Effect of Essential Oil of Leaf and Aerial Part of Rosmarinus officinalis on Passive Avoidance Memory in Aged and Young Mice

In this study, the effect of essential oil of aerial part of Rosmarinus officinalis, which is rich of antioxidants, was investigated on memory of young and aged mice with passive avoidance apparatus. Five groups of each young and aged mice (n = 8) were selected for this study. All doses of essential oils of leaf and aerial part of Rosmarinus officinalis (200, 400, 600, 800 mg/kg) were injected intraperitoneally once a day for 7 days to four groups of age and young mice and fifth group (control) received 10 ml/kg distilled water once daily for 7 days. Mean of step-down latency on day 4 in comparison with day 2 became significantly longer (P<0.05) in all young and aged groups of mice. On the other hand, the mean of step-down latency in all groups received different doses of essential oil to compare with control group showed significant (P< 0.05) improvement in memory test in day 4. Also in all aged group received different doses of essential oil step-down latency were significantly (P<0.05) longer than young groups. The result showed that, the essential oil of Rosmarinus officinalis improves memory in all young and aged animal groups, but it was more effective on aged mice.