α-Linolenic acid rich-chia seed modulates visceral adipose tissue collagen deposition, lipolytic enzymes expression, insulin signaling and GLUT-4 levels in a diet-induced adiposity rodent model.

Given obesity and its associated metabolic disorders have reached epidemic proportions, the study of therapeutic strategies targeting white adipose tissue (WAT) are of main research interest. We previously shown that α-linolenic acid-rich chia seed was able to ameliorate a wide range of metabolic disorders including body fat accretion in sucrose-rich diet (SRD)-fed rats, an experimental model of visceral adiposity and insulin resistance. However, the mechanisms involved are not fully clarified. The aim of this study was to evaluate the effect of chia seed administration upon WAT remodeling and key enzymes that controls lipolysis, insulin signaling (tAKT, pAKT), and GLUT-4 levels in different visceral fat pad depots (epididymal -eWAT- and retroperitoneal -rWAT- adipose tissues) of SRD-fed rats. Results showed that chia seed reduces adipocytes hypertrophy, the increased lipid content and collagen deposition in both WAT. These changes were accompanied by a significant reduction of HSL and ATGL protein levels in eWAT and HSL protein levels in rWAT. Moreover, chia seed restored the altered expression pattern of the pAKT observed in SRD-fed rats, and modulated GLUT-4 levels. Chia seed could be a dietary intervention of great relevance with potential beneficial effects in the management of body fat excess and WAT function.

Alteraciones histológicas hepáticas provocadas por la ingesta crónica de glutamato monosódico / Histological liver changes caused by chronic intake of monosodium glutamate

ntroducción. El glutamato es un aminoácido que está implicado en numerosas reacciones relacionadas con el metabolismo hepático, por lo que la sobreactivación de los receptores de glutamato por acción de la ingesta de glutamato monosódico (GMS) proveniente de la dieta, podría llevar a daño del tejido hepático. Este estudio se realizó con el objetivo de evaluar los cambios histológicos producidos en el hígado de ratas sometidas a la administración crónica de GMS. Metodología. Se trabajó con dos lotes de animales, uno experimental y otro control, cada uno de ellos constituido por seis ratas machos cepa Wistar de cinco semanas de edad. Al grupo experimental se le administró diariamente 0,1 g de queso de bajas calorías que contenía GMS monohidrato de 99% de pureza (grado alimentario puro), diluido en 50 µL de agua desionizada (0,3 g/100 g de peso corporal). Al grupo control se le administró la misma cantidad de sodio que el que contenía el GMS del grupo tratado, pero bajo la forma de NaCl. Al concluir el tratamiento, las ratas pertenecientes a ambos grupos se pesaron y sacrificaron, y se les extrajo el hígado para el estudio histológico. Se obtuvieron cortes histológicos que fueron coloreados con hematoxilina-eosina, PAS y coloración con tricrómico de Masson. El análisis de los cortes histológicos se llevó a cabo por observación directa en microscopio óptico con objetivo de 40x. Resultados. Se observó en general, conservación y apariencia normal de las características histológicas de los acinos hepáticos en el grupo control, en tanto que el hígado de las ratas tratadas con GMS presentó diferentes grados de degeneración hidrópica, cantidades variables de cuerpos hialinos eosinófilos, infiltración inflamatoria de células mononucleares y necrosis focal, principalmente en la zona 1 del acino hepático. Conclusión. Los resultados encontrados permiten aportar evidencias en torno a las alteraciones histopatológicas que la ingesta crónica de GMS provoca sobre el tejido hepático. Se recomienda alertar a la población para reducir la ingesta de alimentos que poseen GMS como saborizante.

