The study’s findings suggest that Met and/or Sem counteract T2DM and PD-induced changes in neurobehavioral and biochemical/molecular indices by boosting endogenous antioxidant systems, lowering lipid peroxidation, suppressing oxidative/inflammatory stress, and—most importantly, regulating Nrf2 and caspase 3. Here, CASP3 is linked to type 2 diabetes mellitus.