Dequalinium chloride (Decabis) , a topical bacteriostat, is a selective blocker of apamin-sensitive K+ channels. It is used in wound dressings and mouth infections and may also have antifungal action, but may cause skin ulceration.

PKC:7 μM-18 μM

Dequalinium chloride effectively inhibits nicotinic responses in skeletal muscles and potassium ion channels sensitive to apamin in bee venom in hepatocytes. It also acts as a ganglionic blocking agent (EC50: 2 μM) and, as a cationic lipophilic PKC inhibitor, shares a similar structure with the dye Rhodamine 123. Dequalinium chloride irreversibly inhibits PKCα/β through covalent binding under UV irradiation. It selectively accumulates in the mitochondria of tumor cells, inducing mitochondrial toxicity by blocking mitochondrial enzymes, thereby disrupting cellular energy production and leading to cell death. Dequalinium inhibits the binding of 125I-monoiodoapamin (Ki: 1.1 μM) and prevents potassium ion loss (induced by angiotensin II, IC50: 1.5 μM). In cultured rat sympathetic neurons, Dequalinium reversibly inhibits the slow component of the afterhyperpolarization (AHP) sensitive to apamin, subsequently generating a single action potential.

In mice bearing MB49 bladder tumor xenografts, Dequalinium chloride (2 mg/kg/day i.p.) exhibited anticancer activity with a T/C value of 210%.