An Early Phase 1 interventional study of [14C]-benzo[a]pyrene and Brussels sprouts before 50 ng dose in Environmental Exposure, sponsored by Oregon State University. Completed at 1 site in United States. Open to participants aged 21 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-06-22.
Sponsored by Oregon State University · Early Phase 1, Interventional, and Basic science
Evaluation of the pharmacokinetics for [14C]-benzo[a]pyrene ([14C]-BaP) and metabolites in plasma and urine over 48 hours following a 50 ng dose (5.4 nCi) alone, following 7 days' consumption of Brussels sprouts, and following 7 days' consumption of a supplement containing 3,3'-diindolylmethane (DIM).
The pharmacokinetics for [14C]-BaP and metabolites will be assessed by UHLPC-Accelerator Mass Spectrometry (AMS, Lawrence Livermore National Laboratory) in plasma and urine collected over 48 hours following oral doses of 50 ng dose (5.4 nCi) alone, following 7 days' consumption of Brussels sprouts, and following 7 days' consumption of a supplement containing 3,3'-diindolylmethane (DIM).
The investigators hypothesize that pre-administration of Brussels sprouts or DIM will alter [14C]-BaP metabolism and increase the rate of elimination consistent with predictions based on a previously developed Physiologically-Based Pharmacokinetic (PBPK) model for BaP. Briefly, this hypothesis will be tested by dosing individuals with 50 ng [14C]-BaP alone and, following a 3-week washout period, ingestion of about 50 g Brussels sprouts or 300 mg of 3,3'-diindolylmethane (DIM) supplement for 7 days prior to the [14C]-BaP micro-dose. The impact of the supplement and the whole food will be assessed with respect to alterations in uptake from the GI tract, metabolism and rate of elimination. The consumption of cruciferous vegetables will be assessed at the beginning of the study by completion of a dietary questionnaire to examine typical eating patterns in the previous 3 months and by collection and extraction of blood and urine to assay for DIM by LC/ESI-MS/MS-SRM). In addition, for each phase, urine will be assayed for DIM as an estimate of crucifer or DIM supplement intake.
In preclinical and clinical studies, administration of Brussels sprouts or DIM impacts the activity of the same enzymes responsible for the phase 1 (CYP1A1 and CYP1B1) and phase 2 enzymes (GSTM1, UGT, SULT). Monitoring changes in β-estradiol metabolites will confirm the mechanism of alteration in the metabolic profile of [14C]-BaP.
Metabolite profiles and kinetics of elimination are predicted to be consistent with a BaP physiologically based pharmacokinetic (PBPK) model developed by Pacific Northwest National Laboratory (PNNL). A non-smoker, not exposed occupationally, receives 270-700 ng of BaP daily; about 95% dietary. The WHO has set an estimated safe daily lifetime (70 year/70 Kg individual, cancer endpoint) exposure to BaP of 42-350 ng. This protocol represents de minimus risk.
Oregon State University is the lead sponsor of 37 studies on the registry; 3 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 4 (67%) have results posted.
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Exclusion Criteria:
Cycle 1: Capsule containing 50 ng (5.4 nCi) \[14C\]-benzo\[a\]pyrene (BaP). Cycle 2: Subjects will consume 50 g (about 1/2 cup) of lightly steamed Brussels sprouts each evening for 7 days prior to taking capsule containing 50 ng (5.4 nCi) \[14C\]-benzo\[a\]pyrene (BaP). Cycle 3: Subjects will consume 300 mg DIM supplement ( 2 capsules of BioResponse DIM® 150) each evening for 7 days prior to taking capsule containing 50 ng (5.4 nCi) \[14C\]-benzo\[a\]pyrene (BaP). A 300 mg DIM dose will be co-administrated with the 50 ng BaP dose. At least 3 weeks will pass between cycles as a washout period.
Drug: [14C]-benzo[a]pyrene · Drug: Brussels sprouts before 50 ng dose · Drug: DIM supplement before 50 ng dose
Oral micro-dose (50 ng) (5.4 nCi)
Also known as: Carcinogenic PAH environmental pollutant
Brussels sprouts for 7 days before 50 ng (5.4 nCi) dose of BaP
Also known as: Brussels sprouts and carcinogenic PAH
DIM supplement for 7 days before 50 ng (5.4 nCi) dose of BaP and coadministration with DIM supplement
Also known as: Cruciferous vegetable supplement and carcinogenic PAH
Peak Plasma Concentration of 14C-BaP Cmax
Determination of highest concentration of 14C-BaP in plasma. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine Cmax.
