• Cancer Epidemiol. Biomarkers Prev. · Dec 1995

    Effects of watercress consumption on metabolism of a tobacco-specific lung carcinogen in smokers.

    • S S Hecht, F L Chung, J P Richie, S A Akerkar, A Borukhova, L Skowronski, and S G Carmella.
    • American Health Foundation, Valhalla, New York 10595, USA.
    • Cancer Epidemiol. Biomarkers Prev. 1995 Dec 1; 4 (8): 877-84.

    AbstractEpidemiological studies indicate that vegetable consumption protects against lung cancer in humans, but the protective constituents have not been identified. Phenethyl isothiocyanate (PEITC), which is release upon chewing of watercress (nasturtium officinale), is a chemopreventive agent against lung cancer induced by the tobacco-specific lung carcinogen 4- (methylnitrosamino)-1-(3-pyridyl-1-butanone (NNK) in rats and mice. PEITC inhibits the carcinogenicity of NNK by inhibiting its metabolic activation and thereby increasing the levels of detoxified metabolites excreted in urine. In this study, our goal was to determine whether watercress consumption would modify NNK metabolism in smokers. Eleven smokers maintained constant smoking habits and avoided cruciferous vegetables and other sources of isothiocyanates throughout the study. They donated 24-h urine samples on 3 consecutive days (baseline period). One to 3 days later, they consumed 2 ounces (56.8 g) of watercress at each meal for 3 days and donated 24-h urine samples on each of these days (watercress consumption period). One and 2 weeks later, they again donated 24-h urine samples on 2-3 consecutive days (follow-up periods). The samples were analyzed for two metabolites of NNK; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and [4-methylnitrosamino)-1-(3-pyridyl)but-1-yl]-beta-omega-D-glucosiduro nic acid (NNAL- Gluc). NNAL-Gluc is believed to be a detoxification product of NNK. The urine samples were also analyzed for PEITC-NAC, a metabolite of PEITC. Minimum exposure to PEITC during the watercress consumption period averaged 19-38 mg/day. Seven of the 11 subjects had increased levels of urinary NNAL plus NNAL-Gluc on days 2 and 3 of the watercress consumption period, compared to the baseline period. Overall, the increase in urinary NNAL plus NNAL-Gluc in this period was significant [mean +/- SD 0.924 +/- 1.12 nmol/24 h (33.5%); P < 0.01]. Urinary levels of NNAl plus NNAL-Gluc returned to near baseline levels in the follow-up periods. The percentage of increase in urinary NNAL plus NNAL-Gluc during days 2 and 3 of the watercress consumption period correlated with intake of PEITC during this period, as measured by total urinary PEITC-NAC (r = 0.62; P = 0.04). The results of this study support our hypothesis that PEITC inhibits this oxidative metabolism of NNK in humans, as seen in rodents, and support further development of PEITC as a chemopreventive agent against lung cancer. This is the first study to report an effect of vegetable consumption on metabolism of a lung carcinogen in humans.

      Pubmed     Free full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

Want more great medical articles?

Keep up to date with a free trial of metajournal, personalized for your practice.
1,704,841 articles already indexed!

We guarantee your privacy. Your email address will not be shared.