Siam_2026_Scientifica.(Cairo)_2026_6124916

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by beta-amyloid deposition, tau hyperphosphorylation, mitochondrial dysfunction, oxidative stress, neuroinflammation, and blood-brain barrier disruption, collectively leading to widespread cortical and subcortical atrophy. Current FDA-approved pharmacotherapies, including acetylcholinesterase inhibitors and memantine, provide only modest symptomatic relief and fail to halt disease progression, underscoring the urgent need for alternative therapeutic approaches. Growing evidence highlights medicinal plants and their bioactive phytoconstituents as promising candidates for AD prevention and treatment because of their multitarget mechanisms, favorable safety profiles, and long history of traditional use. This review synthesizes extensive in vitro, in vivo, and clinical studies demonstrating the neuroprotective potential of plant extracts and isolated compounds that exert antioxidant, anti-inflammatory, antiamyloidogenic, anti-tau, cholinesterase-inhibitory, and synaptic-modulating effects. Key medicinal species, including Abelmoschus esculentus, Brassica oleracea, Cannabis sativa, Citrus reticulata, Lantana camara, Launaea taraxacifolia, Lawsonia inermis, Marrubium vulgare, Markhamia lutea, Persicaria minor, Pithecellobium dulce, Salvia aristata, Trigonella foenum-graecum, and Withania somnifera, show significant cognitive and neuroprotective benefits in experimental AD models. Phytochemicals such as sulforaphane, nobiletin, trigonelline, diosgenin, verbascoside, withaferin A, and withanolides strongly modulate the amyloid, tau, oxidative, and inflammatory pathways. Clinical trials further support the therapeutic potential of several plant-derived interventions for mild cognitive impairment and AD-related dementia. Collectively, these findings highlight medicinal plants and their active constituents as compelling complementary or translational strategies for AD management, warranting further mechanistic and clinical validation. This review aims to evaluate the neuroprotective potential of medicinal plants and their bioactive compounds in preventing and managing AD by summarizing evidence from in vitro, in vivo, and clinical studies.