Endocrine Abstracts

Insulin resistance is one of the metabolic pathogenesis of Type 2 diabetes mellitus which cause neurodegeneration, due to its effects on insulin signaling pathway. The present study focused on the intracerebroventricular administration of streptozotocin (STZ) to induce insulin resistance directly in brain, accounting for alteration in insulin signaling pathway and thus the possible therapeutic effect of Cinnamomum Zeylanicum on the impairment hippocampus of diabetic rats. A total of 32 adult male Wistar rats were divided thus: Groups were labelled A, B, C and D. Group A served as the control and animals were fed ad libitum,receiving a single icv injection of normal saline, Group B animals were administered a daily dose of 200 mg/kg of C. Zeylanicum, In the Group C each animal each animal received 3 mg/kg body weight of STZ intracranially at the beginning using a mechanical stereotaxic apparatus while in the Group D which animal was administered STZ intracranially followed with daily oral dose of Cinnamomum Zeylanicumm. The experiment and animals treatment lasted 28 days. 29 and 30, all neurobehavioural tests were done. Memory patterns were generally altered in the experimental group relative to the control. A significant depletion were observed in open arm entry/duration, close arm duration significantly increased with a reduction in close arm entry, total entry, number of trial and % of alternation in behavioural performance. RNA analysis showed memory deficits in insulin resistance rats as there was a significant increase in BACE-1 and GSK-3β gene with noticeable increases in Insulin and Insulin receptor (IRS) gene when compared to control. Histological demonstration of the hippocampus and immunostaining revealed depolarization of the dendritic with milder neurodegeneration field and Amyloid beta plague generation respectively. Cinnamomum Zeylanicum due to its antioxidant and anti-inflammatory content was seen to have positive effects on STZ-induced insulin resistance on the hippocampus.