Abstract Background and objectives: Bidirectional communication between brain-gut is important in gastrointestinal and brain function. Thus, the purpose of this study was to evaluate the effect of aqueous extract of Aloe vera leaves on the gastric acid secretion, brain and intestinal water content following acetic acid gastric ulcer induction. Materials and Methods: Rats were randomly assigned into three groups, 7 rats in each group: intact group, gastric ulcer group and treatment with Aloe vera group. The acid levels, brain and intestinal water content of each sample were measured eight days after the gastric ulcer induction. Gastric ulcer was induced by injection of 20% acetic acid into the subserosal layer. Results: Gastric acid levels were significantly decreased in treatment group when compared with gastric ulcer group (p<0.05). However, there were no differences in acid output between gastric ulcer and treatment groups with intact group. After treatment, the amount of brain water content had no significantly difference with intact and gastric ulcer groups (p<0.05). The duodenal water content in treatment group was significantly reduced compared with intact group (p<0.05) but gastric ulcer group had no significant difference with intact and treatment group. Histopathologic results showed hyperemia of the vessels and infiltration of white blood cells in the lining of connective tissue. Improve conditions was seen after treatment with Aloe vera. Conclusion: It appears the protective effect of Aloe vera may be due to the inhibitory effect of this extract on the gastric acid secretion.This effect could be due to the presence of the plant lectins.