Studies on absorption and transportation of coumarins in Angelica dahurica 'Yubaizhi' across human intestinal epithelial by using human Caco-2 cell monolayers / 中国中药杂志

The absorption is the key to the resulted efficacy of orally administered drugs and the small intestine is the main site to absorb the orally administered drug. In this paper, internationally recognized human colon adenocarcinoma cell line(Caco-2) monola-yer model which can simulate small intestinal epithelial cell was used to comparatively study the absorption and transportation diffe-rences of total coumarins and main individual coumarin in Angelica dahurica 'Yubaizhi' by separately using 6-and 12-well plates. It was found that apparent permeability coefficient(P_(app)) values of oxypeucedanin hydrate, byakangelicin and phellopterin were at the quantitative degree of 1 × 10~(-5) cm·s~(-1) when the individual administration was conducted independently, indicating that they were well-absorbed compounds. P_(app) ratio of their bi-directional transportation was close to 1, indicating that they can be absorbed across Caco-2 monolayer by passive diffusion mechanism without carrier mediation during the transportation. The similar trend of transportation was also observed for imperatorin, isoimperatorin and bergapten. The P_(app) values of oxypeucedanin hydrate, byakangelicin and bergapten were at quantitative degree of 1 × 10~(-5) cm·s~(-1) when the administration of total coumarins in Angelica dahurica 'Yubaizhi' was conducted, indicating that they were well-absorbed compounds. The results were consistent with those of independent administration of individual coumarins. Whereas, the P_(app) values of imperatorin, phellopterin and isoimperatorin in the total coumarins decreased, indicating that the interaction between compounds may exist although the P_(app) value ratio of bi-directional transportation was between 0.5 and 1.5. The results laid the foundation for intestinal absorption study of Angelica dahurica 'Yubaizhi' coumarins in compound Chinese medicine.

The effect of the shape of nanocarriers on their transmembrane across Caco-2 cell monolayer / 药学学报

Cerasomes with different shapes were constructed to investigate the effect of the nanocarriers' shape on the cellular uptake and transmembrane capacity. Cerasome-forming lipid (CFL) was synthesized via halogenation, nucleophilic addition and acylation reaction and detected by mass spectrometry and nuclear magnetic resonance spectroscopy. CFL and short chain 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) were employed to prepare organic-inorganic hybrid bicelles in discal shapes (nanodisc) by the thin-film hydration method, and CFL was also used to prepare spherical cerasomes (nanosphere). The particle size and zeta potential of nanocarriers were measured by dynamic light scattering analysis, and the morphology was observed by transmission electron microscopy. With human colon cancer cell line Caco-2 as the model, the effect of the shape of nanocarriers on cellular uptake and transmembrane capacity was investigated qualitatively by confocal laser scanning microscope (CLSM), and the transmembrane capacity was analyzed quantitatively by high performance liquid chromatography (HPLC). The results showed that nanosphere and nanodisc had similar particle diameters around 110 nm and similar zeta potential around -25 mV, with regular morphology under transmission electron microscope. The cellular uptake rate of nanodisc was significantly higher than that of nanosphere in 20 minutes. Further research on Caco-2 cell monolayer demonstrated that nanodisc with faster uptake had less accumulation in the monolayer, which means it had a higher transmembrane rate on Caco-2 cell monolayer and the transmembrane capacity of the nanodisc was better than that of nanosphere within 2 h. These results suggest that rational design of the shape of nanocarriers is expected to regulate nano-bio interactions, promote the transmembrane transport of nanocarriers, and improve the drug absorption.

Transmembrane absorption and methylation metabolism of quercetin on a caco-2 monolayer model / 中国药理学与毒理学杂志

OBJECTIVE To study transmembrane transport and methylation metabolism of quercetin based on the human intestinal absorption model. METHODS Caco-2 cell monolayer was used as the human intestinal absorption model. The incubation concentration of quercetin was 9.0 and 18.0 mg-L'1. Samples were collected at 30, 60, 90, 120 and 150 min, and the contents of quercetin, isorhamnetin and tamarixetin on the loading side and receiver side were determined by high performance liquid chromatography-mass spectrometry (LC-MS) method. Bupropion was used as the internal standard, and the injection volume was 20 pL. The specific inhibitors of P-glycoprotein (P-pg) or multidrug resistant protein 2 (MRP2), cyclosporins (CysA) 10 mmol-L-1 or MK571 1 mmol • L-1 (final concentration), were added to the apical side. After 15 min incubation, quercetin 9.0 or 18.0 mg-L-1 (final concentration) was added to the apical side, respectively. The quercetin content on the receiver side was determined by the same method. RESULTS During bi-directional transport, the dynamic change of quercetin residues on the loading side showed a continuous decline within 150 min (P<0.05 between adjacent time points), while the amount of quercetin on the receiver side tended to increase before decreasing, reaching the peak at 120 min and falling at 150 min (P<0.05 between adjacent time points). Isorhamnetin and tamarixetin could be detected on both the loading side and receiver side. But the difference was that when quercetin was loaded on the apical side or the basolateral side, there was much more isorhamnetin and tamarixetin on the apical side than on the basolateral side after 30-60 min. Analysis of the percentage of quercetin, isorhamnetin and tamarixetin on the loading side and receiver side found that when incubated for 30 min, the residual quercetin on the loading side was less than 20%-25%, and quercetin on the receiver side was only about 1% of the loading amount. At 150 min, the residual quercetin decreased to <10%, while quercetin in the receiver side was only 6%-7% of the loading amount, and isorhamnetin and tamarixetinin on both sides were only 0.1%-0.3% of loading quercetin. Compared with the quercetin control group, the addition of CysA or MK571 in advance significantly increased the transport of quercetin from the apical side to the basolateral side (P<0.05). CONCLUSION The transport of quercetin on the Caco-2 monolayer cell model shows a trend of rise and fall, accompanied by methylation metabolism. The efflux of P-pg and MRP2 may have an effect on the transmembrane transport of quercetin.

