Hence, isoflavones significantly boost cholinergic function in the hippocampus, suppress the level of oxidative stress, and increase the expression of extracellular signal-regulated kinase (ERK), brain-derived neurotrophic factor (BDNF), and cAMP response element binding (CREB) protein, thereby exhibiting a neuroprotective effect against scopolamine-induced memory impairment [55,61]. Here, BDNF is linked to memory impairment.