Quercetin-3-O-β-D-glucopyranoside, a dietary flavonoid, protects PC12 cells from H₂O₂-induced cytotoxicity through inhibition of reactive oxygen species.

Since flavonols are antioxidant agents, they could in principle, beneficially affect neurodegenerative diseases where reactive oxygen species are involved. Quercetin derivatives are the most abundant dietary flavonoids, and we have investigated the capacity of quercetin-3-O-β-d-glucopyranoside (Q3G) isolated from Echinophora cinerea to protect PC12 cells from H2O2-induced cytotoxicity. Direct cytotoxic effects of H2O2 on PC12 in presence and absence of Q3G were evaluated. H2O2 induced cytotoxicity in a concentration dependent manner (IC50=118 ± 5.09 μM, 24h). Pretreatment of cells with non-toxic concentrations of Q3G protected cells from H2O2-induced cytotoxicity, leading to a decrease in the generation of reactive oxygen species. These observations qualify Q3G as an interesting dietary compound worth further investigation as a cytoprotective agent.