Oxysterols formation as a reflection of biochemical pathways: summary of in vitro and in vivo studies

abstract Oxysterols are cholesterol (CH)-oxidized products generated in organs via either enzymatic or non-enzymatic pathways. Their presence or absence in cells, tissues and organs may provide informationrelated to, for example, CH level and environmental status, inflammatory conditions near the CHmolecules, activity of specific enzymes at and around the CH site, types and concentrations of biochem-icals interacting with the CH, and the existence of specific signals. Here we present a mini-review of ourlabfindingsonoxysterolsformationinvitroandinvivo,including:theeffectsofdifferentreactivespeciesand availability of endogenous compounds on the type of oxysterol generated, the effects of enhancedactivity of paraoxonase 1 or hemeoxygenase on oxysterol level, the correlation between human diseasessuch as diabetes and oxysterol accumulation, and the correlation between oxidative stress in neuronspre-Parkinsonian conditions in an animal model and intracellular oxidative stress.© 2011 Elsevier Ireland Ltd. Published by All rights reserved.