Evaluation of Memory Enhancing Activity of Chloroform Extract of Plumbago zeylanica Linn. by Different Models in Rats

Abstract

AIM- The aim of the present investigation is to Evaluate Memory Enhancing Activity of Different Extracts of Plumbago zeylanica Linn. with Special Reference to Chloroform Extract. MATERIAL & METHODS- The dried fruits of PZ were extracted by successive solvent extraction method with the help of soxhlet apparatus. The plant material first extracted with petroleum ether then chloroform, ethanol and water. The Morris water maze consists of a circular pool (60 cm in diameter, 26 cm in height), filled with water to the depth of 20 cm and made opaque white color. The pool was divided into four hypothetical quadrants. The elevated plus maze served as the exteroceptive behavioral model (wherein the stimulus existed outside the body) to evaluate learning and memory in mice. The apparatus consisted of two open arms and two covered arms. At the end of experiment, the experimental animals were sacrificed by cervical dislocation and brains were taken out. They were rinsed thoroughly with ice-chilled 0.9% NaCl and weighed. A 10% (w/v) tissue homogenate was prepared in 0.1 M phosphate buffer (pH 7.4). The post nuclear fraction was obtained by centrifugation of the homogenate at 12000g for 60 min at 4ºC. RESULTS- Animals treated with chloroform extract at 100 mg/kg showed an acquisition and retention profile reduction in mean latencies and time spent as 148.53±3.34 and 52.50 ± 1.56 respectively significant as compared to scopolamine control group. Chloroform extract treated groups animals showed significant decrease in transfer latency (s) of acquisition trial as compared to disease control animals, thus suggested marked improvement in memory. The reference standard Piracetam (PC) treated animals showed marked significant decrease in transfer latency (s) of acquisition trial as compared to scopolamine disease control animals. CONCLUSION- On the basis of the preliminary screening of the Plumbago zeylanica extracts we concluded that chloroform extract significantly improved learning memory in several exteroceptive and interoceptive behavioural models of scopolamine induced memory deficit activity, antioxidant activity and by attenuating the biochemical perturbations caused by cognitive impairments.