A Mn3O4 nanozyme (Mnf) having similar ROS-scavenging actions with SOD, CAT, and GPx antioxidant activity was designed by Singh et al. This nanozyme prevented cytotoxicity in an MPP+ (1-methyl-4-phenylpyridinium) treated PD-like model due to modifying the oxidation state of manganese (Mn2+/Mn3+) in the material. Here, CAT is linked to Parkinson disease.