Environmental and Molecular Mutagenesis - Legacy Tobacco ...

epalr-deflcient bacteria) this assay will continue to form the basis of all screening programmes for potential
mutagenicity and carcinogenlcaPt . In addition to the role of the Ames test In screening pure chemicals, It Is
used for InvestlgaUng the mutag7nlclty of complex mixtures, both of chemical and biological otipin . Virtually
every kind of bodily secretion and excretion has been eub)eoted to scrutiny, the outstanding discovery being
the detection of mutagenic activity In the urlne of smokers. Despite the vast quantities of bHormatlon on how
to conduct the S.Imonella/mIcrosome test, purnab and regulatory authorities still ncelw data based on
inadequate tests, or Inadequate data based on adequate tests, or various combinatlons of these defects .
606
STUDY OF TtE ACTION OF AN EXTRACT OF Stryphnodendron obovatim BENTH SEEDS ON DIFFERENT
BIOLOGICAL SYSTEhS .
V .E .P .Vicentini-Dias, C .S .Takahashi, Univ .Est .Maringa-PR, F.F .C .L .R .P .-Univ .SP (Brazil) .
Naturall products of plant origin have been extensively used in human therapeutic .
Stryphnodendron obovatun BENTH, popularly called 'Barbatim'eo" in Brazil, is used in folk
medicine against hemorrhage, leucorrhea, diarrhea, hemia and chronic ulcer, but the
lethal effects in cattle that ingest its pods are acccxtQanied by signs of photosensitization
and liver damage . In view of these effects, we investigated the action of S .
obovatun BFMH seeds on three test systems . An aqueous seed extraot at concentrations
ranging frorn 5 .3 to 23 .8 mg/ml of water drastically inhibited cell division from 16 to
1% after 24 h of treatment in Alliun cepa root tip cells, with no recovery of division
after a period of 6 and 24 h in water. Cell spindle formation was also inhibited, leading
to the appearance of colchicine metaphases (2 .5%) . In bone marrow cells of wistar rats
treated "in vivo" for 24 h, the extract (1 .1 mg/g body weight) did not induce a statistically
significant increase in the frequencies of chromqsome aberrations (2 to 4%) .
In hianan peripheral blood lynphocytes treated in culture (0 .7 µg/ml culture mediun) there
was no increase in the frequencies of chronasome aberrations or in mean nunber of sister
chromatid exchanges (about 7 .5 SCEs/cell) . Even though a clastogenic effect was not observed
in nwnalian cells, treatments with the highest concentrations showed a certain
cytotoxic effect .
r
607
GENOTOXIC ACTIVITY OF 1,3-BUTADIENE, NITROGEN DIOXIDE AND THEIR PHOTOCHEMICAL REACTION
PRODUCTS .
K . Victorina M . Stf,hlberga, L . Buskb H . Cederbergc and J . Ma~nussonc, aInstltute of
Environmental Medicine, Box 60208, S-104 01 STOCKHOLM . Sweden . Svedlsh Food
Administration, Box 622, S-751 26 UPPSALA, Sweden . cUniverstty of Stockholm,
S-106 91 STOCKHOLM, Sweden .
A small exposure system has been developed for mutagenicity studies of gases . UVirradiated
mixtures of nitrogen dioxide and alkenes gave rise to mutagenic effects in
Salmonella, strain TA100, in the order 1,3-butadtene > propene > ethene . A directacting
mutagenic effect was evident after 40 min reaction time and 6 h exposure time at
such low reactant concentrations as 0 .25 ppm each of butediene and nitrogen dioxide .
Butadiene in itself was not mutagenic at 0 .5 - 20 % . Nitrogen dioxide was slightly
mutagenic but also bacteriotoxic at 10 - 15 ppm . In vivo experiments were performed
with the mouse bone-marrow micronucleus assay and the somatic mutation and recombination
test in Drosophila (the wing spot test) . Butadiene alone was not mutagenic in
Drosophila at 1 X, but induced micronuclei in mice at 10 ppm during 23 h . Nitrogen
dioxide was not genotoxic tn either test system . The photochemical reaction products
were toxic but not mutagenic at high doses tn Droso hila (1000 ppm butadiene + 50 ppm
NO2 + UV), and not genotoxic in mouse bone-marrov highest non-toxic mixture 10 ppm
butadiene + 10 pm N02 + UV) . The in vivo experiments thus did not confirm the strong
direct-acting mutagenic activity of the photochemical products in Salmonella .
608
GENOTOXIC RESPONSE IN GROWING AND STATIONARY PHASE YEAST CELLS .
Vierling, Th ., Boehringer Mannheim GmbH, Sandhofer StraBe 116,
D-6800 Mannheim 31, Federal Republic of Germany
Yeasts are known to provide suitable systems for the assessment of
genotoxic potentials of chemicals . The diploid Saccharomyces
cerevisiae strain MP1 allows for screening of intergenic and
interallelic recombination and of forward mutation . In order to•
investigate intrinsic differences in sensitivity of the Saccharomyces
cerevisia,e MP1 testing system, the genetic responses which
were obtained after treatment of proliferating or stationary phase
cells with known genotoxic agents were compared . It was found that
http://legacy.library.ucsf.edu/tid/clb93d00/pdf
A
1989 EMS Abstracts 209
Notes