Ginsenoside Rk1 attenuates radiation-induced intestinal injury through the PI3K/AKT/mTOR pathway.

Radiation-induced intestinal injury (RIII) frequently occurs during radiotherapy; however, methods for treating RIII are limited. Ginsenoside Rk1 (RK1) is a substance that is derived from ginseng, and it has several biological activities, such as antiapoptotic, antioxidant and anticancer activities. The present study was designed to investigate the potential protective effect of Rk1 on RIII and the potential mechanisms. The results showed that RK1 treatment significantly improved the survival rate of the irradiated rats and markedly ameliorated the structural injury of the intestinal mucosa observed by histology. Treatment with RK1 significantly alleviated radiation-induced intestinal epithelial cell oxidative stress apoptosis. Moreover, RNA-Seq identified 388 differentially expressed genes (DEGs) and showed that the PI3K-AKT pathway might be a key signaling pathway by which RK1 exerts its therapeutic effects on RIII. The western blotting results showed that the p-PI3K, p-AKT and p-mTOR expression levels, which were increased by radiation, were markedly inhibited by Rk1, and these effects were reversed by IGF-1. The present study demonstrates that Rk1 can alleviate RIII and that the mechanism underlying the antiapoptotic effects of RK1 may involve the suppression of the PI3K/Akt/mTOR pathway. This study provides a promising therapeutic agent for RIII.