Production of TNF-α, nitric oxide and hydrogen peroxide by macrophages from mice with paracoccidioidomycosis that were fed a linseed oil-enriched diet

Omega-3 polyunsaturated fatty acids (n-3 PUFA) can modulate the immune system and their primary effect is on macrophage function. Paracoccidioidomycosis (PCM) is an endemic systemic mycosis in Latin America that is caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb). Macrophages are the main defence against this pathogen and have microbicidal activity that is dependent on interferon-Γ and tumour necrosis factor (TNF)-α. These cytokines stimulate the synthesis of nitric oxide (NO) and hydrogen peroxide (H2O2), leading to the death of the fungus. To study the effect of n-3 PUFA on the host immune response during experimental PCM, macrophages that were obtained from animals infected with Pb18 and fed a diet enriched by linseed (LIN) oil were cultured and challenged with the fungus in vitro. The macrophage function was analysed based on the concentrations of TNF-α, NO and H2O2. LIN oil seems to influence the production of TNF-α during the development of disease. A diet enriched with LIN oil influences the microbicidal activity of the macrophages by inducing the production of cytokines and metabolites such as NO and H2O2, predominantly in the chronic phase of infection.

Incorporation of n-3 fatty acids by the liver of mice fed linseed oil as a function of feeding duration

The objective of this study was to evaluate the incorporation of omega-3 fatty acids (n-3 FA) on male Swiss mice livers receiving diets based on linseed oil (LO) for up to 56 days. The mice were sacrificed at 7, 14, 28, 42, 56 days and FA concentration was analyzed by gas chromatography. A total of 13 FA were identified on LO feeds presenting alpha-linolenic acid (LNA) contents of 26.97 percent. A total 22 FA were identified in the livers of the mice. Part of the LNA was converted into n-3 FA (20:3n-3, eicosapentaenoic acid-EPA, 22:5n-3, and docosahexaenoic acid-DHA), and some of the LNA was stored in the liver. LNA, EPA and DHA concentrations (mg/g total lipids ) from 0 days for up 56 days increased from 1.29 to 18.90 (LNA), 0.20 to 18.90 (EPA) and 41.26 to 99.17 (DHA).The concentration of n-3 FA in the livers varied with the duration of the LO diet. During LO feed, n-6 FA concentration fell and n-3 FA concentration rose through the experimental period.

Ácidos graxos poli-insaturados n-3 e n-6: metabolismo em mamíferos e resposta imune / Omega-3 and omega-6 polyunsaturated fatty acids: metabolism in mammals and immune response

A experimentação animal apresenta uma grande importância para o desenvolvimento da ciência. O uso de camundongos em experimentos ocorre devido à semelhança destes animais com os seres humanos, fácil criação e manutenção e resposta experimental bastante rápida. Esses animais possuem as mesmas enzimas dessaturases e elongases que os humanos, por isso são usados em pesquisas envolvendo incorporação e síntese de ácidos graxos em tecidos. Os ácidos graxos da família ômega-3 e ômega-6 são de suma importância na dieta humana, pois estes não são sintetizados pela síntese de novo e são precursores dos ácidos graxos poli-insaturados de cadeia muito longa, como os ácidos eicosapentaenóico, docosahexaenóico e araquidônico. Estes desempenham funções importantes no organismo, como a síntese de eicosanóides que estão envolvidos diretamente no sistema imune e nas respostas inflamatórias. A razão entre o consumo de ácidos graxos n-6 e n-3 na dieta é um importante fator para determinar a ingestão adequada de ácidos graxos bem como prevenir o aparecimento de doenças. Este artigo tem como objetivo avaliar a incorporação de ácidos graxos em tecidos de animais e discutir a importância dos ácidos da família n-3 e seus metabólitos no sistema imunológico.

Experiments with animals are very important for the improvement of science. The use of mice in experiments is due to their similarity with humans, the easy of raising and maintaining them and their very fast response. These animals have the same desaturase and elongase enzymes as humans and so they are used in research involving the incorporation and synthesis of fatty acids in tissues. The fatty acids omega-3 and omega-6 are extremely important in the human diet because they are not synthesized de novo and are precursors of very long-chain polyunsaturated fatty acids, such as the eicosapentaenoic, docosahexaenoic and arachidonic acids. These acids play important roles in animals, such as precursors of eicosanoids, which are directly involved in the immune system and inflammatory response. The dietary n-3:n-6 intake ratio is important for assessing proper fatty acid intake and for preventing the development of diseases. Thus, this article assessed the incorporation of fatty acids in animal tissues and discussed the importance of n-3 fatty acids and its metabolites for the immune system.

