• Journal of Life Science
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• v.26 no.9
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• pp.1082-1087
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• 2016

The intestinal tight junction (TJ) plays an important role as a paracellular barrier. Impaired TJ permeability and enhanced proinflammatory cytokine production are crucial pathophysiological mechanisms in inflammatory bowel diseases (IBDs). Although proinflammatory cytokines, tumor necrosis factor-alpha and interluekin-1 beta, which are markedly increased in IBD patients, have been reported to increase intestinal TJ permeability, the role of interleukin-1 alpha (IL-1α) in the TJ has not been studied. Phytochemicals could prevent proinflammatory cytokine-caused TJ alteration. Curcumin (CCM), a biologically active component of turmeric, has a strong anti-inflammatory activity. The purpose of this study was to elucidate the effect of IL-1α on intestinal epithelial TJ permeability and the role of CCM in IL-1α′s action on TJ in an in vitro intestinal epithelial system, Caco-2 monolayers. The TJ integrity of Caco-2 monolayers was estimated by measuring the flux of FITC-labeled dextran and transepithelial electrical resistance (TEER). Apical IL-1α (100 ng/ml) treatment elevated TJ permeability and suppressed TEER of Caco-2 monolayers. Pretreatment with CCM (20 μM) for 30 min significantly inhibited IL-1α-induced TJ alterations, such as increased TJ permeability and decreased in TEER values. These results demonstrated that IL-1α-induced increases in Caco-2 TJ permeability and CCM blocked the action of IL-1α in the TJ.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1102-1108
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• 2003

We studied the effects of phytolaccosides, saponins from Phytolacca americana, on the intestinal absorption of heparin in vitro and in vivo. The absorption enhancing activity of these compounds (phytolaccosides B, $D_2$, E, F, G and I) was determined by changes in transepithelial electrical resistance (TEER) and the transport amount of heparin disaccharide, the major repeating unit of heparin, across Caco-2 cell monolayers. With the exception of phytolaccoside G, all of them decreased TEER values and increased the permeability in a dose-dependent and time-dependent manner. In vitro, phytolaccosides B,$D_2$, and E showed significant absorption enhancing activities, while effects by phytolaccoside F and I were mild. In vivo, phytolaccoside E increased the activated partial thromboplastin time (APTT) and thrombin time, indicating that phytolaccoside E modulated the transport of heparin in intestinal route. Our results suggest that a series of phytolaccosides from Phytolacca americana can be applied as pharmaceutical excipients to improve the permeability of macromolecules and hydrophilic drugs having difficulty in absorption across the intestinal epithelium.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.86-92
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• 2002

The enhancement of paracellular transport of heparin disaccharide using several absorption enhancers across Caco-2 cell monolayers was tested . The cytotoxicity of these enhancers was also examined. The enhancing effects by Quillaja saponin, diponin glycyrrhizinate, $18{\beta}-glycyrrhetinic$ acid, sodium caprate and taurine were determined by changes in transepithelial electrical resistance (TEER) and the amount of heparin disaccharide transported across Caco-2 cell monolayers. Among the absorption enhancers, $18{\beta}-glycyrrhetinic$ acid arid taurine decreased TEER and increased the permeability of heparin disaccharide in a dose-dependent and time-dependent manner with little or negligible cytotoxicity. Our results indicate that these absorption enhancers can widen the tight junction, which is a dominant paracellular absorption route of hydrophilic compounds . It is highly possible that these absorption enhancers can be applied as pharmaceutical excipients to improve the transport of macromolecules and hydrophilic drugs having difficulty in permeability across the intestinal epithelium.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.1046-1060
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• 2022

This study aimed to investigate the effects of the metabolites of Latilactobacillus curvatus BYB3 and indole-activated aryl hydrocarbon receptor (AhR) to increase the tight junction (TJ) proteins in an in vitro model of intestinal inflammation. In a Western blot assay, the metabolites of L. curvatus BYB3 reduced the TJ demage in lipoploysaccharide (LPS) stimulated-Caco-2 cells. This reduction was a result of upregulating the expression of TJ-associated proteins and suppressing the nuclear factor-κB signaling. Immunofluorescence images consistently revealed that LPS disrupted and reduced the expression of TJ proteins, while the metabolites of L. curvatus BYB3 and indole reversed these alterations. The protective effects of L. curvatus BYB3 were observed on the intestinal barrier function when measuring transepithelial electrical resistance. Using high-performance liquid chromatography analysis the metabolites, the indole-3-latic acid and indole-3-acetamide concentrations were found to be 1.73±0.27 mg/L and 0.51±0.39 mg/L, respectively. These findings indicate that the metabolites of L. curvatus BYB3 have increasing mRNA expressions of cytochrome P450 1A1 (CYP1A1) and AhR, and may thus be applicable for therapy of various inflammatory gut diseases as postbiotics.

