Neuroprotective Effect of Quercetin in 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Model of Parkinson’s Disease

Parkinson's disease (PD) is a common neuropathological disorder caused by degeneration of dopaminergic neurons in the substantia nigra pars compacta. Quercetin (SNPC) is a compound with both anti-inflammatory and anti-oxidant effects, which can cross the blood brain barrier. The aim of the present study was to evaluate neuroprotective effect of quercetin in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced model of PD in male mice.

48 male NMRI mice were divided into 6 groups (n=8); control, saline, MPTP, MPTP+ 20mg/kg quercetin, MPTP+ 25mg/kg quercetin, and MPTP+ 30mg/kg quercetin. To induce PD model, MPTP (25mg/ Kg) was injected intraperitoneally (i.e.) for 4 day. Catalepsy test was assessed by test bars one and 21 days after the last injection MPTP. Quercetin (20, 25, 30mg/kg/day) was applied orally for 21 days. Dopaminergic neurons of SNPC were determined by immunohistochemical labeling. The levels of interleukin 10 and TNF-α were determined in the substantia nigra and the striatum using ELISA technique.

Treatment with quercetin was significantly improved catalepsy. Furthermore, quercetin significantly enhanced the number of neurons in SNPC, increased interleukin 10 protein levels, and reduced TNF-α protein values.

Quercetin may exert a neuroprotective effect on progressive cell damage and the neuronal death in the substantia nigra in PD; possibly via modulation of inflammatory mediators.