Clemizole Mitigates Traumatic Brain Injury by Inhibiting Oxidative Stress, Neuroinflammation, and Apoptosis

Traumatic brain injury (TBI) triggers complex secondary pathological mechanisms, including neuroinflammation, oxidative stress, and apoptosis, contributing to long-term cognitive and motor deficits. This study investigates the neuroprotective potential of Clemizole, a known TRPC5 inhibitor, in a weight-drop rat model of TBI. Target prediction analyses using Swiss Target Prediction and CTD databases identified 159 overlapping genes between Clemizole and TBI. Protein-protein interaction network and hub gene analyses highlighted key proteins, such as TNF-α, CASP3, MMP-9, and TRPC5, implicating them in TBI pathogenesis. KEGG pathway enrichment revealed Clemizole-targeted pathways, including PI3K-Akt, TNF signaling, and apoptosis. After TBI, behavioral assessments showed that Clemizole significantly improved neurological scores, grip strength, locomotor activity, and spatial learning deficits. Biochemical assays revealed that Clemizole dose-dependently reduced nitrite and MDA levels while restoring GSH, indicating attenuation of oxidative stress. H&E (hematoxylin and eosin) and cresyl violet staining confirmed reduced neuronal degeneration and preserved cortical integrity. Clemizole also downregulated inflammatory cytokines and glial markers (Iba-1 and GFAP), alongside restoring BBB integrity via upregulation of tight junction proteins and suppressing MMP-9 expression. Furthermore, Clemizole activated the PI3K-Akt signaling pathway, decreasing the expression of pro-apoptotic proteins (Bax, caspase-9 and caspase-3) and restoring Bcl-2 levels. Importantly, Clemizole decreased TRPC5 expression and attenuated CHOP-mediated ER stress, suggesting a mechanistic link between TRPC5 inhibition and PI3K-Akt-mediated neuroprotection. Collectively, these findings demonstrate that Clemizole confers multifaceted neuroprotection following TBI by targeting TRPC5-mediated calcium dysregulation, restoring PI3K-Akt signaling, and attenuating oxidative, inflammatory, and apoptotic cascades. This study identifies Clemizole as a promising therapeutic candidate for mitigating secondary brain injury and promoting functional recovery after TBI.