17-DMAG ameliorated intestinal injury induced by irradiation. Mice received a single oral administration of 17-DMAG (10 mg/kg) 24 h before irradiation at 8.75 Gy. Intestinal tissues were collected 30 days after irradiation for histological assessment. Villus morphology and height were assessed by H & E staining and observation under microscopy (10 ×) in jejunum of mice with (A) vehicle + sham, (B) 17-DMAG + sham, (C) vehicle + RI, and (D) 17-DMAG + RI at day 30 after irradiation, n = 5–6 mice per group. A 200 μm scale bar was shown on the bottom of right panel D. Occurrence of villus edema, decrease in villus heights, and ruptured villus tips were still present 30 days after the insult. 17-DMAG significantly improved recovery of intestinal histological damage with (E) increased villus heights (* p < 0.002 vs. 17-D/RI, error bars indicating the SEM for five or six independent experiments.) and (F) increased crypt numbers (* p < 0.01 vs. 17-D/RI, error bars indicating the SEM for five or six independent experiments) in transverse sections of the full jejunal circumference in 17-D/ RI mice 30 days after irradiation. Veh: vehicle; 17-D: 17-DMAG; RI: radiation injury.