PRO-INFLAMMATORY EFFECT OF VOLCANO ASH IN A COLITIS MODEL

ORSINI DELGADO MARIA LUCIA; PAPA GOBBI RODRIGO; SAMBUELLI ALICIA; DR. GUILLERMO DOCENA

Mardel Plata

Congreso; LXII Reunión Anual de la Sociedad Argentina de Inmunología; 2014

SAi y SAIC

Inflammatory bowel diseases (IBD) are a group of pathologies which major forms, Crohn´s disease (CD) and ulcerative colitis (UC), are characterized by a chronic, robust and relapsing cytokine-driven inflammation of the gastrointestinal tract. It is widely accepted that these multifactorial inherited pathologies result from the effect of environmental (pollution, feeding habits, etc), genetic and other unknown factors. Particulate matter present in the polluted air from volcanoes has been associated with a rise in the incidence of a wide group of pathologies, including IBD. In this work we studied the effect of volcano ash from Patagonia in the drinking water of a colitis mouse model. BALB/c mice received drinking water with or without volcano ash for 14 days. On day 7 mice were intrarectally administered different inflammatory stimuli (TNBS, Flagellin ?FliC) or ethanol (?EtOH), vehicle, as control. Weight was daily monitored, and on day 14 animals were sacrified. Colon was removed and analyzed: weight/length, histology, cytokine expression (IL-1β, IL-6, TNF-α, IFN-γ e IL-13 by qPCR) and assessment of physiological parameters (). We found that the pro-inflammatory stimuli induced a marked weight loss in mice that received drinking water with ash compared with mice that received only drinking water or were treated with ETOH. The macroscopic analysis of colon showed a greater ratio weight/length in animals that received ash compared with controls (28,38±4,39 vs 31,34±2,42 for EtOH vs EtOH+ash; 28,31±0,1 vs 33,68±4,2 for TNBS vs TNBS+ash; and 24,65±4,01 vs 31,49±5,98 for FliCvsFliC+ash). The histologic activity index (HAI), defined with H&E staining, was 1 vs 3 (EtOH vs EtOH+ash); 3,25±0,35 vs 4,33±0,58 (TNBS vs TNBS+ash); and 2,33±0,58 vs 4 (FliC vs FliC+ash) with an increased cellular infiltration of the intestinal wall and vascularization in mice that received ash compared with controls. Accordingly, pro-inflammatory cytokines were augmented. In conclusion, the oral administration of ash induced an increased inflammation and vascularization in the colonic mucosa and submucosa, in mice with TNBS- or FliC-driven colitis, thus suggesting that volcano ash could exert a pro-inflammatory effect that exacerbate the mucosal inflammation in patients with IBD.