scholarly journals Evaluation on Intestinal Permeability of Phlorotannins Using Caco-2 Cell Monolayers

2022 ◽  
Vol 17 (1) ◽  
pp. 1934578X2110704
Author(s):  
Naoki Murata ◽  
Saki Keitoku ◽  
Hideo Miyake ◽  
Reiji Tanaka ◽  
Toshiyuki Shibata

Among the phlorotannins of seaweed polyphenols, eckols which have a dibenzodioxin linkage are known to have various physiological functions. The purpose of this study was to investigate the intestinal epithelial absorption of eckols using Caco-2 cell monolayers of the small intestinal membrane model. Each compound permeated from the apical (AP) side to the basolateral (BL) side in the monolayers was identified and quantitated by liquid chromatography-mass spectrometry with electrospray ionization. In the transport assays using five types of eckols (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8'-bieckol), only the monomeric eckol showed limited transepithelial absorption with relatively small apparent permeability values (0.30  ±  0.04  ×  10−8 cm/s). Analyzing the Hanks’ balanced salt solution in the receiver on the BL side showed that phloroglucinol was detected in all experimental sections using eckols, and it's concentration increased with time over the course of the incubation. The other molecules corresponding to the unconjugated and conjugated metabolites of eckols were not detected in the AP and BL sides through the assays. These results suggest that eckols, including monomeric eckol, may be decomposed into phloroglucinol in the intestinal epithelium and the resulting phloroglucinol permeates to the BL side.

Author(s):  
Liliya Logoyda

Objective: A simple, rapid high-performance liquid chromatography-mass spectrometry (HPLC MS/MS) method was developed for the determination of enalapril maleate from confluent Caco-2 monolayers and aqueous solution.Methods: Chromatography was achieved on Discovery C18, 50×2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A [acetonitrile-water-formic acid, 5: 95:0.1 v/v] and eluent B [acetonitrile-formic acid, 100:0.1 v/v]). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.4 ml/min into the mass spectrometer ESI chamber. The sample volume was 5 μl.Results: Under these conditions, enalapril maleate was eluted at 1.52 min. According to the Caco-2 test results, enalapril showed low permeability. It should be noted that the recovery value for enalapril is 100.62 %. Low in vitro permeability data for enalapril are in good agreement with the literature data.Conclusion: From results of the analysis, it can be concluded that developed method is simple and rapid for determination of enalapril maleate from confluent Caco-2 monolayers and aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for examination of enalapril from Caco-2 cell monolayers.


2020 ◽  
Vol 21 (17) ◽  
pp. 6389
Author(s):  
Hongmei Zeng ◽  
Jingjing Cai ◽  
Hidemi Hatabayashi ◽  
Hiroyuki Nakagawa ◽  
Hiromitsu Nakajima ◽  
...  

In the biosynthesis of aflatoxin, verA, ver-1, ordB, and hypA genes of the aflatoxin gene cluster are involved in the pathway from versicolorin A (VA) to demethylsterigmatocystin (DMST). We herein isolated each disruptant of these four genes to determine their functions in more detail. Disruptants of ver-1, ordB, and hypA genes commonly accumulated VA in their mycelia. In contrast, the verA gene disruptant accumulated a novel yellow fluorescent substance (which we named HAMA) in the mycelia as well as culture medium. Feeding HAMA to the other disruptants commonly caused the production of aflatoxins B1 (AFB1) and G1 (AFG1). These results indicate that HAMA pigment is a novel aflatoxin precursor which is involved at a certain step after those of ver-1, ordB, and hypA genes between VA and DMST. HAMA was found to be an unstable substance to easily convert to DMST and sterigmatin. A liquid chromatography-mass spectrometry (LC-MS) analysis showed that the molecular mass of HAMA was 374, and HAMA gave two close major peaks in the LC chromatogram in some LC conditions. We suggest that these peaks correspond to the two conformers of HAMA; one of them would be selectively bound on the substrate binding site of VerA enzyme and then converted to DMST. VerA enzyme may work as a key enzyme in the creation of the xanthone structure of DMST from HAMA.


