Effect of phosphamidon on cognition and oxidative stress and its modulation by ascorbic acid and 4′-chlorodiazepam in rats

Neurosteroids and micronutrient are known to possess neuromodulator and neuroprotective activities. The present study was designed to investigate the effect of 4'-chlorodiazepam (4CD) or ascorbic acid (Vit C) on phosphamidon (PM) induced modulation of cognitive function and oxidative stress in male Wistar rats. Cognitive function was measured by using step-down latency (SDL) on a continuous avoidance apparatus and transfer latency (TL) on an elevated plus maze. Oxidative stress was estimated by measuring brain malondialdehyde (MDA) level, protein carbonyl (PC) and reduced glutathione (GSH) activity. A significant reduction in both acquisition and retention in SDL was found for the PM treated group at weeks 6 and 8 as compared to the control (p < 0.001). PM caused a significant prolongation in both acquisition and retention in TL at 6 and 8 weeks as compared to the control (p < 0.001). Two-week treatment of 4CD or Vit C antagonized the effect of PM on SDL and TL at 8th week. PM produced a statistically significant increase in the brain MDA and PC levels (p < 0.001) and a significant decrease in the brain GSH activity (p < 0.001). Treatment with 4CD or Vit C attenuated the effect of PM on MDA, PC and GSH activities. Results of this study suggest that Vit C and 4CD have potential in reversing cognitive dysfunction and oxidative stress induced by toxicants like PM in the brain. Crown Copyright (c) 2012 Published by Elsevier Inc. All rights reserved.