Protective effects of 18β-glycyrrhetinic acid on LPS-induced injury in intestinal epithelial cells

doi:10.1016/S1875-5364(13)60003-5

Chinese Journal of Natural Medicines

Volume 11, Issue 1, January 2013, Pages 24-29

https://doi.org/10.1016/S1875-5364(13)60003-5 Get rights and content

Abstract

Aim

To investigate the protective effects of 18β-glycyrrhetinic acid (GA) on lipopolysaccharide (LPS)-induced injury in the intestinal epithelial cell line (IEC-6).

Methods

IEC-6 cells were treated by LPS (100 μg·mL⁻¹) with or without GA (0. 1, 1.0 or 10 μmol·L⁻¹) for 24 h. The inflammatory cytokines in the cultured medium, TNF-α and IL-6, were measured by ELISA. The supernatant nitric oxide (NO) production was detected by nitrite assay. Reactive oxygen species (ROS) were estimated by flow cytometry. Epithelial tight junction was determined by transepithelial resistance (TER), and protein levels were measured by Western blotting.

Results

With GA treatment, LPS-stimulated TNF-α and IL-6 were inhibited, ROS and NO were decreased, the transepithelial permeability was recovered, ZO-1 (tight junction related protein) was reversed, the protein level of cyclooxygenase-2 (COX-2) was down-regulated, and 15-hydroxyprostaglandin dehydrogenase (PGDH) was up-regulated.

Conclusions

These results suggest that GA has the protective capacity to attenuate LPS-induced injury in intestinal epithelial cells and protect the epithelial tight junction. The underlying mechanism was related to a decrease in proinflammatory factor and regulating COX-2 and PGDH.

References (30)

G Bonizzi et al.
Cell type-specific role for reactive oxygen species in nuclear factor-kappaB activation by interleukin-1[J]
Biochem Pharmacol
(2000)
S Matsui et al.
Glycyrrhizin and related compounds down-regulate production of inflammatory chemokines IL-8 and eotaxin 1 in a human lung fibroblast cell line[J]
Int Immunopharmacol
(2004)
T Kaisho et al.
Toll-like receptor function and signaling[J]
J Allergy Clin Immunol
(2006)
JC Kalff et al.
Surgically induced leukocytic infiltrates within the rat intestinal muscularis mediate postoperative ileus[J]
Gastroenterology
(1999)
RM Locksley et al.
The TNF and TNF receptor superfamilies: integrating mammalian biology[J]
Cell
(2001)
D Burger et al.
Is IL-1 a good therapeutic target in the treatment of arthritis[J]?
Best Pract Res Clin Rheumatol
(2006)
SY Choi et al.
Nobiletin from citrus fruit peel inhibits the DNA-binding activity of NF-kappaB and ROS production in LPS-activated RAW 264.7 cells[J]
J Ethnopharmacol
(2007)
E Cario et al.
Toll-like receptor 2 enhances ZO-1-associated intestinal epithelial barrier integrity via protein kinase C[J]
Gastroenterology
(2004)
M Keskek et al.
Increased expression of cyclooxygenase-2 (COX-2) in radiation-induced small bowel injury in rats[J]
J Surg Res
(2006)
T Iwamoto et al.
Establishment of intestinal epithelial cell lines from adult mouse small and large intestinal crypts[J]
Biosci Biotechnol Biochem
(2011)

IG De Plaen et al.

Lipopolysaccharide activates nuclear factor kappaB in rat intestine: role of endogenous platelet-activating factor and tumour necrosis factor[J]

Br J Pharmacol

(2000)

K Ebnet et al.

Junctional adhesion molecules (JAMs): more molecules with dual functions[J]?

J Cell Sci

(2004)

C Geraud et al.

Unique cell type-specific junctional complexes in vascular endothelium of human and rat liver sinusoids[J]

PLoS One

(2012)

X Han et al.

Loss of guanylyl cyclase C (GCC) signaling leads to dysfunctional intestinal barrier[J]

PLoS One

(2011)

K Hodges et al.

Infectious diarrhea: Cellular and molecular mechanisms[J]

Gut Microbes

(2010)

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Available online 20 Jan. 2013

Research funding This project was supported by the National Natural Science Foundation of China (Nos. 90913023 and 81001465) and the Innovative Scholar Project of Natural Science Foundation of Jiangsu Province (No. BK2008022).

These authors have no conflict of interest to declare.

View full text

Protective effects of 18β-glycyrrhetinic acid on LPS-induced injury in intestinal epithelial cells

Abstract

Aim

Methods

Results

Conclusions

Biochem Pharmacol

Int Immunopharmacol

J Allergy Clin Immunol

Gastroenterology

Cell

Best Pract Res Clin Rheumatol

J Ethnopharmacol

Gastroenterology

J Surg Res

Establishment of intestinal epithelial cell lines from adult mouse small and large intestinal crypts[J]

Biosci Biotechnol Biochem

Lipopolysaccharide activates nuclear factor kappaB in rat intestine: role of endogenous platelet-activating factor and tumour necrosis factor[J]

Br J Pharmacol

Junctional adhesion molecules (JAMs): more molecules with dual functions[J]?

J Cell Sci

Unique cell type-specific junctional complexes in vascular endothelium of human and rat liver sinusoids[J]

PLoS One

Loss of guanylyl cyclase C (GCC) signaling leads to dysfunctional intestinal barrier[J]

PLoS One

Infectious diarrhea: Cellular and molecular mechanisms[J]

Gut Microbes