Introduction. Glutamate is an amino acid that is involved in numerous reactions related to liver metabolism, so the overactivation of glutamate receptors due to the ingestion of monosodium glutamate (MSG) from the diet could lead to liver tissue damage. The aim of this study was to evaluate the histological changes produced in the liver of rats subjected to chronic administration of MSG. Methodology. Two sets of animals were used, an experimental and a control group, each consisting of six five-week-old Wistar male rats. The experimental group was administered 0.1 g of low-calorie cheese containing 99% purity MSG monohydrate (pure food grade) diluted in 50 µL of deionized water (0.3 g/100 g of weight) daily. The control group was administered the same amount of sodium as that contained in the MSG of the treated group, but in the form of NaCl. At the end of the treatment, the rats belonging to both groups were weighed and sacrificed, and their liver was removed for histological analysis. Histological sections were obtained and stained with hematoxylineosin, PAS and Masson's trichrome. The analysis of the histological sections was carried out by direct observation with an optical microscope and a 40x objective. Results. In general, conservation and normal appearance of the histological characteristics of the liver acini were observed in the control group, while the liver of the rats treated with MSG presented different degrees of hydropic degeneration, variable amounts of eosinophilic hyaline bodies, inflammatory infiltration of mononuclear cells and focal necrosis, that affected mainly zone 1 of the liver acinus. Conclusion. The results allow us to provide evidence about the histopathological alterations that the chronic intake of MSG causes on the liver tissue. It is recommended to alert the population to reduce the intake of foods that have GMS for flavoring.

MELANOMACRÓFAGOS HEPÁTICOS Y ACTIVIDAD DE LA ENZIMA GLUTATION S-TRANSFERASA EN Leptodactylus chaquensis (ANURA, LEPTODACTYLIDAE) COMO BIOMARCADORES DE ESTRÉS OXIDATIVO POR LA EXPOSICIÓN A CLORPIRIFOS / Liver Melanomacrophages and Gluthation S-Transferase Activity in Leptodactylus chaquensis (Anura, Leptodactylidae) as Biomarkers of Oxidative Stress Due to Chlorpyrifos Exposition

RESUMEN Se cuantificaron y compararon los melanomacrófagos (MM) y la actividad de la enzima Glutatión S-Transferasa (GST) en hígados de ejemplares adultos de Leptodactylus chaquensis (Anura, Leptodactylidae) colectados en un cultivo de arroz (CA) (siete días posteriores a la aplicación de clorpirifos, CPF) y en un sitio de referencia (SR) en el departamento San Javier, provincia de Santa Fe (Argentina). El análisis histológico reveló una mayor cantidad (p = 0.028) y área ocupada por MM (p = 0.017) y se registró una inhibición en la actividad de la GST (p = 0.030) en individuos del CA respecto a los del SR. Los efectos descriptos evidencian el riesgo ecotoxicológico para los anuros en los cultivos de arroz con aplicaciones de CPF.

ABSTRACT We quantified and compared the hepatic melanomacrophage (MM) and glutathione S-transferase (GST) enzyme activity (two oxidative stress biomarkers) in the liver of Leptodatylus chaquensis adults (Anura, Leptodactylidae) collected in a rice field (CA) in San Javier department, Santa Fe (Argentina), seven days after the application of chlorpyrifos and in a reference site (SR). The histological analysis revealed a significant amount (p = 0.028) and area occupied by MM (p = 0.017) in livers of CA compared to SR. Furthermore, a significant inhibition of GST activity was recorded in the CA frogs compared to the SR (p = 0.030). The histopathological and enzymatic effects provide evidences of ecotoxicological risk for anurans in rice field with CPF application.

Dietary Salba (Salvia hispanica L) improves the altered metabolic fate of glucose and reduces increased collagen deposition in the heart of insulin-resistant rats.

This study reports the effects of dietary Salba (chia) seeds on the mechanisms underlying impaired glucose metabolism in the heart of dyslipemic insulin-resistant rats fed a sucrose-rich diet (SRD). Wistar rats were fed a SRD for 3 months. Afterwards, half the animals continued with the SRD; in the other half's diet chia seeds replaced corn oil (CO) for three months (SRD+chia). In the control group, corn starch replaced sucrose. The replacement of CO by chia seeds in the SRD restored the activities of key enzymes involved in heart glucose metabolism decreasing fatty acid oxidation. Chia seeds normalized insulin stimulated GLUT-4 transporter, the abundance of IRS-1 and pAMPK, changed the profile of fatty acid phospholipids, reduced left-ventricle collagen deposition and normalized hypertension and dyslipidemia. New evidence is provided concerning the effects of dietary chia seeds in improving the altered metabolic fate of glucose in the heart of dyslipemic insulin-resistant rats.