o-Phenylenediamine is a chemical intermediate used in the synthesis of fungicides, corrosion inhibitors, pigments, and pharmaceuticals. It is also used to remove elemental sulfur in mining ores, and to remove aldehyde color formers in polymeric products. o-Phenylenediamine is also a substrate of enzyme-catalyzed oxidation reactions. 2,3-Diaminophenazine was detected as a product of peroxidase-catalyzed oxidation of o-phenylenediamine dihydrochloride in ELISA procedures. o-Phenylenediamine is a methaemoglobin-producer. Oral administration of o-phenylenediamine led to significantly increased incidences of liver tumors in the rat and mouse.

Thiabendazole (TBZ, trade names Mintezol, Tresaderm, and Arbotect) was first introduced in 1962. This drug is a fungicide and parasiticide and is indicated for the treatment of: strongyloidiasis (threadworm), cutaneous larva migrans (creeping eruption), visceral larva migrans, trichinosis: relief of symptoms and fever and a reduction of eosinophilia have followed the use of this drug during the invasion stage of the disease. But usage of this drug was discontinued. The precise mode of action of thiabendazole on the parasite is unknown, but it may inhibit the helminthspecific enzyme fumarate reductase. It was shown, also that thiabendazole reversibly disassembles newly established blood vessels, marking it as vascular disrupting agent (VDA) and thus as a potential complementary therapeutic for use in combination with current anti-angiogenic therapies. Was shown, that vascular disruption by TBZ results from reduced tubulin levels and hyper-active Rho signaling. In addition, was confirmed, that thiabendazole slowed tumor growth and decreased vascular density in preclinical fibrosarcoma xenografts and thus, it could lead directly to the identification of a potential new therapeutic application for an inexpensive drug that is already approved for clinical use in humans.