Effect of carbimazole on rabbit central nervous system: histological and immunohistochemical study

Abstract

Carbimazole is a widely used antithyroid drug, but its potential effects on the central nervous system (CNS) remain poorly understood. This study aimed to investigate the histological and immunohistochemical changes induced by repeated exposure to carbimazole in the brain tissue of female rabbits. Ten Female rabbits were divided into control and treated groups. Histological evaluation was performed using Hematoxylin and Eosin (H&E), Masson's Trichrome, and Toluidine Blue stains. Immunohistochemical analysis was conducted using P53, GFAP, and Neurofilament markers to assess neuronal damage, astrocyte reactivity, and axonal integrity. Histological findings in treated animals revealed neuronal degeneration, inflammatory infiltration, and fibrotic changes, particularly in the cerebral cortex and hippocampus. Immunohistochemistry showed upregulation of P53, indicating apoptotic activity, increased GFAP expression, reflecting astrocyte activation, and reduced Neurofilament staining, suggesting axonal damage. Carbimazole administration induced significant neurohistological and immunohistochemical alterations, supporting its potential neurotoxic effects. These results emphasize the need for further research into the neurological safety of long-term carbimazole use