Transport mechanism of isorhapontigenin based on human intestinal Caco-2 cells / 中国中药杂志

Isorhapontigenin (ISO) is suggested to have many different kinds of pharmacology activities, such as anti-inflammatory effect, anti-oxidation effect and anti-cancer effect. This paper mainly discussed the transport mechanism of ISO in Caco-2 cell models. The concentration of ISO was determined by UPLC method with PDA detector at 310 nm, and then the apparent permeability coefficient Papp was calculated. The cytotoxic of different concentrations of ISO was investigated on Caco-2 cells to determine the concentration of drug administration. The effects of ISO concentration, time, temperature and transporter inhibitors on the transport of ISO were investigated. The test results showed that, ISO didn't have significant cytotoxicity at 10-60 μmol•L ⁻¹ in 14 hours. The transportation of ISO on Caco-2 cells was related to the concentration to a certain extent. Papp of ISO was higher than 10×10-6 cm•s ⁻¹ and ISO was absorbed easily by Caco-2 cells. The transport volume of ISO at BL side reached maximum at 3 h and was slightly decreased at 6 h. Papp (AP-BL) and Papp(BL-AP) at 4 ℃ were lower than those at 37 ℃. Papp (AP-BL) of ISO was significantly increased after adding P-gp inhibitor verapamil and Papp (BL-AP) of ISO was significantly decreased after adding MRP-2 inhibitor (probenecid or MK-571). The results suggested that transport mode of ISO was mainly passive diffusion in Caco-2 cell models, and P-gp and MRP may be involved in the transport of ISO.

Intestinal Absorption Characters of Mosapride Citrate Using Caco-2 Cells and Single-Pass Intestinal Perfusion Methods / 中国药学杂志

OBJECTIVE: To investigate the intestinal absorption characters of mosapride citrate(MC) and its tablets. METHODS: The Caco-2 cell monolayer was cultured and the in situ single-pass intestinal perfusion(SPIP) in rat model was created for studying the drug absorption properties, using phenol red method to revise the perfusate volume, a HPLC method was developed to simultaneously detect the phenol red and MC, the absorptive coefficient of Papp and Peff was calculated. RESULTS: MC was absorbed by the whole intestine segments in rats, mainly at upper small intestine. The tablets showed high permeability and good intestinal absorption in Caco-2 cells and SPIP in rats. CONCLUSION: In the Caco-2 cells and rats SPIP models, the tablets are prepared showed good consistency with the branded drug.

Metabolism and Transport of 7，4'-dihydroxyflavone in Caco-2 Cell Model / 医药导报

Objective To study the effects of different transport protein on the transport of 7,4'-dihydroxyflavone (7,4'-DHF) and its metabolite (7,4'-DHF-S) in Caco-2 cell model.Methods Ultra performance liquid chromatography was employed to determinethe content of 7,4'-DHF and 7,4'-DHF-S incubation buffer,their structures were identified by LC-MS/MS.Bidirectional transport of Caco-2 cells model was used to investigate the influence of ko143 (the inhibitor of BCRP) and MK571 (the inhibitor of MRP2) on the transport of 7,4'-DHF and 7,4'-DHF-S,respectively.Results Metabolic product of 7,4'-DHF in Caco-2 monolayer cell was identified as one monosulfate;PDR of 7,4'-DHF was (1.43 ± 0.11),PDR of ko143 and MK571 on the apparent permeability of 7,4'-DHF was (1.59 ± 0.04) and (1.48 ± 0.07) (P ＞ 0.05);PDR of 7,4'-DHF-S was (1.60 ± 0.06);ko143 could significantly reduce the apparent permeability of 7,4'-DHF-S,and the PDR was (0.23 ±0.03) (P ＜ 0.01);MK571 had no significant effect on the apparent permeability of the 7,4'-DHF-S,and the PDR was (1.51±0.04) (P ＞ 0.05).Conclusion Caco-2 cells can mediate the suffonated reaction of 7,4'-DHF;7,4'-dihydroxyflavone sulfonated combination product may be a substrate for BCRP.

