Honokiol, a Neolignan from Magnolia officinalis, Attenuated Fructose-Induced Hepatic Fat Accumulation by Improving Intestinal Barrier Function in Mice

Background

Fructose (Fru) consumption has been suggested to contribute to metabolic diseases including metabolic dysfunction-associated steatotic liver disease (MASLD), at least in part, by disturbing intestinal barrier function and intestinal nitric oxide (NO) homeostasis. Honokiol (Hon), a neolignan found in Magnolia officinalis, has been suggested to affect intestinal integrity and barrier function.

Objectives

We assessed whether Hon affects Fru-induced small intestinal permeability in settings of early MASLD.

Methods

Female 8–10-wk-old C57BL/6J mice (n = 7/group) received either a 30% Fru solution + vehicle or plain drinking water + vehicle ± Hon (10 mg/kg bw/d) for 4 wk. Liver damage [e.g. nonalcoholic fatty liver disease activity score (NAS), number of neutrophils, interleukin-6 (IL-6) protein concentration], markers of intestinal permeability (bacterial endotoxin, tight junction proteins), and NO homeostasis in the small intestine were determined in vivo as well as ex vivo in an everted sac model and in Caco-2 cells. One-way and 2-way analysis of variance were performed, respectively.

Results

Hon diminished the development of MASLD, which was associated with a significant lower NAS (–38%), number of neutrophils (–48%), and IL-6 protein concentrations (–38%) in livers of Fru-fed mice. Hon also attenuated Fru-induced alterations of markers of intestinal barrier function with Fru+Hon-fed mice showing lower bacterial toxin levels in portal plasma (–29%, P = 0.075), higher tight junction protein concentrations (+2.4-fold, P < 0.05), and lower NOx concentration (–44%, P < 0.05) as well as NO synthase activity (–35%) in the small intestine compared with Fru+vehicle-fed mice. Moreover, the decrease in AMP-activated protein kinase phosphorylation found in the small intestine of Fru-fed mice was significantly attenuated (+5.3-fold) by the concomitant treatment with Hon in Fru-fed mice. In support of the in vivo findings, Hon significantly attenuated Fru-induced intestinal permeability ex vivo and in Caco-2 cells.

Conclusions

Our data suggest that Hon diminished the development of Fru-induced early MASLD by alleviating impairments in intestinal barrier function.