Dietary intake of plant sterols stably increases plant sterol levels in the murine brain.
There is general agreement that the blood-brain barrier efficiently protects the brain from the influence of peripheral sterols. Here, we demonstrate for the first time that increased dietary intake of plant sterols results in a concentration-dependent, almost irreversible accumulation of plant sterols within the murine brain. Transendothelial flux efficiency is determined by the molecular complexity of the side-chain, with a selective advantage for campesterol over sitosterol. In addition, we showed in vitro and ex vivo, that plant sterols preferentially accumulate within DRM´s of brain cells, most probably influencing g-secretase-mediated cleavage of APP in lipid rafts. These data indicate the need for further studies on the influence of long-term plant sterol intake on normal and pathological brain function and its influence on b-amyloid pathology in Alzheimer Disease.