2.6. Acetic Acid-Induced Chronic Gastric Lesions

Chronic gastric lesions were induced as described by Okabe et al. [25]. After a 24 h fast, 28 Wistar rats were anesthetized with 2% isoflurane in 70% nitrous oxide and 30% oxygen. After each abdomen was opened by small midline incision and the stomach was slightly lifted out, 500 μL of 100% acetic acid was instilled into a 6 mm diameter plastic cylinder and allowed to remain on the serosa of the stomach for 1 min. After aspiration of acetic acid, the serosa was washed with saline, the stomach was replaced carefully into the abdomen, and then the abdominal incision was closed. After surgical recovery, the 28 rats were randomly assigned to three groups: control (n = 10), omeprazole 20 mg/kg (n = 10), and PCE 300 mg/kg (n = 8). Beginning two days after ulcer induction, samples were administered by oral gavage at a volume of 10 mL/kg body weight twice a day for a week, and the control group received the vehicle (distilled water) at the same volume. At the end of the treatment period, the rats were euthanized by cervical dislocation and the stomachs were quickly removed. The gastric ulcer lesion area and index were determined as described above.