Endogenous and environmental factors can influence the lipid contents of fishes among which, in the Amazon River, seasonal dynamics influences stand out. Herein, nine most consumed Amazonian fish species had their lipid composition evaluated in terms of effects of tissue, season and eating habits. Higher amounts of lipids were obtained from fish livers than dorsal muscles. Statistical analysis has shown that Amazonian fishes presented different lipid profiles according to their eating habits, which mainly comprised saturated fatty acids to distinguish detritivorous livers, and linolenic acid, cholesterol, polar lipids for carnivorous and piscivorous fish muscles. Furthermore, in Amazonian fish, some very important lipids for human nutrition were found, such as w-3 and w-6 fatty acids whose availability depended on the tissue metabolism and fishes’ eating habit along with the seasonal periods. For example, our findings indicated that the piscivorous fish C. monoculus presented higher levels of linoleic acid for livers than linolenic acid and the opposite occurred for muscles. The w-6 and w-3 fatty acids ratio was influenced by the season dynamic of the Amazon River and availability of food according to each specific eating habit, pointing mainly to the piscivorous fishes as the healthiest fish for human consumption.

Aim: To study the effects of different protocols of fish oil lipid emulsion (FOLE) infusion on acute inflammation in a rat model of colitis. Methods: Adult male Wistar rats (n = 51) were randomized into 5 groups to receive parenteral infusion of saline (SS) or soybean oil lipid emulsion (SO), as controls, and FOLE composed of: fish oil alone (FO); a mixture (9:1 v/v) of SO with FO (SO/FO); or 30% soybean oil, 30% medium-chain triglycerides, 25% olive oil, and 15% fish oil (SMOF). After 72 h of intravenous infusion, experimental colitis was induced with acetic acid. After 24 h, colonic samples were analyzed for histological and cytokine changes. Results: In relation SS group, macroscopic necrosis was less frequent in the FO group and histological necrosis was more frequent in the SMOF group. There was a direct and inverse relation of colon interleukin (IL)-1 and IL-4 respectively, with histological necrosis. In comparison to the SS group, FO increased IL-4 and IFN-gamma and decreased TNF-alpha, SO/FO decreased TNF-alpha, and SMOF increased IL-1 and decreased IL- 4. Conclusion: In acetic acid-induced colitis, the isolate infusion of FOLE composed of fish oil alone was more advantageous in mitigating inflammation than the infusion of FOLE containing other oils, and this difference may be due the influences of their different fatty acid contents.

Objetivo: Estudiar los efectos de los diferentes protocolos de infusión de la emulsion de lípidos de aceite de pescado (Fole) sobre la inflamación aguda en el modelo de colitis en la rata. Material y métodos: Ratas Wistar macho adultas (n = 51) fueron asignados al azar en 5 grupos para recibir infusión parenteral de solución salina (SS) o emulsión de lípidos de aceite de soja (SO), como controles, y Fole compone de: aceite de pescado solo (FO), una mezcla (9:1 v/v) de SO con FO (SO/FO), o 30% de aceite de soja, 30% triglicéridos de cadena media, 25% de aceite de oliva, y 15% de aceite de pescado (SMOF). Después de 72 h de infusión intravenosa, colitis experimental fue inducida con ácido acético. Después de 24 h, las muestras de colon se analizaron para determinar cambios histológicos y citoquinas. Resultados: En relación en el SS grupo, necrosis macroscópica fue menos frecuente en el grupo FO y necrosis histológica fue más frecuente en el grupo de SMOF. Existe una relación directa e inversa de colon interleuquina (IL) -1 e IL-4, respectivamente, con necrosis histológica. En comparación con el grupo SS, en el FO hubo aumento de IL-4 e IFN-gamma y disminución de TNF-alfa, SO/FO disminuyó TNF-alfa, y en el SMOF hubo aumento de IL-1 y la disminución de IL-4. Conclusión: En la colitis inducida por ácido acético, la infusion aislada de Fole compuesto de aceite de pescado por sí solo fue más ventajosa en la atenuacion de la inflamación do que la infusión de Fole contiendo otros aceites, y esta diferencia puede ser debida las influencias de su diferente contenido de ácido graso.

O modelo de colite experimental induzida por ácido acético (CEAA) vem sendo extensamente utilizado em estudos sobre doenças inflamatórias intestinais (DII). Lesões no tecido colônico em portadores de DII parecem estar relacionados à produção local aumentada de citocinas pró-inflamatórias (IL-1, IL-6, TNF-alfa e IFN-gama). OBJETIVO: Avaliar o padrão de expressão de citocinas identificadas por imunohistoquímica em tecido colônico após CEAA e relacioná-lo à presença de lesões macroscópicas. MATERIAL E MÉTODOS: Ratos machos Wistar adultos (n=39) foram submetidos ou não à CEAA e sacrificados para retirada do tecido colônico em dois períodos distintos, perfazendo 4 grupos aleatórios: SC45 e SC24 (sem colite; sacrifício 45 minutos e 24 horas, respectivamente); CC45 e CC24 (com colite; sacrifício 45 minutos e 24 horas, respectivamente). Avaliaram-se alterações macro e microscópicas do cólon e sua expressão de citocinas foi avaliada por imunohistoquímica. RESULTADOS: Após 24 horas, a expressão de IL-1 foi maior no grupo com colite, em relação ao sem colite. IL-4 foi mais expressa no grupo CC45. Houve aumento de INF-gama e IL-6, relacionados à presença de necrose da mucosa colônica, nos grupos com colite, em ambos os períodos avaliados. CONCLUSÃO: A técnica de imunohistoquímica foi eficiente para a análise da expressão de citocinas na mucosa colônica. Houve aumento da expressão das citocinas pró-inflamatórias IL-1 e de IL-6 e IFN-gama associado à presença de necrose colônica. A CEAA é um bom modelo para o desenvolvimento de estudos destinados a avaliar o papel das citocinas na inflamação da mucosa e terapias anti-citocinas.

Experimental colitis induced by acetic acid has been used extensively as a model for intestinal inflammatory disease. Colonic tissue lesions of intestinal inflammatory disease patients seem to be related to the increased local production of pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha, and IFN-gamma). PURPOSE: To assess the cytokine expression pattern identified through immunohistochemistry in colonic mucosa after experimental colitis induced by acetic acid and establish the relationship between this pattern and the presence of macroscopic lesions. MATERIALS AND METHODS: Adult male Wistar rats (n = 39) were divided at random into 4 groups: NC45 and NC24 (control without colitis; sacrificed at 45 minutes and 24 hours, respectively); and WC45 and WC24 (with experimental colitis induced by acetic acid; sacrificed at 45 minutes and 24 hours, respectively). Macroscopic and microscopic alterations in colonic tissue were evaluated, and cytokine expression was assessed through immunohistochemistry. RESULTS: After 24 hours, IL-1 expression was greater in the groups with colitis when compared to the groups without colitis. IL-4 expression was higher in the WC45 group. There was an increase in both INF-gamma and IL-6 related to the presence of necrosis of the colonic mucosa in the groups with colitis for both periods evaluated. CONCLUSION: The immunohistochemical technique was efficient for the analysis of various cytokine expressions in the colonic tissue. There was an increase in the IL-1 pro-inflammatory cytokines as well as in IL-6 and IFN-gamma associated with the presence of colonic necrosis. Experimental colitis induced by acetic acid is a useful model for the development of studies assessing the role of cytokines in the inflammation of mucosa as well as anti-cytokine therapies.