Abstract
Rhizoma coptidis has been clinically used for a long time for the treatment of various
diseases in China, such as hypertension, diabetes, and inflammation. Previous studies
have shown that alkaloid components of Rhizoma coptidis extract could be extensively
metabolized and the metabolites were also considered to be the therapeutic material
basis. However, until now, pharmacokinetic studies of the in vivo metabolites have not been revealed yet. The aim of the present study was to characterize
the pharmacokinetics and excretions of five main alkaloids (berberine, jatrorrhizine,
palmatine, epiberberine, and coptisine) and their seven metabolites (berberrubine,
demethyleneberberine, jatrorrhizine-3-O-β-D-glucuronide, thalifendine-10-O-β-D-glucuronide, berberrubine-9-O-β-D-glucuronide, demethyleneberberine-2-O-sulfate, and demethyleneberberine-2-O-β-D-glucuronide) in rats after oral administration of
Rhizoma coptidis extract. Meanwhile, comparative pharmacokinetics and excretions
of these analytes in diabetic model rats were also investigated, since Rhizoma coptidis
is widely used for the treatment of diabetes. Our results showed that the in vivo existing forms of alkaloid components were phase II metabolites, highlighting the
glucuronidation metabolic pathway. In diabetic model rats, the utilization of Rhizoma
coptidis alkaloids was significantly increased and the biotransformation of berberine
into berberrubine was significantly inhibited.
Key words
Coptis chinensis
- Ranunculaceae - pharmacokinetics - excretion - diabetic rats - phase II metabolites