Antioxidant activity, cellular bioavailability, and iron and calcium management of neuroprotective and nonneuroprotective flavones

Few studies have been undertaken on the relationship of the structure of flavones and neuroprotection. Previously, we described the structural determinants of the neuroprotective activity of some natural flavones in cerebellar granule neurons in culture against an oxidative insult (H2O2). In the present work, we analyzed anti-oxidant activity, cellular iron, and Ca(2+) levels and cellular bioavailability of neuroprotective and nonneuroprotective flavones in the same experimental paradigm. Oxidative cellular damage produced by H2O2 was prevented by all of the studied flavones with rather similar potency for all of them. Labile Iron Pool was neither affected by protective nor nonprotective flavones. Intracellular Ca(2+) homeostasis was not affected by protective flavones either. Nonetheless, fisetin, the nonprotective flavone, decreased Ca(2+) levels modifying Ca(2+) homeostasis. Methylation of the catechol group, although weakens anti-oxidant capacity, keeps the neuroprotective capacity with less degradation and lower toxicity, constituting promising structural alternatives as leads for the design of neuroprotective molecules.