Background and Aim: There are numerous reports that different models of stress can cause memory loss. On the other hand, investigations determined that Cyperus rotundus rhizome can effectively improve memory and enhance recall. In the present study we assessed the possible improving effects of hydroalcoholic extract of Cyperus rotundus rhizomes on stress-induced memory retrieval impairment.
Methods: Adult male mice were divided to two  main groups, stress and non-stress, and each of these groups was divided into two subgroups: saline-receiving control and treated with Cyperus rutundus extract. First, the mice received the material by daily gavage for 7 or 21 days. One day after the last gavage, the animals were trained by step-through method. 24 hours after the training, they were exposed to elevated platform stress before the test. Step-through latency (STL) to enter dark chamber and spent time in dark chamber (STD) were recorded as measures of passive avoidance memory retrieval.
Results: Pre-test stress significantly reduced STL and increased STD. Pre-training gavage of Cyperus rotundus extract reversed the STL and also significantly reduced the STD.
Conclusion: It seems that treatment with hydroalcoholic extract of Cyperus rotundus rhizomes improves ability to retrieve information from long-term memory and  ameliorates stress-induced memory impairment in a time-dependent manner.
‎