Does the intestinal microenvironment have an impact on the choleretic effect of inchinkoto, a hepatoprotective herbal medicine?

AIM

The choleretic effects of inchinkoto (ICKT), a hepatoprotective herbal medicine, are variable among patients. This study sought to investigate the correlation between the choleretic effects of ICKT and the intestinal microenvironment in patients with biliary obstruction.

METHODS

Patients with biliary obstruction who underwent external biliary drainage were enrolled. The concentrations of total bilirubin and bile acid in the bile, and genipin, a major active ingredient of ICKT, in the bloodstream before and after ICKT treatment were measured. Feces were collected from the patients to determine bacterial count and organic acid concentrations.

RESULTS

Samples from 37 patients were collected and analyzed. The serum concentration of genipin increased 3 h after ICKT treatment and showed a positive correlation with the percent changes of biliary concentrations of bile acid, total bilirubin, and direct bilirubin. Serum genipin concentration also showed a positive correlation with the fecal concentrations of representative obligate anaerobes such as the Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium, and the Atopobium cluster. In sharp contrast, so-called harmful bacteria such as Clostridium difficile, Enterobacteriaceae, and Enterococcus showed a negative correlation with the concentration of genipin. Genipin concentration after ICKT administration showed a positive correlation with the fecal concentration of short chain fatty acids such as propionic acid and butyric acid, and a negative correlation with the fecal concentration of lactic acid.

CONCLUSIONS

The absorption of genipin was variable among patients. This variability may be associated with the fecal microenvironment profile and partly explain the variable choleretic effects of ICKT among patients.