Introduction: Reactive gliosis contributes to damage and recovery patterns in hydrocephalus. This research aims to evaluate the impact of Methods: A total of 30 male Wistar rats were injected with 25% kaolin directly into the cisterna magna. Twenty-one days after kaolin injection, hydrocephalic rats were randomly divided into four groups, and the presence of hydrocephalus was confirmed by magnetic resonance imaging (MRI) to determine the lateral ventricle volume. Then, the rats received different doses of OEO for 10 days. Additionally, to assess the expression levels of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba-1), immunohistochemical and Western blot analyses were performed 10 days after the completion of the treatment course. Results: The size of the lateral ventricle in hydrocephalic rats treated with OEO was less than that in those treated with kaolin alone. Based on GFAP and Iba-1 immunostaining data, hydrocephalic rats showed more reactive astrocytes and activated microglia than OEO-treated animals. The findings of the immunohistochemistry analysis were also validated by Western blot. In terms of GFAP and Iba-1 expression levels, a significant difference was observed between the hydrocephalic control group and rats treated with OEO at a dose of 200 mg/kg/d. Conclusion: Compared to hydrocephalic rats, the OEO-treated groups exhibited stable ventricular dilatation. According to the results of this research, OEO may reduce hydrocephalus-related damage in kaolin-induced rat brains, potentially by lowering the expression of GFAP and Iba-1. Therefore, OEO intervention might be effective as a novel treatment technique.