Memory-Enhancing Effects of Daidzin, Possibly Through Dopaminergic and AChEergic Dependent Pathways.

The soy isoflavone daidzin (DZN) possesses cognitive-enhancing effects in animals. However, the mechanism for this effect is yet to be discovered. For this, we investigate its memory-enhancing capacity using the mouse models of marble burying, dust removal, an open-field study, and in silico studies. Adult male Swiss albino mice were randomly assigned to different groups consisting of control (vehicle: 10 mL/kg), DZN 5, 10, and 20 mg/kg, dopamine (agonist: 22 mg/kg), galantamine (inhibitor: 3 mg/kg), and a combination of DZN-10 with standards. DZN dose-dependently and significantly (P < 0.05) increased marble burying and removed dust while decreasing the total distance in the open-field test (OFT). DZN-10 enhanced dopamine's effect significantly (P < 0.05). In silico findings suggest that DZN has strong binding capacities of -10.3, -7.5, -9.8, and -9.2 kcal/mol to the acetylcholinesterase (AChE), D₁, D₃, and D₅ receptors, respectively. Taken together, DZN may exert its memory-enhancing ability by interacting with AChE and dopamine receptors.