Arachidonic acid intestinal absorption: Mechanism of transport and influence of luminal factors on absorption in vitro

Standard models used for evaluating the absorption of nanoparticles like Caco-2 ignore the presence of vascular endothelium, which is a part of the intestinal multi-layered barrier structure. Therefore, a coculture between the Caco-2 epithelium and HMEC-1 (Human Microvascular Endothelial Cell type 1) on a Transwell® insert has been developed. The model has been validated for (a) membrane morphology by transmission electron microscope (TEM); (b) ZO-1 and β-catenin expression by immunoassay; (c) membrane integrity by trans-epithelial electrical resistance (TEER) measurement; and (d) apparent permeability of drugs from different biopharmaceutical classification system (BCS) classes. Lipid nanocapsules (LNCs) were formulated with different sizes (55 and 85 nm) and surface modifications (DSPE-mPEG (2000) and stearylamine). Nanocapsule integrity and particle concentration were monitored using the Förster resonance energy transfer (FRET) technique. The result showed that surface modification by DSPE-mPEG (2000) increased the absorption of 55-nm LNCs in the coculture model but not in the Caco-2. Summarily, the coculture model was validated as a tool for evaluating the intestinal absorption of drugs and nanoparticles. The new coculture model has a different LNCs absorption mechanism suggesting the importance of intestinal endothelium and reveals that the surface modification of LNCs can modify the in vitro oral absorption.

Download Full-text

In vitro and in situ study on characterizationand mechanismofthe intestinal absorptionof 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v3 ◽

2020 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

Concentration Time ◽

In Situ Experiments ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods: This study used Caco-2 cell monolayer model and single-passintestinal perfusion modelto explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed. Results: TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro and in situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2. Conclusions: It wasconcluded that the gastrointestinalabsorption mechanisms ofTSG involved processes passive transport and the participation ofefflux transporters.

Download Full-text

In vivo and in vitro study on characterization and mechanism of the intestinal absorption of 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v1 ◽

2019 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

In Vitro Study ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

Concentration Time ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibits a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound has poor bioavailability and the underlying absorption mechanisms has not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods: This study used the Caco-2 cell monolayer model and the single-passintestinal perfusion modelto explore the intestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.In addition, the susceptibility of TSG absorption process to treatment with three inhibitors, such as P-gp inhibitors verapamil hydrochloride and quinidine, and the MRP2 inhibitor probenecid were also assessed. Results: TSG is poorly absorbed in the intestines and the absorption of TSG in the stomach is much higher than that in the intestine. Both in vivo and in vitro experiments showed that the absorption of TSG was saturated with increasing concentration. and it was better absorbed in a weakly acidic environment with a pH of 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG is not only the substrate of the P-gp and MRP2, but also affects the expression of P-gp and MRP2. Conclusions: It can be concluded that the intestinal absorption mechanismsofTSG involve processes passive transport and the participation of efflux transporters.

Download Full-text

Vitamin A1 intestinal absorption in vivo: influence of luminal factors on transport.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1977.232.5.e471 ◽

1977 ◽

Vol 232 (5) ◽

pp. E471 ◽

Cited By ~ 1

Author(s):

D Hollander ◽

K S Muralidhara

Keyword(s):

Intestinal Absorption ◽

Absorption Rate ◽

Sodium Taurocholate ◽

Water Layer ◽

Metabolic Inhibitors ◽

Absorption Mechanism ◽

Lymphatic Circulation ◽

Passive Absorption

Intestinal absorption of [3H]retinol was studied in the unanesthetized rat. Luminal perfusate was recirculated through isolated intestinal segments with intact vascular and lymphatic circulation. Apparent saturation kinetics were found in physiological concentrations of retinol, whereas a linear relationship between the concentration and absorption rate was found at pharmacological concentrations of retinol in the perfusate. In physiological concentrations, retinol uptake in vitro by everted gut sacs was unaffected by anoxia or metabolic inhibitors and uncouplers. In vivo retinol absorption rate was decreased when sodium taurocholate concentration was raised above 5 mM, or when 2.5 mM linoleic or linolenic acids were added to the perfusate. Absorption increased markedly as the thickness of the unstirred water layer was diminished. Variations in perfusate pH from 4.5 to 8.6 did not change the retinol absorption rate. In vivo absorption of retinol in physiological concentrations is mediated by a saturable, carrier-mediated passive absorption mechanism modified by the presence of fatty acids of varying chain length.

