New Research Suggests: Lentinan from Shiitake Mushrooms Could Be a New Hope for Combating Alzheimer’s and Parkinson’s Diseases

Shiitake mushrooms, a common edible fungus, are not only delicious but also rich in nutritional value. Recently, a research team from Tianjin University of Science and Technology published a paper in the international journal ACS Chemical Neuroscience, unveiling the potential of lentinan (a polysaccharide from shiitake mushrooms) in combating Alzheimer’s disease (AD) and Parkinson’s disease (PD).

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are two common neurodegenerative diseases. Their pathological characteristics include the misfolding and aggregation of β-amyloid (Aβ) and α-synuclein (α-syn), respectively, which are closely related to amyloid plaques in AD and Lewy bodies in PD. In recent years, various natural inhibitors have been explored to combat the aggregation of these proteins in the search for effective treatments.

The research team conducted in vitro experiments to evaluate the effects of lentinan on the fibril formation of Aβ and α-syn and validated its efficacy in animal models through in vivo experiments.

Key Findings:

1. Inhibition of Protein Aggregation:

   • Lentinan significantly inhibited the fibril formation of Aβ and α-syn.
   • Observations through ThT fluorescence assays and atomic force microscopy (AFM) showed that lentinan effectively broke down preformed fibrils into smaller aggregates.

2. Reduced Cytotoxicity and Improved Cell Viability:

   • The disintegration of mature fibrils led to a significant reduction in cytotoxicity and an increase in cell survival rates.
   • The fluorescence intensity of Aβ40 fibrils decreased by 62.63%, while that of α-syn fibrils reduced by 54.47%.

3. Improved Survival in Animal Models:

   • In AD model nematodes (C. elegans, strain CL4176), lentinan extended the median survival time from 6 days to 8 days and the maximum lifespan from 11 days to 14 days.
   • In PD model nematodes (strain NL5901), lentinan increased the median survival time from 7 days to 9 days and the maximum lifespan from 11 days to 16 days.

4. Improved Symptoms in Mouse Models:

   • In AD model mice, lentinan significantly improved spatial memory impairments induced by Aβ42 injections.
   • In PD model mice, lentinan alleviated motor dysfunction caused by MPTP induction.

The study demonstrated that lentinan effectively inhibited Aβ and α-syn fibril aggregation in both in vitro and in vivo experiments, while also mitigating the neurotoxicity and behavioural deficits caused by these aggregates.

Implications:

These findings suggest that lentinan could serve as a potential therapeutic agent for preventing and treating AD and PD. This research provides new insights into the application of natural polysaccharides in managing neurodegenerative diseases.

With the rising global prevalence of Alzheimer’s and Parkinson’s diseases, finding effective preventive and therapeutic strategies has become increasingly important. This study not only offers valuable guidance for clinicians but also presents a new perspective to the public: incorporating natural foods like shiitake mushrooms into the diet could help detect and address potential health risks early.

It is hoped that more people will recognise this potential and take proactive steps to improve their overall health.