BDNF and Parkinson disease: Yang et al. described the protective effects of curcumin on the injured hippocampus in an 6-OHDA model of PD, including a significant improvement in mental status, weight gain, neurobehaviors, learning and memory, levels of dopamine and norepinephrine, neural regeneration in hippocampal tissue, and cell survival-related signaling pathways such as BDNF, TrkB, and PI3K [73].