Enhanced inhibition of free radical-induced deoxyribose breakdown by Alzheimer brain homogenates

The ability of homogenates from Alzheimer and control brains to inhibit for mation of thiobarbituric acid reactive products (TBAR) induced by free radi cals was compared. The assay for TEAR was modified by adding 1% sodium dode cyl sulfate (SDS) to prevent chromogen adsorption by biological matrices, a nd by extending the incubation time. The inhibitory activities required sma ller equivalents of Alzheimer brain homogenates than control homogenates. S imilar inhibitory activities were seen in homogenates from amygdala, tempor al cortex and cerebellum. The inhibitory activities were similar in brain h omogenates from individuals with different apolipoprotein E status. These r esults indicate that Alzheimer brain tissue has either increased content of free radical scavengers or is more sensitive to free radical attack than c ontrol brains. (C) 1999 Elsevier Science ireland Ltd. All rights reserved.