An agent that causes irreversible and hereditary (mutation) changes in cellular genetic material, deoxyribonucleic acid (DNA) is defined as a mutagen. Changes in DNA caused by mutagens can damage the cells and cause certain diseases, such as cancer. Among the oldest and most recognized tests for the detection of mutagens we can mention those of Ames, which works with bacteria, and the test of the onion or Allium cepa test. One of the most effective ways to minimize the harmful effect of mutagenic substances is through the use of natural antimutagens. Natural antimutagenic substances, which may be present in plants, human diet and other sources have protective effects against mutagens. We showed that vitamin C and green tea infusions, in the Ames test, significantly mitigate the mutagenicity of sulfatiazole (a sulfa drug, an antibacterial commonly used) and nitrite (a food preservative and a normal body component) mixtures in acidic medium.