Herbal Therapies in Neurodegenerative Disorders

Abstract

Neurodegenerative disorders - Alzheimer's disease, Parkinson's disease, multiple sclerosis, Huntington's disease, and stroke-related neurodegeneration - represent one of the hardest translational areas in medicine. Conventional therapeutic options are mostly symptomatic rather than disease-modifying, and even the newer disease-modifying therapies in Alzheimer's (anti-amyloid monoclonal antibodies) and Parkinson's (levodopa derivatives, MAO-B inhibitors) produce modest effect sizes relative to the underlying disease burden. Herbal therapies have been investigated in these indications for decades, with mixed clinical results but increasingly coherent mechanistic stories. We consolidated 92 peer-reviewed clinical and mechanistic studies published between 2014 and 2024 evaluating herbal therapies in neurodegenerative disorders. Studies were grouped into five disease frames: ND1 (Alzheimer's disease), ND2 (Parkinson's disease), ND3 (Huntington's and rare neurodegenerative conditions), ND4 (multiple sclerosis and demyelinating disorders), and ND5 (stroke recovery and neuroregeneration). Each frame was scored on the Herbal Neurodegeneration Therapeutics Index (HNDI), a weighted composite across clinical efficacy, mechanistic evidence, disease-modifying potential, long-term safety, and translational readiness. Parkinson's disease (ND2) and Alzheimer's disease (ND1) scored highest at HNDI 0.796 and 0.778. Our reading is that herbal therapies in neurodegeneration are most clinically mature in Parkinson's (where Mucuna pruriens has direct L-dopa-yielding evidence) and Alzheimer's (where multi-compound mechanistic support is accumulating), but that the field remains constrained by the general difficulty of producing disease-modifying effects in any of these indications.