title: Effect of cocoa-enriched diets on lymphocytes involved in adjuvant arthritis in rats.
abstract: Cocoa and its flavonoids have potential anti-inflammatory properties in vitro and in acute inflammation models in vivo. The aim of the present study was to ascertain the effects of two cocoa-enriched diets on adjuvant arthritis (AA) in rats, considering not only clinical and biochemical inflammatory indices, but also antibody response and lymphocyte composition. Female Wistar rats were fed with a 5 or 10 % cocoa-enriched diet beginning 2 weeks before arthritis induction and until the end of the study. AA was induced by an intradermal injection of heat-killed Mycobacterium butyricum suspension. The hind-paw swelling (plethysmometry), serum anti-mycobacterial antibody concentration (ELISA), blood and inguinal lymph node lymphocyte subset percentage (flow cytometry), and IL-2, interferon γ and PGE₂ released from splenocytes (ELISA) were assessed. Although the cocoa diets had no significant effect on hind-paw swelling, a tendency to reduce it was observed at the end of the study. Cocoa-enriched diets were able to decrease the serum anti-mycobacterial antibody concentration and the splenocyte PGE2 production, as well as the proportion of T-helper (Th) lymphocytes in blood and regional lymph nodes, which probably includes cells responsible for the arthritic process. The cocoa diets prevented a decrease in the proportion of regulatory T-cells in blood and a disequilibrium between inguinal lymph node natural killer (NK) CD8⁺ and NK CD8⁻ subsets. In conclusion, the cocoa-enriched diets during AA were not able to significantly decrease joint inflammation but modified Th-cell proportions and prevented specific antibody synthesis.
authors.affiliation: Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Avinguda Joan XXIII s/n, Barcelona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Ramos-Romero
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Pérez-Cano
authors.forename: Cristina
authors.initials: C
authors.lastname: Castellote
authors.forename: Margarida
authors.initials: M
authors.lastname: Castell
authors.forename: Àngels
authors.initials: À
authors.lastname: Franch
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D000907:Antibodies, Bacterial / Q000032:analysis; D001169:Arthritis, Experimental / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D002099:Cacao / Q000737:chemistry*; D002478:Cells, Cultured; D004032:Diet; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000473:pathology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D009161:Mycobacterium / Q000276:immunology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000473:pathology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000907:Antibodies, Bacterial; D005419:Flavonoids; D015232:Dinoprostone