Time frame: 0-48 hours for each of 3 dosing cycles, with a washout period of 3 weeks between each dosing cycle
Time at Highest Plasma Concentration of 14C-BaP Tmax
Determination of time at which plasma concentration of 14C-BaP is highest. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine Tmax.
Time frame: 0-48 hours for each of 3 dosing cycles, with a washout period of 3 weeks between each dosing cycle
Area Under Plasma Concentration of 14C-BaP Versus Time Curve AUC
Integration of concentration of 14C-BaP in plasma over time. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine AUC.
Time frame: 0-48 hours for each of 3 dosing cycles, with a washout period of 3 weeks between each dosing cycle
Rate of Elimination of 14C-BaP (Half Life)
Determination of constants for rate of elimination of 14C-BaP from plasma. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine half-life.
Time frame: 0-48 hours for each of 3 dosing cycles, with a washout period of 3 weeks between each dosing cycle
| Milestone | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| Started | 7 |
| Completed | 7 |
| Not completed | 0 |
Determination of highest concentration of 14C-BaP in plasma. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine Cmax.
| fg [14C]-BaP/mL plasma | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| 50 ng [14C] BaP | 3.69 ± 4.12 |
| Brussels sprouts before 50 ng [14C] BaP | 1.67 ± 1.03 |
| DIM supplement before 50 ng [14C] BaP | 0.68 ± 0.51 |
Determination of time at which plasma concentration of 14C-BaP is highest. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine Tmax.
| hour | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| 50 ng [14C] BaP | 1.58 ± 1.16 |
| Brussels sprouts before 50 ng [14C] BaP | 1.14 ± 0.90 |
| DIM supplement before | 14.00 ± 19.17 |
Integration of concentration of 14C-BaP in plasma over time. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine AUC.
| fg [14C]-BaP/mL plasma x hour | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| 50 ng [14C] BaP | 10.93 ± 9.19 |
| Brussels sprouts before 50 ng [14C] BaP | 9.34 ± 10.02 |
| DIM supplement before 50 ng [14C] BaP | 5.51 ± 6.17 |
Determination of constants for rate of elimination of 14C-BaP from plasma. Blood samples collected at 0 (baseline), 0.25, 0.5, 1, 2, 3, 4, 8, 24, and 48 hour after dosing. All time points were used to determine half-life.
| hour | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| 50 ng [14C] BaP | 3.69 ± 3.80 |
| Brussels sprouts before 50 ng [14C] BaP | 3.86 ± 4.62 |
| DIM supplement before 50 ng [14C] BaP | 9.75 ± 13.25 |
Collected over 9 days for Brussels sprouts (BS) and DIM cycles- Participants were assessed for adverse events beginning beginning 7 days prior to the [14c]-BaP dose administration (time= 0 hour), when participants began consuming BS or DIM supplements. They were assessed until 0.25h after the final blood sample collection time point (time = 48 hour) and removal of the peripheral IV catheter. 48.5 h for BaP-only cycle - 0.25h prior to dose until 0.25 hr after final blood sample at 48 h.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose | 0/7 (0%) | 0/7 (0%) | 0/7 (0%) |
| Age, Categorical(Participants) | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 7 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| Female | 1 |
| Male | 6 |
| Ethnicity (NIH/OMB)(Participants) | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| Hispanic or Latino | 0 |
| Not Hispanic or Latino | 7 |
| Unknown or Not Reported | 0 |
| Race (NIH/OMB)(Participants) | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 1 |
| White | 6 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(participants) | 50 ng Dose; Brussels Sprouts Before 50 ng Dose; DIM Supplement Before 50 ng Dose |
|---|---|
| United States | 7 |
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Plan to share: No — Deidentified samples sent to Lawrence Livermore National Laboratory Deidentified data sent to Pacific Northwest National Laboratory
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Oregon State University