Quercitrin, a glycoside form of quercetin, prevents lipid peroxidation in vitro

Reactive oxygen species have been demonstrated to be associated with a variety of diseases including neurodegenerative disorders. Flavonoid compounds have been investigated for their protective action against oxidative mechanisms in different in vivo and in vitro models, which seems to be linked to their antioxidant proper-ties. In the present study, we examine the protective mechanism of quercitrin, a glycoside form of quercetin, against the production of TBARS induced by different agents. TBARS production was stimulated by the incubation of rat brain homogenate with Fe2+, Fe2+ plus EDTA, quinolinic acid (QA), sodium nitroprusside (SNP) and potassium ferricyanide ([Fe(CN)(6)](3-)). Quercitrin was able to prevent the formation of TBARS induced by pro-oxidant agents tested; however, it was more effective against potassium ferricyanide ([Fe(CN)(6)](3-), IC50 = 2.5), than quinolinic acid (QA, IC50 = 6 mu g/ml) and sodium nitroprusside (SNP, IC50 = 5.88 mu g/ml) than Fe2+ (Fe2+, IC50 = 14.81 mu g/ml), Fe2+ plus EDTA (Fe2+ plus EDTA, IC50 = 48.15 mu g/ml). The effect of quercitrin on the Fenton reaction was also investigated (deoxyribose degradation). Quercitrin caused a significant decrease in deoxyribose degradation that was not dependent on the concentration. Taken together, the data presented here indicate that quercitrin exhibits a scavenger and antioxidant role, and these effects probably are mediated via different mechanisms, which may involve the negative modulation of the Fenton reaction and NMDA receptor. (c) 2006 Elsevier B.V. All rights reserved.