Experimental Study of the Antioxidant Effect of Taurine Against Radiation-induced Intestinal Injuries / 胃肠病学

ABSTRACT

Background: Oxidative stress is crucial for the development of ionizing radiation-induced intestinal injuries and inflammation. Taurine is a sulfur-containing amino acid distributed in tissues and organs throughout the body. It possesses several important physiological functions, including anti-oxidative activity and anti-inflammatory effects. Aims: To investigate the therapeutic effect and underlying mechanism of taurine against radiation-induced intestinal injuries. Methods: CCK-8 assay and DCFH-DA, a fluorescence probe of intracellular reactive oxygen species (ROS) were applied to determine the effects of taurine on radiation-induced inhibition of cell viability and ROS accumulation in human intestinal epithelial cell line HIEC-6. The modulatory effects of taurine on expressions of oxidative stress-related genes in intestinal cells after exposure to radiation were measured by real-time PCR in in vitro and in vivo studies. The roles of taurine in maintenance of intestinal morphology and suppression of cell apoptosis in mice receiving whole body radiation were assessed by HE staining and TUNEL staining. Results: In in vitro study, taurine improved the radiation-induced inhibition of cell viability and reduced intracellular ROS accumulation in HIEC-6 cells. The expression levels of catalase (CAT) and glutathione peroxidase 1 (GPx1) in HIEC-6 cells were up-regulated by taurine treatment. In vivo study showed that taurine activated the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway, alleviated intestinal villi disorganization and loss of crypt cells, and suppressed cell apoptosis in mice after radiation. Conclusions: Taurine can reduce the intracellular ROS accumulation via activating Nrf2/HO-1 antioxidant signaling pathway, and thereby, exerts protective effect against radiation-induced intestinal injuries. It might be a candidate for treatment of intestinal injuries in patients undergoing radiotherapy.