A. RIPA-soluble (RIPA) Aβ1-40 and Aβ1-42 levels in brain homogenates of 15 months old 3xTg mice receiving placebo (CTR) or zileuton (ZIL) were measured by sandwich ELISA (** p<0.01). B. Representative sections of brains from the same two groups of mice immunostained with 4G8 antibody. C. Quantification of the area occupied by Aβ immunoreactivity in brains of the same two groups of mice (*p<0.05). D. Representative western blots analyses of APP, ADAM-10, BACE-1, Nicastrin, APH-1, PS1 and Pen-2 levels in brain homogenates from15 months old 3xTg mice receiving placebo (CTR) or zileuton (ZIL). E. Densitometric analyses of the immunoreactivities to the antibodies shown in the previous panel (*p<0.05). Results are mean ± sem.