• Journal of Pharmaceutical Investigation
• /
• v.29 no.4
• /
• pp.287-293
• /
• 1999

Transport study of horseradish peroxidase and transferrin-horseradish peroxidase conjugate was performed using an in vitro Caco-2 cell cultured monolayer grown on a polycarbonate membrane of $Transwell^{\circledR}$, Horseradish peroxidase was not transported across Caco-2 cell monolayer. Transferrin-horseradish peroxidase conjugate was transported through Caco-2 cell monolayer. The apparent membrane permeability coefficient $(P_{app})$ of transferrin horseradish peroxidase conjugate was $6.54{\times}10^{-7}\;cm/sec$. The $P_{app}$ value of transferrin-horseradish peroxidase conjugate across Caco-2 cell monolayer was increased to $11.9{\times}10^{-7}\;cm/sec$ in the presence of $50\;{mu}g/ml$ brefeldin-A. These results suggest the transferrin receptor mediated transcytosis of transferrin-horseradish peroxidase conjugate across Caco-2 cell monolayer.

• Journal of Applied Biological Chemistry
• /
• v.63 no.1
• /
• pp.35-41
• /
• 2020

(-)-epigallocatechin-3-gallate (EGGG), a flavonoid found in green tea, is known to have low bioavailability. In this study, we determine whether piperine, a natural bioenhancer, can increase the absorption rate of EGCG. Using a Caco-2 cell monolayer, permeability experiments were performed in Hanks' balanced salt solution (HBSS) and EGCG stability was adjusted to pH 6.5 and pH 5.5 by ascorbic acid treatment. When HBSS was adjusted to pH 6.5, EGCG remained at 94.78% for up to 2 h and remained at 86.04% after 4 h and the net efflux decreased compared to the control. As a result, uptake was significantly increased in the piperine co-administered group compared to the EGCG-alone group, showing that piperine increased the permeability of EGCG in the Caco-2 cell monolayer. These results suggest that piperine inhibits EGCG glucuronidation and efflux, allowing for greater absorption of EGCG.

• Journal of Pharmaceutical Investigation
• /
• v.35 no.2
• /
• pp.111-116
• /
• 2005

The unstirred water layer (UWL), which has been known to exist in the boundary of the intestinal lumen and intestinal wall, often behaves as an absorption barrier especially for lipophilic drugs. The intestinal absorption of drugs is often characterized using Caco-2 cell monolayers grown on Transwell polycarbonate membranes. The permeability $(P_{app})$ of drugs across the cell monolayer might be influenced by the agitation of the donor compartment, since the width of UWL on the surface of the cell monolayer would be reduced by the agitation. In this study, the effect of agitation of the donor compartment with 60 rpm on the permeability was measured for 12 drugs with a wide range of lipophilicity and permeability. The $P_{app}$ of mannitol, tributylmethyl ammonium, cimetidine, ranitidine, hydrocortisone, benzylpenicillin and loxoprofen was not influenced by the agitation, while the $P_{app}$ of theophylline, propranolol, YH439, phenylpropanolamine and testosterone was increased by the agitation. There was a significant correlation between the increase of $P_{app}$ by agitation and the lipophilicity for the compounds having $P_{app}>2{\times}10^{-5}$ cm/sec. No correlation was observed for the difference in $P_{app}$ by agitation and the molecular weight, or lipophilicity of the drugs. Therefore, the agitation rate of the donor compartment in the Caco-2 cell monolayer study should be carefully controlled in order to estimate $P_{app}$ reproducibly especially for lipophilic drugs.

