TYR and early-onset autosomal dominant Alzheimer disease: It is believed that α-glucosidase, acetylcholinesterase (AChE), and tyrosinase are important metabolic enzymes relating with oxidative stress, and they are shown to be the key targets of T2DM, Alzheimer’s disease (AD), mammalian melanogenesis, and fruit or vegetable enzymatic browning, respectively [30,31,32].