Astaxanthin as an adjunct therapy in Alzheimer's disease and multiple sclerosis: neuroprotective mechanisms and future perspective.

Background: Alzheimer's disease (AD) and Multiple sclerosis (MS) are progressive neurodegenerative conditions. AD is characterized by neuroinflammation, plaques, tangles, and synaptic loss, while MS involves inflammatory demyelination. Although AD and MS have different pathogenesis, they may share some neurodegenerative mechanisms, so similar therapeutic strategies could potentially be effective for both. Research suggests that natural substances such as carotenoids may be beneficial for neurological disorders. Notably, Astaxanthin (AXT) has demonstrated promising effects as an adjunct therapy.

Methods: In this review, we aimed to shed light on the effects of AXT on MS and AD by searching published articles from inception to 1 August 2024, in the Scopus, Google Scholar, PubMed, and PubMed/Medline databases.

Results: The therapeutic effects of AXT in neurodegenerative disorders are associated with its antioxidant, anti-inflammatory, anti-apoptotic, and neuroplasticity improvement properties. Literature have confirmed that AXT can positively impact AD by modulating anti-inflammatory and pro-inflammatory cytokines, mitochondrial function, amyloid beta production, and microglial activation, which collectively leads to memory and learning enhancement. Additionally, AXT has demonstrated advantages in MS by reducing demyelination and preserving nerve functions through its effects on pro- and anti-inflammatory cytokines, as well as promoting the differentiation of oligodendrocyte precursors into mature oligodendrocytes.

Conclusion: AXT, as a promising versatile adjunctive neuroprotective therapy, can influence multiple recovery pathways rather than focusing on a single target or mechanism. According to the results of preclinical studies, we can recommend assessing AXT effects in clinical trials of AD and MS.