Metabolic Interaction of the Active Constituents of Coptis chinensis in Human Liver Microsomes

Coptis chinensis is commonly used in traditional Chinese medicine. The study investigated metabolic interaction of the active constituents (berberine, coptisine, palmatine, and jatrorrhizine) of Coptis chinensis in human liver microsomes. After incubation of the four constituents of Coptis chinensis in HLMs, the metabolism of the four constituents was observed by HPLC. The in vitro inhibition experiment between the active constituents was conducted, and IC(50) value was estimated. Coptisine exhibited inhibitions against the formation of the two metabolites of berberine with IC(50) values of 6.5 and 8.3 μM, respectively. Palmatine and jatrorrhizine showed the weaker inhibitory effect on the formation of the metabolites of berberine. Berberine showed a weak inhibitory effect on the production of coptisine metabolite with an IC(50) value of 115 μM, and palmatine and jatrorrhizine had little inhibitory effect on the formation of coptisine metabolite. Berberine, coptisine, and jatrorrhizine showed no inhibitory effect on the generation of palmatine metabolite (IC(50) > 200 μM). The findings suggested that there are different degrees of metabolic interaction between the four components. Coptisine showed the strongest inhibition toward berberine metabolism.