Plant-derived therapies in Parkinson's disease: a systematic review of clinical evidence
In brief
Mucuna pruriens matches levodopa for motor gains and adds ON time
In a systematic review of 23 trials, the bean extract Mucuna pruriens showed Grade A evidence for improving motor symptoms, delivering benefits comparable to standard levodopa while extending ON time and not worsening dyskinesia. Other botanicals (celery, turmeric, bacopa, soy, cannabis) showed modest, symptom-specific effects, but overall evidence remains limited and calls for larger randomized trials.
- Journal
- Journal of neural transmission (Vienna, Austria : 1996) (Q1)
- Published
- 23 July 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Narumol Sukmueng, Onanong Phokaewvarangkul, Roongroj Bhidayasiri
- PMID
- 42489905
- DOI
- 10.1007/s00702-026-03239-4
Why clinicians should know about it
- Picked for Complementary and Alternative Medicine (top studies of the week, 26 July 2026): Systematic review of RCTs on plant-derived PD therapies
- Picked for Neurology (clinical) (top studies of the week, 26 July 2026).
Abstract
Levodopa remains the cornerstone of Parkinson's disease (PD) treatment; however, long-term use is associated with motor complications, including fluctuations and dyskinesia. Non-motor symptoms also worsen over time, reflecting both disease progression and treatment-related effects. These limitations have prompted interest in plant-derived therapies as potential adjunctive options, although clinical evidence remains unclear. To systematically review clinical evidence on plant-derived therapies in PD, focusing on motor symptoms, non-motor symptoms, and motor complications. PubMed, Scopus, and ScienceDirect were searched to identify eligible studies assessing plant-derived therapies for PD. Risk of bias and evidence classification were assessed using established methods. The review followed PRISMA 2020 guidelines and was registered in PROSPERO (CRD420261276805). Twenty-three included studies evaluated six plant-derived therapies. Mucuna pruriens was supported by Grade A evidence for motor improvement, with benefits comparable to levodopa and increased ON time without worsening dyskinesia. It also reduced dyskinesia (Grade B). Apium graveolens improved motor symptoms, sleep, and quality of life (Grade B). Curcuma longa improved autonomic and non-motor symptoms (Grade C). Bacopa monnieri improved emotional symptoms (Grade B). Glycine max increased ON time and reduced dyskinesia (Grade C). Cannabis sativa showed no motor benefit (Grade A), with inconclusive non-motor outcomes. Selected plant-derived therapies may offer symptom-specific benefits in PD. However, the available evidence is limited, and grading reflects study hierarchy rather than the certainty of clinical effect. Therefore, interpretation of this information should be cautious. Larger, well-designed randomised trials are required to confirm efficacy and safety.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.