PON1 and PON3 in Alzheimer's Disease: Similar Functions but Different Roles.

Paraoxonase 1 (PON1) and Paraoxonase 3 (PON3) are enzymes located on the surface of high-density lipoprotein (HDL) and share similar antioxidant properties, possibly modulated by other proteins such as Myeloperoxidase (MPO), which drives the shift from functional to dysfunctional HDL. PON1 has been extensively studied in relation to Alzheimer's Disease (AD), but the role of PON3 remains unknown. To fill this knowledge gap, the study analyzed PON3 protein levels and PON1-arylesterase activity in 99 AD patients, 100 patients with mild cognitive impairment (MCI), and 79 cognitively normal controls.