Effect of the new synthetic vitamin E derivative ETS-GS on radiation enterocolitis symptoms in a rat model

Radiation enterocolitis is a severe adverse event that occurs after radiotherapy for malignant abdominal tumors. In this study, the therapeutic effects of ETS-GS, a novel vitamin E derivative with antioxidative and anti-inflammatory abilities, were examined in a rat model of radiation enterocolitis. The radiation enterocolitis model was created by irradiation of male rats with a single dose of 10 Gy. ETS-GS was administered subcutaneously (10 mg/kg/day) for five consecutive days from two days prior to irradiation. The animals were sacrificed three days after irradiation; following which, ileal tissue samples were analyzed for macroscopic and histological findings, presence of apoptosis, degree of oxidative stress and inflammation. In the irradiated group, severe erosion was observed in the small intestine in addition to necrosis of the mucosal layer, swelling and invasion of inflammatory cells of the submucosal layer, and shortening of the crypts. In irradiated rats that received ETS-GS, mucosal injury in the small intestine was milder compared with that of irradiated rats that received no ETS-GS. In addition, ETS-GS decreased apoptosis in the small intestine and reduced the activity of myeloperoxidase and malondialdehyde, which are markers for inflammation and oxidative stress. ETS-GS with antioxidant activity has a therapeutic effect on the symptoms of radiation enterocolitis in a rat model.