Exploring the therapeutic potential of NLRP3 inhibitors in Parkinson's Disease: a systematic review of in-vivo studies.

BACKGROUND

Parkinson's disease is a progressive neurodegenerative disorder characterized by motor symptoms such as tremors, rigidity, and bradykinesia. Although the exact etiology is unknown, the nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome-induced inflammation, plays a crucial role in the pathogenesis of Parkinson's disease. Many NLRP3 inhibitors are recognized for their role as potential therapeutic interventions for Parkinson's disease.

METHODS

A systematic literature search was performed in PubMed, Embase, and Science Direct databases for papers published during the 10 years prior to May 2023. All animal interventional studies assessing the effects of NLRP3 inhibitors on Parkinson's disease animal models were included. Primary outcomes included NLRP3 inflammasome inhibition, microglial activation reduction, oxidative stress, and anti-inflammatory marker reduction. The secondary outcomes included dopaminergic neuron loss alleviation and behavioral motor function attenuation. Quality assessment and narrative synthesis of the studies were performed.

RESULTS

Twenty-four studies out of 796 papers initially identified met the inclusion criteria. All the included studies, except one, found a reduction in NLRP3 inflammasome activation and anti-inflammatory markers in Parkinson's disease animal models after treatment with various NLRP3 inhibitors compared to control groups without inhibitors. Additionally, eighteen out of twenty-four inhibitors decreased microglial activation and behavioral deficits. Moreover, ten inhibitors attenuated oxidative stress, and twenty-two out of twenty-four alleviated dopaminergic neuron loss. The inhibitors utilized different mechanisms and pathways to exert their effects, including the NLRP3/Caspase-1 pathway, the NF-κB/NLRP3 pathway, inhibition of ROS and/or pyroptosis, as well as autophagy and mitophagy.

CONCLUSION

NLRP3 inhibitors represent a prospective therapy for Parkinson's disease, demonstrating efficacy in lowering neuroinflammation and protecting against dopaminergic loss. However, constraints, such as a male animal focus, apparent regional bias from China-centric studies, and diversity in induction models, entail the results presented herein require cautious interpretation. Further research, including preclinical and clinical studies, is required to thoroughly examine the safety, effectiveness, and generalizability of NLRP3 inhibitors in Parkinson's disease.