NFE2L2 and memory impairment: The beneficial effect of caffeine in reducing memory impairment by regulating the expression of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) or by regulating the expression of nuclear erythroid 2-related factor (Nrf2) and Toll-like receptor 4 (TLR 4)-induced glial cells-mediated neuronal cell death and neuroinflammation [46].