Neurodegenerative diseases (NDDs) are recognized by the World Health Organization as the second leading cause of mortality worldwide, and their prevalence continues to rise at an alarming rate. Current treatment strategies primarily provide symptomatic relief without effectively targeting the complex and multifactorial pathogenesis of NDDs, which involves oxidative stress, neuroinflammation, mitochondrial dysfunction, and abnormal protein aggregation. Therefore, there is an urgent need for novel, multi-target therapeutic strategies. In recent years, marine biodiversity has gained growing attention as a rich reservoir of pharmacologically active natural products. Marine algae, in particular, contain diverse bioactive metabolites including polyphenols, polysaccharides, carotenoids, and phlorotannins, many of which exhibit potent neuroprotective properties. To address the existing knowledge void and limitations, we propose to present a thorough review that updates information on the neuroprotective effects of marine algal compounds and their therapeutic advancements. For this, about 31800 articles were reviewed via databases like PubMed, Science Direct, Google Scholar, and Web of Science. They were reduced to 1263 using MeSH words like 'marine algae, neurodegeneration, and neuroprotection' coupled with Boolean operators. The compiled findings demonstrated that marine algal compounds modulate multiple neuroprotective pathways, including PI3K/Akt, Nrf2/HO-1, and PKA/CREB/BDNF, and exert antioxidant, anti-inflammatory, anti-amyloidogenic, and neurotrophic effects. These multifaceted mechanisms highlight their potential in mitigating key pathological processes associated with NDDs. In conclusion Marine algae represent a promising yet underexplored source of phytotherapeutic agents. Further preclinical and clinical investigations are warranted to validate their efficacy and advance their development as potential neuroprotective therapeutics.
