ABSTRACT
Radiation enteritis (RE) is a common syndrome in the radiotherapy of abdominal and pelvic malignant tumors, heavy influencing living quality, but no specific clinical regimens are available. Long oil (LO) is composed of the fat components from cuttlebone, safflower, walnut oil and rapeseed oil and has been clinically used for wound healing. In this study, oral LO was applied for the prevention and treatment of RE and the mechanisms were explored. Animal experiments were approved by the Ethics Committee of the Beijing Institute of Radiation Medicine, Academy of Military Medical Sciences, and the experiments were conducted in accordance with relevant guidelines and regulations. An RE mouse model was established after single whole abdominal γ-ray radiation of 13 Gy. LO (8 mL·kg-1) was intragastrically administered to the mice 1 h pre-radiation. Compared to the models, the mice of the LO group had more regenerated intestinal crypts and longer villus on day 3.5, and remarkable increase in the abundance of gut microbiota on day 7, especially the amounts of probiotics including Eubacterium and Lactobacillus. Moreover, the mice of the LO group showed longer total movement distance, shorter immobility time, and higher speed than the model mice on day 7. On day 14, the mice of the LO group showed the high descending of proinflammatory factors including tumor necrosis factor-α and interleukin-6, close to the normal levels. Therefore, oral LO can alleviate the inflamed syndromes of RE and improve the repair of damaged intestinal tissues. Moreover, the mice of the LO group had highly low permeability of intestinal mucosa according to the fluorescence labeling experiment, which was close to the normal level. Oral LO can protect intestine mucosa and prevent RE by modification of the intestinal microenvironment, alleviation of the inflammatory response, and promotion of tissue repair.