Hydroxystilbamidine

Hydroxystilbamidine isethionate is a member of the diamidines, a large family of biochemially and pharmacologically interesting compounds. It has a rather unusual combination of properties, exhibiting antitrypanosomal, antimaliarial, antifungal and carcinostatic activities. It also appears to act as an immunosuppressant. This drug may be used in the treatment of blastomycosis, a disease cased by the dimorphic fungus or mold called Blastomyces dermatitids. Blastomycosis is a pulmonary infection that can lead to fever, cough and (rarely) symptoms similar to tuberculosis. Hydroxystilbamidine has largely been replaced with amphotericin B.

Hydroxystilbamidine isethionate (HSB) acts on extracellular DNA and lysosomes. In Trypanosomes there is extensive and selective binding of HSB to the kinetoplastic DNA. This inhibits cell division and reproduction. In yeast there is evidence of binding to extranuclear DNA causing numerous mutations. HSB is also taken up in the lysosomes and leads to a significant increase in the number of lysosome-like bodies and secretion granules in trypanosomal organisms. HSB may also stabilize lysosomal membranes. HSB has also been found to bind RNA and is a powerful inhibitor of cellular ribonucleases.