# Clinical Trial of Watercress in Detoxification of Environmental Toxicants and Carcinogens

> **NIH NIH R01** · UNIVERSITY OF MINNESOTA · 2020 · $639,083

## Abstract

Clinical Trial of Watercress in Detoxification of Environmental Toxicants and Carcinogens
Summary
In a recently completed clinical trial, we observed that 2-phenethyl isothiocyanate (PEITC) enhanced the detoxification of
the environmental toxicants and carcinogens benzene, acrolein, and crotonaldehyde, as determined by increased excretion
of the corresponding mercapturic acids in the urine of subjects who took 40 mg of PEITC orally per day. The significant
enhancing effect was particularly strong in individuals who were null for the glutathione-S-transferase genes GST-T1,
GST-M1, or both. These exciting results, which signal enhanced detoxification of commonly occurring environmental
agents in subjects exposed to PEITC, led to the design of the current clinical trial of watercress, a common vegetable
which is an abundant and practically unique natural dietary source of PEITC. When watercress is chewed or otherwise
macerated, PEITC is released from its parent constituent gluconasturtiin. Thus, consumption of 10 grams wet weight of
watercress exposes one to about 3 mg of PEITC. We hypothesize that watercress can enhance the detoxification of
multiple environmental toxicants and carcinogens, thus emerging as an inexpensive and plentiful dietary constituent with
potential for prevention of cancer and possibly other environmentally linked diseases. Therefore, we propose a clinical
study of watercress with the following specific aims:
1. Prepare and standardize a watercress-derived beverage or capsules and appropriate placebo for the study. Two
 approaches will be investigated. A). Freeze-dry the watercress to obtain a powder which will be added to a mixture of
 fruit juices to mask the bitter watercress flavor. Subjects will drink this juice 10 min after mixing. B). Homogenize the
 watercress followed by freeze drying to produce a PEITC-containing powder which will be formulated into capsules.
2. Perform a clinical trial with 350 subjects to determine the effects of the watercress preparation on detoxification of
 environmental toxicants and carcinogens. Using a crossover design, subjects will consume the watercress beverage or
 capsules, or placebo, 3 times per day for 2 weeks with a 4 week washout period between watercress and placebo
 treatment. The target dose will be 40 mg/day of PEITC, as in our previous study. Urine, oral cells, saliva, and blood
 will be collected.
3. Using liquid chromatography-tandem mass spectrometry, analyze urine samples for mercapturic acids of specific
 toxicants (e.g. benzene, acrolein, crotonaldehyde, propylene oxide, etc.) and for mercapturic acids generally. Our
 hypothesis is that detoxification of these toxicants by conjugation with glutathione, as indicated by mercapturic acid
 levels in urine and DNA adduct levels in oral cells, will be significantly elevated compared to placebo in subjects who
 consumed the watercress preparation and are null for GSTM1, GSTT1, or both.
The results of this study will provide a c...

## Key facts

- **NIH application ID:** 9963154
- **Project number:** 5R01CA222005-03
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** DOROTHY K HATSUKAMI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $639,083
- **Award type:** 5
- **Project period:** 2018-08-03 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9963154

## Citation

> US National Institutes of Health, RePORTER application 9963154, Clinical Trial of Watercress in Detoxification of Environmental Toxicants and Carcinogens (5R01CA222005-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9963154. Licensed CC0.

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