Indole-3-carbinol (I3C): Inhibition Effect on Monoamine Oxidase A (MAO-A), Monoamine Oxidase B (MAO-B) and Cholinesterase Enzymes, Antioxidant Capacity and Molecular Docking Study

Monoamine oxidase A and B (MAO-A and MAO-B) isoenzymes play key roles in neurodegenerative diseases like Parkinson's disease (PD) and Alzheimer's disease (AD), arising from dopamine metabolism defects. Acetylcholinesterase (AChE) catalyzes acetylcholine (ACh) metabolism, linked to AD. This study investigated indole-3-carbinol (I3C) for in vitro inhibition on AChE, BChE, MAO-A, and MAO-B. In inhibition studies, I3C showed potent inhibitory potential against AChE and BChE enzymes (IC50 values of 239.29 mu M and 21.51 mu M, respectively). Corresponding K-i values were 243.52 mu M for AChE and 2.78 mu M for BChE, indicating significant inhibitory activity. Additionally, I3C effectively inhibited MAO-A and MAO-B enzymes (IC50 values of 19.52 mu M and 40.05 mu M, respectively). Its antioxidant and radical scavenging capabilities were assessed using various methods, including Fe3+-Fe2+ reducing capacity, cupric ion (Cu2+) reduction by Cuprac method, reducing capacity by FRAP method, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH center dot) scavenging method, and 2,2'-azino-bis(3-ethylbenzthiazoline-6sulfonic acid) radical (ABTS(*+)) scavenging. I3C showed potent inhibitory effects on AChE, BChE, MAO-A, and MAO-B enzymes. Additionally, I3C displayed a strong antioxidant capacity, suggesting its therapeutic potential as an antioxidant agent. Molecular docking simulations provided insights into I3C's interactions with the target enzymes, informing the design of novel therapeutic agents for neurodegenerative diseases.