Composição e estabilidade lipídica da farinha de espinhaço de tilapia / Composition and lipid stability of tilapia fishbone flour

Espinhaços de tilápias (Oreochromis niloticus) são partes do peixe de composição desconhecida. A composição lipídica dos espinhaços não é citada na literatura, bem como a estabilidade da farinha do espinhaço durante o armazenamento. Nesse sentido, realizou se estudo de processamento dos espinhaços envolvendo etapas de cocção, trituração, secagem, peneiramento e armazenamento da farinha. A farinha ficou armazenada sob refrigeração por um período de 90 dias, sendo sua qualidade monitorada por meio da composição em ácidos graxos, índice de acidez e análises microbiológicas. Os resultados da composição centesimal foram de 14,2 por cento (umidade), 40,8 por cento (proteína), 18,3 por cento (resíduo mineral fixo) e 25,3 por cento de lipídios totais. Nos lipídios totais foi identificado um total de 24 ácidos graxos, com predominância dos ácidos graxos (porcentagem média) de 27.4 por cento (ácido palmítico, 16:0), 35,15 por cento (ácido oléico, 18:1n-9) e 11,82 por cento (ácido linoléico, 18:2n-6) e, em menor proporção: 0,88 por cento (ácido alfa-linolênico, 18:3n-3), 0,08 por cento (ácido eicosapentaenóico, 20:5n-3) e 0,59 (ácido docosahexaenóico, 22:6n-3). Durante os 90 dias de armazenamento, foram observadas algumas alterações no índice de acidez e composição de alguns ácidos graxos, no entanto, para 60 dias de armazenamento, não foram observadas alterações na composição de nenhum ácido graxo, do índice de acidez e nas análises microbiológicas.

The composition of the tilapia (Oreochromis niloticus) fishbone is unknown. Lipid composition fishbone is not cited in the literature, and neither is the stability of the flour of the fishbone during storage. We studied the processing of fishbone cooking, grinding, drying, sieving and the storage of the flour. The flour was stored in a refrigerator for a period of 90 days, and its quality was monitored through fatty acid composition, acid index and microbiology control. The results of the proximate composition were of 14.2 percent (moisture), 40.8 percent (protein), 18.3 percent (ash), and 25.3 percent total lipids. In the total lipids identified 24 fatty acids were identified, with predominance of the fatty acids (medium percentage) of 27.4 percent (palmitic acid, 16:0), 35.15 percent (oleic acmid, 18:1n-9) and 11.82 percent (linoleic acid , 18:2n-6) and, in smaller proportion: 0.88 percent (alpha-linolenic acid, 18:3n-3), 0.08 percent (eicosapentaenoic acid, 20:5n-3) and 0.59 (docosahexaenoic acid, 22:6n-3). During the 90 days of storage some alterations were observed in the acid index and composition of some fatty acids, however, for 60 days of storage no alterations were observed in the fatty acids composition, acid index, and microbiology control.

Effect of flaxseed oil in diet on fatty acid composition in the liver of Nile Tilapia (Oreochromis niloticus)

This study analyzed the effects of different concentrations of flaxseed oil (FO) on the proximate composition and the contents of alpha-linolenic acid (LNA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), and docosahexaenoic (DHA, 22:6n-3) fatty acids in the liver of cultured Nile tilapia (Oreochromis niloticus). During the fivemonth culture period, tilapias were given diets with incremental concentrations of FO (0.00%; 1.25%; 2.50%; 3.75%, and 5.00%) as a replacement of sunflower oil (control). There was no significant difference in moisture and ash content in the liver between treatments. Protein values ranged from 12.1% (treatment II) to 13.9% (treatment V) and total lipids ranged from 5.6% (treatment V) to 7.2% (treatment II). There was no significant difference between most treatments. Fatty acid methyl esters (FAMEs) were quantitatively analyzed by capillary gas chromatography against a C23:0 internal standard. Variations in concentrations (in mg g-1 of total lipids) of fatty acids between treatment I and treatment V ranged from 4.2 to 51.2 (LNA), from 0.2 to 2.3 (EPA), and from 10.6 to 56.2 (DHA), respectively. This experiment demonstrated that increasing amounts of LNA in feed may markedly increase the amounts of LNA, EPA, and DHA in the liver of Nile tilapia.

Este estudio analiza los efectos de diversas concentraciones del aceite de linaza (AL) en la composición centesimal y el contenido del ácido alfa-linolenico (LNA, 18:3 n-3), eicosapentaenoic (EPA, 20:5 n-3), y (DHA, 22:6 n-3), los ácidos grasos docosahexaenoic en el hígado del tilapia del Nilo (Oreochromis niloticus) criada em cautiverio. Durante un período de cinco meses, a las tilapias le fueron administradas dietas con concentraciones crecientes de AL (0,00%; 1,25%; 2,50%; 3,75%, y 5,00%) como reemplazo del aceite de girasol (control). No se encontró diferencia significativa en el contenido de humedad y de ceniza en el hígado entre los tratamientos. Los valores de la proteina variaron entre 12,1% (tratamiento II) y (al tratamiento 13,9% V) y los lípidos totales entre el 5,6% (tratamiento V) y 7,2% (tratamiento II). No se encontró diferencia significativa entre la mayoría de los tratamientos. Los ésteres metílicos de los ácidos grasos (FAMEs) fueron analizados cuantitativamente por cromatografía de gas capilar contra la CA. 23:0 estándares internos. Las variaciones en concentraciones (en mg g-1 de lípidos totales) de ácidos grasos entre el tratamiento I y el tratamiento V variaron entre 4,2 y 51,2 (LNA), 0,2 y 2,3 (EPA), y 10,6 a 56,2 (DHA), respectivamente. Esto experimento demostró que cantidades crecientes de LNA en la alimentación puede aumentar significativamente las cantidades de LNA, de EPA, y de DHA en el hígado de la tilapia del Nilo.