arsenic

Arsenic is a naturally occurring metalloid element with the symbol As and atomic number 33. It exists in several allotropic forms and is found in both organic and inorganic compounds. Arsenic has a long history of medicinal use, particularly in traditional Chinese medicine for over two millennia, as well as notorious use as a poison. In modern medicine, certain arsenic compounds—most notably arsenic trioxide—are used to treat acute promyelocytic leukemia (APL) and other hematological malignancies due to their anti-tumor properties[4][7]. The mechanism of action involves disruption of cellular metabolism by binding to thiol groups on enzymes, inhibition of lipoic acid-dependent enzymes such as pyruvate dehydrogenase, interference with ATP production via uncoupling oxidative phosphorylation, induction of oxidative stress through increased hydrogen peroxide production, and promotion of apoptosis in malignant cells[5][4]. Arsenic is highly toxic; its toxicity depends on chemical form—with inorganic forms being more hazardous than organic ones—and dose. Chronic exposure can cause multisystem organ damage including skin lesions and cancer[1][8].

Other names

Asatomic number 33realgar (arsenic disulfide mineral)orpiment (arsenic trisulfide mineral)white arsenic (arsenic trioxide, As2O3)