• The Journal of Internal Korean Medicine
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• v.37 no.1
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• pp.16-25
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• 2016

Objectives: Gilgyung-tang (GGT) has been used as one of the main multi-herb formulas to treat “Peo-ong” (lung abscess). In this study, we investigated the inhibitory effects of water extracts of GGT on cell migration and invasion, two critical cellular processes that are often deregulated during metastasis, in human bladder cancer 5637 cells.Methods: Effects on cell viability were quantified using an MTT assay. To analyze the anti-metastatic effects, we conducted a wound healing migration assay, an in vitro invasiveness assay, and a measurement of the transepithelial electrical resistance (TER). The expression of protein and mRNA were measured by Western blotting and real-time polymerase chain reaction (RT-PCR), respectively.Results: GGT markedly inhibited the cell motility and invasiveness of 5637 cells within the concentration range that was not cytotoxic. The inhibitory effects of GGT on cell invasiveness were associated with tightening of the tight junctions (TJs), which was demonstrated by an increase in the TER. The RT-PCR and Western blotting results indicated that GGT decreased the levels of claudin proteins. GGT also inhibited the activity and expression of matrix metalloproteinase (MMP)-2 and -9 and simultaneously increased the levels of tissue inhibitor of metalloproteinase-1 and -2.Conclusions: Our findings suggest that GGT reduces both the migration and the invasion of 5637 cells by modulating the activity of TJs and MMPs.

• Journal of Periodontal and Implant Science
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• v.48 no.5
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• pp.284-294
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• 2018

Purpose: Epithelial barrier dysfunction is involved in the pathophysiology of periodontitis and oral lichen planus. Estrogens have been shown to enhance the physical barrier function of intestinal and esophageal epithelia, and we aimed to investigate the effect of estradiol (E2) on the regulation of physical barrier and tight junction (TJ) proteins in human oral epithelial cell monolayers. Methods: HOK-16B cell monolayers cultured on transwells were treated with E2, an estrogen receptor (ER) antagonist (ICI 182,780), tumor necrosis factor alpha ($TNF{\alpha}$), or dexamethasone (Dexa), and the transepithelial electrical resistance (TER) was then measured. Cell proliferation was measured by the cell counting kit (CCK)-8 assay. The levels of TJ proteins and nuclear translocation of nuclear factor $(NF)-{\kappa}B$ were examined by confocal microscopy. Results: E2 treatment increased the TER and the levels of junctional adhesion molecule (JAM)-A and zonula occludens (ZO)-1 in a dose-dependent manner, without affecting cell proliferation during barrier formation. Treatment of the tight-junctioned cell monolayers with $TNF{\alpha}$ induced decreases in the TER and the levels of ZO-1 and nuclear translocation of $NF-{\kappa}B$. These $TNF{\alpha}-induced$ changes were inhibited by E2, and this effect was completely reversed by co-treatment with ICI 182,780. Furthermore, E2 and Dexa presented an additive effect on the epithelial barrier function. Conclusions: E2 reinforces the physical barrier of oral epithelial cells through the nuclear ER-dependent upregulation of TJ proteins. The protective effect of E2 on the $TNF{\alpha}-induced$ impairment of the epithelial barrier and its additive effect with Dexa suggest its potential use to treat oral inflammatory diseases involving epithelial barrier dysfunction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.881-887
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• 2012

This study was designed to examine influence of bacteria and herbal applications of Lonicerae Flos on the permeability of intestinal epithelial cells. The HCT-116 human intestinal cell was used as an in vivo model of "leaky gut". Dextran sodium sulphate (DSS) was used to induce an increase in the permeability of epithelial cell tight junctions. Probiotics including Lactobacillus acidophilus, Lactobacillus plantarum, Salomonella spp. and Staphylococcus aureus were used to evaluate bacterial influence on the intestinal epithelial cells. Herbal extract Lonicerae Flos was also assessed to find out what kind of effects it has when used alone or fermented with Lactobacillus plantarum. The permeability of intestinal cell lines was assessed using transepithelial electrical resistance (TEER) and horseradish peroxide (HRP) assessments. This data provides evidence for the probiotic benefits of intestinal permeability. The data also provides promising evidence of herbal effects on reducing intestinal permeability, especially when fermented with probiotics.

