Curcumin and Retinal Study

Curcumin and Retinal Amyloid-beta Pilot Study

To test how two weeks of curcumin supplementation would cross the blood brain barrier (BBB) and attach to amyloid beta proteins, to assess the feasibility (safety and bioavailability), and to explore the resulting abundance/composition of gut microbiota.

Study Overview

• Status: Recruiting
• Conditions: Bioavailability; Safety; Gut Microbiome
• Intervention / Treatment: Drug: Low curcumin group; Drug: High curcumin group

Detailed Description

Alzheimer's disease (AD) leads to progressive cognitive decline. Increased amyloid beta (Aβ) burden and Aβ deposits have been shown in the AD retina. Aβ accumulation inside retinal pericytes in AD and pericyte degeneration in the retina mirror prominent features of brain AD pathology. Curcumin, a derivative of turmeric, has a high affinity for amyloid beta. Thus, curcumin would bind to amyloid beta plaques and emit a strong fluorescent signal, suggesting it can be a powerful diagnostic tool for AD. Emerging evidence has shown the connection between the brain and GI tract (gut microbiome), and its potential implications for both metabolic and neurologic diseases including AD. This pilot study is to test how two weeks of curcumin supplementation would cross the blood brain barrier and attach to amyloid beta proteins and to explore the resulting abundance/composition of gut microbiota. The investigators plan to recruit subjects through direct person-to-person solicitation in the Ophthalmology clinics, health fairs, community events, flyers, non-solicited email system, campus announcements, Clinical Research Institute Volunteer Database website, local radio, newspapers, senior newsletters, and TV scripts. The Clinical Research Institute Volunteer database will also be queried and potential subjects contacted as requested in their form. The investigators plan to enroll approximately 100-150 patients to obtain 30-40 qualified subjects at the start of the study. After screening, qualified participants will be randomly assigned to a low curcumin group or high curcumin group. Thus, this pilot study would focus on characterizing the distribution, manifestation, and prevalence of curcumin-loaded retinal Aβ deposits in study subjects with existing Aβ plaque (primary outcome). In addition, this study will assess safety, bioavailability, and fecal microbiome composition (secondary outcome). All outcomes will be assessed at baseline and after 2 weeks of intervention. Data will be analyzed statistically.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Chwan-Li (Leslie) Shen, PhD; Phone Number: 8067432815; Email: leslie.shen@ttuhsc.edu

Study Locations

• United States
  • Texas
    • Lubbock, Texas, United States, 79430
      • Recruiting
      • Texas Tech University Health Sciences Center
      • Contact: Chwan-Li (Leslie) Shen, PhD; Phone Number: 806-743-2815; Email: Leslie.Shen@ttuhsc.edu
      • Principal Investigator: Chwan-Li (Leslie) Shen, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 89 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion:

• Both male and female, age 40 - 89 years.
• Diagnosed with Aβ deposits in retina (peripheral superior quadrants)--to be confirmed after consent obtained. If there is documentation the potential participant has been diagnosed with Aβ deposits in retina within 6 months before the consent session, we will use this diagnosis/documentation for eligibility criteria. Otherwise, the ophthalmic exam will be repeated after consent is obtained for the study.
• No pre-existing liver or kidney diseases by self-report.

Exclusion:

• Patients with ocular diseases (macular degeneration, severe diabetes retinopathy)
• Had used systemic antibiotics within 1 month prior to the start of the study intervention
• Had taken any turmeric or curcumin products within 2 weeks prior to the start of the study intervention
• Had a known allergy to black pepper
• Women that are pregnant or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Low curcumin group	Drug: Low curcumin group; One curcumin capsule (250 mg curcumin) after each meal, 3 times a day for 2 weeks.
Active Comparator: High curcumin group	Drug: High curcumin group; One curcumin capsule (500 mg curcumin) after each meal, 3 times a day for 2 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retinal imaging- amyloid fluorescent intensity	To access amyloid fluorescent intensity	Baseline
Retinal imaging-amyloid fluorescent deposit number	To access amyloid fluorescent deposit number	Baseline
Retinal imaging-amyloid fluorescent location	To access amyloid fluorescent location	Baseline
Retinal imaging-amyloid fluorescent intensity	To access amyloid fluorescent intensity	After 2 weeks
Retinal imaging-amyloid fluorescent deposit number	To access amyloid fluorescent deposit number	After 2 weeks
Retinal imaging-amyloid fluorescent location	To access amyloid fluorescent location	After 2 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Bioavailability- curcumin concentrations in plasma	To measure curcumin concentrations in plasma	Baseline
Bioavailability-curcumin concentrations in red blood cells	To measure curcumin concentrations in red blood cells	Baseline
Bioavailability-curcumin concentrations in plasma	To measure curcumin concentrations in plasma	After 2 weeks
Bioavailability-curcumin concentrations in red blood cells	To measure curcumin concentrations in red blood cells	After 2 weeks
Liver function-serum AST	To assess serum AST	Baseline
Liver function-serum ALT	To assess serum ALT	Baseline
Kidney function-serum BUN	To assess serum BUN	Baseline
Liver function-serum ALT	To assess serum ALT	After 2 weeks
Kidney function-serum BUN	To assess serum BUN	After 2 weeks
Gut microbiome-abundance	To measure the abundance of intestinal bacterial in feces	Baseline
Gut microbiome-composition	To measure the composition of intestinal bacterial in feces	Baseline
Gut microbiome-abundance	To measure the abundance of intestinal bacterial in feces	After 2 weeks
Gut microbiome-composition	To measure the composition of intestinal bacterial in feces	After 2 weeks

Collaborators and Investigators

• Sponsor: Texas Tech University Health Sciences Center
• Investigators: Principal Investigator: Chwan-Li (Leslie) Shen, PhD, Texas Tech University Health Sciences Center

Study record dates

Study Major Dates

• Study Start (Actual): August 21, 2023
• Primary Completion (Estimated): March 31, 2025
• Study Completion (Estimated): March 31, 2025

Study Registration Dates

• First Submitted: February 23, 2023
• First Submitted That Met QC Criteria: March 15, 2023
• First Posted (Actual): March 20, 2023

Study Record Updates

• Last Update Posted (Actual): August 24, 2023
• Last Update Submitted That Met QC Criteria: August 21, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Enzyme Inhibitors; Analgesics; Sensory System Agents; Anti-Inflammatory Agents, Non-Steroidal; Analgesics, Non-Narcotic; Anti-Inflammatory Agents; Antirheumatic Agents; Antineoplastic Agents; Curcumin
• Other Study ID Numbers: Curcumin-Retinal Pilot Study

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No