Nardostachys jatamansi extract prevents chronic restraint stress-induced learning and memory deficits in a radial arm...

Nardostachys jatamansi is traditionally used in alternative medicine for treatment of neuropsychiatric disorders. We investigated the potential of N. jatamansi extract (NJE) in protecting against chronic stress-induced impairments in spatial learning and memory. The rats were exposed to 21 days of chronic restraint stress and simultaneously received 100 mg or 200 mg/kg body weight of NJE following which acquisition and retention of hippocampus-dependent spatial memory were tested in a partially-baited eight arm radial maze. Animals treated with 200 mg/kg body weight NJE had learning curves comparable to control unstressed animals, made significantly more correct choices (38%, P < 0.001), and fewer reference memory errors (53%, P < 0.01) on the eighth day of training compared to untreated stressed animals as well as stressed animals which received vehicle or a lower dose (100 mg/kg) of NJE. NJE-treated animals also made significantly higher correct choices (31%, P < 0.001) than untreated animals in a retention test 10 days after the training period. We propose that NJE has a protective effect of stress-induced impairments in hippocampus-dependent learning and memory behavior in rats.