Effect of standardized extract of Marsilea minuta on learning and memory performance in rat amnesic models

Abstract

Context: Marsilea minuta Linn (Marsileaceae) is a common Indian hydrophytic plant. Traditionally, the plant has been used as a sedative for the treatment of insomnia and other mental disorders. Background information of this plant has encouraged us to investigate its antiamnesic activity in rat.

Objective: Standardized ethanol extract of M. minuta was investigated for their putative role in learning and memory performance in normal and amnesic rats.

Materials and methods: Ethanol extract of M. minuta (EMM) was standardized for marsiline using HPLC. The effect of standardized extract of M. minuta (1.15% w/w marsiline) was tested in amnesic rat using elevated plus maze (EPM) and passive avoidance (PA) test. Amnesia was induced after scopolamine (1 mg/kg, s.c.) and electroconvulsive shock (150 mA, 0.2 s) treatment. Behavioral studies were further substantiated with acetylcholinesterase (AChE) activity and radioligand muscarinic receptor binding studies in rat brain regions.

Results: Oral administration of EMM at 200 and 400 mg/kg/day for 3 days significantly reversed the amnesia whereas, no per se effect was observed. In comparison to control, AChE activity in frontal cortex and hippocampus was found to be significantly (P < 0.05) inhibited by EMM. EMM at doses 200 and 400 mg/kg has significantly (P < 0.05) increased (+34 % and +40 % change in affinity, respectively) the binding of 3H-QNB in frontal cortex indicating the up regulation of the muscarinic receptors.

Discussion and conclusion: These findings suggest that standardized extract of M. minuta have excellent antiamnesic activity, probably mediating through central cholinergic system.

Keywords::

• Acetylcholinesterase
• antiamnesic
• electroconvulsive shock
• muscarinic receptor
• scopolamine

Acknowledgements

Subrat Kumar Bhattamisra is grateful to University Grant Commission, India for providing Senior Research Fellowship. We express our sincere thanks to Dr. N.K. Dubey, Professor, Department of Botany, Banaras Hindu University, India for identifying the plant. We are thankful to Dr Vinay Kumar Khanna, Scientist, Developmental Toxicology Division, Industrial Toxicology Research Centre, Lucknow 226 001, Uttar Pradesh, India for his permission and contribution towards radioligand binding assay.

Declaration of interest: The authors report no declarations of interest.