Cocoa intake attenuates oxidative stress associated with rat adjuvant arthritis.

Cocoa contains flavonoids with antioxidant properties. The aim of this study was to ascertain the effect of cocoa intake on oxidative stress associated with a model of chronic inflammation such as adjuvant arthritis. Female Wistar rats were fed with a 5% or 10% cocoa-enriched diet or were given p.o. a quercetin suspension every other day for 10 days. Arthritis was induced by a heat-killed Mycobacterium butyricum suspension. Reactive oxygen species (ROS) produced by macrophages, and splenic superoxide dismutase (total, cytoplasmic and mitochondrial) and catalase activities were determined. Clinically, joint swelling in arthritic rats was not reduced by antioxidants; however, the 5% cocoa diet and quercetin administration reduced ROS production. Moreover, the 5% cocoa diet normalized the activities of superoxide dismutase and catalase. In conclusion, a cocoa diet reduces the oxidative stress associated with a chronic inflammatory pathology, although it was not enough to attenuate joint swelling.

[The bowel: a key component of the immune system]. / El intestino: pieza clave del sistema inmunitario.

The gut is constantly exposed to a high antigenic load coming from the diet and commensal bacteria. The Gut-Associated Lymphoid Tissue (GALT) constitutes the most extensive and complex part of the immune system and is capable of efficiently distinguishing invasive pathogens from innocuous antigens. The knowledge of its unique structure consisting on organised tissue, inductor of the immune response (Peyer's patches and mesenteric lymph nodes), and diffused tissue, effector of the immune response (intraepithelial lymphocytes and lamina propria lymphocytes), allow us to understand the development and regulation of the immune response in the gut and how this one can be extended to the rest of the organism.

El intestino: pieza clave del sistema inmunitario / No disponible

El intestino se halla expuesto constantemente a una elevada cargaantigénica procedente de la dieta y de bacterias comensales. Eltejido linfoide asociado al intestino (Gut-Associated Lymphoid Tissue,GALT) constituye la parte más extensa y compleja del sistemainmunitario y es capaz de discriminar de forma eficaz entre patógenosinvasivos y antígenos inocuos. El conocimiento de su particularsubdivisión en tejido organizado, inductor de la respuesta inmunitaria(placas de Peyer y ganglios linfáticos mesentéricos), y tejido difuso,efector de la respuesta inmunitaria (linfocitos intraepiteliales ylinfocitos de lámina propia), nos permite comprender cómo se desarrollay regula la respuesta inmunitaria en el intestino y como estapuede extenderse al resto del organismo

The gut is constantly exposed to a high antigenic load comingfrom the diet and commensal bacteria. The Gut-Associated LymphoidTissue (GALT) constitutes the most extensive and complexpart of the immune system and is capable of efficiently distinguishinginvasive pathogens from innocuous antigens. The knowledgeof its unique structure consisting on organised tissue, inductorof the immune response (Peyer’s patches and mesentericlymph nodes), and diffused tissue, effector of the immune response(intraepithelial lymphocytes and lamina propria lymphocytes),allow us to understand the development and regulation ofthe immune response in the gut and how this one can be extended to the rest of the organism (AU)

Spleen lymphocyte function modulated by a cocoa-enriched diet.

Previous studies have shown the down-regulating in vitro effect of cocoa flavonoids on lymphocyte and macrophage activation. In the present paper, we report the capacity of a long-term rich cocoa diet to modulate macrophage cytokine secretion and lymphocyte function in young rats. Weaned rats received natural cocoa (4% or 10% food intake), containing 32 mg flavonoids/g, for 3 weeks. Spleen immune function was then evaluated through the analysis of lymphocyte composition, their proliferative response and their ability to secrete cytokines and Ig. In addition, the status of activated peritoneal macrophages was established through tumour necrosis factor (TNF)-alpha secretion. The richest cocoa diet (10%) caused a reduction of TNF-alpha secretion by peritoneal macrophages showing anti-inflammatory activity. Similarly, although a 10% cocoa diet increased lymphocyte proliferation rate, it down-regulated T helper 2 (Th2)-related cytokines and decreased Ig secretion. These changes were accompanied by an increase in spleen B cell proportion and a decrease in Th cell percentage. In summary, these results demonstrate the functional activity of a cocoa-high dosage in down-regulating the immune response that might be beneficial in hypersensitivity and autoimmunity.