Environmental and Molecular Mutagenesis - Legacy Tobacco ...

265 1989 EMS Abstracts
MUTAGENICITIES OF THAI FOLKLORE MEDICINES AND THEIR NITROSATION PRODUCTS Notes
C . Ieamworapong, K . Kangsadalumpai and W . Rojanapo, National Cancer Institute, Bangkok
and Institute of Nutrition, Nakornpathom, Thailand .
Crude ethanol extracts from 10 commonly used Thai folklore medicinal plants namely
Cassia alata Linn, Casstia angusti.foiia Vahl, Carthamua tinctoriue Linn, Centeila asiatica
Urban, Andrographis paniculata Nees, Cassia fi.stula Linn, Curcwna domeattica Val,
Curcumazedcartia Rosc, Cyperus rotundus Linn and Orosylum indiown Vent were prepared and
tested for their mutagenic activity using the Salmonella/microsome mutagenicity tast .
The first 4 plant extracts, i .e . C . alata, C . angusttifoltia, C. tinotorius and C . asfattiea
exhibited mutagenic activity preferably to strain TA 98 only in the presence of
S-9 mix . However, an extract of C . angustifolia showed highest mutagenicity and it was
also mutagenic to strain TA 100 when tested in the presence of S-9 mix . After nitrosation
of the above 10 plant extracts with nitrite under acidic condition, extracts from
A . paniculata, C . rotundus and Oro2ylum indioum became mutagenic towards both strain
TA 98 and TA 100 either tested in the presence or absence of S-9 mix . In addition,
extracts of C. alata, C . angusttifolia and C . ttinctortius in which all of them were found
to be mutagenic were also mutagenic towards both tester strains after nitrosation . The
mutagenicities of these nitrosation products were markedly stronger than those of
extracts before nitrosation . Results in the present study demonstrate that some commonly
used Thai folklore medicinal plants contains mutagen especially C . angusttif0ltia
which is now widely used as laxative drug . More interestingly, these results indicate
that some of these plant extracts especially C . alata and 0 . tindiOLm contain chemicaUs)
capable of being nitrosated to become strongly mutagenic compounds .
266
LUMINOL . AN INHIBITOR OF POLY (ADP-R I BOSE) POLYMERASE, IS A STRONG INDUCER OF SISTER
CHROMATID EXCHANGES (SCEs) .
T . Ikushima, Research Reactor Inst .,Kyoto Univ ., Kumatori, Osaka 590-04 (Japan)
SCEs provide one of sensitive short-term tests for screening environmental
mutagens . The disturbance of the programmmed replication timing of replicons in the
processes of DNA replication is thought to be involved in the SCE formation
(Ikushima, T . 1980, Annu . Rep . Res . Reactor Inst ., Kyoto Univ .13, 67) . Its has been
suggested that there is a positive correlation between the inhibition of
poly(ADP-ribose) polymerase and SCE induction . The specific loss of the oncogenes
induced by inhibition of the enzyme has been recently shown in the transformants Jq
vitro. Here, SCE inducibility of luminol . (5-atino-2,j3-dihydro-l,4-phtalazinedione :
Sigma), a potent inhibitor of the enzyme, has been tested in cultured Chinese
hamster V79 cells . The actively growing cells were treated with luminol for the
two cell cycles, the last one, or the pre-one cycle at various concentrations during
bromodeoxyuridine-labelling, and SCEs were detected by FPG method in
colcemid-arrested metaphase chromosomes . Very high SCE frequencies were obtained
after treatments with low concentrations (e .g . 82 SCEs/cell at 0 .5 mM) . Luminol was
more than four times as effective to induce SCEs as 3-aminobezamide, a NAD site
inhibitor of the enzyme . No enhancement of SCE level was observed after the
pre-cycle treatment, in contrast with other strong SCE-inducers such as cis-platin
or mytomycin C . SCEs might be formed during DNA replication by inhibition of
poly(ADP-ribosyl)ation, accompanying the gene amplification or elimination .
267
SUPPRESSIVE EFFECT OF VANILLIN ON MICRONUCLEI INDUCED BY MITOMYCIN C OR X-RAYS .
T .Inouye, Y .F .Sasakl, H .Imanishi, M .Wetanabe, T .Kato, K .Matsumoto, T .Ohta and
Y .Shirasu, Institute of Environmental Toxicology, Kodaira, Tokyo 187, (Japan)
Vanillin is a component of vanilla essence flavour . We previously reported the
antimutaQenlc effect of vanillin on mutagenesis in bacteria(1) and its anticlastogenic
activity in a cytogenetice study ueing cultured cells(2) . In order to
find out in vivo anticlastogenic effect of vanillin, bone marrow micronucleous test
was conducted. BDF1 male mice at 7 weeks old were treated with mitomycin C(MMC) or
ionizing radiation . Thereafter vanillin at 500 mg/kg was given orally . Bone marrow
cells were sampled 24 h after injection of 2 mg/kg MMC . In the experiments the time
interval between MMC injection and vanillin treatment was varied, a significant
reduction in the frequencies of micronucleated polychromatic erythrocytes(MN-PCEs) by
38-50/ was observed from 6 to 9 h after YlAC injection . The frequencies of IQ)-PCEe
induced by X-rays (200R, 150kV, 5mA) plus vanillin treatment was less than those of
X-rays only (mean.SD :3 .1a1 .1/ vs 4 .97+0 .95), when bone marrow cells were sampled 24 h
after X-irradfetion . When sampled at 15 h, however, the similar frequencies were
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