Potential of carnosine, a histamine precursor in rat model of bilateral common carotid artery occlusion-induced vascular dementia.

The present study investigates the potential of Carnosine, a histamine precursor in rat model of bilateral common carotid artery occlusion (BCCAo)-induced vascular dementia (VaD). Wistar rats were subjected to BCCAo procedure under anaesthesia to induce VaD. The rats were subjected to Morris water maze (MWM) test (6th day onwards post-surgery). MWM test was employed to assess learning and memory of the animals whereby escape latency time, time spent in target quadrant and Path length (distance travelled) taken as important parameters. Serum nitrite level; Brain thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) levels; Brain acetylcholinesterase (AChE) activity; brain Myeloperoxidase activity (MPO) and neutrophil count were estimated as per standard procedures. BCCAo in rats produced a significant vascular endothelial dysfunction, as reflected by decrease in serum nitrite levels. Further, these animals showed poor performance on MWM, depicting impairment of learning and memory. There was a significant rise in brain oxidative stress level as indicated by increase in TBARS and decrease in GSH levels. An increase in brain AChE activity was also observed. Moreover, these rats also exhibited an increase in MPO activity and neutrophil infiltration in brain (as marker of inflammation). Treatment of Carnosine (200 and 400 mg/kg, i.p.)/Donepezil (0.3 mg/kg, i.p.) ameliorated BCCAo-induced memory deficits; endothelial dysfunction; biochemical and histopathological changes. It is concluded that Carnosine has shown efficacy in rat model of BCCAo-induced VaD and can be considered as an important therapeutic agent for the treatment of VaD.