Protective role of exogenous αα-lipoic acid (ALA) on hippocampal antioxidant status and memory function in rat pups exposed to sodium arsenite during the early post-natal period

The present work focussed on the effect of exogenous alpha alpha-lipoic acid (ALA) administration on retention memory and oxidative stress markers in the hippocampus subsequent to early post-natal exposure of rat pups to sodium arsenite (NaAsO2). Wistar rat pups were divided into the control groups receiving either no treatment (Ia) or distilled water by intraperitoneal route (i.p.) (Ib) and the experimental groups receiving either NaAsO2 alone (1.5 and 2.0 mg/kg body wt.) (IIa, IIb) or NaAsO2 (1.5 and 2.0 mg/kg body wt.) followed by ALA (70 mg/kg body wt.) (IIIa, IIIb) (i.p.) from post-natal day (PND) 4--15. The initial and retention transfer latency (ITL and RTL) was determined on PND 14 and 15 using elevated plus maze. The animals were sacrificed by cervical decapitation (PND 16) and the brains were obtained. The dissected out hippocampus was processed for estimation of oxidative stress markers, glutathione (GSH), and superoxide dismutase (SOD). NaAsO2 exposure resulted in longer RTL in animal groups IIa and IIb, thereby suggestive of arsenic-induced impairment in retention memory. RTL was significantly shorter in animal groups (IIIa, IIIb) receiving ALA following NaAsO2, thereby suggestive of improvement in retention memory. GSH and SOD levels were significantly decreased in animals receiving NaAsO2 alone as against group Ib and administration of ALA following NaAsO2 increased the levels of hippocampal GSH and SOD. These observations are suggestive of the role of exogenous ALA in ameliorating the adverse effects induced by NaAsO2 exposure of rat pups on retention memory and oxidative stress markers.</.