Overview
flowchart TD
Tocotrienols_in_Parkinson_s_Di["Tocotrienols in Parkinsons Disease Trial NCT0449"] -->|"references"| TH["TH"]
Tocotrienols_in_Parkinson_s_Di["Tocotrienols in Parkinsons Disease Trial NCT0449"] -->|"references"| SIRT1["SIRT1"]
style Tocotrienols_in_Parkinson_s_Di fill:#4fc3f7,stroke:#333,color:#000
This Phase 2 clinical trial investigates the neuroprotective potential of tocotrienols, a potent isoform of vitamin E, in patients with [Parkinson's disease](/diseases/parkinsons-disease). The study is conducted by the National Neuroscience Institute in Singapore and represents a promising approach to disease modification through a well-tolerated nutritional intervention.
Tocotrienols have garnered significant attention in neurodegenerative disease research due to their superior neuroprotective properties compared to the more commonly used tocopherols. The trial addresses a critical unmet need in Parkinson's disease care: disease-modifying therapies that can slow or halt disease progression rather than merely managing symptoms.
Trial Details
...Overview
Mermaid diagram (expand to render)
This Phase 2 clinical trial investigates the neuroprotective potential of tocotrienols, a potent isoform of vitamin E, in patients with [Parkinson's disease](/diseases/parkinsons-disease). The study is conducted by the National Neuroscience Institute in Singapore and represents a promising approach to disease modification through a well-tolerated nutritional intervention.
Tocotrienols have garnered significant attention in neurodegenerative disease research due to their superior neuroprotective properties compared to the more commonly used tocopherols. The trial addresses a critical unmet need in Parkinson's disease care: disease-modifying therapies that can slow or halt disease progression rather than merely managing symptoms.
Trial Details
| Field | Value |
|-------|-------|
| NCT ID | NCT04491383 |
| Status | Recruiting |
| Phase | Phase 2 |
| Study Type | Interventional |
| Allocation | Randomized |
| Intervention Model | Parallel Assignment |
| Masking | Double-Blind |
| Sponsor | National Neuroscience Institute, Singapore |
| Intervention | Tocotrienols (vitamin E isoform) |
| Enrollment | 60 participants |
| Start Date | June 2020 |
| Expected Completion | December 2025 |
| Location | Singapore |
Scientific Rationale
Oxidative Stress in Parkinson's Disease
[Oxidative stress](/mechanisms/oxidative-stress) is a central mechanism in Parkinson's disease pathogenesis. The substantia nigra pars compacta (SNc) of PD patients shows evidence of:
- Elevated ROS: Increased production of reactive oxygen species
- Lipid peroxidation: Enhanced membrane damage from oxidized lipids
- DNA oxidation: Oxidative DNA damage (8-OHdG accumulation)
- Protein oxidation: Carbonyl group formation on proteins
- Mitochondrial dysfunction: Complex I deficiency increases ROS
The dopaminergic neurons in the SNc are particularly vulnerable due to:
- High metabolic demand and oxygen consumption
- Dopamine metabolism generating ROS
- Neuromelanin accumulation
- Limited antioxidant capacity
Tocotrienol Advantages Over Tocopherols
Vitamin E exists in eight isoforms divided into two classes:
| Property | Tocopherols | Tocotrienols |
|----------|-------------|--------------|
| Saturated side chain | Yes | Unsaturated (3 double bonds) |
| Tissue distribution | Limited | Broad, including CNS |
| Antioxidant potency | Moderate | 10-50× more potent |
| Cholesterol-lowering | No | Yes |
| Neuroprotection | Limited | Enhanced |
The unsaturated side chain of tocotrienols provides several advantages[@gopalan2019]:
Enhanced membrane incorporation: Better integration into neuronal membranes
Superior antioxidant recycling: More efficient regeneration after oxidation
Broader tissue distribution: Crosses blood-brain barrier more effectively
Anti-inflammatory effects: Potent inhibition of NF-κB signalingMechanism of Action
Tocotrienols exert neuroprotective effects through multiple pathways[@khatri2011]:
Antioxidant Effects
- ROS scavenging: Direct neutralization of free radicals
- Lipid peroxidation inhibition: Prevents membrane damage
- Endogenous antioxidant enhancement: Upregulates SOD, catalase, glutathione peroxidase
- Metal chelation: Reduces iron-catalyzed oxidative damage
Anti-Inflammatory Effects
- NF-κB inhibition: Blocks pro-inflammatory transcription factor
- COX-2 downregulation: Reduces prostaglandin synthesis
- TNF-α modulation: Decreases pro-inflammatory cytokine production
- Microglial activation: Inhibits microglial-mediated neuroinflammation
Mitochondrial Protection
- Complex I preservation: Protects mitochondrial electron transport
- ATP maintenance: Preserves cellular energy production
- Apoptosis inhibition: Prevents mitochondrial pathway of cell death
- Mitophagy enhancement: Promotes clearance of damaged mitochondria
Neuroprotective Signaling
- AMPK activation: Enhances cellular stress resilience
- mTOR modulation: Promotes autophagy
- SIRT1 activation: Supports cellular longevity pathways
- FOXO3a deacetylation: Enhances antioxidant gene expression
Additional Mechanisms
- NMDA receptor modulation: Reduces excitotoxicity
- Calcium homeostasis: Stabilizes intracellular calcium
- Autophagy induction: Enhances protein aggregate clearance
- Synaptic protection: Preserves synaptic function
Study Design
Treatment Arms
| Arm | Intervention | Dose | Duration |
