Thonzonium

Thonzonium bromide causes dispersion and penetration of cellular debris and exudate, thereby promoting tissue contact of the active ingredients contained in the administered medication. It is an inhibitor of vacuolar ATPase that uncouples and blocks the function of the pump without inhibiting ATP hydrolysis.

Thonzonium bromide is a suface-active agent added in nasal and ear drops that potentiates and lenghten the time of skin contact with the active compounds and penetration through the cellular debris. Thonzonium bromide uncouples vacuolar ATPase in pathogenic fungi such as *Candida albicans* and inhibit cell growth in vitro. It interacts with the tether of subunit a (Vph1p) of the membrane-bound V0 subunit that forms the proton transport path. Disruption of the essential pump function prevents redistribution of cytosolic protons into the vacuolar lumen, resulting in acidification of the cytosol and cell death. A study reports that thonzonium bromide mediates an antiresorptive action on osteoclasts by inhibiting RANKL-induced osteoclast formation. It is shown to block the RANKL-induced activation of NF-jB, ERK and c-Fos as well as the induction of NFATc1 which is essential for OC formation. It also disrupted F-actin ring formation resulting in disturbances in cytoskeletal structure in mature OCs during bone resorption.