What does cytotoxicity mean?

Cytotoxicity Means a substance or process that can damage cells or cause them to die. “Cyto” refers to cells and “toxic” refers to poison.

You may hear this term when talking about chemotherapy drugs that kill cancer cells. It can also describe other toxins, such as snake venom. The human immune system even has cytotoxic cells: T cells kill bacteria, viruses and cancer cells.

This article will introduce different types of cytotoxic substances. You will also learn how to protect yourself from cytotoxic substances.

How does chemotherapy affect your immune system?

cytotoxic drugs

An example of a cytotoxic drug is chemotherapy, which acts on cancer cells. These drugs work on very fast growing cells. Cancer cells, hair follicles, bone marrow, and cells in the stomach and intestines are examples of fast-growing cells.

Cytotoxic drugs disrupt cells at certain points in the growth cycle. Since cells are in different locations during division, they cannot be killed all at once. This is why chemotherapy regimens often include combinations of drugs and cycles of treatment must be repeated.

Cytotoxicity and Cytostatic

Although the names seem similar, cytotoxic agents are not the same as cytostatics. Cytostatic drugs stop cells from dividing and growing, but do not directly cause cell death.

How long does chemotherapy take?

Chemotherapy drugs kill all fast-growing cells—even normal cells. However, not all drugs used to treat cancer are cytotoxic.

Newer treatments such as targeted therapy and immunotherapy are not cytotoxic. Instead, they work by hindering the growth of cancer cells. They can also use the immune system to fight cancer cells.

Some immunotherapies are considered somewhat cytotoxic because they exploit the cell-destroying effects of the body’s own T cells. An example of this type of treatment is CAR-T therapy.

What happens during CAR-T therapy?

Cytotoxic agents in humans and animals

Cytotoxic substances can also be found in humans and animals.

Cytotoxic T cells

Our bodies produce cytotoxic T cells, also known as cytotoxic T lymphocytes. These types of T cells search for, find and destroy virus-infected cells. They can also kill cancer cells.

An exciting area of ​​cancer research is the use of the body’s own cytotoxic cells to fight cancer. For example, CD8+ cells and natural killer lymphocytes are the immune system’s own cytotoxic cells.

These treatments work in different ways. Some help T cells “see” previously hidden cancer cells, while others harvest and make more cells.

Cancer cells and normal cells

cytotoxic venom

Humans are not the only organisms with cytotoxic T cells. For example, the venom in vipers, cobras and violin spiders is cytotoxic.


Cytotoxic substances are harmful to cells. Cytotoxic drugs, such as chemotherapy drugs, are used to kill cancer cells or stop them from growing. Other cytotoxic substances are also found in nature, such as the venom of some snakes.

Your body even produces its own cytotoxic cells, which play a key role in your immune system.


Cytotoxic agents can kill cells in several ways. The agent may weaken the cell membrane, which usually causes the cell to explode (called lysis). Some agents stop cells from growing and dividing.

There are also reagents that work with DNA inside cells.these are genotoxicityrather than cytotoxic substances.

Cytotoxicity and Genotoxicity

It is easy to confuse the terms “cytotoxicity” and “genotoxicity”. Cytotoxicity refers to substances that cause damage to cells. Genotoxicity refers to the direct damage of a substance to DNA in cells.

When DNA is damaged, it may or may not die. Cells with damaged DNA are said to have mutations. If the mutated cells are not repaired, it can lead to cancer.

Cancer usually occurs when two genes are mutated:

  • Genes encoding proteins that drive cell growth (oncogenes)
  • An example of such a gene is the BRCA gene, a gene encoding a protein that repairs damaged DNA or causes cell death when DNA cannot be repaired (tumor suppressor).

Genes, DNA and Chromosomes

Carcinogenicity and Mutagenicity

To understand cytotoxicity, two other important words need to be understood: carcinogen and mutagenesis.

  • A carcinogen is a cytotoxic substance that can cause DNA damage that ultimately leads to cancer.
  • If something is mutagenic, it is a cytotoxic substance that can damage the chromosomes or genes of the fetus.

The risk of cancer and potential effects on the developing fetus are important reasons why cytotoxic substances are handled with great care.


Cytotoxic drugs can kill cells or prevent them from growing and dividing. Genotoxic drugs cause damage to DNA within cells.

Carcinogens damage DNA in cells. This can lead to mutations that can lead to cancer. Mutagenic substances can damage the genes of a developing fetus.

Danger of Cytotoxic Substances

Cytotoxic drugs kill cancer cells but also damage normal, healthy cells. Many of the side effects of chemotherapy are related to this process.

take precautions

People using cytotoxic drugs or substances need to be very careful. The exact steps they need to take depend on how they were exposed to a substance.

Precautions people may need to take when handling cytotoxic substances include:

  • The shirt cuffs of the gloves are tucked under the gloves
  • long sleeve clothing
  • Disposable dress
  • goggles
  • respiratory protection

Patients receiving cancer treatment may need to take cytotoxic precautions when they go home. These measures protect their families, who may be accidentally exposed to bodily fluids containing cytotoxic chemicals.

8 things to know before your first chemo

Cytotoxicity test

Cytotoxicity testing helps people stay safe where they live and work. It also helps companies keep products such as medical devices safe. If something is marked as cytotoxic, one knows that precautions need to be taken when handling it.

Cytotoxicity tests are used by many manufacturers, including those that make drugs and cosmetics. The botanical products used in the extract are also tested for toxicity.


People handling cytotoxic substances need to be very careful. There are steps they can take to stay safe, such as wearing gloves and gear to protect them from these substances.

People undergoing chemotherapy may need to take precautions to avoid accidental exposure of those around them to the cytotoxic drugs they are taking.

What is Dioxin?


Cytotoxic substances damage or kill cells. Drugs such as chemotherapy are cytotoxic. The venom produced by some animals may be cytotoxic. Even certain cells in your body are considered cytotoxic.

People who have to deal with cytotoxic substances need to be very careful. Since these substances damage cells, they can increase the risk of cancer. They may also negatively affect the fetus.

VigorTip words

The word “cytotoxicity” can seem scary — especially when you see the label of a drug you need to take. The word means a substance that can damage or kill cells. However, these substances also exist in nature. Your body even makes its own cytotoxic substances to help your immune system fight.

It is important to understand how cytotoxic substances work because they are dangerous. If you handle them, you need to take precautions to protect yourself and the environment from their harsh effects.

EPA plans to regulate toxic, widely used ‘permanent chemicals’