閉経後女性におけるアルツハイマー病理の軽減におけるエストロゲンの神経保護の可能性の活用：レビュー

Alzheimer's disease (AD) is a progressive disorder that affects the brain and leads to cognitive decline and memory loss, with postmenopausal women being unduly affected. Estrogen is believed to exert neuroprotective effects by influencing amyloid-beta accumulation, tau hyperphosphorylation, oxidative stress, synaptic function, neuroinflammation, and brain-derived neurotrophic factor (BDNF) signalling. This review examines the role of estrogen in AD pathogenesis among postmenopausal women. A systematic literature search was conducted using PubMed, Scopus, and Web of Science. Keywords included "estrogen", "Alzheimer's disease", "neuroprotection", "amyloid-beta," and "BDNF." Inclusion criteria were peer-reviewed studies from the past 10 years focusing on estrogen's effects on AD mechanisms, neurobiology, and therapeutic relevance. Articles were screened by title and abstract. Followed by a full-text review to ensure methodological rigour and relevance. Evidence indicates that estrogen reduces amyloid beta burden, inhibits tau phosphorylation, mitigates oxidative stress, preserves synaptic connectivity, and suppresses neuroinflammation. Estrogen also modulates ApoE-linked lipid metabolism and enhances BDNF signalling, supporting neuronal survival and cognitive resilience. Declining estrogen after menopause increases vulnerability to AD. Understanding estrogen's neuroprotective mechanisms may support targeted therapeutic strategies. Hormone replacement therapy (HRT) and selective estrogen receptor modulators (SERMs) show potential, but further research is needed to optimise timing, dosage, and patient selection in postmenopausal AD prevention and management.