Other studies have used mouse models for PD induced by neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and KPF, at doses of 25, 50, and 100 mg per kg, as therapy, and the authors have observed that KPF improved motor coordination, increased levels of striatal dopamine and its metabolites, increased endogenous antioxidants SOD and glutathione peroxidase (GSH-PX) levels, and reduced malondialdehyde (MDA) levels (Li and Pu, 2011). This evidence concerns the gene SOD1 and Parkinson disease.