who had no history of occupational exposure. Environmental and biological monitoring of BTX exposure was performed using blood and urine. RESULTS: The GSA group showed increased BTX concentrations in relation to the non-exposed group (p < 0.001). The GSA group showed elevated protein carbonyl (PCO) levels and pro-inflammatory cytokines, decreased expression of CD80 and CD86 in monocytes, and reduced glutathione S-transferase (GST) activity compared to the non-exposed group (p < 0.05). BTX levels and trans,trans-muconic acid levels were positively correlated with pro-inflammatory cytokines and negatively correlated with interleukin-10 contents (p < 0.001). Increased levels of pro-inflammatory cytokines were accompanied by increased PCO contents and decreased GST activity (p < 0.001). Furthermore, according to the multiple linear regression analysis, benzene exposure was the only factor that significantly contributed to the increased pro-inflammatory cytokines (p < 0.05). CONCLUSIONS: Taken together, these findings show the influence of exposure to BTX compounds, especially benzene, on the immunological, inflammatory, and oxidative stress biomarkers evaluated. Furthermore, the data suggest the relationship among the evaluated biomarkers of effect, which could contribute to providing early signs of damage to biomolecules in subjects occupationally exposed to BTX compounds.

Evaluation of toxic metals and essential elements in children with learning disabilities from a rural area of southern Brazil.

Children's exposure to metals can result in adverse effects such as cognitive function impairments. This study aimed to evaluate some toxic metals and levels of essential trace elements in blood, hair, and drinking water in children from a rural area of Southern Brazil. Cognitive ability and δ-aminolevulinate dehydratase (ALA-D) activity were evaluated. Oxidative stress was evaluated as a main mechanism of metal toxicity, through the quantification of malondialdehyde (MDA) levels. This study included 20 children from a rural area and 20 children from an urban area. Our findings demonstrated increase in blood lead (Pb) levels (BLLs). Also, increased levels of nickel (Ni) in blood and increase of aluminum (Al) levels in hair and drinking water in rural children were found. Deficiency in selenium (Se) levels was observed in rural children as well. Rural children with visual-motor immaturity presented Pb levels in hair significantly increased in relation to rural children without visual-motor immaturity (p < 0.05). Negative correlations between BLLs and ALA-D activity and positive correlations between BLLs and ALA-RE activity were observed. MDA was significantly higher in rural compared to urban children (p < 0.05). Our findings suggest that rural children were co-exposed to toxic metals, especially Al, Pb and Ni. Moreover, a slight deficiency of Se was observed. Low performance on cognitive ability tests and ALA-D inhibition can be related to metal exposure in rural children. Oxidative stress was suggested as a main toxicological mechanism involved in metal exposure.

Evaluation of lipid damage related to pathological and physiological conditions.

Several diseases and xenobiotics are known to generate reactive species that may trigger oxidative stress when not properly scavenged by the antioxidant defenses and result in tissue damage. We investigated lipid peroxidation (LPO) as a possible mechanism for tissue damage in some pathologies, in the normal aging process, and in subjects exposed to organic solvents. Plasmatic malondialdehyde (MDA) was quantified by high-performance liquid chromatography with visible wavelength detection in 239 subjects and divided into the following: acute myocardium infarction (AMI), diabetes without complications (D) and hemodialysis (HD) patients; into healthy children, adults, and elderly, all nonexposed to xenobiotics; and into painters occupationally exposed to organic solvents (P). Troponin, glycated hemoglobin, and transminases [aspartate aminotransferase (AST) and alanine aminotransferase] were analyzed. An increase in LPO was observed in AMI, D, HD, and P groups, when compared to healthy adults. No correlation between MDA and age was found. Further, we found positive correlations between MDA versus troponin (r = 0.47), MDA versus HbA1c (r = 0.56), and MDA versus AST (r = 0.41) in AMI, diabetics, and painters, respectively. This work has demonstrated increased lipid and protein damages in myocardium and blood, along with an alteration of hepatic transaminase activities and induction of LPO, suggesting that MDA levels are important to evaluate the extent of tissue alterations and development of acute and chronic conditions.

Subchronic toxicity of Citrus aurantium L. (Rutaceae) extract and p-synephrine in mice.

