Neurobehavioural and Microscopic Evaluation of the Therapeutic Potential of Trans-cinnamaldehyde on the Cerebral Cortex of Insulin-resistant Wistar Rats
Insulin-resistance and type-2 diabetes are associated with altered cognitive function, both conditions have been linked to neurodegenerative disease which is a progressive impairment in the functionality of the brain usually resulting from loss or death of neurons traceable to multiple causes. The aim of this study was to explore the therapeutic potentials of transcinnamaldehyde (TCA) on the behavioral and histomorphology of cerebrum of high fat diet (HFD) and streptozotocin (STZ) induced insulin-resistant in Wistar rats. Forty Wistar rats were fed with HFD for 8 weeks and then treated with STZ (30 mg/kg intraperitoneally) to induce insulin resistance. 40 and 60 mg/kg of TCA were orally administered for 4 weeks once daily after the induction of the insulin resistance. Thereafter, open field test (OPT) was used to determine line crossing and rearing frequency, histological examination (haematoxylin and eosin (H&E) and Cresyl fast violet (CFV-to show the Nissl substance in neurons and cell nuclei), and immunohistological assessments to quantify the level of betaamyloid, Glial fibrillary acidic protein (GFAP) and neuronal nuclear protein (NeuN), were conducted. HFD and STZ induced insulin- resistant caused behavioral alteration, changes in cerebral histoarchitecture, pyknotic pyramidal neurons, sparse Nissl distribution, hypertrophied astrocytes, amyloid plaque formation, however TCA administration to insulinresistant rats reduced pyknosis, astrogliosis, and neurodegenerative changes in the cerebrum when compared with untreated insulin-resistant rats. The study concluded that TCA protected the cerebrum from insulin-resistance-induced behavioural deficits and neuronal degeneration. The study recommended that trans-cinnamaldehyde be explored as a therapy for insulinresistance-induced neurodegenerative changes
Key Words: Cerebrum, High-fat Diet, Insulin-resistant, Trans-cinnamaldehyde.