Ergosterol endoperoxide is a derivative of ergosterol. It has been isolated from a variety of fungi, yeast, lichens and sponges. Ergosterol endoperoxide has been shown to inhibit the growth of some cancer cells and to induce apoptosis of HL60 human leukemia cells. Ergosterol endoperoxide also decreases lipid peroxidation of rat liver microsomes and suppresses the proliferation of mouse and human lymphocytes stimulated with mitogens. It has been reported as having immunosuppressive, antiplasmodial, antimycobacterial, antiviral, anti-inflammatory and antitumoural properties. The interaction of Trypanosoma cruzi with ergosterol peroxide in vitro resulted in a strong lytic activity possibly due to the disruption of the parasite membrane.