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Alzheimer's disease (AD) is clinically characterized by progressive loss of cognitive abilities and usually is accompany with elevated oxidative stress. Chamomile is a plant with antioxidant activity with is currently used in Iranian folk medicine as sedative, analgesic, antipyretic and antispasmodic agent. The present study was investigated the effect of Matricaria chamomilla (MC) on learning and memory functions in scopolamine-induced memory deficit in rats. Memory enhancing activity in scopolamine-induced amnesic rats was investigated by assessing the Morris water maze and passive avoidance paradigm. Forty-two male Wistar rats were divided into 6 equal groups as bellow: 1 – control (received water), 2 – SCOP (received scopolamine 1 mg/kg for 15 days), 3 and 4 – SCOP + MC (received scopolamine and MC extract 200 and 500 mg/kg b.w. per day for 15 days), 5 and 6 – intact groups (received MC extract 200 and 500 mg/kg b.w. per day for 15 days). M. Chamomilla ethanolic extract produced significant memory enhancing activity when evaluated by Morris water maze and passive avoidance paradigm models. Our results suggest that M. chamomilla ethanolic extract has repairing effects on memory deficit and might be beneficial in patients with Alzheimer's disease and behavioral disorders. The memory enhancing activity of the extract may be attributed to the free radical scavenging activity, which would have been afforded by the active constituents present in the extract.

This study investigated the effects of pretreatment with different doses of Lavandula officinalis ethanolic extract on memory, learning and nociception in male Wistar rats. In this experimental study, 32 male Wistar rats were studied in 4 groups of 8 each. The control group received distilled water while three treatment groups received oral Lavender extract. Then 2 h after the last dose Morris water maze, shuttle box and rotarod test were performed. To study the analgesic activity the hot plate was used. The rats received orally Lavender extract one hour prior to beginning of the experiment for analgesic activity. The treatment groups with doses of 100, 200 and 400 mg/kg of the Lavender extract improved learning and memory compared with the control group in final trails in Morris water maze test. Lavender extract increased the latency to fall off for each rat in 100 and 200 mg/kg Lavender groups in rotarod test. Lavender extract with 400 mg/kg dose significantly increased latency to respond to heat stimulus 5 and 15 minutes after beginning of experiment. Although further studies are needed, the results indicate that lavender extract improves memory and learning, and might be beneficial in patients with these disorders, particularly the patients suffering pain.

Alzheimer's disease (AD) is a degenerative disorder that leads to progressive cognitive decline. The memory dysfunction of AD has been associated with a cortical cholinergic deficiency and loss of cholinergic neurons of the nucleus basalis of Meynert (NBM). This study investigated the effect of Cyperus rotundus tubers ethanolic extract on learning and memory in the rat model of Alzheimer's and intact rats. In this experimental study, 49 male Wistar rats were divided randomly into seven groups. Wistar rats received bilateral electric lesions of the NBM. The NBM-lesioned rats received Cyperus rotundus tubers ethanolic extract (100 and 200 mg/kg; ip) for 15 days while the control and sham groups received distilled water. Intact rats received extract without any surgery. Passive avoidance learning and memory performance was assessed using passive avoidance paradigm, and Morris water maze test used for spatial learning and memory evaluation. In shuttle box test, the initial latency significantly decreased in Alzh+ CRT (NBM-lesioned rats that received extract) groups. Step through latency significantly increased in Alzh+ CRT groups. In Morris water maze task, in the probe trial, Alzh+ CRT groups demonstrated a significant preference for the quadrant in which the platform was located on the preceding day. The decrease in the escape latency improved significantly in Alzh+ CRT groups when compared with Alzh (NBM-lesioned rats) group. The results suggest that Cyperus rotundus tubers ethanolic extract has some repairing effects on the memory and behavioral disorders produced by lesioning of the NBM in rats.