College Papers

In a number of compounds or materials which

In everyday life a person gets exposed to a number of
compounds or materials which cause damage to the DNA causing mutations which
may lead to cancer. This simply means Genotoxins affect the integrity of the
DNA. Genotoxins are those compounds having a property of genotoxicity. Effects
of genotoxicity are most commonly being of 3 types. 1) Carcinogenic effects 2)
Mutagenic effects 3) Teratogenic effects. Carcinogens are cancer causing,
mutagens are mutation causing, teratogens are birth defect causing compounds or
agents. Majority of genotoxins are mutagenic in nature. All mutagens are
genotoxic but not all genotoxins are mutagenic. Every cell has a property of
DNA repair but when cell fails to repair then these compounds leads to
genotoxicity in the cell. Generally, by the process of apoptosis or DNA repair
genotoxic mutations are avoided by all cells but these mutations get expressed
when exposure to the genotoxic compound is frequent or continuous. It is not
sure that a damage caused will always be fixed. So, a DNA damage that cannot be
fixed causes mutation or other genotoxic effects. Genotoxicity can be on both
somatic as well as on germ cells. If genotoxins affect somatic cells then it
may lead to cancer or cardiovascular diseases but if genotoxins affect germ
cell then they can cause genetic diseases like cystic fibrosis, sickle cell
anemia or Haemophilia and multifactorial diseases like Psychosis,
cardiovascular diseases and diabetes. These genetic diseases are inheritable to
next generation. When integrity of the DNA is damaged then it leads to cause
cancer in the body. A number of techniques have been developed to check the
potential of a chemical compound to cause genotoxicity like Ames test, Comet
test and various in vitro in vivo toxicology tests. Ames test is a very a very
commonly used test to determine the genotoxicity of a compound using a
bacterium. It is very popular test because of its quick results while many old
standard tests usually take about two to three years to complete. Ames test is
a quick alternative for these tests. Comet test is an alternative name of comet
assay is SCGE (Single cell gel electrophoresis assay). Comet test detects the
DNA damage at individual eukaryotic cell level. It is a very simple and quick
to detect and is most commonly employed technique. Micronucleus test is the one
of the most reliable assays which are recognized at present. It has two
versions of this test. 1) In Vivo 2) In Vitro. In vivo experiments are
performed on live animals while in vitro experiments are performed on cells and
microorganisms. This type of experiments is commonly called as test tube
experiments. Genotoxin simply means any substance which is toxic to the genome.