Nardostachys jatamansi Improves Learning and Memory in Mice

Cure of cognitive disorders such as amnesia, attention deficit, and Alzheimer's disease is still far from being realized in the field of medicine. Nootropic agents such as piracetam, aniracetam, and choline esterase inhibitors like donepezil are being used for improving memory, mood, and behavior, but the resulting side effects associated with these agents have made their applicability limited. In Ayurveda, the roots of Nardostachys jatamansi have been clinically employed for their anti-ischemic, antioxidant, anticonvulsant, and neuroprotective activities. The present study was undertaken to assess the potential of N. jatmansi as a memory enhancer. The elevated plus maze and the passive avoidance paradigm were employed to evaluate learning and memory parameters. Three doses (50, 100, and 200 mg/kg, p.o.) of an ethanolic extract of N. jatamansi were administered for 8 successive days to both young and aged mice. The 200 mg/kg dose of N. jatmansi ethanolic extract significantly improved learning and memory in young mice and also reversed the amnesia induced by diazepam (1 mg/kg, i.p.) and scopolamine (0.4 mg/kg, i.p.). Furthermore, it also reversed aging-induced amnesia due to natural aging of mice. As scopolamine-induced amnesia was reversed, it is possible that the memory improvement may be because of facilitation of cholinergic transmission in the brain. Hence, N. jatmansi might prove to be a useful memory restorative agent in the treatment of dementia seen in elderly persons. The underlying mechanism of action can be attributed to its antioxidant property.