Introduction: Stem cells are cells capable of creating any type of cell in the body. Under the influence of different growth factors in the culture medium, they can be converted into cells with specific functions such as heart muscle cells or insulin- producing cells, pancreas, etc. These cells also have their own renewal capability, meaning they are able to perform mitosis divisions in order to preserve their population. An epithelial cell is a specialized cell that forms a thin tissue barrier, which can be on the surface or inside a tissue. Different types of epithelial cells, including epithelial tissue, skin, mouth, respiratory tract, etc. can be found throughout the body. Oral mucosa is constantly exposed to environmental forces and must be constantly renewed. Accordingly, oral mucosal epithelium contains a large reservoir of epithelial stem cells, which is essential for tissue homeostasis. If stem cells change, they can become cancer cells. The only difference between cancer stem cells and stem cells is they also have tumorigenic power. Some environmental factors can turn them into cancer cells by affecting stem cells. Cigarettes are one of these cancer-causing substances, accounting for 22 percent of all cancer deaths annually. Cigarette smoke in terms of physical nature has two parts: gas (95%) and particles (5%), which contains substances such as droplets, which is the most important known carcinogen in nature. More than 5000 elements have also been found in cigarette smoke, among which at least 150 compounds contain free radicals, which can cause systemic disorders such as heart disease, cancer and lung disease. Recently, it has been proven that imbalances in the level of free radicals and reactive oxygen species along with antioxidants may play a key role in the onset and development of several inflammatory oral injuries. When smoking, smoke from cigarettes has direct contact with most stem cells (epithelial) of the palate, which can cause oral cavity cancer. Oral cancer is a cancer that occurs as a result of the growth of malignant cells. This cancer, which occurs in the area of mouth, tongue, foam, palate, mouth and gums, is more common in smokers. Oral cavity cancer is often caused by abnormal division of stem cells (epithelial). In a healthy body, there are thousands of billions of cells that are divided according to the body's needs. Healthy cells have life cycles, reproduction and death based on their type. With the death of old or damaged cells, new cells replace them. they will be One of the environmental factors that disrupts this process and alters stem cells is oxidant or oxygen free radicals in cigarette smoke, which changes epithelial stem cells to cancer stem cells that eventually lead to tumors and cancer. The main reason for the oxidant damage is that free radicals lack a whole pair of electrons, take electrons from other molecules and damage those molecules in the process. Antioxidants neutralize free radicals by losing some of their electrons, thereby no longer harming the body and improving the general health of the body. Vitamin C is one of the substances with high antioxidant properties and studies have shown that vitamin C consumption can have a great impact on preventing cancer.
Methods: In this review article, searches were conducted in electronic and scientific databases, Magiran, SID, PubMed, Google Scholar and other valid databases and 50 valid articles related to the subject were used.
Results: The results show that the damage caused by smoking is caused by substances called oxidants. These substances affect them by disrupting stem cell niches and turning them into cancer cells and can eventually cause cancer. To prevent damage caused by oxidants to the body, antioxidants can be used. Vitamin C is one of the examples of unnecessary antioxidants and people who smoke can first avoid smoking to prevent cancer and if unable to, Use vitamin C to maintain your health.
Conclusion: The oxidant in cigarette smoke causes oral cavity cancer and other cancers that can reduce the oxidant effect by using antioxidants, especially vitamin C.
Keywords: Stem cells, cancer, cigarette smoke and antioxidants.