Effect of Quercetin on d-Galactose aging model in human erythrocytes

Blood is not only a supplier of O2 and nutrients for tissues, but also removes metabolic waste and oxidative species, thus playing a special role in aging. Aging may exert its impact on plasma membrane and, among integral membrane proteins, on the Cl- /HCO3 - exchanger, which is involved in gas exchange and acts as a major site of cytoskeleton attachment to the membrane. The aim of the present work was to verify the possible beneficial effect of 10 µM Quercetin (Q), a polyphenolic flavonoid compound with strong antioxidant activity, on a model of accelerated aging represented by human erythrocytes exposed to 50 or 100 mM d Galactose for 24 hours. The rate constant for SO4 2− uptake through the anion exchanger Band 3 protein (B3p) has been monitored along with lipid peroxidation, SH- groups oxidation and glycated hemoglobin (A1c) levels, all of which are known to critically affect B3p function. Our results show that: i)d-Gal accelerates the rate constant for SO4 2- uptake, induces lipid peroxidation, SH-group oxidation and A1c; ii)Q attenuates d-Gal effect by preventing the rate constant acceleration, lipid peroxidation and total SH- group oxidation, rather than A1c formation. These findings may help to clarify the mechanism of aging in human erythrocytes and propose Q as a potential dietary supplement for novel therapeutic strategies to counteract oxidative age-related disturbances linked to B3p dysfunction. Future experiments are needed to elucidate Q possible antiglycant effect.