Types of Mutagens and its Effects

Introduction: What are Mutagens?

Our genes can get their configuration altered due to the effect of some physical and chemical substances. Such alterations are known as mutation. The mutation is a natural process but in some cases, it may be artificial. Mutations often cause cancer and hence the substances that cause mutations are known as carcinogenic substances. These substances that alter the configuration of genes are known as mutagens.

Examples of mutagens may be ultraviolet rays, x−rays, radioactive substances, and some chemicals. Since most mutagens cause cancer, they are considered to be carcinogenic in nature.

The existence of mutagens dates back to 2,000 years prior to the discovery of DNA, the building blocks of genes. Radioactivity and carcinogens were not known to human beings at that period but their effects have been recorded clearly since that time. One such case was associated with the miners. It has been recorded that many miners had died due to a disease called waste disease which was later found to be lung cancer. The reason behind this disease was a gas called radon which is tasteless, odorless, and colorless in nature. The accumulation of radon in mines led to lung cancer in miners. Radon is therefore a mutagen that has been discovered at one of the earliest periods of history.

Types of Mutagens

Mutagens are divided into three types depending on their origin which are as follows:

Chemical Mutagens

Some chemicals such as Nickel, Chromium, and Arsenic have the power to alter the genetic configuration of human beings. Some organic compounds such as Benzene are also found to be mutagenic in nature.

Physical Mutagens

Physical Mutagens include ionizing radiations, such as X−rays, Gamma rays, and alpha radiations. These radiations have been found to change the genetic configuration in some instances. Ultraviolet rays are also considered to be a potential physical mutagen.

Biological Mutagens

Apart from physical and chemical mutagens, there are biological entities that can act as a genetic configuration modifier. Examples of such biological mutagens are viruses and transposons. Certain bacteria such as Helicobacter pylori are also carcinogenic in nature as they can cause stomach cancer. Such bacteria are also considered to be mutagenic in nature.

Effects of Mutagens

Mutagens are called to be genotoxic in nature because they alter or change the genetic configuration. In many cases, a genotoxic response causes a carcinogenic outcome. In these cases, carcinogens impair the functions of the genetic materials. In some other cases, the mutagens override the genetic compounds to create a carcinogenic effect. Such overrides on the functionality of genetic materials result in a malfunction of genes which is found to be the reason for many cancerous formations. However, the exact reason for mutagens being lethal is not substantiated by scientific perspectives. For example, the substances that are mutagenic in nature for one organism do not show the same effects in another one. That is although the mutagens create cancer in human cells, they may be ineffective in some other animals or organisms.

In some cases, mutagens affect the non−coding DNA for which silent mutations occur. These silent mutations are not visible and they remain undiscovered until a medical inspection is done. In some other cases, the effect is much more visible and as the mutagens attack coding DNAs, their implications could be lethal in nature.

It is notable that the exact reasons for mutagens being lethal and so effective have not been discovered by scientists yet. While the effects of mutagens have been identified, the exact pathway of the mutagens affecting the hosts has not been discovered in many cases yet. However, the research on carcinogenic substances is going on in full swing as it remains one of the most lethal diseases ever faced by human beings.

Protection Against Mutagens

Although mutagens are lethal in nature, there are certain measures that can help us stay away from the effects of mutagens.

• For example, avoiding exposure to high−energy radiation and ultraviolet rays can protect us from physical mutagens. As radiation is carcinogenic in nature, research and development as well as the use of rays for energy and other purposes should be done in locations that are away from public residences.

• By limiting the use of carcinogenic chemicals, one can stay away from the ill effects of chemical mutagens. However, since many chemicals that are carcinogenic are used in day−to−day lives, such as pesticides, we need to be aware of and limit their use as much as possible. Government policies and barring people from using carcinogenic substances is also better way to deal with chemical mutagens.

• Chemical mutagen effects can also be negated with the help of antioxidants. Antioxidants are found in vegetables and fruits. So, the consumption of more fruits and vegetables can protect us from chemical carcinogens. It has been found that antioxidants inhibit the onset of cancer to a large extent. Therefore, eating more vegetables and fruits could be a good way to deal with chemical mutagens.

Mutagen in Anti−Carcinogenic Roles

Mutagens are used in anti−cancerous roles for the same reasons that cause cancer.

• For example, some mutagens stop cells from proliferating faster which can help stop the spread of DNA mutations in a quick manner. This can help stop the cancerous cells to grow and spread faster. It is therefore done with radiation to stop the spreading of cancerous growth in cells.

• However, it must be done with care because the radiation may expose non-cancerous cells to danger and show undesirable effects such as hair loss.

• It has been found that a mix of radiation and intercalating agents works best for the treatment of cancer. The ionization rays help to stop the affected DNAs from spreading and proliferating, which stops the onset of cancer in other cells’ DNAs.

• Furthermore, it has been observed that the treatments available till now are capable to save lives until the cancerous stage is under a certain level. When the critical point of spread of cancerous cells is crossed, it is often hard to treat the DNAs to bring them back to their original state.

Conclusion

Mutagens are of special interest to humans because they are behind one of the most difficult medical challenges human beings have ever faced, cancer. The progress in cancer research deals with mutagens and seeks to find a possible cure for the alterations of DNAs. It is therefore of high importance to human beings to study mutagens and understand their exact roles in the onset of the disease. Only then an exclusive cure can be found.

Frequently Asked Questions

Qns 1. How many types of mutagens are there? Give two examples of each.

Ans. There are three types of mutagens which are:

• Chemical: Benzene and Arsenic.

• Physical: X-ray and Ultraviolet Ray

• Biological: Transposons and Viruses.

Qns 2. How do mutagens impact genetic material? Describe briefly.

Ans. Mutagens are called to be genotoxic in nature because they alter or change the genetic configuration. In many cases, a genotoxic response causes a carcinogenic outcome. In these cases, carcinogens impair the functions of the genetic materials.

Qns 3. Why should more fruits and vegetables be eaten to counter chemical mutagens?

Ans. Chemical mutagens can be stopped from having their effects by antioxidants that are found in fruits and vegetables. That is why more fruits and vegetables should be eaten to counter chemical mutagens.