Explosively Puffed Ginseng Ameliorates Ionizing Radiation-Induced Injury of Colon by Decreasing Oxidative Stress-Related Apoptotic Cell Execution in Mice

Abstract

Although radiation therapy (RT) is a feasible treatment approach for early colorectal cancer, RT is considerably toxic to normal tissues due to the increased reactive oxygen species production, which can induce tissue damage. Ginseng, a natural antioxidant agent, exhibits the protective effects against ionizing radiation (IR)-induced damage in in vitro and in vivo models. The explosive puffing of ginseng has been investigated as a process to improve the efficacy of ginseng due to the resulting physicochemical changes in its functional components. In this study, we provided the evidence for promotion in the beneficial role of puffed ginseng extract (PGE) and associated mechanisms of action, in comparison with white ginseng extract (WGE), against IR-induced colorectal injury, using in vivo study on a mouse model. To study the role of PGE in preventing IR-induced damage, we examined colorectal injury and apoptotic changes in mice exposed to ¹³⁷Cs at 8 Gy. High-performance liquid chromatography analysis showed that PGE had an increased total ginsenoside concentration with new generation of Rg3, Rg5, and Rk1, compared with the concentrations in WGE. Administering PGE, but not WGE, significantly ameliorated IR-induced colorectal cell death through negative regulation of apoptotic signaling pathways. These antiapoptotic effects of PGE were linked to the capacity to suppress the p53-mediated DNA damage response and NF-κB-mediated apoptotic signaling. Moreover, IR-induced oxidative stress in the colorectal epithelium was markedly reduced by PGE administration. Collectively, this study establishes a mechanism of action by which PGE counteracts IR-induced colorectal injury as a novel radioprotective agent.