Influence of coexisting components in Coptidis Rhizoma on excretion of magnoflorine in rat bile, urine, and feces

Abstract

Magnoflorine is an important aporphine alkaloid in Coptidis Rhizoma. As reported previously, coexisting components in Coptidis Rhizoma can change the pharmacokinetic characteristics of magnoflorine. To illustrate the interactional links of magnoflorine with its coexisting components in Coptidis Rhizoma, the present study investigated the influence of coexisting components in Coptidis Rhizoma on the excretion of magnoflorine in rat bile, urine, and feces. The rats were dosed with magnoflorine(30 mg·kg~(-1)) and water decoction of Coptidis Rhizoma(equivalent to 30 mg·kg~(-1) magnoflorine) via intragastric administration, and magnoflorine(10 mg·kg~(-1)) by intravenous administration, respectively, and the excretion of magnoflorine in rat bile, urine, and feces in 24 h was observed. The excretion rates of magnoflorine in bile and urine in 24 h were 0.90% and 37.11% respectively after intravenous administration of magnoflorine, which suggested that urination was the main excretive way of magnoflorine. The excretion rates of magnoflorine in feces were 8.77% and 6.18% respectively after intragastric administration of magnoflorine and water decoction of Coptidis Rhizoma, which indicated that defecation was the main excretion route of magnoflorine. The cumulative excretion rates of magnoflorine in the bile, urine, and feces in the Coptidis Rhizoma water decoction group were 77.78%, 79.44%, and 70.47% of those in the magnoflorine group. The results showed that the cumulative excretion rates of magnoflorine in rat bile, urine, and feces were not high, suggesting that magnoflorine was metabolized significantly in rats. The coexisting components of Coptidis Rhizoma could inhibit the excretion of magnoflorine in rat bile, urine, and feces, which was consistent with the decrease in the elimination rate of magnoflorine in the pharmacokinetics of Coptidis Rhizoma water decoction. It indicated interactions between drugs. This study is expected to provide references for the development of magnoflorine-containing new drugs and rational clinical medication of Coptidis Rhizoma.