Previous studies have demonstrated a decrease in manganese superoxide dismutase (MnSOD) in both Barrett's epithelium of patients and columnar esophageal epithelium of rats after esophagoduodenal anastomosis (EDA). Curcuma aromatica, an herbal medicine, has been shown to display anti-carcinogenic properties in a wide variety of cell lines and animals. This study was designed to investigate the ability of Curcuma aromatica oil for the prevention of BE and EAC, possibly through its ability to preserve MnSOD function. EDA was performed on rats and Curcuma aromatica oil was administered by i.p. injection. Histological changes and oxidative damage were determined after EDA of 1, 3, and 6 months. MnSOD protein level and MnSOD enzymatic activity were evaluated. Lipid peroxidation was determined by TBARs assay and 8-hydroxy-deoxyguanosine for DNA oxidative damage was measured by immunohistochemical staining. In addition, the indexes of both apoptosis and proliferation were determined by PCNA staining and TUNEL assay, respectively. Severe esophagitis were seen in EDA rats, and morphological transformation within the esophageal epithelium was observed with intestinal metaplasia and EAC identified after 3 months. The EDA rats treated with Curcuma aromatica oil showed that both MnSOD enzymatic activity and protein level were similar to sham controls. Decreased incidences of intestinal metaplasia and EAC also were observed in the EDA rats with Curcuma aromatica oil treatment. Curcuma aromatica oil prevented loss of MnSOD in EDA rat esophageal epithelium, and this preservation of MnSOD is associated with the potential protective mechanism against transformation of esophageal epithelial to BE to EAC.