Toxicology is a science that deals with poisons, their effect, and the problems involved. The xenobiotics included food ingredient, drugs, metal, toxic gas, trace element, toxin, nanomaterials, and so on. With the development of the society, the xenobiotics bring a high potential risk to human and animals. It is pivotal to explore the detailed mechanistic understanding of the ways in which xenobiotic substances perturb biological systems and lead to adverse outcomes. The paper focused on the therapeutic and toxic mechanism of xenobiotics, which is appreciated in this special issue. We invite investigators to contribute review and original research articles describing recent findings and future perspectives in the field of the toxic effects of xenobiotics on the health of humans and animals.

Potential topics include but are not limited to the following:

• Environmental exposures with potential risks for adverse effects in humans and animals
• The interrelationships between nutrition and toxicology
• New techniques for assessing potential toxicity, including molecular biology
• Mechanisms underlying toxic phenomena
• The interactions of multiple stressors and their resulting effects