The authors observed that long-term administration of L-dopa (30 mg/kg) produced neurotoxicity through Caspase-3 and c-Jun expression mediated by the ERK/JNK system; however, with fucoxanthin treatment, a decrease in ERK1/2, JNK1/2, c-Jun phosphorylation, and Caspase-3 was verified, improving the exercise ability of PD mice. This evidence concerns the gene JUN and Parkinson disease.