Author(s):  
Liliya Logoyda ◽  
Dmytro Korobko

 Objective: A simple, rapid high-performance liquid chromatography–mass spectrometry (MS)/MS method was developed for the determination of bisoprolol from confluent Caco-2 monolayers and from aqueous solution.Methods: Chromatography was achieved on discovery C 18, 50 mm×2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A [acetonitrile:water:formic acid, 5:95:0.1 v/v] and eluent B [acetonitrile:formic acid, 100:0.1 v/v]). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and to 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.400 ml/min into the mass spectrometer ESI chamber. The sample volume was 5 μl.Results: Under these conditions, bisoprolol was eluted at 1.49 min. According to the Caco-2 test results, bisoprolol appeared to have moderate to high permeability. It should be noted that the recovery value for bisoprolol is 97.69%. Caco-2 permeability values for bisoprolol are in agreement with BCS Class I classification for these drugs and their known high bioavailability in humans.Conclusion: From results of analysis, it can be concluded that developed method is simple and rapid for the determination of bisoprolol from confluent Caco-2 monolayers and from aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for the examination of bisoprolol from Caco-2 cell monolayers.


Author(s):  
Liliya Logoyda

Objective: A simple, rapid high-performance liquid chromatography–mass spectrometry/mass spectrometry (MS/MS) method was developed for the determination of amlodipine from confluent Caco-2 monolayers and from aqueous solution.Methods: Chromatography was achieved on Discovery C18, 50×2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A [acetonitrile-water-formic acid, 5:95:0.1 v/v], eluent B [acetonitrile-formic acid, 100:0.1 v/v]). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and to 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.400 ml/min into the MS electrospray ionization chamber. The sample volume was 5 μl.Results: Under these conditions, amlodipine was eluted at 1.61 min. According to the Caco-2 test results, amlodipine appeared to have moderate to high permeability. Recovery value for amlodipine is 52.33%. Caco-2 permeability values for amlodipine are in agreement with BCS Class I classification for these drugs and their known high bioavailability in humans.Conclusion: A new rapid method was developed for the determination of amlodipine from confluent Caco-2 monolayers and from aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for the examination of amlodipine from Caco-2 cell monolayers.


2014 ◽  
Vol 7 ◽  
pp. IJTR.S16800 ◽  
Author(s):  
Magdalena E. Kegel ◽  
Maria Bhat ◽  
Elisabeth Skogh ◽  
Martin Samuelsson ◽  
Kristina Lundberg ◽  
...  

Several studies suggest a role for kynurenic acid (KYNA) in the pathophysiology of schizophrenia. It has been proposed that increased brain KYNA levels in schizophrenia result from a pathological shift in the kynurenine pathway toward enhanced KYNA formation, away from the other branch of the pathway leading to quinolinic acid (QUIN). Here we investigate the levels of QUIN in cerebrospinal fluid (CSF) of patients with schizophrenia and healthy controls, and relate those to CSF levels of KYNA and other kynurenine metabolites from the same individuals. CSF QUIN levels from stable outpatients treated with olanzapine (n = 22) and those of controls (n = 26) were analyzed using liquid chromatography-mass spectrometry. No difference in CSF QUIN levels between patients and controls was observed (20.6 ± 1.5 nM vs. 18.2 ± 1.1 nM, P = 0.36). CSF QUIN was positively correlated to CSF kynurenine and CSF KYNA in patients but not in controls. The CSF QUIN/KYNA ratio was lower in patients than in controls ( P = 0.027). In summary, the present study offers support for an over-activated and imbalanced kynurenine pathway, favoring the production of KYNA over QUIN in patients with schizophrenia.


2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199226
Author(s):  
Tsukasa Iwashina ◽  
Rinchen Yangzom ◽  
Hari Prasad Devkota ◽  
Takayuki Mizuno

Five flavonol O-glycosides and 4 C-glycosylflavones were isolated from the flowers of the Himalayan Megacodon stylophorus (Gentianaceae). They were characterized as quercetin 3- O-glucoside (1), quercetin 3- O-rutinoside (2), kaempferol 3- O-glucoside (3), isorhamnetin 3- O-glucoside (4) and kaempferol 3,7-di- O-glucoside (5) (flavonols), and isovitexin (6), isoorientin (7), isovitexin X″- O-arabinoside (8) and isovitexin 4′- O-glucoside (9) ( C-glycosylflavones) by ultraviolet, liquid chromatography-mass spectrometry, acid hydrolysis, nuclear magnetic resonance, and/or high-performance liquid chromatography and thin-layer chromatography comparisons with authentic samples. On the other hand, 5 C-glycosylflavones were isolated from the leaves and identified as 6, 7, 9, vitexin (10), and orientin (11). Although many C-glycosylflavones and xanthones have been reported from Gentianaceae species, flavonols are minor occurrence in the family. Flavonoids were reported from the Megacodon species for the first time.


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