Memory enhancing activity of Lawsonia inermis Linn. leaves against scopolamine induced memory impairment in Swiss albino mice

The objective of the present study was to evaluate the memory enhancing activity of Lawsonia inermis Linn. leaves against scopolamine induced amnesia by elevated plus maze and Y-maze test. The Powdered leaf materials were extracted with 95% ethanol. The dried extract was subjected to phytochemical analysis and free radical scavenging activity. Acute oral toxicity was performed as per OECD guidelines 425. A dose level 200 mg/kg and 400 mg/kg were selected for pharmacological screening. Swiss albino mice of male sex were divided into ten groups of six animals each. Five groups were subjected to evaluation by elevated plus maze and remaining by Y-maze model. Immediately after evaluation, the whole brain of each animal was subjected to determination of acetyl cholinesterase (AChE), malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) activity. Extract at dose levels of 200 mg/kg and 400 mg/kg showed a significant increase in inflexion ratio in elevated plus maze and increase in percentage alternation in Y-maze model compared to negative control animals in respective models. A significant decrease in brain AChE and MDA with a significant increase in GSH, CAT and SOD levels were noted in animals treated with extract in both models. The preliminary analysis of extract showed the presence of phenolics, tannins, flavonoids and a potent invitro free radical scavenging activity. These findings suggest that, the memory enhancing effect of Lawsonia inermis leaves might be due to enhancement of cholinergic neurotransmission through inhibition of AChE activity and by stabilizing the antioxidant system. © 2017, Institute of Korean Medicine, Kyung Hee University and Springer Science+Business Media Dordrecht.