DPP4 and Alzheimer disease: Under the optimal extraction condition, the three OCP extracts were further evaluated regarding their phytochemical contents, antioxidant activities, enzyme inhibitory activities against the key enzymes relevant to obesity (lipase), type II diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), Alzheimer’s disease (cholinesterases and β-secretase), hypertension (angiotensin-converting enzyme), and genotoxicity.