Download Full-text

In vitro and in situ study on characterizationand mechanismofthe intestinal absorptionof 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

10.21203/rs.2.15497/v2 ◽

2019 ◽

Author(s):

Cheng Wang ◽

Yimeng Zhou ◽

Xiaohong Gong ◽

Li Zheng ◽

Yunxia Li

Keyword(s):

Intestinal Absorption ◽

High Performance ◽

Cell Monolayer ◽

Absorption Mechanism ◽

Pharmacological Activities ◽

In Situ Study ◽

Concentration Time ◽

Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods:This study used Caco-2 cell monolayer model and single-passintestinal perfusion modelto explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed. Results: TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro andin situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2. Conclusions: It wasconcluded that the gastrointestinalabsorption mechanisms ofTSG involved processes passive transport and the participation ofefflux transporters.

Download Full-text

Chlorobutanol, a Preservative of Desmopressin, Inhibits Human Platelet Aggregation and Release In Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647339 ◽

1990 ◽

Vol 64 (03) ◽

pp. 473-477 ◽

Cited By ~ 4

Author(s):

Shih-Luen Chen ◽

Wu-Chang Yang ◽

Tung-Po Huang ◽

Shiang Wann ◽

Che-ming Teng

Keyword(s):

Arachidonic Acid ◽

Platelet Aggregation ◽

Atp Release ◽

Free Calcium ◽

Dependent Manner ◽

Antiplatelet Effect ◽

Human Platelet Aggregation ◽

Acid Pathway ◽

Arachidonic Acid Pathway

SummaryTherapeutic preparations of desmopressin for parenteral use contain the preservative chlorobutanol (5 mg/ml). We show here that chlorobutanol is a potent inhibitor of platelet aggregation and release. It exhibited a significant inhibitory activity toward several aggregation inducers in a concentration- and time-dependent manner. Thromboxane B2 formation, ATP release, and elevation of cytosolic free calcium caused by collagen, ADP, epinephrine, arachidonic acid and thrombin respectively were markedly inhibited by chlorobutanol. Chlorobutanol had no effect on elastase- treated platelets and its antiplatelet effect could be reversed. It is concluded that the antiplatelet effect of chlorobutanol is mainly due to its inhibition on the arachidonic acid pathway but it is unlikely to have a nonspecitic toxic effect. This antiplatelet effect of chlorobutanol suggests that desmopressin, when administered for improving hemostasis, should not contain chlorobutanol as a preservative.

Download Full-text

The d-Enantiomer Form of Indobufen Totally Accounts for the Anti-Cyclooxygenase and Antiplatelet Activity Ex Vivo and for the Increase in Bleeding Time by Indobufen in Man

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648422 ◽

1992 ◽

Vol 67 (02) ◽

pp. 258-263 ◽

Cited By ~ 12

Author(s):

Raffaele De Caterina ◽

Rosa Sicari ◽

An Yan ◽

Walter Bernini ◽

Daniela Giannessi ◽

...

Keyword(s):

Arachidonic Acid ◽

Platelet Aggregation ◽

Plasma Levels ◽

Bleeding Time ◽

Ex Vivo ◽

Random Sequence ◽

Antiplatelet Agent ◽

Antiplatelet Drug ◽

Double Blind

SummaryIndobufen is an antiplatelet drug able to inhibit thromboxane production and cyclooxygenase-dependent platelet aggregation by a reversible inhibition of cyclooxygenase. Indobufen exists in two enantiomeric forms, of which only d-indobufen is active in vitro in inhibiting cyclooxygenase. In order to verify that also inhibition of platelet function is totally accounted for by d-indobufen, ten patients with proven coronary artery disease (8 male, 2 female, age, mean ± S.D., 58.7 ± 7.5 years) were given, in random sequence, both 100 mg d-indobufen and 200 mg dl-indobufen as single administrations in a double-blind crossover design study with a washout period between treatments of 72 h. In all patients thromboxane (TX) B2 generation after spontaneous clotting (at 0, 1, 2, 4, 6, 8, 12, 24 h), drug plasma levels (at the same times), platelet aggregation in response to ADP, adrenaline, arachidonic acid, collagen, PAF, and bleeding time (at 0, 2, 12 h) were evaluated after each treatment. Both treatments determined peak inhibition of TXB2 production at 2 h from administration, with no statistical difference between the two treatments (97 ±3% for both treatments). At 12 h inhibition was 87 ± 6% for d-indobufen and 88 ± 6% for dl-indobufen (p = NS). Inhibition of TXB2 production correlated significantly with plasma levels of the drugs. Maximum inhibitory effect on aggregation was seen in response to collagen 1.5 pg/ml (63 ± 44% for d-indobufen and 81 ± 22% for dl-indobufen) and arachidonic acid 0.5-2 mM (78 ± 34% for d-indobufen and 88 ± 24% for dl-indobufen) at 2 h after each administration. An effect of both treatments on platelet aggregation after 12 h was present only for adrenaline 2 μM (55 ± 41% for d-indobufen and 37 ± 54% for dl-indobufen), collagen 1.5 pg/ml (69 ± 30% for d-indobufen and 51 ± 61% for dl-indobufen), arachidonic acid 0.5-2 mM (56 ± 48% for d-indobufen and 35 ± 49% for dl-indobufen). The extent of inhibition of TX production and the extent of residual platelet aggregation were never significantly different between treatments. Bleeding time prolongation was similar in the two treatment groups without showing a pronounced and long lasting effect (from 7.0 ± 2.0 min to 10.0 ± 3.0 min at 2 h and 8.0 ± 2.0 min at 12 h for d-indobufen; from 6.0 ±1.0 min to 8.5 ± 2.0 min at 2 h and 8.0 ± 1.0 min at 12 h for dl-indobufen). These results demonstrate that the biological activity of dl-indobufen as an antiplatelet agent in vivo is totally accounted for by d-indobufen.

