[Absorption of Inula cappa extract based on everted intestinal sac method]

Area of Science:

• Pharmacology
• Natural Products Chemistry
• Gastrointestinal Physiology

Background:

• Inula cappa is a traditional medicinal herb.
• Understanding its intestinal absorption is crucial for efficacy.
• Key compounds within the extract require characterization for absorption.

Purpose of the Study:

• To investigate the in vitro intestinal absorption characteristics of Inula cappa extract.
• To determine the absorption sites and mechanisms of nine key compounds.
• To elucidate the selective absorption profile of Inula cappa ingredients.

Main Methods:

• Rat everted intestinal sac method for in vitro absorption studies.
• Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) for quantification.
• Analysis of absorption across different intestinal segments (duodenum, jejunum, ileum).

Main Results:

• Eight out of nine studied compounds exhibited passive diffusion transport.
• Scopolin demonstrated active intestinal transport.
• Specific absorption sites varied: duodenum (chlorogenic acid), jejunum (cryptochlorogenic acid, 1,3-O-dicaffeoylquinic acid, luteolin-7-glucoside, 3,4-O-dicaffeoylquinic acid), and ileum (neochlorogenic acid, scopolin, 4,5-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid).
• Absorption of all compounds was influenced by pH and bile.

Conclusions:

• Inula cappa extract exhibits selective intestinal absorption.
• Different compounds possess distinct absorption mechanisms and preferred intestinal locations.
• These findings provide insights into the pharmacokinetic behavior of Inula cappa constituents.