Mutagens

“A mutagen is defined as any physical or chemical substance that can change the genetic material of an organism, thereby causing a mutation.”

Table of Contents

• Introduction
• Discovery of Mutagens
• Types of Mutagens
• Effects of Mutagens
• Protection Against Mutagens
• Mutagens in Anti-cancer roles

Mutations are natural, but the mutations brought about by the mutagens are above the natural background level. Furthermore, most mutations have the potential to cause cancer, hence, mutagens are possibly carcinogenic in nature.

The first ever instance of mutagens was linked to carcinogenic substances more than 2,000 years prior to the discovery of DNA. Though knowledge of radioactivity or carcinogens was non-existent during that time, its effects were clearly recorded throughout history.

One of the well-documented cases of exposure to mutagens was miners working in poorly ventilated mines. The miners were described to have a “wasting disease”, which was later identified to be lung cancer. This was caused due to the accumulation of radon, a colourless, tasteless, odourless gas that is classified as a health hazard today due to its radioactivity.

Read More: Mutation

Mutagens can be classified into 3 types based on their origin. They are as follows:

• Physical mutagens: These include ionizing radiation, such as X-rays, gamma rays and alpha particles. Ultraviolet radiations can also behave as potential mutagens.

• Chemical mutagens: Elements such as arsenic, nickel and chromium are considered to be mutagens. Some organic compounds like benzene are also considered to be mutagenic in nature. 

• Biological mutagens: Examples of biological mutagens involve transposons and viruses. Furthermore, certain bacteria such as Helicobacter pylori can increase the risk of developing stomach cancer. 

Mutagens are substances that alter or change the genetic material of an organism, hence they are termed genotoxic. In most cases, the mutagens can incite carcinogenic responses or impair the functions of certain genes. Or they can completely ride a gene of its functionality, thereby causing various medical conditions. 

However, the effects of most mutagens cannot be substantiated from a scientific perspective. For instance, a mutagen that shows a possible carcinogenic effect on one organism may not hold true for another organism.

Some mutagens cause silent mutations, where there are no visible effects because these affect the non-coding DNA. Other mutations are much more noticeable and can cause debilitating or lethal implications in their host.

Also Read: Genetic Code and Mutation

As mentioned above, there are many types of mutagens. Exposure to physical mutagens obviously involves limiting or avoiding high-energy radiation.

The effects of some chemical mutagens can be reduced through the help of antioxidants. Antioxidants are found in fruits and vegetables and are heralded as anticarcinogenic compounds. In other words, antioxidants inhibit the onset of cancer.

Certain mutagens are highly toxic to proliferating cells and as a result, some are used to eradicate cancer cells. However, an obvious downside is that the mutagen can also affect the non-cancerous cells, leading to undesirable side effects such as hair loss.

For example, we do know that ionizing radiation can be carcinogenic, and can damage the cell’s DNA. But it is for the same property that mutagens are used as a part of cancer treatment. Mutagens (specifically a combination of ionizing radiation and intercalating agents) can effectively destroy cancer cells’ DNA, impairing the ability to proliferate or spread.

Also Read: Molecular Basis of Mutation

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