Download Full-text

Effects of Dipyrone on Prostaglandin Production by Human Platelets and Cultured Bovine Aortic Endothelial Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657338 ◽

1983 ◽

Vol 49 (02) ◽

pp. 132-137 ◽

Cited By ~ 16

Author(s):

A Eldor ◽

G Polliack ◽

I Vlodavsky ◽

M Levy

Keyword(s):

Endothelial Cells ◽

Arachidonic Acid ◽

Competitive Inhibition ◽

Inhibitory Effect ◽

Human Platelets ◽

Ionophore A23187 ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Aortic Endothelial

SummaryDipyrone and its metabolites 4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoan- tipyrine inhibited the formation of thromboxane A2 (TXA2) during in vitro platelet aggregation induced by ADP, epinephrine, collagen, ionophore A23187 and arachidonic acid. Inhibition occurred after a short incubation (30–40 sec) and depended on the concentration of the drug or its metabolites and the aggregating agents. The minimal inhibitory concentration of dipyrone needed to completely block aggregation varied between individual donors, and related directly to the inherent capacity of their platelets to synthesize TXA2.Incubation of dipyrone with cultured bovine aortic endothelial cells resulted in a time and dose dependent inhibition of the release of prostacyclin (PGI2) into the culture medium. However, inhibition was abolished when the drug was removed from the culture, or when the cells were stimulated to produce PGI2 with either arachidonic acid or ionophore A23187.These results indicate that dipyrone exerts its inhibitory effect on prostaglandins synthesis by platelets or endothelial cells through a competitive inhibition of the cyclooxygenase system.

Download Full-text

In Vitro Incorporation and Metabolism of Icosapentaenoic and Docosahexaenoic Acids in Human Platelets - Effect on Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661603 ◽

1986 ◽

Vol 56 (01) ◽

pp. 057-062 ◽

Cited By ~ 56

Author(s):

Martine Croset ◽

M Lagarde

Keyword(s):

Arachidonic Acid ◽

Fatty Acid ◽

Platelet Aggregation ◽

Fatty Acid Distribution ◽

Thromboxane A2 ◽

Human Platelets ◽

Aggregation Response ◽

Docosahexaenoic Acids ◽

Membrane Level

SummaryWashed human platelets were pre-loaded with icosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or EPA + DHA and tested for their aggregation response in comparison with control platelets. In fatty acid-rich platelets, an inhibition of the aggregation could be observed when induced by thrombin, collagen or U-46619. The strongest inhibition was observed with DHA-rich platelets and it was reduced when DHA was incorporated in the presence of EPA.Study of fatty acid distribution in cell lipids after loading showed that around 90% of EPA or DHA taken up was acylated into phospholipids and a very small amount (less than 2%) remained in their free and hydroxylated forms. DHA was more efficiently acylated into phosphatidylethanolamine (PE) than into phosphatidylinositol (PI) in contrast to what observed with EPA, and both acids were preferentially incorporated into phosphatidylcholine (PC). EPA inhibited total incorporation of DHA and increased its relative acylation into PE at the expense of PC. In contrast, DHA did not affect the acylation of EPA. Upon stimulation with, thrombin, EPA was liberated from phospholipids and oxygenated (as judged by the formation of its monohydroxy derivative) whereas DHA was much less metabolized, although consistently transferred into PE.It is concluded that EPA and DHA might affect platelet aggregation via different mechanisms when pre-loaded in phospholipids. Whereas EPA is known to alter thromboxane A2 metabolism from endogenous arachidonic acid, by competing with it, DHA might act directly at the membrane level for inhibiting aggregation.

Download Full-text

Characterization and In Vitro Evaluation of Intestinal Absorption of Liposomes Encapsulating Zanamivir

Current Drug Delivery ◽

10.2174/156720111795767915 ◽

2011 ◽

Vol 8 (4) ◽

pp. 392-397 ◽

Cited By ~ 8

Author(s):

Boontarika Boonyapiwat ◽

Narong Sarisuta ◽

Sarinnate Kunastitchai

Keyword(s):

Intestinal Absorption ◽

In Vitro Evaluation

Download Full-text