We hypothesized that interindividual variability in the bioavailability of caffeic acid (CA) would influence its anticolitic
efficacy and that...
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We hypothesized that interindividual variability in the bioavailability of caffeic acid (CA) would influence its anticolitic
efficacy and that mice may be appropriate for modeling human gut microbial metabolism of CA, which is thought to
influence CA bioavailability. Anaerobic human fecal and mouse cecal sample mixtures were incubated with CA derivatives
from Echinacea purpurea and compound disappearance rates were measured, which were similar in both sample types.
CA metabolism, including formation of its main metabolite,m-hydroxyphenylpropionate, in the mouse cecum may usefully
model human gut metabolism of this compound. Ten-week-old CD-1/IGS female mice were fed 120 mg CA/kg (n = 36) or
control diet for 7 d (n = 12); one-half of each group then drank 1.25% dextran sulfate sodium (DSS) in water for 5 d. DSStreated
mice fed CA showed lessened colitic damage than did mice given DSS alone, with longer colons, greater body
weight, and colonic Cyp4b1 expression. Cluster analysis of the cecal histopathological score showed that mice with
severe cecal damage (mean cecal score = 8.5; n = 11) also had greater myeloperoxidase (MPO) activity and lower plasma
CA compared with mice showing mild cecal damage (mean cecal score = 4.5; n = 4) (P , 0.05). Cecal score was positively
correlated with colonic MPO activity (r = 0.72; P , 0.05) and negatively correlated with plasma CA (r = 20.57; P , 0.05).
These studies indicated that the anticolitic efficacy of CA was related to variability in CA bioavailability, which may be
influenced by gut microbial metabolism of this compound.
