Bifonazole (Bay H-4502) acts to destabilize the fungal cytochrome p450 51 enzyme (also known as Lanosterol 14-alpha-demethylase). It works by inhibiting the production of a substance called ergosterol, which is an essential component of fungal cell membranes. This is vital in the cell membrane structure of the fungus. Its inhibition leads to cell lysis. The disruption in production of ergosterol disrupts the cell membrane and causes holes to appear. The cell membranes of fungi are vital for their survival. They keep unwanted substances from entering the cells and stop the contents of the cells from leaking out.

Bifonazole, a broad spectrum antifungal agent, inhibits monooxygenase activity and induces a type II binding spectrum in 2B4dH(H226Y), a modified enzyme previously crystallized in the presence of 4-(4-chlorophenyl)imidazole (CPI). [1] Bifonazole (40 mM) releases Ca2+ from the store sensitive to 1 mM thapsigargin, an endopolasmic reticulum Ca2+ pump inhibitor. Bifonazole (40 mM) per se induces capacitative Ca2+ entry while reduces 1 mM thapsigargin-induced capacitative Ca2+ entry. [2] Bifonazole is calmodulin antagonists which most effectively reduce glycolysis and ATP level in B16 melanoma cells. Bifonazole acts through allosteric regulation and detachment of glycolytic enzymes from cytoskeleton. [3] Bifonazole blocks PGE2 formation induced by 2 μm and 4 μm arachidonic acid clearly better than at 6 or 10 μm of the agonist. Bifonazole shows the same characteristics in MC3T3-E1 and UMR-106 cells stimulated by ionomycin or various concentrations of arachidonic acid. [4]

Bifonazole, but not clotrimazole, exhibits the characteristics of a peroxisome proliferator including hepatomegaly (increase in liver:body weight ratio), up to a 4-fold induction of lauric acid omega-hydroxylase activity and an 8-fold induction of palmitoyl-CoA oxidation by rat liver peroxisomes. Bifonazole also induces P402B1/2B2, P4503A and P4501A1, but not P4502E1. [5]