TH and Parkinson disease: For example, exenatide intake [102] reduced the severity of symptoms in PD patients; NLY01 had a beneficial effect on young patients with PD (aged less than 60 years) [86]; lixisenatide and liraglutide showed neuroprotective effects in the MPTP mouse model of PD by preventing motor impairment and reduction in TH levels in the SNpc and basal ganglia [101].