What is the mechanism of action of polyenes like nystatin?

Polyenes, such as nystatin, function primarily by binding to ergosterol, a crucial component of fungal cell membranes. Ergosterol plays a similar role in fungal cells as cholesterol does in human cells, contributing to membrane fluidity and integrity. When polyenes interact with ergosterol, they disrupt the membrane structure, increasing its permeability. This disruption leads to leakage of essential cellular components, ultimately resulting in cell death.

The specific interaction with ergosterol is what differentiates polyenes from other antifungal agents that might target different cellular processes, such as cell wall synthesis, RNA synthesis, or DNA replication. Therefore, understanding this mechanism is vital for recognizing how nystatin and other polyenes effectively treat fungal infections.