Tau Protein: Bridging Neurobiology to Multifaceted Pathologies and Therapeutic Interventions in Herbal Medicine

Microtubule-associated proteins (MAPs), including MAP1, MAP2, MAP4, and the tau protein family, are essential for interactions with the cytoskeleton’s “microtubules.” These “microtubules” play a key role in maintaining cell shape, promoting growth, and facilitating signalling, all of which are influenced by the stabilizing or destabilizing actions of MAPs. Although different cells express different MAP types, tau is prominent in neuropathologies. Abundant in neuronal axons, tau stabilizes microtubule bundles, which are crucial for microtubule dynamics, along with other destabilizing MAPs, such as stathmin. Tauopathies are characterized by the accumulation of tau within cells, forming neurofibrillary tangles (NFTs) due to abnormal, excessive phosphorylation accompanied by neuroinflammation and disruption of the blood-brain barrier (BBB). Inflammatory responses can alter capillary structure, compromise BBB function, and facilitate immune cell infiltration. Additionally, inflammation leads to morphological changes in capillaries, including pericyte atrophy and fragmentation, increased laminin levels in the basement membrane, and enhanced permeability of blood vessels to plasma proteins. Tau “hyperphosphorylation” occurs transiently during hypothermia and anesthesia but is implicated in various pathologies. In addition to neuropathologies, tau is linked to diabetes, cancer, hypertension, and multiple sclerosis. Compared to other MAPs, Tau families are widely implicated in diverse disease pathologies. This review explores the role of Tau in various diseases and the potential of herbal remedies for clearing Tau aggregation.