To investigate the cognition-enhancing effects of aqueous extract of Indigofera tinctoria Linn
(ITE, Fabaceae) in experimental amnesic mice.
Scopolamine (2 mg/kg, i.p.) was used to induce amnesia in mice. The cognitive-enhancing
activity of the ITE (5, 10 and 20 μg/mL) was studied by passive avoidance response, elevated plus
maze and Y-maze behavioral paradigm in normal and scopolamine-induced amnesic mice. Antioxidant
activities were also determined based on the ability of ITE to inhibit lipid peroxide, superoxide and
Scopolamine-induced cognitive deficits were significantly reversed by ITE (p < 0.001 at 20
mg/kg) in a dose-dependent fashion in all the behavioral paradigms tested. Furthermore, ITE dosedependently
scavenged lipid peroxide, superoxide and hydroxyl free radicals with 50 % inhibition
concentration (IC50) of 7.28 ± 0.37, 5.25 ± 0.28 and 7.62 ± 0.43 μg/mL, respectively.
ITE possesses cognitive-enhancing properties in amnesic mice due to its potent