en Histopathology Histopathology Original Article Original Article <p style="text-align: justify;">Reactive oxygen and nitrogen species (ROS/RNS) play a crucial role in inflammatory bowel disease (IBD) exacerbating the chronic inflammatory process. Endogenous and diet antioxidants can neutralize these compounds. The apple is widely consumed, with several antioxidant activity compounds. The present study evaluated the effects of concentrated apple extract (CAE) in acetic acid induced colitis. 29 Wistar male rats were randomized into 5 groups. G1 &ndash; Sham/saline solution, G2 &ndash; CAE/control, G3 &ndash; acetic acid/control, G4 &ndash; curative-CAE treatment and G5 &ndash; preventive-CAE treatment. 8 days later, the animals were euthanized and the colonic segment resected for macroscopic and histological analysis. Gene expression was evaluated for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), catalase and copper and zinc superoxide dismutase (CuZnSOD) by quantitative real time PCR, while protein expression was assessed for iNOS, COX-2 and 8-hydroxy-20-deoxyguanosine (8-OHdG) by immuno-histochemistry. The groups G3, G4 and G5 had weight loss, while G5 had weight increase at the end of the experiment. The treatment with CAE reduced the macroscopic and microscopic injury, decreased iNOS mRNA expression and increased CuZnSOD mRNA expression in animals with induced acetic acid-colitis. The findings of the present study suggest that CAE treatment exerts an antioxidant role by downregulating iNOS and upregulating CuZnSOD.</p> <p align="JUSTIFY" class="western" style="text-indent: 1.25cm; margin-bottom: 0cm; line-height: 200%"></p> Experimental colitis, apple extract, antioxidant, iNOS, CuZnSOD 38 49 http://ijmcmed.org/browse.php?a_code=A-10-954-2&slc_lang=en&sid=1 Maurício Mercaldi Pastrelo mmpastrelo@hotmail.com 10031947532846008662 10031947532846008662 No Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Carla Caroline Dias Ribeiro carla.caroldi@gmail.com 10031947532846008663 10031947532846008663 No Department of Medicine, Discipline of Gastroenterology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Joselmo Willamys Duarte jwillamys@terra.com.br 10031947532846008664 10031947532846008664 No Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Andréa Pitelli Boiago Gollucke pitelli@unisanto.com.br 10031947532846008665 10031947532846008665 No Department of Biosciences, Universidade Federal de São Paulo, Santos, Brazil. Ricardo Artigiani-Neto ricardoartigiani@hotmail.com 10031947532846008666 10031947532846008666 No Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Daniel Araki Ribeiro daribeiro@unifesp.br 10031947532846008667 10031947532846008667 No Department of Biosciences, Universidade Federal de São Paulo, Santos, Brazil. Sender Jankiel Miszputen sender.miszputen@unifesp.br 10031947532846008668 10031947532846008668 No Department of Medicine, Discipline of Gastroenterology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Celina Tizuko Fujiyama Oshima celina.oshima@gmail.com 10031947532846008669 10031947532846008669 No Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. Ana Paula Ribeiro Paiotti a.paiotti@unifesp.br 10031947532846008670 10031947532846008670 Yes Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.