Quercetin-modulated erythrocyte membrane sodium-hydrogen exchanger during human aging: correlation with ATPase's

Content: Quercetin uptake by erythrocytes is rapid. The sodium-hydrogen exchanger (NHE) is a secondary active transporter, regulating intracellular pH, Na+ concentration and cell volume. Objective: The aim of present study was to investigate NHE as a function of human age and effect of quercetin on its activity. The NHE activity was correlated with erythrocytes ATPases. Materials and methods: We analyzed normal, healthy subjects of both sexes (20-82 years). NHE activity was estimated in terms of amiloride-sensitive H+-efflux from acid-loaded cells. Results: A significant age-dependent increase in NHE activity was observed during aging in humans. Concentration (10(-3) M to 10(-8) M)-dependent in vitro treatment with quercetin causes inhibition of NHE activity. The Na+/K+ -ATPase (r = 0.8882) and Ca2+-ATPase (r = 0.9540) activities positively correlated with it. Discussion and conclusion: The present data show an additional mechanism where dietary flavonoids may exerts beneficial effect during aging.