The effect of ghrelin hormone on level of tumor necrosis factor alpha and gene expression of cytochrome b and interleukin 10 in substantia nigra in an animal model of Parkinson’s disease

Inflammatory pathways play an important role in incidence and progression of Parkinson’s disease (PD). Ghrelin has anti-inflammatory and antioxidant effects and inhibits the release of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) .This study has aimed to investigate the effect of ghrelin hormone on amount of TNF-α, and gene expression of cytochrome b and interleukin10 in Parkinson’s disease induced by1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in male mice.

Thirty male NMRI mice were randomly divided to 5 groups (six mice in each) including control, saline, ghrelin hormone, Parkinson, and Parkinson + ghrelin hormone. Parkinson’s disease was induced by intraperitoneal (i.p.) injection of 25mg/kg MPTP for 4 days. Ghrelin was injected for 28 days (0.4μg/kg, i.p.). Catalepsy was evaluated by bar test at the 1st, 7th, 14th, 21th, and 28th day after injection of MPTP. TNF-α level and gene expression of cytochrome b, and interleukin10 were measured in Substantia nigra and Corpus striatum by ELISA and Real time PCR techniques at the 29th day.

Catalepsy and TNF-α level significantly increased in substantia nigra and corpus striatum of the Parkinson group, whereas gene expression of cytochrome b, and interleukin10 decreased (p < 0.001). On the other hand, ghrelin hormone significantly decreased catalepsy and TNF-α level while increased gene expression of cytochrome b, and interleukin10 (p < 0.001).

It seems that ghrelin hormone improves catalepsy, decreases TNF-α level, and increases gene expression of cytochrome b, and interleukin10 by inhibiting inflammatory pathways involved in PD.