Polysaccharides improve cognitive impairment in mice: A meta-analysis

Area of Science:

• Neuroscience and Pharmacology
• Biochemistry and Molecular Biology

Background:

• Mild cognitive impairment (MCI) is a transitional stage between normal aging and dementia, characterized by deficits in cognition, behavior, and language.
• Polysaccharides (PS) are bioactive compounds with known immunomodulatory, anti-inflammatory, and antioxidant properties, and they can promote neuronal growth.

Purpose of the Study:

• To systematically review and meta-analyze existing research on the efficacy of polysaccharide (PS) extracts in improving cognitive and behavioral deficits in animal models of mild cognitive impairment (MCI).
• To evaluate the impact of PS extracts on behavioral performance and key biochemical indicators associated with MCI.

Main Methods:

• A comprehensive systematic search of electronic databases (PubMed, Web of Science, Cochrane Library, Embase, MEDLINE) was conducted up to April 2025.
• Included studies involved mouse models of MCI induced by various methods, comparing outcomes between PS extract treatment groups and control groups.
• Data were analyzed using a random effects model, adhering to Cochrane systematic review and PRISMA guidelines to assess intergroup heterogeneity.

Main Results:

• The meta-analysis included 84 studies across 9 mouse strains and over 40 types of PS, examining 6 mechanisms of action.
• PS treatment significantly improved performance in behavioral tests, including the Morris water maze (SMD=-2.19), Y-maze (SMD=0.12), and new object recognition test (SMD=0.2).
• Significant differences were observed in biochemical markers, with PS intervention positively affecting acetylcholinesterase activity, oxidative stress markers (superoxide dismutase and malondialdehyde), and anti-inflammatory effects compared to untreated MCI models.

Conclusions:

• Polysaccharide (PS) extracts demonstrate a significant capacity to enhance learning and cognitive functions in animal models of mild cognitive impairment (MCI).
• The therapeutic effects are attributed to multiple mechanisms, including the promotion of neuronal regeneration, and the exhibition of anti-inflammatory, antioxidant, and anti-protein aggregation properties.