• Food Science of Animal Resources
• /
• v.21 no.2
• /
• pp.133-141
• /
• 2001

Adherence of probiotic bacteria to intestinal epithelium is found to be the most principal characteristics among the various physiological functionality. This study was conducted to investigate the effect of bifidobacterial growth properties and condition on the Caco-2 cell adherence and to construct a basic data on adherence-related research. Among 20 strains of bifidobacteris tested, when measured by cell surface hydrophobicity(CSH) and cell agglutination(CA), Bifidobacterium bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 were selected. Using these strains, variations of Caso-2 cell adherence depending upon experimental condition were analyzed. The results obtained are as follows : Even though Bif. bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 reached more 85% cell surface hydrophobicity there was no significant difference in cell agglutination, when reached 31.54$\pm$0.54mg/ml. By direct count method for adherence, viable cell count of M3, K1, K2, K8, K9 and K10 reached more 100 counts per 100 Caco-2 cells. When Bif. bifidum ATCC29521, Bif. adolescentistis K8, and Bif. infantis K9 were used to compare the adherence depending upon viable cell counts, reaction time, and growth phase, the more viable cell count, and the more adhered cell counts, the less adherence percentage. In addition, there was no difference in adherence percentage of bifidobacteria when bifidobacteria was incubated from 1 to 8 hrs after Caco-2 cells already formed monolayer. Considering of the effect of growth phase of bifidobacteria on adherence variation, all strains showed the highest adherence during the early stage of stationary phase. In conclusion, adherence of bifidobacteria was affected by strain specificity, viable cell count, and growth activity.

• Korean Journal of Food Science and Technology
• /
• v.42 no.3
• /
• pp.335-342
• /
• 2010

Bioactive components involved in the tight junction stabilization of intestinal epithelial cells from Korean red ginseng were studied by analyzing transepithelial electrical resistance (TEER) values of the Caco-2 cell monolayer between the apical and basolateral sides for 96 hr. The treatment with less than $20\;{\mu}g/mL$ of the Korean red ginseng extract to the apical side of Caco-2 cell monolayer gave higher TEER values than the control. However, the treatment with more than $130\;{\mu}g/mL$ of the Korean red ginseng extract drastically decreased the TEER values, and these effects were not due to its cytotoxicity. When fractions of low molecular weight compounds, polysaccharides, proteins, saponins, and polyphenols derived from Korean ginseng were applied to the apical side of the Caco-2 cell monolayer, polyphenols showed high tight junction stabilizing activity and saponins showed low activity, but the others showed no significant activity. These results suggest that Korean red ginseng might be useful for the prevention of food allergy by stabilizing the tight junction of intestinal epithelial cells leading to hindering absorption of food allergens.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.12
• /
• pp.1583-1588
• /
• 2022

In this study, we investigated the effect of lactic acid bacteria (LAB) strains used as starters for kimchi fermentation, namely Lactococcus lactis WiKim0124, Companilactobacillus allii WiKim39, Leuconostoc mesenteroides WiKim0121Leuconostoc mesenteroides WiKim33, and Leuconostoc mesenteroides WiKim32, on the intestinal epithelial tight junctions (TJs). These LAB strains were not cytotoxic to Caco-2 cells at 500 ㎍/ml concentration. In addition, hydrogen peroxide (H₂O₂) decreased Caco-2 viability, but the LAB strains protected the cells against H₂O₂-induced cytotoxicity. We also found that lipopolysaccharide (LPS) promoted Caco-2 proliferation; however, no specific changes were observed upon treatment with LAB strains and LPS. Our evaluation of the permeability in the Caco-2 monolayer model confirmed its increase by both LPS and H₂O₂. The LAB strains inhibited the increase in permeability by protecting TJs, which we evaluated by measuring TJ proteins such as zonula occludens-1 and occludin, and analyzing them by western blotting and immunofluorescence staining. Our findings show that LAB strains used for kimchi fermentation can suppress the increase in intestinal permeability due to LPS and H₂O₂ by protecting TJs. Therefore, these results suggest the possibility of enhancing the functionality of kimchi through its fermentation using functional LAB strains.