Extracts of Citrus aurantium L. (Rutaceae) unripe fruits have gained popularity for the treatment of obesity. Due to the wide use of C. aurantium/p-synephrine-containing products, this research was undertaken to evaluate its subchronic toxicity in mice and their actions in oxidative stress biomarkers. Groups of 9-10 mice received for 28 consecutive days a commercial C. aurantium dried extract (containing 7.5% p-synephrine) 400, 2000 or 4000 mg/kg and p-synephrine 30 or 300 mg/kg by oral gavage. There was a reduction in body weight gain of animals treated with both doses of p-synephrine. Organs relative weight, biochemical and hematological parameters were not altered in all treated mice. There was an increase in reduced glutathione (GSH) concentration in groups treated with C. aurantium 4000 mg/kg and p-synephrine 30 and 300 mg/kg. In glutathione peroxidase (GPx), there were an inhibition of the activity in C. aurantium 400 and 2000 mg/kg and p-synephrine 30 and 300 mg/kg treated animals, respectively, and was no alteration in malondialdehyde (MDA) levels. Thus, the results indicate a low subchronic toxicity of the tested materials in mice and a possible alteration in the oxidative metabolism. However, further tests are required to better elucidate the effects of these compounds in the antioxidant system.

Quantificação laboratorial de cobre sérico por espectrofotometria Vis comparável à espectrometria de absorção atômica com chama / Laboratorial quantification of serum copper by Vis spectrophotometry in comparison to flame atomic absorption spectrometry

INTRODUÇÃO: O cobre é um nutriente essencial para os humanos, e a manutenção dos seus níveis é importante, uma vez que seu metabolismo está envolvido com estresse oxidativo e patologias, como a Doença de Wilson. Neste trabalho, um método de espectrofotometria visível (espectrofotometria Vis) foi validado, aplicado em indivíduos jovens e comparado com espectrometria de absorção atômica com chama (EAA-chama). MÉTODOS: Concentrações séricas de cobre foram medidas por EAA-chama e por espectrofotometria Vis, através da reação de cobre com batocuproína, l = 484 nm. Curvas analíticas em solução aquosa e com adição de padrão foram efetuadas para verificar linearidade, recuperação e precisão do método espectrofotométrico. Amostras de sangue de 12 indivíduos (média de idade 22 anos) foram analisadas por ambos os métodos e comparadas entre si. Os resultados foram expressos em média ± desvio-padrão. RESULTADOS: As curvas com adição de padrão e aquosa (n = 5) apresentaram coeficientes de regressão superiores a 0,99 e de variação inter e intradia inferiores a 15 por cento. Os valores de cobre sérico encontrados para o método espectrofotométrico foram 1,17 ± 0,39 e 0,73 ± 0,14 mg/l para mulheres e homens, respectivamente. Para EAA-chama foram encontrados 1,13 ± 0,43 e 0,59 ± 0,13 mg/l para mulheres e homens, respectivamente. Os resultados mostraram correlação de Pearson significativa (r = 0,946; p < 0,05). Os níveis séricos de cobre foram significativamente maiores em mulheres do que em homens (p < 0,05). CONCLUSÃO: O método espectrofotométrico visível demonstrou ser linear, reprodutível e aplicável, oferecendo uma alternativa confiável à quantificação de cobre por EAA-chama. Além disso, é uma técnica simples, rápida e barata, que pode ser utilizada na rotina laboratorial clínica.

BACKGROUND: Copper is an essential nutrient for humans and maintenance of its adequate levels is important, since its metabolism is involved with oxidative stress and patolologies, such as Wilson's disease. In this work, a visible spectrophotometric method was validated, applied in young subjects and compared to flame atomic absorption spectrometry (FAAS) in serum copper levels determination. METHODS: Serum copper concentrations were measured by FAAS and by spectrophotometry, through copper reaction with bathocuproine, l = 484 nm. Aqueous curves and spiked serum curves were realized to verify linearity, recovery and precision of the visible spectrophotometric method. Blood samples from 12 subjects (mean 22 years) were analyzed in both methodologies and compared to each other. The results were expressed by mean ± standard deviation. RESULTS: Spiked serum and aqueous curves (n = 5) showed coefficient of regression superior to 0.99 and inter and intra-day coefficient of variation lower than 15 percent. The serum copper values found to Vis spectrophotometric method were 1.17 ± 0.39 and 0.73 ± 0.14 mg/l to women and men, respectively. To FAAS 1.13 ± 0.43 and 0.59 ± 0.13 mg/l were found to women and men, respectively. Both results showed a significant Pearson correlation (r = 0.946; p < 0.05). Besides, serum copper levels were significantly higher in women than in men (p < 0.05). CONCLUSION: The Vis spectrophotometric method demonstrated to be linear, reproducible and applied, offering a reliable alternative to FAAS copper quantification. Moreover, Vis spectrophotometry is a simple, quickly and not expensive technique, and it could be widely used as routine in clinical laboratory.