Impaired cognitive performance and metabolic disturbance in streptozotocin-nicotinamide induced type 2 diabetes mellitus and the protective effect of Nigerian propolis
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Date
2016
Journal Title
Journal ISSN
Volume Title
Publisher
Nigerian Journal of Neuroscience
Abstract
Defects in insulin signaling and oxidative stress are implicated in cognitive dysfunction in diabetes. This
study evaluated the effects of propolis on cognitive impairment in streptozotocin-nicotinamide model of
type 2 diabetes mellitus in Wistar rats. Diabetes was induced by single intraperitonieal administration of
streptozotocin (65 mg/kg) 15 min after nicotinamide (110 mg/kg) had been adminstered. Diabetic
animals were treated with glibenclamide (5 mg/kg), propolis (200 and 300 mg/kg), or normal saline for 4
weeks after which spatial memory was assessed with the Morris’ water maze (MWM). At the end of the
study the animals were euthanized and blood collected via cardiac puncture while the brain was
homogenized. Insulin was assayed from plasma while malondialdehyde (MDA), superoxide dismutase
(SOD), gluthatione (GSH) and catalase were assayed from brain homogenate. Homeostatic model
assessment (HOMA) was used as marker for insulin resistance. Significant rise in blood glucose,
plasma insulin, and brain MDA (P < 0.05) with reduction in SOD, GSH, and catalase levels were
observed in the diabetic group. Treatment with 200 and 300 mg/kg propolis and glibenclamide
significantly decreased blood glucose, plasma insulin, and MDA (P < 0.05) and increased brain levels
of SOD, GSH and catalase. Propolis (200 and 300 mg/kg) also significantly (P < 0.05) decreased
escape latency in the MWM in comparison to the diabetic group. Nigerian propolis thus seems to
protect against impaired cognitive performance in experimental diabetes mellitus.
Description
Keywords
Spatial memory, insulin resistance, oxidative stress, Morris water maze, Nigerian propolis
Citation
Amin, A., Saliu, H., Solomon, E.O., Shehu, T., Imam, A., Abdulmajeed, W.I., Alli-Oluwafuyi, A., Ibrahim, R.B., & Owoyele, B.V. (2016). Impaired cognitive performance and metabolic disturbance in streptozotocin-nicotinamide induced type 2 diabetes mellitus and the protective effect of Nigerian propolis. Nigerian Journal of Neuroscience, 8(1), 22–31.