Possible protective effect of dietary extra-virgin olive oil on experimentally induced acute colitis in adult male albino rats: a histological and immunohistochemical study

Introduction Many therapies are used nowadays to control colitis, but side effects limit long-term effectiveness. There is growing interest in the use of dietary supplements to avoid undesirable effects that accompany the classical treatment. Considerable attention has been focused on the use of extra-virgin olive oil (EVOO) in colitis. Aim of the work The aim of the study was to investigate the effect of pretreatment with dietary EVOO on modulating the extent and severity of experimentally induced acute colitis in adult male albino rats. Materials and methods Thirty-five adult male albino rats were divided randomly into three groups: group I, which served as the control group; group II (the colitis group), in which colitis was induced by intracolonic injection of 1 ml of 2% acetic acid daily for 3 days; and group III (the protection group), in which animals received 1 ml of EVOO /100 gm body weight daily by oral gavage for 10 days starting 7 days before the induction of colitis as in the previous group. At the end of the experiment, the distal part of the colon was removed and prepared for light and scanning electron microscopic study. Statistical and morphometric studies were also performed. Results Induction of colitis in group II showed massive mucosal ulceration, hemorrhage, and mononuclear cellular infiltration. Moreover, submucosal exudate and vacuolation in the muscularis externa were also detected. Immunohistochemical examination showed intense infiltration by tumor necrosis factor-α immunoreactive cells. Pretreatment with EVOO in group III protected the colon from acetic acid-induced colitis, which was manifested by preservation of crypts and their lining epithelium and by decrease in mononuclear cellular infiltration. Conclusion Administration of EVOO to adult male albino rats had an ameliorating effect on experimentally induced acute colitis, and therefore it could be used as a protective dietary measure to attenuate colitis in high-risk people.