Effects of exercise on α-synuclein in rodent models of Parkinson's disease: a systematic review and meta-analysis.

This study evaluated the effects of exercise on α-synuclein (α-syn) expression in preclinical models of Parkinson’s disease (PD), examining the impact of exercise protocol, animal age, model types, brain region, and α-syn species. A systematic search of PubMed, Web of Science, Embase, and Scopus was conducted for studies published up to August 10, 2025. Of 1,835 records, 22 provided data suitable for meta-analysis. Exercise significantly reduced α-syn levels in PD models (-1.40, [-1.83, -0.97]). Region-specific analyses showed significant reductions in the substantia nigra (-1.34, [-1.75, -0.93]), and striatum (-1.67, [-2.35, -0.98]). Exercise also showed differential effects across α-syn species, with the greatest reduction observed in phosphorylated α-syn (-2.46, [-3.60, -1.33]), followed by oligomeric (-1.91, [-2.73, -1.09]) and aggregated α-syn (-1.59, [-2.99, -0.19]). Overall, these findings suggest that exercise reduces α-syn burden in preclinical PD models and may exert neuroprotective effects.