Anticarcinogenic activities of sulforaphane and structurally related synthetic norbornyl isothiocyanates

Yuesheng Zhang, Thomas W. Kensler, Cheon Gyu Cho, Gary H. Posner, Paul Talalay

Research output: Contribution to journalArticle

Abstract

Sulforaphane [1-isothiocyanato-4-(methylsulfinyl)butane] was recently isolated from one variety of broccoli as the major and very potent inducer of phase 2 detoxication enzymes in murine hepatoma cells in culture. Since phase 2 enzyme induction is often associated with reduced susceptibility of animals and their cells to the toxic and neoplastic effects of carcinogens and other electrophiles, it was important to establish whether sulforaphane could block chemical carcinogenesis. In this paper we report that sulforaphane and three synthetic analogues, designed as potent phase 2 enzyme inducers, block the formation of mammary tumors in Sprague-Dawley rats treated with single doses of 9,10-dimethyl-1,2-benzanthracene. The analogues are exo-2-acetyl-exo-6- isothiocyanatonorbornane, endo-2-acetyl-exo-6-isothiocyanatonorbornane, and exo-2-acetyl-exo5-isothiocyanatonorbornane. When sulforaphane and exo-2- acetyl-exo-6-isothiocyanatonorbornane were administered by gavage (75 or 150 μmol per day for 5 days) around the time of exposure to the carcinogen, the incidence, multiplicity, and weight of mammary tumors were significantly reduced, and their development was delayed. The analogues endo-2-acetyl-exo- 6-isothiocyanatonorbornane and exo-2-acetyl-exo-5-isothiocyanatonorbornane were less potent protectors. Thus, a class of functionalized isothiocyanates with anticarcinogenic properties has been identified. These results validate the thesis that inducers of phase 2 enzymes in cultured cells are likely to protect against carcinogenesis.

Original languageEnglish (US)
Pages (from-to)3147-3150
Number of pages4
JournalProceedings of the National Academy of Sciences of the United States of America
Volume91
Issue number8
DOIs
StatePublished - Apr 12 1994

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Keywords

  • chemoprotection
  • dimethylbenzanthracene
  • enzyme induction
  • quinone reductase
  • rat mammary tumors

ASJC Scopus subject areas

  • General

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