Efeito do néctar de manga Ubá na modulação do estresse oxidativo e da inflamação em ratos obesos
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2014-12-12
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Universidade Federal de Viçosa
Resumo
A elevada prevalência da obesidade nas últimas décadas tem sido considerada um grave problema de saúde pública. Essa patologia é caracterizada por um quadro de inflamação sistêmica e estresse oxidativo, que pode ser prevenido e melhorado com uma dieta rica em compostos bioativos com atividade antioxidante, como os compostos fenólicos. A manga Ubá é uma fruta tropical encontrada na Zona da Mata Mineira que se destaca nesse contexto por conter elevado conteúdo de antioxidantes na polpa e na casca, mas que até o momento não foram utilizados em pesquisas in vivo para combater a obesidade. O objetivo desse trabalho foi avaliar o efeito de néctares de manga Ubá com e sem adição de antioxidantes da casca na modulação do estresse oxidativo e da inflamação em ratos obesos. A manga Ubá foi coletada no município de Ubá, Minas Gerais, em fevereiro de 2013. Foram desenvolvidas duas formulações de néctar, sendo um controle com 50% de polpa + 50% de água filtrada, e outro com substituição da água pelo extrato da casca de manga. Foram realizadas análises físico químicas para caracterização dessas bebidas em diferentes condições de armazenamento. Utilizou-se 32 ratos machos da linhagem Wistar, mantidos em grupos de quatro, em caixas de polietileno, por 60 dias, consumindo ração comercial e água destilada ad libitum. Na fase I, os animais foram alocados em gaiolas individuais, de aço inoxidável e divididos conforme o peso corporal: o controle negativo foi mantido com dieta AIN-93M e os outros três grupos experimentais receberam dieta hiperlipídica (HFD), durante 49 dias. Após esse período, foram avaliados o índice de massa corporal (IMC), a glicemia de jejum e os triglicerídios séricos, por meio de punção da veia caudal. Conforme a diferença encontrada nesses valores e para manter a homogeneidade dentro do mesmo grupo experimental, os três grupos que receberam HFD foram realocados. Por mais 56 dias, fase II, manteve-se o grupo controle positivo (HFD) e iniciou-se dois grupos testes, um recebendo HFD e néctar de manga (MHFD) e outro com HFD e néctar adicionado de extrato da casca de manga (HMHFD). A ingestão dos néctares foi controlada diariamente em, aproximadamente, 35mL e semanalmente monitorou-se o peso e o consumo alimentar. O teste de tolerância oral à glicose (TTOG) foi realizado utilizando solução de glicose na concentração de 200mg/kg, seguindo o mesmo protocolo descrito anteriormente. A glicemia foi mensurada nos tempos 0, 30, 60, 90 e 120 minutos. Ao final do experimento, os ratos ficaram em jejum por 12 horas, foram anestesiados e submetidos à eutanásia por punção cardíaca. Foram realizadas as medidas biométricas anteriormente citadas e calculados os índices de adiposidade e hepatossomático. Os valores bioquímicos séricos foram determinados no soro dos animais por meio de kits específicos para cada análise. Foram também quantificadas citocinas pró e antiinflamatória (TNF-α, IL-10) assim como a capacidade antioxidante total do plasma. Finalmente foram analisadas a histomorfometria e histopatologia do tecido adiposo epididimal e do fígado. A polpa e os néctares apresentaram valores médios de acidez titulável, pH e sólidos solúveis correspondentes às exigências da legislação brasileira. A composição química centesimal, a concentração de fenólicos totais e a atividade antioxidante foram superiores para o néctar enriquecido e as diferentes condições de armazenamento não alteraram as concentrações dos antioxidantes. Os grupos que receberam os néctares de manga apresentaram ganho de peso corpóreo, peso do tecido adiposo visceral, índice hepatossomático e adiposidade corpórea semelhantes ao AIN-93M. Além disso, o perímetro abdominal e o IMC confirmaram a indução da obesidade nos grupos HFD, reduzindo após a intervenção com o néctar enriquecido. Houve aumento da citocina pró- inflamatória TNF-α no grupo HFD e os néctares foram capazes de reverter o quadro inflamatório para os níveis fisiológicos normais (p≤0,05). A capacidade antioxidante total do plasma dos animais que ingeriram o néctar controle foi menor em relação aos demais (p≤0,05) e o grupo HMHFD apresentou valor semelhante (p>0,05) ao HFD. A histologia dos tecidos hepático e adiposo confirmou a indução da obesidade no controle positivo e o efeito antioxidante dos néctares de manga ao reduzir a gordura e a inflamação hepáticas, assim como a hipertrofia dos adipócitos (p≤0,05). Portanto, os néctares desenvolvidos corresponderam às exigências da legislação e apresentaram elevado conteúdo de fenólicos totais e atividade antioxidante, que aumentou com a adição de casca. A dieta hiperlipídica foi eficaz em induzir obesidade nos animais e os néctares de manga reduziram fatores de riscos metabólicos relacionados com a inflamação e com o estresse oxidativo.
