Evaluation of anxiolytic effect of Medicago sativa in mice

Medicago sativa Linn. (Leguminosae) has a long tradition of use as an Ayurvedic and Homoeopathic medicine in a variety of central nervous system (CNS) disorders. Traditionally, M. sativa is used to improve the memory, as a rejuvenator, antidiabetic, antioxidant, anti-inflammatory, and in CNS disorders. Despite a long tradition of use, no systematic phytochemical and pharmacological work has been carried out on this potential plant. M. sativa was subjected to preliminary anti-anxiety screening studies, with a view to ascertain the verity of its traditional use as an anxiolytic.

Various extracts, viz., petroleum ether, chloroform, methanol and aqueous extract from the aerial parts of M. sativa was subjected to preliminary anti-anxiety screening studies, with a view to ascertain the truth on evidence of its traditional use as an anxiolytic.

The aerial parts of the plant were extracted using solvents in order of increasing polarity, viz., petroleum ether (60-80 °C), chloroform, methanol and distilled water. All the crude extracts were evaluated for anti-anxiety activity in mice using elevated plus-maze apparatus. Diazepam was used as the standard drug.

Among all extracts, only the methanol extract exhibited significant (p < 0.05) anti-anxiety activity by increasing the average time spent, and number of entries in open arms at a dose of 100 mg/kg in mice with respect to the vehicle treated control as well as the standard (2 mg/kg).

These results suggest that administration of M. sativa exerts anxiolytic effect on mice, and it could serve as a new approach for the treatment of anxiety.