Effects of Mimosa caesalpiniifolia pre-formulation on the intestinal barrier during sodium dextran sulfate-induced colitis in Wistar rats / Efectos de la preformulación de Mimosa caesalpiniifolia sobre la barrera intestinal durante la colitis inducida por sulfato de dextrano sódico en ratas Wistar

Introduction. Anti-inflammatories, immunosuppressants, and immunobiological are commonly used in the treatment of inflammatory bowel disease. However, some patients do not present an adequate response or lose effective response during the treatment. A recent study found a potential anti-inflammatory effect of the hydroalcoholic extract of Mimosa caesalpiniifolia on trinitrobenzene sulfonic acid-induced colitis in Wistar rats. Objective. To evaluate the effects of M. caesalpiniifolia pre-formulation on the intestinal barrier using dextran sulfate sodium-induced colitis model. Materials and methods. Leaf extracts were prepared in 70% ethanol and dried with a Buchi B19 Mini-spray dryer using 20% Aerosil® solution. Thirty-two male Wistar rats were randomized into four groups: basal control, untreated colitis, pre-formulation control (125 mg/kg/day), and colitis treated with pre-formulation (125 mg/kg/day). Clinical activity index was recorded daily and all rats were euthanized on the ninth day. Colon fragments were fixed and processed for histological and ultrastructural analyses. Stool samples were collected and processed for analysis of the short-chain fatty acid. Results. Treatment with the pre-formulation decreased the clinical activity (bloody diarrhea), inflammatory infiltrate, and the ulcers. Pre-formulation did not repair the epithelial barrier and there were no significant differences in the goblet cells index. There was a significant difference in butyrate levels in the rats treated with the pre-formulation. Conclusions. The pre-formulation minimized the clinical symptoms of colitis and intestinal inflammation, but did not minimize damage to the intestinal barrier.

Introducción. Los antiinflamatorios, inmunosupresores e inmunobiológicos se utilizan comúnmente para tratar la enfermedad intestinal inflamatoria. Sin embargo, algunos pacientes no presentan una respuesta adecuada o pierden respuesta efectiva durante el tratamiento. En un estudio reciente, se encontró un potencial efecto antiinflamatorio del extracto hidroalcohólico de Mimosa caesalpiniifolia en la colitis inducida por el ácido trinitrobenceno sulfónico utilizando ratas Wistar. Objetivo. Evaluar los efectos de la preformulación de M. caesalpiniifolia sobre la barrera intestinal durante la colitis inducida por sulfato de dextrano sódico. Materiales y métodos. Los extractos de hojas se prepararon con una solución que contenía 70 % de etanol y se secaron con un secador por aspersión Mini B19 de Buchi usando una solución con 20 % de Aerosil®. Treinta y dos ratas Wistar macho se aleatorizaron en cuatro grupos: control basal, colitis sin tratar, control con preformulación (125 mg/kg/ día) y colitis tratada con preformulación (125 mg/kg/día). El índice de actividad clínica se registró diariamente y todas las ratas se sacrificaron el noveno día. Los fragmentos de colon se fijaron y se procesaron para análisis histológicos y ultraestructurales. Se recolectaron muestras de heces y se procesaron para el análisis de ácidos grasos de cadena corta. Resultados. El tratamiento con la preformulación disminuyó la actividad clínica (diarrea sanguinolenta), el infiltrado inflamatorio y las úlceras. La preformulación no reparó la barrera epitelial y no hubo diferencias significativas en el índice de células caliciformes. Se obtuvo una diferencia significativa en los niveles de butirato en las ratas tratadas con la preformulación. Conclusiones: La preformulación minimizó los síntomas clínicos de colitis e inflamación intestinal pero no minimizó el daño a la barrera intestinal.

Effects of reperfusion under moderate hypothermia on ischemic brain damage

Moderate hypothermia induced prior to recirculation of ischemic brain would conceivably inhibit the enzyme mediators of reperfusion injury. To challenge that hypothesis, groups of Wistar rats underwent 60 min or longer normothermic ischemia (37 degrees Celsius) induced by 4-vessel occlusion (4-VO). In group A, ischemia was prolonged for 30 min required for cooling and temperature stabilization at 33.O degrees Celsius, whilst in group B, the animals were reperfused at 60 min ischemia, maintained normothermic for 30 min, and then cooled down to 33 degrees Celsius. Hypothermia was sustained up to perfusion-fixation at 7 h and 7.5 h after recirculation in groups A and B respectively. Histological evaluation demonstrated partial neuronal loss in the hippocampus and cortex, without significant differences between the 2 groups (Mann-Whitney U-test). In constrast, untreated animals subjected to 60 min of normothermic ischemia (group C) consistently died prior to 7 h recovery, showing massive necrosis upon macroscopic examination of fresh brains. The animals of an additional group (D) initially treated as group A and rewarmed at 7 h recovery regained consciousness after rewarming, and showed no progression of neuronal loss at 24 h survival. These results indicate that the possible benefit of reperfusion under moderate hypothermia following 60 min normothermic ischemia does not surpass the consequences of a 50 per cent prolongation of carotid clamping.