• Mass Spectrometry Letters
• /
• v.8 no.2
• /
• pp.34-38
• /
• 2017

The purpose of this study was to develop a cocktail approach for the measurement of the permeability of marker compounds, caffeine and propranolol (high permeability), ofloxacin (intermediate), atenolol (low), and quinidine (P-glycoprotein substrate), simultaneously. Then we compared the permeability in Caco-2 cells with that in rat intestinal segments. The difference between individual measurement and cocktail approach was less than 20 %, and the permeabilities of these compounds were similar to those previously reported, suggesting that the cocktail transport study and simultaneous drug analysis were successfully developed and validated in this study. Additionally, in the application of this cocktail method, the permeability of five drugs in rat jejunum was similar to that in ileum but different from that in colon, which was measured using the Ussing chamber system. Moreover, permeability in jejunum and ileum was similar to that in Caco-2 cells. In conclusion, the permeability in Caco-2 cells was equivalent to the permeability in rat jejunum and ileum determined with the Ussing system. Therefore, this newly developed cocktail assay and its application to the Ussing system can be a useful tool for robust and rapid screening for site-specific permeability in rat intestine, thus accelerating the prediction of absorption of new chemical entities.

• Microbiology and Biotechnology Letters
• /
• v.50 no.1
• /
• pp.51-62
• /
• 2022

Lactobacillus rhamnosus SKG34 (LrSKG34), a potential probiotic strain, was successfully isolated from Sumbawa Mare's milk. Our previous studies showed that the strain is resistant to gastrointestinal conditions, possesses antioxidant activity, and lowers blood cholesterol levels. Further clarification of the potential probiotic characteristics and safety assessment are necessary. This study aimed to evaluate the adhesion of LrSKG34 to Caco-2 cell monolayers and its effect on mucosal integrity in vitro. We also examined the LrSKG34 safety profile based on antimicrobial susceptibility testing, haemolytic activity determination, Caco-2 cell monolayer translocation evaluation, and in vivo investigation of the effect of LrSKG34 on the physiology, biochemical markers, and histopathological appearance of major organs in an animal model. LrSKG34 attached to Caco-2 cell monolayers and maintained mucosal integrity in vitro. The typical resistance of lactobacilli to ciprofloxacin, gentamicin, vancomycin, trimethoprim-sulfamethoxazole, and metronidazole was confirmed for LrSKG34. No haemolytic activity was observed on blood agar plates, and no LrSKG34 translocation was observed in Caco-2 cell monolayers. Administration of LrSKG34 to Sprague-Dawley rats did not adversely affect body weight. No abnormalities in hematological parameters, serum biochemistry levels, or histopathological structures of major organs were observed in LrSKG34-treated rats. Collectively, the results implicate LrSKG34 as a promising and potentially safe probiotic candidate for further development.

• Nutrition Research and Practice
• /
• v.3 no.1
• /
• pp.9-14
• /
• 2009

Aloe products are one of the top selling health-functional foods in Korea, however the adequate level of intake to achieve desirable effects are not well understood. The objective of this study was to determine the intestinal uptake and metabolism of physiologically active aloe components using in vitro intestinal absorption model. The Caco-2 cell monolayer and the everted gut sac were incubated with $5-50{\mu}M$ of aloin, aloe-emodin, and aloesin. The basolateral appearance of test compounds and their glucuronosyl or sulfated forms were quantified using HPLC. The % absorption of aloin, aloe-emodin, and aloesin was ranged from 5.51% to 6.60%, 6.60% to 11.32%, and 7.61% to 13.64%, respectively. Up to 18.15%, 18.18%, and 38.86% of aloin, aloe-emodin, and aloesin, respectively, was absorbed as glucuronidated or sulfated form. These results suggest that a significant amount is transformed during absorption. The absorption rate of test compounds except aloesin was similar in two models; more aloesin was absorbed in the everted gut sac than in the Caco-2 monolayer. These results provide information to establish adequate intake level of aloe supplements to maintain effective plasma level.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.09a
• /
• pp.45-45
• /
• 2005