In a rotenone-induced PD rat model, spermidine treatment effectively counteracted rotenone’s effects by restoring motor function, alleviating oxidative stress, decreasing pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6), and replenishing striatal catecholamines and gamma-aminobutyric acid (GABA) concentrations [166]. Here, TNF is linked to Parkinson disease.