|-----|-------------|------|----------|
| Active | Tocotrienols (mixed isoforms) | TBD | 12 months |
| Placebo | Matching placebo | N/A | 12 months |
Inclusion Criteria
Diagnosis: Idiopathic Parkinson's disease (UK Brain Bank criteria)
Disease stage: Hoehn & Yahr stage 1-3
Age: 40-80 years
Medication: Stable PD medication for ≥4 weeks
Cognitive status: MMSE ≥24Exclusion Criteria
Allergy: Known vitamin E allergy
Bleeding disorders: History of bleeding diathesis
Anticoagulation: Current anticoagulant therapy
Supplements: Concurrent antioxidant supplements
Neurological: Severe cognitive impairment (MMSE <24)
Medical: Significant hepatic or renal diseaseOutcome Measures
Primary Endpoints
Motor Function
- Unified Parkinson's Disease Rating Scale (UPDRS) Part III
- Change from baseline to 12 months
- Assessed in OFF and ON medication states
- Administered by certified raters
Safety Assessment
- Adverse event monitoring
- Vital signs
- Laboratory values (lipid panel, liver function)
- Bleeding risk assessment
Secondary Endpoints
Quality of Life
- PDQ-39: Parkinson's Disease Questionnaire-39
- MDS-UPDRS Parts I, II, IV: Non-motor experiences, daily activities, motor complications
Cognitive Function
- MoCA: Montreal Cognitive Assessment
- Trail Making Test: Executive function assessment
Biomarker Analysis
- Oxidative stress markers:
- 8-OHdG (DNA oxidation)
- Malondialdehyde (lipid peroxidation)
- Total antioxidant capacity
- Inflammatory markers:
- IL-6, TNF-α
- Neurodegeneration markers:
- Neurofilament light chain (NfL)
Neuroimaging (in subset)
- DaT SPECT imaging
- MRI volumetric analysis
Preclinical Evidence
Animal Model Studies
Tocotrienols have demonstrated neuroprotection in multiple PD models[@peng2012]:
| Model | Findings |
|-------|----------|
| MPTP model | Preserved TH+ neurons, improved behavior |
| 6-OHDA model | Reduced lesion volume, enhanced DA release |
| Alpha-synuclein transgenic | Reduced aggregation, improved survival |
| Rotenone model | Restored mitochondrial function |
Mechanism Studies
- Reduced lipid peroxidation in substantia nigra
- Preserved complex I activity
- Decreased microglial activation
- Enhanced autophagy flux
- Reduced alpha-synuclein aggregation
Clinical Evidence Context
Vitamin E and PD Risk
Epidemiological studies have examined vitamin E and Parkinson's disease risk[@molinuevo2020]:
| Study | Finding |
|-------|---------|
| Health Professionals Follow-up | High vitamin E intake associated with reduced PD risk |
| Nurses' Health Study | Moderate association |
| Finnish Mobile Clinic | No significant association |
| Meta-analysis | Possible protective effect for dietary vitamin E |
Note: These studies largely examined tocopherols; tocotrienols have not been studied as extensively in humans.
Safety Profile
Tocotrienols have a favorable safety profile at typical doses:
| Adverse Event | Frequency | Notes |
|--------------|-----------|-------|
| Gastrointestinal upset | Rare | Usually mild |
| Bleeding risk | Theoretical | Monitor in anticoagulated patients |
| Headache | Rare | Usually transient |
Maximum tolerated dose in humans: ~1000mg/day
Expected Outcomes and Clinical Significance
Primary Expected Outcomes
Motor function preservation: Slower UPDRS progression vs. placebo
Safety confirmation: Favorable safety profile in PD population
Biomarker response: Reduction in oxidative stress markersClinical Implications
If successful, this trial would establish:
- Disease-modifying option: First disease-modifying nutritional intervention
- Accessible therapy: Low-cost, widely available treatment
- Combination potential: Synergy with dopaminergic medications
- Prevention approach: Potential for use in prodromal PD
Comparison to Other Neuroprotective Trials
| Trial | Intervention | Target | Status |
|-------|-------------|--------|--------|
| NCT04491383 | Tocotrienols | Antioxidant | Recruiting |
| NCT06162013 | NAD+ precursors | Metabolic | Recruiting |
| INMOND | Inosine | Urate | Completed |
| TIRAMISU | Talidomide analogs | Neuroinflammation | Terminated |
Cross-References
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Oxidative Stress in PD](/mechanisms/oxidative-stress-pd)
- [Neuroinflammation Mechanism](/mechanisms/neuroinflammation)
- [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)
- [Vitamin E and Neuroprotection](/therapeutics/vitamin-e-pd)
- [Tocotrienols as Dietary Supplements](/nutrients/tocotrienols)
- [Alpha-Synuclein Aggregation](/proteins/alpha-synuclein)
External Links
- [ClinicalTrials.gov - NCT04491383](https://clinicaltrials.gov/study/NCT04491383)
- [National Neuroscience Institute Singapore](https://www.nni.com.sg/)
- [Michael J. Fox Foundation - PD Research](https://www.michaeljfox.org/)
- [Parkinson's Foundation](https://www.parkinson.org/)
References
[NCT04491383 - Tocotrienols in PD](https://clinicaltrials.gov/study/NCT04491383)
[Gopalan et al., Tocotrienols as neuroprotective agents (2019)](https://pubmed.ncbi.nlm.nih.gov/31154876/)
[Khatri et al., Tocotrienols in neurodegenerative disease models (2011)](https://pubmed.ncbi.nlm.nih.gov/21947823/)
[Peng et al., Tocotrienol rich fraction in PD models (2012)](https://pubmed.ncbi.nlm.nih.gov/22429462/)
[Molinuevo et al., Vitamin E and Parkinson's disease risk (2020)](https://pubmed.ncbi.nlm.nih.gov/32855341/)See Also
- [SIRT1 Gene](/wiki/genes-sirt1) — references
- [TH Gene](/wiki/genes-th) — references