• Journal of Korean Medicine for Obesity Research
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• v.13 no.1
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• pp.24-32
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• 2013

Objectives: The aim of this study is to investigate anti-imflammatory and protective effect for intestinal epithelial cells with Atractylodes macrocephae (AM), a traditional Korean Herbal medicine and fermented Atractylodes macrocephae (FAM) with Lactobacillus plantarum. Methods: HCT-116 and Raw 264.7 cells were used in this study. Using NO assay, we measured lipopolysaccharide (LPS)-induced anti-inflammatory effect. We measured permeability of intestinal epithelial cells with transepithelial electrical resistance and horseradish peroxide flux assay. Water soluble tetrazolium salt assay was used to see cell proliferation. All the results were presented in mean and standard deviation. We used Student's t-test for analyzing significance of results. Results: In Raw 264.7 cells NO production decreased 22.4% with pre-treatment of AM and FAM, especially with FAM in high concentration. In HCT-116 cells LPS-induced intestinal permeability had a protective effect with both AM and FAM, which was also tend to be proportional to the concentration. Cell viability increased up to 135.52% after treatment of high concentration of FAM in HCT-116, while there was no significant change in Raw 264.7 cells with herb treatments. Conclusions: These results show evidence that AM, especially fermented ones, significantly reduced intestinal membrane permeability. They also had a protective effect as well as an anti-inflammation effect for HCT-116 and Raw 264.7 cells. This suggest that FAM may be a therapeutic agent for Leaky gut syndrome by reducing intestinal permeability.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.207-218
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• 2023

Hepatocellular carcinoma (HCC) has a poor prognosis and high metastasis and recurrence rates. Although extracts of Alnus hirsuta (Turcz. ex Spach) Rupr. (AH) have been demonstrated to possess potential anti-inflammatory and anti-cancer activities, the underlying mechanism of AH in HCC treatment remains to be elucidated. We investigated the effects and potential mechanisms of AH on migration and invasion of Hep3B cells. Within the non-cytotoxic concentration range, AH significantly inhibited motility and invasiveness of Hep3B cells in a concentration-dependent manner. Inhibitory effects of AH on cell invasiveness are associated with tightening of tight junctions (TJs), as demonstrated by an increase in transepithelial electrical resistance. Immunoblotting indicated that AH decreased levels of claudins, which form major components of TJs and play key roles in the control and selectivity of paracellular transport. Furthermore, AH inhibited the expression and activity of matrix metalloproteinase (MMP)-2 and MMP-9 and simultaneously increased the levels of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. These effects were related to inactivation of the phosphoinositide 3-kinase (PI3K)/AKT pathway in Hep3B cells. Therefore, AH inhibits migration and invasion of Hep3B cells by inhibiting the activity of MMPs and tightening TJs through suppression of claudin expression, possibly by suppressing the PI3K/AKT signaling pathway.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.105-113
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• 2024

Background: Aflatoxin B1 (AFB1) is a toxic metabolite generated by Aspergillus species and is commonly detected during the processing and storage of food; it is considered a group I carcinogen. The hepatotoxic effects, diseases, and mechanisms induced by AFB1 owing to chronic or acute exposure are well documented; however, there is a lack of research on its effects on the intestine, which is a crucial organ in the digestive process. Dogs are often susceptible to chronic AFB1 exposure owing to lack of variation in their diet, unlike humans, thereby rendering them prone to its effects. Therefore, we investigated the effects of AFB1 on canine small intestinal epithelial primary cells (CSIc). Methods: We treated CSIc with various concentrations of AFB1 (0, 1.25, 2.5, 5, 10, 20, 40, and 80 μM) for 24 h and analyzed cell viability and transepithelial-transendothelial electrical resistance (TEER) value. Additionally, we analyzed the mRNA expression of tight junction-related genes (OCLN, CLDN3, TJP1, and MUC2), antioxidant-related genes (CAT and GPX1), and apoptosis-related genes (BCL2, Bax, and TP53). Results: We found a significant decrease in CSIc viability and TEER values after treatment with AFB1 at concentrations of 20 μM or higher. Quantitative polymerase chain reaction analysis indicated a downregulation of OCLN, CLDN3, and TJP1 in CSIc treated with 20 μM or higher concentrations of AFB1. Additionally, AFB1 treatment downregulated CAT, GPX1, and BCL2. Conclusions: Acute exposure of CSIc to AFB1 induces toxicity, and exposure to AFB1 above a certain threshold compromises the barrier integrity of CSIc.