25 Hydroxycholesterol (2140-46-7) is a metabolite resulting from the action of cholesterol 25-hydroxylase on cholesterol. However, since cholesterol 25-hydroxylase knock-out mice still have significant levels of 25-hydroxycholesterol there must be alternate pathways of generation that have yet to be determined.1 Likewise, the biological role of 25-hydroxycholesterol remains somewhat unclear. 25-Hydroxycholesterol is frequently mentioned as an important regulator of cholesterol metabolism, but apparently normal cholesterol regulation in organisms with both high and low levels of the compound make this association unclear. More recent reports have linked 25 hydroxycholesterol and one of it's metabolites to immunoregulatory roles2, but more information is needed before it is clear if that is indeed a primary role for the compound.
References/Citations - 25 Hydroxycholesterol
1) Diczialusy (2013), On the formation and possible biological role of 25-hydroxcholesterol; Biochimie, 95 455
2) McDonald and Russell (2010), 25-hydroxycholesterol: a new life in immunology: J. Leuko. Biol. 88 1071