Evaluation of Broccoli Seed and Sprout Extract for Detoxification of Carcinogens in Firefighters

Overview

This phase II randomized, placebo-controlled trial evaluates whether daily supplementation with broccoli seed and sprout extract (BSSE), also known as Avmacol Extra Strength (ES), enhances the body's natural ability to detoxify carcinogens commonly encountered by firefighters. Firefighters are routinely exposed to harmful chemicals such as benzene and polycyclic aromatic hydrocarbons (PAHs) through smoke inhalation, structural fires, and fuel leak incidents exposures that contribute to their elevated cancer risk. BSSE contains bioactive compounds known to activate phase II detoxification enzymes that help eliminate reactive toxins from the body. A single dose of acetaminophen (Tylenol) is administered at both baseline and end-of-intervention as a metabolic probe to assess changes in detoxification enzyme activity. Acetaminophen is metabolized through the same pathways as benzene and PAHs, making it a useful surrogate for evaluating the effect of BSSE on the detoxification of fire-related toxicants. Participants were originally randomized into one of total four study groups. Groups I and II, now closed to accrual, were designed to assess BSSE effects before and after controlled flashover fire training exercises. These arms were discontinued after it was determined that training fires produced insufficient real-world toxicant exposure to evaluate the intervention's impact. Groups III and IV were subsequently open and represent the active phase of the study. Group III participants receive BSSE daily for 12 weeks, while Group IV participants receive a matched placebo. Both groups include acetaminophen challenge at baseline and end-of-intervention, with biospecimen collection to evaluate detoxification capacity and explore genetic and epigenetic modifiers of response. Although the protocol includes four study groups, only two are currently active. Groups I and II remain part of the study record but are closed and will not contribute to the primary outcome analyses.

PRIMARY OBJECTIVE: I. To determine whether BSSE increases the urinary excretion of mercapturic acid of acetaminophen, a surrogate for detoxification of the carcinogen benzene in healthy, incumbent firefighters. SECONDARY OBJECTIVES: I. To evaluate the effects of BSSE on urinary excretion of acetaminophen glucuronide, a surrogate for detoxification of polycyclic aromatic hydrocarbons (PAHs). II. To evaluate the safety and tolerability of BSSE. EXPLORATORY OBJECTIVES: I. To determine whether the GSTM1 and GSTT1 genotypes are important genetic modulators of BSSE-induced detoxification of carcinogens. II. To evaluate the effects of BSSE on urinary metabolomics. III. To determine the effects of BSSE on the urinary excretion of the mercapturic acid of benzene after fire/fuel leak activities. IV. To determine the effects of BSSE on the urinary excretion of metabolites of PAHs after fire/fuel leak activities. V. To determine the effects of BSSE on epigenetic modifications (blood microribonucleic acid \[RNA\] and deoxyribonucleic acid \[DNA\] methylation). OUTLINE: Participants are randomized to Group III or Group IV. GROUP I (BSSE-PLACEBO) (CLOSED TO ACCRUAL 10/07/2024): Participants receive BSSE orally (PO) daily (QD) for 7-10 days then undergo the first flashover training between day 7-10 of agent intervention. Participants then receive placebo PO QD for 7-10 days then undergo second flashover training after a washout period of 2 weeks to 3 months. Participants also undergo urine sample collection throughout the study. GROUP II (PLACEBO-BSSE) (CLOSED TO ACCRUAL 10/07/2024): Participants receive placebo PO QD for 7-10 days then undergo the first flashover training between day 7-10 of agent intervention. Participants then receive BSSE for 7-10 days then undergo second flashover training after a washout period of 2 weeks to 3 months. Participants also undergo urine sample collection throughout the study. GROUP III: Participants receive BSSE PO QD for 12 weeks on study. Participants also receive acetaminophen PO once prior to starting BSSE and once following completion of BSSE on study. Participants undergo blood and urine sample collection throughout the study. GROUP IV: Participants receive placebo PO QD for 12 weeks on study. Participants also receive acetaminophen PO once prior to starting placebo and once following completion of placebo on study. Participants undergo blood and urine sample collection throughout the study. After completion of study intervention, participants are followed up at 2 weeks.