Administration of quercetin improves mitochondria quality control and protects the neurons in 6-OHDA-lesioned Parkinson's disease models

Abstract

Mounting evidence suggests that mitochondrial dysfunction and impaired mitophagy lead to Parkinson's disease (PD). Quercetin, one of the most abundant polyphenolic flavonoids, displays many health-promoting biological effects in many diseases. We explored the neuroprotective effect of quercetin <i>in vivo</i> in the 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD and <i>in vitro</i> in 6-OHDA-treated PC12 cells. <i>In vitro</i>, we found that quercetin (20 μM) treatment improved mitochondrial quality control, reduced oxidative stress, increased the levels of the mitophagy markers PINK1 and Parkin and decreased α-synuclein protein expression in 6-OHDA-treated PC12 cells. Moreover, our <i>in vivo</i> findings demonstrated that administration of quercetin also relieved 6-OHDA-induced progressive PD-like motor behaviors, mitigated neuronal death and reduced mitochondrial damage and α-synuclein accumulation in PD rats. Furthermore, the neuroprotective effect of quercetin was suppressed by knockdown of either <i>Pink1</i> or <i>Parkin</i>.