Beneficial effect of aqueous root extract of Glycyrrhiza glabra on learning and memory using different behavioral models: An experimental study

BACKGROUND: In the traditional system of medicine, the roots and rhizomes of Glycyrrhiza glabra (Gg) (family: Leguminosae) have been studied for their ability to improve a variety of health ailments. AIMS: The present study was designed to investigate the beneficial effects of Gg root extract on learning and memory in 1-month-old male Wistar albino rats. Four doses (75, 150, 225, and 300 mg/kg) of aqueous extract of root of Gg was administered orally for six successive weeks. MATERIALS AND METHODS: The aqueous extracts were evaluated for their effect on spatial learning and memory in rats using the elevated plus maze, Hebb–William maze, and Morris water maze tests which served as the exteroceptive behavioral model. Diazepam-induced amnesia served as the interoceptive behavioral model. RESULTS: Results showed that all the doses of aqueous root extract of Gg significantly enhanced the memory; however, in the doses of 150 and 225 mg/kg, it showed a significant (P < 0.01) enhancement in learning and memory. Furthermore, Diazepam-induced amnesia was reversed by the aqueous root extract of Gg (150 and 225 mg/kg, p.o.). CONCLUSION: These findings suggest that the memory enhancement effects of Gg may be mediated by its antioxidant and anti-inflammatory activities. Thus, Gg appears to be a promising drug for improving memory in the management of impaired learning, dementia, Alzheimer's disease, and other neurodegenerative disorders.