Alternariol is the mycotoxin produced by Alternaria fungi. It occurs naturally in foodstuffs and is frequently found as contaminant in fruit and grain products. It forms reactive oxygen species and interacts with DNA topoisomerase, thereby generating both single- and double-strand DNA beaks. Alternariol demonstrated dual inhibition of acetylcholinesterase (AChE) and monoamine oxidase (MAO-A) enzymes extracted from whole and five different parts of male albino rat brains; namely: frontal cortex, basal ganglia, cerebellum, pons, medulla oblongata. In vitro studies have suggested that Alternariol may be linked to reduced immune response in case of infections and/or a disturbed balance of the adaptive immune system. Although the absorption appears to be relative low, it is nevertheless important to further clarify the mode of genotoxicity.