Abstract
This study investigated the effects of zonisamide treatment on cerebellar tissues in an experimental alcohol addiction (AA) model and its potential mechanisms of action, particularly regarding apoptotic protease activating factor-1 (APAF-1) and tumor necrosis factor-alpha (TNF-α) expression. Thirty rats were divided into three groups: sham, ethanol (EtOH), and EtOH + zonisamide. AA was induced by administering 6 cc of EtOH orally every 8 h for 4 days. Zonisamide (100 mg/kg) was given to rats once daily before EtOH administration. Motor defects were evaluated using an open field maze. Serum TNF-α levels were measured from blood samples. Cerebellar sections were processed for histological examination and immunostained for APAF-1 and TNF-α. Protein interaction networks were constructed using Cytoscape, and functional annotations were performed with ShinyGO (version 0.80) software. The traveled area in the EtOH group was significantly reduced compared to the sham group (p = 0.0005). Rats in the EtOH + zonisamide group covered a larger area, with zonisamide treatment significantly improving locomotor ability compared to the EtOH group (p = 0.0463). Serum TNF-α levels were significantly elevated in the EtOH group compared to the sham group (p < 0.0001) and were significantly decreased in the EtOH + zonisamide group compared to the EtOH group (p = 0.0309). Regular cerebellar histological layers were observed in the sham group, while EtOH induction caused loss of cerebellar tissue integrity, neuronal degeneration, vascular dilatation and congestion, reduced myelin density, and neuropils in the EtOH group. Zonisamide treatment improved these pathologies, enhancing myelination and neuropil formation. Negative APAF-1 and TNF-α expressions were observed across cerebellar layers in the sham group. Due to EtOH toxicity, APAF-1 and TNF-α expression were upregulated in the EtOH group compared to the sham group (p < 0.001 for both). Zonisamide treatment downregulated these protein expressions in the EtOH + zonisamide group compared to the EtOH group (p < 0.001 and p = 0.0087, respectively). APAF-1 was primarily associated with AA through antifolate resistance, endopeptidases, and the interleukin-1 pathway, while TNF-α was predominantly enriched in infections and choline-binding, indicating zonisamide's impact on immune and inflammatory pathways. In conclusion, zonisamide treatment significantly mitigated ethanol-induced cerebellar damage and inflammation in an AA model. Zonisamide improved locomotor function and reduced serum TNF-α levels, as well as APAF-1 and TNF-α expression in cerebellar tissues. These findings suggest that zonisamide exerts its protective effects by modulating immune and inflammatory pathways, thereby preserving cerebellar integrity and function.