Neuroprotective Potential of Ethoxzolamide Targeting Oxidative Stress and Inflammation in Experimental Models of Intracerebral Hemorrhage.

Background: As antioxidant and anti-inflammatory agents, carbonic anhydrase inhibitors can exert potentially useful therapeutic effects following central nervous system trauma, including intracerebral hemorrhage (ICH). However, the therapeutic efficacy of ethoxyzolamide (ETZ) as a novel carbonic anhydrase inhibitor for ICH has not yet been determined.

Methods: An autologous blood injection method was used to establish ICH models, which were then used to establish the effects of intraperitoneal injection of ETZ on ICH. Neuronal damage, apoptotic protein expression, oxidative and inflammatory factor content, microglia marker Iba-1 positivity, hepatic and renal pathological changes, and serum concentrations of hepatic and renal function indices were assessed by Nissl staining, western blotting, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, hematoxylin and eosin (HE) staining, and automatic biochemical analysis in brain tissues.

Results: The ICH group showed massive hemorrhagic foci; significant increases in brain water content, modified mouse neurological deficit scoring (mNSS) score, pro-apoptotic protein expression, oxidative factors, pro-inflammatory factors, and Iba-1 positivity; and significant reductions in Nissl body size, anti-apoptotic protein expression, and antioxidant factors, all of which were reversed by ETZ in a dose-dependent manner. ETZ has a good biosafety profile with no significant burden on the human liver or kidneys. The Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was mildly activated in ICH mice, and was further increased after ETZ injection. Molecular docking experiments revealed that ETZ could dock onto the Nrf2-binding domain of keap1.

Conclusions: ETZ, as a novel carbonic anhydrase inhibitor, further activated the Keap1/Nrf2 pathway by docking with the Nrf2-binding domain of keap1, thereby exerting antioxidant, anti-inflammatory, anti-apoptotic, and cerebral neuroprotective effects in ICH mice.