Cyanidin-3-O-glucoside inhibits different enzymes involved in central nervous system pathologies and type-2 diabetes

Cyanidin-3-O-glucoside, also known as kuromanin, is one of the most important anthocyanins in nature. The scope of this paper is to discuss the potential role of this anthocyanin as therapeutic agent to prevent or treat chronic diseases in which oxidative stress may be involved through a modulation of certain enzymes. The inhibitory potential of cyanidin-3-O-glucoside against enzymatic targets of neurodegenerative or metabolic diseases was tested using monoamine oxidase A (MAO-A), acetylcholinesterase (AChE), tyrosinase (TYR), fatty acid amide hydrolase (FAAH), α-glucosidase (α-GLU) and dipeptidyl peptidase-4 (DPP-4). The antioxidant activity was evaluated through the xanthine/xanthine oxidase system. Cyanidin-3-O-glucoside inhibited MAO-A, TYR and FAAH enzymes whereas it could not inhibit AChE activity. IC 50 values for these assays were 7.6 μM, 18.1 μM and 152.1 μM, respectively. Additionally, cyanidin-3-O-glucoside was able to inhibit α-GLU (IC 50 = 479.8 μM) and DPP-4 (IC 50 = 125.1 μM). Finally, the antioxidant activity of cyanidin-3-O-glucoside was confirmed by the xanthine/xanthine oxidase method, being more efficient than gallic acid as superoxide radical scavenger. In conclusion, cyanidin-3-O-glucoside has demonstrated to be a candidate as enzyme inhibitor with neuroprotective, antioxidant and antidiabetic potential.