Environmental and Molecular Mutagenesis - Legacy Tobacco ...

240 1989 EMS Abstracts _ ._ -- - .
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
Notes "~CHEMOPREVENTI*fOFTMTOXICITY IN VIVO . Wattenber~, L . W . Dept . of Laboratory
Medicine and Pathology . Univers~iLy' o-Minnesota, Minneapolis, MN 55455, USA .
Cnemopreventiqp gi56he effects of genotoxic compounds in vivo can be brought about
by compounds ("bloc~c'Tng agents") that prevent the genotoxi~c agent from reaching or
reacting with critical cellular targets or by compounds ("suppressing agents") that
prevent manifestations of genotoxicity in cells in which the target molecules have
already been hit . Using carcinogens as an example of one type of genotoxic compound,
blocking agents can be shown to act via three mechanisms : (1) by inhibiting activation
reactions of carcinogens requiring metabolic activation in order to form reactive
electrophiles, (2) by enhancing carcinogen detoxification and (3) by trapping
reactive carcinogenic species . Examples of all three will be discussed . Particular
emphasis will be on naturally-occurring organosulfur compounds and aromatic
isothiocyanates that can both induce increased activity of detoxification systems and
can inhibit carcinogen activation . Trapping agents to be discussed will include aromatic
thiols and sodium thiosulfate . Data relating to suppressive effects of cruciferous
vegetables and citrus fruit oils will be presented . Current evidence indicates
that there are surprisingly large numbers of pure chemicals and natural products
that can inhibit genotoxicity in vivo . Supported by Grant SIG 5A from the
American Cancer Society .
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