Effect of Sulforaphane-rich Broccoli Sprout Homogenate on Ozone Induced Inflammation Through Modulation of NRF2 (BroccOz)
|Healthy||Dietary Supplement: Broccoli sprout homogenate Dietary Supplement: alfalfa sprout homogenate|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
|Official Title:||Down Regulation of Oxidant Induced Airway Inflammation Through Modulation of NRF2|
- Change in % neutrophils in induced sputum, comparing the 4 hr post O3 placebo v. SFN treatment periods. [ Time Frame: baseline, 4 and 24 hours post exposure ]Induced sputum will be collected and % neutrophils will be measured after each exposure and will be compared to baseline and to each other.
- Spirometry (FEV1, FVC, FEF25-75) for assessment of changes in lung function [ Time Frame: prior to and after exposures ]Lung function testing will be performed prior to, after and 24 hours post exposure
- SFN levels [ Time Frame: at baseline (sputum & plasma); immediately before the O3 exposure (plasma), 4 hours & 24 hours post O3 (sputum & plasma). ]Sulforaphane levels will be measured in blood and sputum at predetermined intervals
- Cytokine concentration and flow cytometric assessment of surface markers in sputum supernatants [ Time Frame: baseline, 4 and 24 hours post exposure ]GM-CSF, IL-1β, IL-6, IL-8, IL-10, IL-12p70, TNF-α, PGE2
- mRNA expression of NRF2 and phase II antioxidant enzymes in nasal epithelial cells and in induced sputum macrophages [ Time Frame: baseline and 1 hour (nasal epithelial cells only) 4 and 24 hours post exposure (sputum) ]GSTM1, GSTP1, NQO1, and HO1)
|Study Start Date:||October 2013|
|Study Completion Date:||June 2015|
|Primary Completion Date:||May 2015 (Final data collection date for primary outcome measure)|
Active Comparator: broccoli sprout homogenate (BSH)
Two hundred grams of BSH is equivalent to approximately 111 grams fresh sprouts (about one 4 oz package). Commercially available Broccosprouts® (Brassica Protection Products LLC) will be homogenized with water.
Dietary Supplement: Broccoli sprout homogenate
Commercially available Broccosprouts® (Brassica Protection Products LLC) will be homogenized with water using a ratio of 1:1.2 in a clean blender. The homogenate will then be frozen in aliquots at -20 degrees C.
Other Name: Broccosprouts® (Brassica Protection Products LLC)
Placebo Comparator: alfalfa sprout homogenate
Two hundred grams of commercially available alfalfa sprouts will be homogenized with water using a ratio of 1:1.2 in a clean blender. The homogenate will then be frozen in aliquots at -20 degrees C.
Dietary Supplement: alfalfa sprout homogenate
200 grams of alfalfa sprouts will be homogenized with water using a ratio of 1:1.2 in a clean blender. The homogenate will then be frozen in aliquots at -20 degrees C.
Potential subjects will be seen for a baseline screening visit at which time informed consent will be obtained, a 12 lead ECG will be performed and spirometry with subsequent sputum induction will be performed. Only subjects meeting the lung function criteria as well as criteria for adequate sputum production will continue in the study. If the sample is considered "borderline" by the study team, the subject maybe invited back to repeat collection of another sputum sample. Subjects will be required to abstain from caffeine for 12 hours prior to all study visits and must not use/ingest non-steroidal anti-inflammatory medications, anti-oxidant vitamins, juices/drinks fortified with extra vitamin supplement and cruciferous vegetables 7 days prior to all visits. Subjects will be provided with a list of cruciferous vegetables.
Qualified volunteers will next be seen for a training visit at which time they will undergo physical exam by a study physician. After baseline spirometry is evaluated, the subject will exercise on a treadmill, and measurements of minute ventilation will be collected. Treadmill speed and/or elevation will be adjusted until the subject's minute ventilation is at the target level of 30-40 L/min. The resulting speed and elevation will be used during the ozone exposure sessions. At the training visit, participants will also undergo nasal epithelial biopsy from one nare, and a buccal swab will be collected for genotyping. Baseline blood samples will also be collected at this time for analyses of markers of inflammation, cytokine assessments, SFN levels and complete blood cell count with differential.
After completion of the training session, the subject will return for 4 sequential days. During the first 3 days, subjects will ingest (observed ingestion) either broccoli sprout homogenate or alfalfa sprout homogenate based on earlier randomization. One hour after the supplement dose on the 3rd day, the volunteer will undergo exposure to 0.4 ppm ozone for a 2 hour period. During exposure, subjects will perform 15 minutes of moderate exercise on a treadmill (minute ventilation = 30-40 L/min), each separated by 15 minutes of seated rest. Heart rate and rhythm will be continuously monitored throughout the exposure. Spirometry and symptom scoring will be performed both prior to and after exposure. One hour after the end of exposure, a nasal epithelial biopsy will be collected from the nare that is contralateral to that used at the prior visit. Four hours after completion of the exposure, blood will be drawn for study endpoints and a sputum induction will be performed. The following day the subject will return for a follow-up visit to include vital signs, symptom scoring, spirometry, sputum induction and venipuncture for blood endpoints.
Subjects will be required to abstain from a list of vegetables for 1 week prior to each study session until the completion of that session. Subjects will also be asked to maintain a food diary for the same time.
After a 2 to 6 weeks washout period, participants will again return for a repeated sequence of 4 days with 3 days of supplement ingestion followed by ozone exposure using the alternate supplement and a 24 hour post exposure follow-up visit. Samples for analyses will be collected at the same time points as those used in the initial sequence.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01625130
|United States, North Carolina|
|UNC Center for Environmental Medicine, Asthma and Lung Biology|
|Chapel Hill, North Carolina, United States, 27599-7310|
|Principal Investigator:||Michelle Hernandez||University of North Carolina, Chapel Hill School of Medicine|