Phytic acid attenuates inflammatory responses and the levels of NF-κB and p-ERK in MPTP-induced Parkinson's disease model of mice

Phytic acid (PA) is a naturally occurring constituent which exhibits protective action in Parkinson's disease (PD). Inflammation in the central nervous system (CNS) is strongly associated with neuronal death in PD. However, the molecular mechanism of the protective effect of PA in PD has not been fully elucidated. In this study, we tried to testify the protection of PA on neuron and inflammatory responses in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model of mice and investigated the mechanism involved in them. Motor behavior test and tyrosine hydroxylase (TH) immunohistochemistry method showed PA significantly inhibited MPTP-induced dopaminergic cell loss in the substantia nigra (SN). Moreover, using immunohistochemistry method and quantitative polymerase chain reaction (qPCR), microglial activation and inducible nitric oxide synthase (iNOS) were found to be markedly repressed by PA. Via western blot assay, expressions of nuclear factor κB (NF-κB) and phosphorylated extracellular signal-regulated kinase (p-ERK) were significantly attenuated by PA. In conclusion, it is suggested that PA has a neuroprotective effect in MPTP-induced PD model and the neuroprotection is correlated with its anti-inflammatory effect which may be associated with suppression of pathways that involved in NF-κB and p-ERK.