Inhibitory effects of coptisine on monoamine oxidase activity.

The effects of coptisine on monoamine oxidase (EC 1.4.3.4; MAO) activity in mouse brain were investigated. Coptisine showed an inhibitory effect on MAO activity with a concentration-dependent manner. Coptisine exhibited 51.0% inhibition of MAO activity at . The value of coptisine was . Coptisine inhibited MAO activity competitively with kynuramine as a substrate. The value of coptisine was . These results indicate that coptisine functions to regulate the catecholamine content at biologically active sites.