Curcumin Attenuates Amyloid-β Aggregate Toxicity and Modulates Amyloid-β Aggregation Pathway

Area of Science:

• Neuroscience
• Biochemistry
• Pharmacology

Background:

• Alzheimer's disease (AD) involves amyloid-β (Aβ) peptide misfolding and aggregation.
• Soluble Aβ oligomers are potent neurotoxins contributing to cognitive decline.
• Curcumin, a natural polyphenol, shows potential neuroprotection in AD, but its mechanism is unclear.

Purpose of the Study:

• Investigate curcumin's effects on Aβ40 aggregation.
• Determine curcumin's impact on Aβ40 aggregate-induced neurotoxicity.
• Elucidate the neuroprotective mechanisms of curcumin in AD.

Main Methods:

• Studied curcumin's influence on amyloid-β (Aβ40) aggregation kinetics.
• Assessed the neurotoxicity of Aβ40 aggregates in the presence of curcumin.
• Examined curcumin's effect on cell membrane permeabilization induced by Aβ.

Main Results:

• Curcumin did not inhibit Aβ40 fibril formation.
• Curcumin promoted the formation of non-toxic, off-pathway soluble Aβ oligomers and prefibrillar aggregates.
• Curcumin reduced Aβ-induced neurotoxicity across various Aβ conformers and decreased membrane permeabilization.

Conclusions:

• Curcumin exerts neuroprotection against Aβ toxicity through dual pathways.
• Curcumin modifies Aβ aggregation towards less toxic species.
• Curcumin offers non-specific neuroprotection, potentially by stabilizing cell membranes.