Neuroprotective and Anti-Inflammatory Effects of Pioglitazone on Parkinson's Disease: A Comprehensive Narrative Review of Clinical and Experimental Findings

Parkinson's disease (PD) is a chronic and progressive neurological disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). The pathogenesis of PD is strongly related to mitochondrial dysfunction, oxidative stress, and neuroinflammation. This indicates that PD can be treated with anti-oxidative substitutes and anti-inflammatory compounds. The neuroprotective and anti-inflammatory effects of peroxisome proliferator-activated receptor γ (PPAR-γ) agonists decrease cell death and halt the increase in neurodegeneration, which is why they have been given a lot of importance in research. Antidiabetic and anti-inflammatory effects have been observed to be generated by pioglitazone (PG), a selective peroxisome proliferator-activated receptor γ (PPAR-γ) agonist that regulates neural plasticity in various neurodegenerative disorders. The neuroprotective and anti-inflammatory effects of PG are assessed in this article. It was found that the patients with DM who received PG treatment were noticeably at a lower risk of PD. However, some clinical studies have not proven a strong link between the therapeutic effects of PG on PD. As per suggestions of preclinical studies, the therapeutic effects of PG treatment include; increased life expectancy of neurons, decreased oxidative stress, halted microglial activity, lower inflammation (reduced NF-κB, COX-2, and iNOS), reduced mitochondrial dysfunction, rise in motor function (motor agility) and non-motor function (lowered cognitive dysfunction). In conclusion, we determined that PG exerts neuroprotective and anti-inflammatory effects in PD models and it can be considered a potential therapeutic candidate for PD.