Vol. 7, Issue 2, Part C (2025)

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder characterised by cognitive deterioration, synaptic dysfunction, and irreversible neuronal loss, representing a major global health burden. Despite decades of research, currently available pharmacotherapies offer only symptomatic relief and fail to halt disease progression, highlighting the urgent need for novel, disease-modifying interventions. In this context, marine algae have emerged as a promising yet underexplored source of neuroprotective agents owing to their unique phytochemical composition and ecological adaptation to extreme marine environments. The present narrative review critically evaluates the phytopharmacological potential of marine algae in the prevention and management of Alzheimer’s disease, emphasising experimental evidence reported between 2015 and 2025.
Marine macroalgae, including green (Chlorophyta), brown (Phaeophyceae), and red (Rhodophyta) species, are rich reservoirs of structurally diverse bioactive compounds such as phlorotannins, sulfated polysaccharides, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids. These metabolites have demonstrated multifaceted neuroprotective effects through mechanisms relevant to Alzheimer’s pathology, including inhibition of acetylcholinesterase activity, attenuation of β-amyloid aggregation, modulation of tau hyperphosphorylation, suppression of neuroinflammation, and mitigation of oxidative stress-induced neuronal damage.
This review synthesizes decade-long evidence from in vitro assays, animal models, and limited translational studies, presenting a chronological narrative of scientific progress in this domain. Additionally, it discusses mechanistic insights, pharmacological relevance, safety considerations, and translational challenges associated with marine algal therapeutics. By integrating phytochemical diversity with neurobiological mechanisms, this review aims to provide a comprehensive academic resource and highlight marine algae as viable candidates for future neuroprotective drug discovery in Alzheimer’s disease.