The high prevalence of obesity in recent decades has been considered a serious public health problem. This pathology is characterized by a systemic inflammation and oxidative stress above which can be prevented and improved with a diet rich in bioactive compounds with antioxidant activity, such as phenols. The Uba mango is a tropical fruit found in the Zona da Mata Mineira that stands out in this context because it contains high content of antioxidants in flesh and skin, but so far have not been used in in vivo research to combat obesity. The aim of this study was to evaluate the mango nectar effect Uba with and without added peel antioxidants in the modulation of oxidative stress and inflammation in obese rats. The Uba sleeve was collected in the city of Uba, Minas Gerais, in February 2013. They were developed two nectar formulations, and a control with 50% pulp and 50% of filtered water, and one with replacement of water by peel extract. Physico-chemical characterization of these tests for drinks in different storage conditions were carried out. We used 32 male Wistar rats were kept in groups of four in plastic boxes for 60 days, consuming commercial feed and distilled water ad libitum. In Phase I, animals were placed in individual cages and divided stainless steel as body weight: negative control was maintained with AIN-93M diet and the other three groups received high fat diet (HFD) for 49 days. After this period, we evaluated the body mass index (BMI), fasting plasma glucose and serum triglycerides, through puncture of the tail vein. As the difference found in these values and to maintain homogeneity within the same experimental group, the three groups that received HFD were relocated. For over 56 days, phase II, remained the positive control group (HFD) and started two tests groups, one receiving HFD and mango nectar (MHFD) and another with HFD and nectar added mango bark extract (HMHFD). The intake was monitored daily nectars in approximately 35ml monitored weekly and the weight and food consumption. The oral glucose tolerance test (OGTT) was performed using glucose solution at a concentration of 200 mg/ kg, using the same protocol described above. Blood glucose was measured at 0, 30, 60, 90 and 120 minutes. At the end of the experiment, rats were fasted for 12 hours were anesthetized and euthanized by cardiac puncture. Biometric measures above and calculated indexes of adiposity and liver somatic were performed. Serum biochemical values were determined in the serum of animals by specific kits for each analyte. Were also quantified and pro-inflammatory cytokines (TNF-α, IL-10) as well as total plasma antioxidant capacity. Finally we analyzed the histomorphometry and histopathology of epididymal adipose tissue and liver. The pulp and nectars showed average values of titratable acidity, pH and soluble solids corresponding to the requirements of Brazilian law. The proximate chemical composition, the concentration of total phenolics and antioxidant activity were higher for the enriched nectar and different storage conditions did not affect the concentrations of antioxidants. The groups that received the mango nectar showed body weight gain, weight visceral adipose tissue, liver somatic index and body fat similar to AIN-93M. In addition, BMI and waist circumference confirmed the induction of obesity in HFD groups after intervention reducing enriched with nectar. There was an increase of TNF-α proinflammatory cytokine in the HFD group and nectars were able to reverse the inflammation to normal physiological levels (p≤0.05). The total antioxidant capacity of plasma from rats consuming nectar control was lower compared to the others (p≤0.05) and the HMHFD group showed similar value (p>0.05) to HFD. The histology of the liver and adipose tissues confirmed the induction of obesity and the positive control of antioxidant effect mango nectar to reduce fat and liver inflammation and hypertrophy of the adipocytes (p≤0.05). Therefore the developed nectars corresponded to the requirements of legislation and showed a high content of phenolic compounds and antioxidant activity, which increased with the addition of bark. The fat diet was effective in inducing obesity in animals and mango nectars reduced metabolic risk factors related to inflammation and oxidative stress.
