The metabolic profile elucidation of Lonicera japonica flos water extract and the metabolic characteristics evaluation of bioactive compounds in human gastrointestinal tract in vitro.

ABSTRACT

Lonicera japonica Flos (LJF) is taken orally as a health food and medicinal plant in China for a long time. The gastrointestinal metabolism of LJF was investigated in vitro by three independent models (gastric juice, intestinal juice, and human intestinal bacteria), qualitative analyzed by UPLC-LTQ-Orbitrap-MSn and quantified by HPLC-DAD. 72 prototype compounds were detected in LJF water extraction (LJF-WE), including 14 organic acids, 43 iridoids, 14 flavonoids and one other compound. The prototype and metabolic components of LJF-WE bio-transformed by simulated gastric fluid (70 and 12), intestinal fluid (69 and 12) and human fecal bacteria (29 and 70) were characterized, respectively. The metabolites were formed through desaccharization, isomerization, hydrogenation, methylation, dehydration, and then cyclization, glucuronization and dimethylation followed. 8 bioactive compounds including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, sweroside, secoxyloganin, isochlorogenic acid B, isochlorogenic acid A and isochlorogenic acid C were much stable in simulated gastric fluid and intestinal fluid, compared with human fecal bacteria. Especially, sweroside and secoxyloganin with glucoside bonds degradated extraordinarily fast, because of the abundant ß-glucosidases in human fecal bacteria.