The effect of oral feeding of Withania somnifera L. alcoholic extract on intracerebroventricular streptozotocin-induced cognitive deficits in male rat

Alzheimer’s disease is a prevalent central nervous system disease with no definitive treatment till now. So, in the present study the effect of an important herbal medicine, withania somnifera (Ws), was investigated on progression of Alzheimer’s disease. We used intracerebroventricular streptozotocin (STZ) injection as a model for Alzheimer's disease. Learning and memory performance was assessed using passive avoidance paradigm and for spatial cognition evaluation, Y maze task was used. The studied animals were divided into control, control+Ws, STZ and STZ+Ws. The STZ-injected rats received Ws extract (p.o) one day pre-surgery for three weeks and were then subjected to Y maze and passive avoidance learning and memory tests. Finally, the acquired data were subjected to proper statistical analysis. It was found out that treatment with the extract (200 mg/kg) could markedly increase the step through latency (STL) time (43.5 ± 3.48) as an index of recall in comparison to STZ-injected rats (33.1 ± 3.1). Also, alternation behavior as spatial memory index was augmented from 45.21 ± 4.81 in control animals to 67.68 ± 5.21 and 63.26 ± 6.27 in 100 and 200 mg/kg treated animal groups, respectively. Therefore, chronic treatment with Ws extract could antagonize memory deficits induced by STZ-ICV injection in rats. Perhaps, this plant could be a potential factor in the treatment of neurodegenerative diseases such as Alzheimer's disease (AD).