Zataria multiflora Boiss. extract improves spatial memory and learning capacity in scopolamine-induced amnesic rats

Zataria multiflora (Zm) has been proposed for memory enhancing in Persian traditional medicine; but to now, no study has been carried out in this field yet. The aim of this research was to study the plant effect on spatial memory in scopolamine-induced amnesia and investigate in vivo anticholinesterase effect of Zm.

Aerial parts of the plant were extracted with methanol and standardized on the basis of rutin content. Male rats received three doses of Zm extract (100, 200 and 400 mg/kg, intraperitoneal (ip) for 7 days) and 30 min after the latest dose, scopolamine (1 mg/kg) was administered to animals. Learning capacity and spatial memory were studied using morris water maze (MWM) and passive avoidance test (PAT) methods. Anticholinesterase activity was studied using Ellman's method. Physostigmine (0.3 mg/kg) and piracetam (200 mg/kg) were used as positive controls.

All doses of Zm extract significantly decreased the distance and time spent to find the platform in MWM and increased the time latency in PAT test. In both MWM and PAT tests, the highest effect of Zm was observed at 200 mg/kg which was in accordance with AChE inhibitory effect of the plant.

Our findings indicate that Zm has anti-amnesic effect and might improve memory deficit through anticholinesterase activity.