Efeito neuroprotetor do extrato butanólico de Ilex Paraguariensis na toxidade induzida por paraquat em hipocampo de ratos pré-púberes

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Bioquímica, Florianópolis, 2016O paraquat (PQ) é um herbicida amplamente utilizado no Brasil, apesar de ser descrito como indutor da doença de Parkinson (DP) em modelo animal e em estudos epidemiológicos. A flora brasileira apresenta grande diversidade de plantas medicinais e inúmeros extratos de plantas são utilizados na medicina popular, demonstrando a relevância de investigar o potencial terapêutico de compostos naturais. Neste contexto, já foram descritas atividades antioxidante, antiparkinsoniana, antiobesogênica e anticarcinogênica para a erva-mate (Ilex paraguariensis St. Hilaire). O presente estudo investigou as alterações bioquímicas induzidas pela exposição in vivo ao herbicida PQ em hipocampo de ratos de 27 dias de idade, assim como o efeito neuroprotetor da erva-mate. Os animais receberam 10 mg/Kg de peso de PQ via intraperitoneal por 5 dias consecutivos, o grupo controle recebeu solução salina durante o mesmo período. Para avaliar o efeito neuroprotetor do extrato butanólico (BuOH) de I. paraguarienses, os animais receberam 200 mg/kg de peso do extrato via gavagem, o grupo controle recebeu o mesmo volume de água, 1 dia antes e durante o tratamento com PQ. Foram determinados marcadores de dano oxidativo, da neurotransmissão glutamatérgica e do metabolismo energético em hipocampo dos animais. Os resultados obtidos mostraram: aumento do influxo de 45Ca2+; diminuição da captação de 14C-glutamato e da atividade da glutamina sintetase (GS); diminuição da captação de 14C-2-desoxi-D-glicose; aumento da atividade das enzimas alanina aminotransferase (ALT), aspartato aminotransferase (AST) e lactato desidrogenase (LDH). Em relação as defesas antioxidantes, houve diminuição da atividade da gama glutamil transferase (GGT), da glicose-6-P desidrogenase (G6PD), aumento da atividade da superóxido dismutase (SOD) e catalase (CAT) e aumento da peroxidação lipídica causados pela exposição ao PQ. O tratamento com I. paraguariensis preveniu o efeito do paraquat na captação de glicose, na atividade da LDH e da ALT e na captação de glutamato, além de exercer efeito neuroprotetor nos mecanismos de defesa antioxidante avaliados, como na atividade da G6PD, SOD, GGT e conteúdo de glutationa (GSH). Os resultados obtidos neste estudo poderão sugerir o potencial terapêutico da erva-mate como protetor dos danos induzidos pela exposição a pesticidas. Abstract: Paraquat (PQ) is widely used in Brazil, despite being described as a Parkinson's disease (PD) inductor in animal models and in epidemiological studies. Considering that Brazilian flora has a great diversity of medicinal plants and many plant extracts are used in folk medicine, the investigation of the therapeutic potential of a natural compound is an important challenge to researchers. Considering that, several properties have been described such as antioxidant, anti-Parkinson, anti-obesity and anticarcinogenic for yerba mate (I. paraguariensis St. Hilaire). The present study investigated the biochemical changes induced by in vivo exposure to the herbicide PQ on hippocampus of 27 days old rats, as well as the neuroprotective effect of yerba mate. Animals received PQ (10 mg/kg body weight, i.p.) for 5 consecutive days, the control group received saline for the same period. In order to evaluate the neuroprotective effect of the butanolic (BuOH) extract of I. paraguarienses, rats received 200 mg/kg body weight by gavage) and the control group received the same amount of water, 1 day before and during PQ treatment. Biomarkers of oxidative damage, glutamatergic neurotransmission and energy metabolism were determined on hippocampus. The present study showed increased 45Ca2+ influx associated with decreased glutamate uptake and glutamine synthetase (GS) activity. Moreover, glucose uptake was decreased while alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities were increased. Regarding the antioxidant defenses, PQ leads to decreased gamma-glutamyl transferase (GGT) and glucose-6-P dehydrogenase (G6PD) activities, as well as increased superoxide dismutase (SOD) and catalase (CAT) activities, which were associated with increased lipid peroxidation all caused by PQ exposure. The co-treatment with I. paraguariensis prevented the effect of PQ on glucose uptake, LDH and ALT activities and glutamate uptake. Besides, I. paraguariensis exerted neuroprotective effect on antioxidant defense mechanisms evaluated in this study, such as G6PD, SOD, GGT and GSH levels. In conclusion, these findings suggested the therapeutic potential of yerba mate as damage protector induced by exposure to pesticides

Dietary patterns, obesity markers and leukocyte telomere length among Brazilian civil servants: cross-sectional results from the Pro-Saude study

Abstract Objective: Dietary patterns express the combination and variety of foods in the diet. The partial least squares method allows extracting dietary patterns related to a specific health outcome. Few studies have evaluated obesity-related dietary patterns associated with telomeres length. This study aims to identify dietary patterns explaining obesity markers and to assess their association with leukocyte telomere length (LTL), a biological marker of the ageing process. Design: Cross-sectional study. Setting: University campuses in the state of Rio de Janeiro, Brazil Participants: 478 participants of a civil servants’ cohort study with data on food consumption, obesity measurements (total body fat, visceral fat, BMI, leptin and adiponectin) and blood samples. Results: Three dietary patterns were extracted: (1) fast food and meat; (2) healthy and (3) traditional pattern, which included rice and beans, the staple foods most consumed in Brazil. All three dietary patterns explained 23·2 % of food consumption variation and 10·7 % of the obesity-related variables. The fast food and meat pattern were the first factor extracted, explaining 11–13 % variation of the obesity-related response variables (BMI, total body fat and visceral fat), leptin and adiponectin showed the lowest percentage (4·5–0·1 %). The healthy pattern mostly explained leptin and adiponectin variations (10·7 and 3·3 %, respectively). The traditional pattern was associated with LTL (β = 0·0117; 95 % CI 0·0001, 0·0233) after adjustment for the other patterns, age, sex, exercise practice, income and energy intake. Conclusion: Leukocyte telomere length was longer among participants eating a traditional dietary pattern that combines fruit, vegetables and beans