Genistein attenuates D-galactose-induced oxidative damage through decreased reactive oxygen species and NF-κB binding activity in neuronal PC12 cells.

Aims: We investigated the mechanism of D-galactose (DG)-induced oxidative damage and the neuroprotective action of genistein in PC12 cells.

Main Methods: PC12 cells were treated with 40mM DG dissolved in medium containing 85% RPMI1640, 10% HBS and 5% FBS with or without genistein. We measured the protein expression of β-amyloid (Aβ), advanced glycation end products (AGEs), IκB-α and manganese-superoxide dismutase (MnSOD) by western blotting, intracellular reactive oxygen species (ROS) by 2, 7-dichlorofluorescin-diacetate, and the binding activity of nuclear factor kappa B (NF-κB) by electrophortic mobility shift assay.

S-Adenosylhomocysteine increases beta-amyloid formation in BV-2 microglial cells by increased expressions of beta-amyloid precursor protein and presenilin 1 and by hypomethylation of these gene promoters.

S-Adenosylhomocysteine (SAH) has been implicated as a risk factor for neurodegenerative diseases such as Alzheimer's disease. As SAH is a potent inhibitor of all cellular methyltransferases, we herein examined the hypothesis that SAH may increase the formation of amyloid beta-peptide (Abeta) in BV-2 mouse microglial cells through hypomethylation of presenilin 1 protein (PS1) and beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), both of which cleave Abeta precursor protein (APP) to form Abeta. The results showed that SAH increased Abeta protein formation in a concentration-dependent manner (10-500 nM), and this effect of SAH was accompanied by significantly increased expression of APP and PS1 proteins, although SAH only significantly increased the expression of BACE1 at the highest concentration used (500 nM).

Soy isoflavones attenuate oxidative stress and improve parameters related to aging and Alzheimer's disease in C57BL/6J mice treated with D-galactose.

d-galactose (DG)-induced aging in C57BL/6J (B6) mice (3-4 mo) was used to examine the effects of soy isoflavones (SIF). Mice were divided into six groups: corn oil control, DG treatment, DG+melatonin (1 mg/kg BW), and DG+low (0.1 mg/kg), median (0.