Macroscopic appearance of esophageal and gastric mucosa in pretreatment groups. Panels: (a) sham, (b) control, (c) OMP, (d) PD 200, (e) PD 100, and (f): PD50. Compared to sham (a), severe focal lesions with hemorrhage and ulcer exhibited in the esophageal and gastric mucosa of control (b). However, the macroscopic lesions were dose-dependently reduced by treatment with OMP (c) or PD (d, e, f). PD: platycodin D, OMP: omeprazole.