The high prevalence of obesity in recent decades has been considered a serious public health problem. This pathology is characterized by a systemic inflammation and oxidative stress above which can be prevented and improved with a diet rich in bioactive compounds with antioxidant activity, such as phenols. The Uba mango is a tropical fruit found in the Zona da Mata Mineira that stands out in this context because it contains high content of antioxidants in flesh and skin, but so far have not been used in in vivo research to combat obesity. The aim of this study was to evaluate the mango nectar effect Uba with and without added peel antioxidants in the modulation of oxidative stress and inflammation in obese rats. The Uba sleeve was collected in the city of Uba, Minas Gerais, in February 2013. They were developed two nectar formulations, and a control with 50% pulp and 50% of filtered water, and one with replacement of water by peel extract. Physico-chemical characterization of these tests for drinks in different storage conditions were carried out. We used 32 male Wistar rats were kept in groups of four in plastic boxes for 60 days, consuming commercial feed and distilled water ad libitum. In Phase I, animals were placed in individual cages and divided stainless steel as body weight: negative control was maintained with AIN-93M diet and the other three groups received high fat diet (HFD) for 49 days. After this period, we evaluated the body mass index (BMI), fasting plasma glucose and serum triglycerides, through puncture of the tail vein. As the difference found in these values and to maintain homogeneity within the same experimental group, the three groups that received HFD were relocated. For over 56 days, phase II, remained the positive control group (HFD) and started two tests groups, one receiving HFD and mango nectar (MHFD) and another with HFD and nectar added mango bark extract (HMHFD). The intake was monitored daily nectars in approximately 35ml monitored weekly and the weight and food consumption. The oral glucose tolerance test (OGTT) was performed using glucose solution at a concentration of 200 mg/ kg, using the same protocol described above. Blood glucose was measured at 0, 30, 60, 90 and 120 minutes. At the end of the experiment, rats were fasted for 12 hours were anesthetized and euthanized by cardiac puncture. Biometric measures above and calculated indexes of adiposity and liver somatic were performed. Serum biochemical values were determined in the serum of animals by specific kits for each analyte. Were also quantified and pro-inflammatory cytokines (TNF-α, IL-10) as well as total plasma antioxidant capacity. Finally we analyzed the histomorphometry and histopathology of epididymal adipose tissue and liver. The pulp and nectars showed average values of titratable acidity, pH and soluble solids corresponding to the requirements of Brazilian law. The proximate chemical composition, the concentration of total phenolics and antioxidant activity were higher for the enriched nectar and different storage conditions did not affect the concentrations of antioxidants. The groups that received the mango nectar showed body weight gain, weight visceral adipose tissue, liver somatic index and body fat similar to AIN-93M. In addition, BMI and waist circumference confirmed the induction of obesity in HFD groups after intervention reducing enriched with nectar. There was an increase of TNF-α proinflammatory cytokine in the HFD group and nectars were able to reverse the inflammation to normal physiological levels (p≤0.05). The total antioxidant capacity of plasma from rats consuming nectar control was lower compared to the others (p≤0.05) and the HMHFD group showed similar value (p>0.05) to HFD. The histology of the liver and adipose tissues confirmed the induction of obesity and the positive control of antioxidant effect mango nectar to reduce fat and liver inflammation and hypertrophy of the adipocytes (p≤0.05). Therefore the developed nectars corresponded to the requirements of legislation and showed a high content of phenolic compounds and antioxidant activity, which increased with the addition of bark. The fat diet was effective in inducing obesity in animals and mango nectars reduced metabolic risk factors related to inflammation and oxidative stress.
Descrição
Palavras-chave
Manga, Obesidade, Inflamação, Estresse oxidadtivo
Citação
NATAL, Dorina Isabel Gomes. Efeito do néctar de manga Ubá na modulação do estresse oxidativo e da inflamação em ratos obesos. 2014. 48f. Dissertação (Mestrado em Ciência da Nutrição) - Universidade Federal de Viçosa, Viçosa. 2014.