5β,6β-epoxy Cholestanol is an oxidative metabolite of cholesterol that is formed via radical and non-radical oxidation of cholesterol at the 5,6-double bond.[1] [2] It induces release of lactate dehydrogenase (LDH) and apoptosis in macrophage-differentiated U937 cells.[3] 5β,6β-epoxy Cholestanol has been found in human fatty streaks and advanced atherosclerotic lesions but is not present in normal aortic tissue.[4]
Reference:
[1]. Pulfer, M.K., and Murphy, R.C. Formation of biologically active oxysterols during ozonolysis of cholesterol present in lung surfactant. The Journal of Biological Chemisty 279(25), 26331-26338 (2004).
[2]. Aringer, L., and Eneroth, P. Formation and metabolism in vitro of 5,6-epoxides of cholesterol and β-sitosterol. J. Lipid Res. 15(4), 389-398 (1974).
[3]. Lordan, S., O'Brien, N.M., and Mackrill, J.J. The role of calcium in apoptosis induced by 7β-hydroxycholesterol and cholesterol-5β,6β-epoxide. J. Biochem. Mol. Toxicol. 23(5), 324-332 (2009).
[4]. Garcia-Cruset, S., Carpenter, K.L., Guardiola, F., et al. Oxysterol profiles of normal human arteries, fatty streaks and advanced lesions. Free Radic. Res. 35(1), 31-41 (2001).