title: Memory enhancing activity of Glycyrrhiza glabra in mice.
abstract: In the traditional system of medicine, the roots and rhizomes of Glycyrrhiza glabra (family: Leguminosae) have been employed clinically for centuries for their anti-inflammatory, antiulcer, expectorant, antimicrobial and anxiolytic activities. The present study was undertaken to investigate the effects of Glycyrrhiza glabra (popularly known as liquorice) on learning and memory in mice. Elevated plus-maze and passive avoidance paradigm were employed to test learning and memory. Three doses (75, 150 and 300 mg/kg p.o.) of aqueous extract of Glycyrrhiza glabra were administered for 7 successive days in separate groups of animals. The dose of 150 mg/kg of the aqueous extract of liquorice significantly improved learning and memory of mice. Furthermore, this dose significantly reversed the amnesia induced by diazepam (1 mg/kg i.p.) and scopolamine (0.4 mg/kg i.p.). Anti-inflammatory and antioxidant properties of liquorice may be contributing favorably to the memory enhancement effect. Since scopolamine-induced amnesia was reversed by liquorice, it is possible that the beneficial effect on learning and memory was due to facilitation of cholinergic-transmission in mouse brain. However, further studies are necessitated to identify the exact mechanism of action. In the present investigation, Glycyrrhiza glabra has shown promise as a memory enhancing agent in all the laboratory models employed.
authors.affiliation: Pharmacology Division, Department of Pharmaceutical Sciences, P.O. Box 38, Guru Jambheshwar University, Hisar 125001, Haryana, India. din_dhingra@yahoo.com
authors.forename: Dinesh
authors.initials: D
authors.lastname: Dhingra
authors.forename: Milind
authors.initials: M
authors.lastname: Parle
authors.forename: S K
authors.initials: SK
authors.lastname: Kulkarni
mesh_terms: D000284:Administration, Oral; D000647:Amnesia / Q000139:chemically induced / Q000517:prevention & control; D000818:Animals; D003975:Diazepam; D004305:Dose-Response Relationship, Drug; D006035:Glycyrrhiza; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects*; D051379:Mice; D018697:Nootropic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D018517:Plant Roots; D027343:Rhizome; D012601:Scopolamine
chemical_list: D018697:Nootropic Agents; D010936:Plant Extracts; D012601:Scopolamine; D003975:Diazepam