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.