Natural products against tau hyperphosphorylation-induced aggregates: Potential therapies for Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and memory impairments and is considered the most prevalent form of dementia. Among the contributing factors to AD lies the hyperphosphorylation of the microtubule-associated protein tau. Phosphorylated tau reduces its affinity for microtubules and triggers other posttranslational modifications that result in its aggregation and assembly into filaments. These structures progressively accumulate within neurons leading to neurodegeneration. While current AD medications often involve undesirable side effects, the exploration of natural products as a potential therapeutic alternative has gained considerable attention. Numerous compounds have shown potential capacity for reducing tau pathology through different mechanisms, such as inhibiting kinases to reduce tau hyperphosphorylation, enhancing phosphatase activity, and blocking fibril formation. Since tau hyperphosphorylation-induced aggregation is pivotal in AD onset, this review aims to elucidate the potential of natural products in modulating this crucial molecular mechanism.