Arachidonic acid diet attenuates brain Aß deposition in Tg2576 mice.

The amyloid ß-protein (Aß) is believed to play a causative role in the development of Alzheimer's disease (AD). Because the amyloid precursor protein (APP), a substrate of Aß, and ß-secretase and γ-secretase complex proteins, which process APP to generate Aß, are all membrane proteins, it is possible to assume that alterations in brain lipid metabolism modulate APP and/or Aß metabolism. However, the role of polyunsaturated fatty acids in Aß metabolism remains unknown. We report here that 9 months-treatment of Tg2576 mice with arachidonic acid (ARA)-containing (ARA+) diet prevented brain Aß deposition in 17-month-old Tg2576 mice. APP processing to generate soluble APPα, CTF-ß, and Aß synthesis was attenuated in Tg2576 mice fed with the ARA+ diet. These findings suggest that ARA+ diet could prevent Aß deposition through the alteration of APP processing in Tg2576 mice.