Bioavailability in vivo and in vitro transepithelial transport across Caco-2 cell monolayer of pueraria flavonoids bio-adhesive and floating pellets / 药学学报

To study the bioavailability of pueraria flavonoids bio-adhesive and floating pellets, the absorption of puerarin was studied using Caco-2 cell monolayer by liquid chromatography (HPLC) method, comparing the Papp of pueraria flavonoids bio-adhesive and floating pellets with different bio-adhesive materials. Drugs were administered at a dose of 100 mg·kg-1 via ig. The plasma concentration of puerarin was determined by HPLC, the pharmacokinetics were calculated with the WinNonlin 6.0 software. The results showed that the Papp of bio-adhesive and floating pellets with hydroxypropyl methylcellulose (HPMC)-cabomer was largest, which had a significant difference (P0-t of pueraria flavonoids bio-adhesive and floating pellets was 1.79 times of pueraria flavonoids, the Cmax of pueraria flavonoids bio-adhesive and floating pellets and pueraria flavonoids had a significant difference (P<0.05). What's more the MRT had prolonged. In conclusion, pueraria flavonoids bio-adhesive and floating pellets with HPMC-cabomer could significantly facilitate the transport of puerarin on Caco-2 cellular monolayers. The bioavailability of pueraria flavonoids bio-adhesive and floating pellets with HPMC-cabomer was increased more than pueraria flavonoids with a sustained release effect.

Mechanistic studies of the transport of peimine in the Caco-2 cell model

Fritillaria thunbergii Miq. has been widely used in traditional Chinese medicine for its expectorant, antitussive, antiinflammatory and analgesic properties. Moreover, modern pharmacological studies have demonstrated that F. thunbergii Miq. has efficacy in the treatment of leukemia and cancers of the liver and cervix. Although the alkaloid, peimine, is largely responsible for these pharmacological effects, it has very low oral bioavailability. The aim of this study was to investigate the intestinal absorption of peimine in Caco-2 cell monolayers. Having demonstrated that peimine is non-toxic to Caco-2 cells at concentrations <200 μmol/L, the effect of peimine concentration, pH, temperature, efflux transport protein inhibitors and EDTA-Na2 on peimine transport were studied. The results show that peimine transport is concentration-dependent; that at pH 6.0 and 7.4, the P app(AP-BL) of peimine is not significantly different but the P app(BL-AP)) is; that both P app(AP-BL) and P app(BL-AP) at 4 °C are significantly higher than their corresponding values at 37 °C; that the P-glycoprotein (P-gp) inhibitors, verapamil and cyclosporin A, increase absorption of peimine; and that EDTA-Na2 has no discernible effect. In summary, the results demonstrate that the intestinal absorption of peimine across Caco-2 cell monolayers involves active transport and that peimine is a substrate of P-gp.

Promotion of suet oil to absorption and transportation of total flavonoids from Epimedii Folium / 中草药

Objective: To study the promotion mechanism of suet oil to the intestinal absorption of the total flavonoids from Epimedii Folium (EF). Methods: The in vivo intestinal perfusion model and Caco-2 cell monolayer model of rats were used to study the influence of processing excipient suet oil in self-assembled micelles on the intestinal absorption of total flavones from EF. Results: In the in vivo intestinal perfusion model of rats, there were differences of absorption of icariin in the total flavonoids from EF in the four segments of the intestines. After the suet oil was added and self-assembled micelles were formed, the permeabilities of icariin in the total flavonoids from EF were increased significantly in duodenum and jejunum segments. In Caco-2 cell monolayer model of rats, the absorptive permeability coefficients were small for icariin in the total flavonoids from EF, after the suet oil was added and the self-assembled micelles were formed, the absorptive permeability coefficients were increased significantly, the efflux ratios were decreased from 4.72 to 2.31. Conclusion: The total flavonoids from EF have a bad intestinal absorption, after the suet oil added and the self-assembled micelles formed, the intestinal absorption of the total flavonoids from EF could be improved.

Absorption properties and mechanism of trolline and veratric acid and their implication to an evaluation of the effective components of the flowers of Trollius chinensis / 中国天然药物

AIM@#To study the absorption properties and mechanism of two important components, trolline and veratric acid, from the flowers of Trollius chinensis, in order to better understand the contribution of these two compounds to the effectiveness of these flowers.@*METHOD@#The human Caco-2 cell monolayer model was employed to study the transport of trolline and veratric acid from apical side (AP) to basal side (BL), and from BL to AP by determining the transport rates as the function of time and concentration and calculating apparent permeability coefficients (Papp).@*RESULTS@#Trolline and veratric acid were transported across Caco-2 cell monolayer through different mechanisms in a concentration dependent manner. Trolline was transported at a Papp level of 10(-6) cm·s(-1) with a Papp AP→BL/Papp BL→AP ratio of more than 1.8 or less than 0.8, while veratric acid was transported at a Papp level of 10(-5)cm·s(-1) with a Papp AP→BL/Papp BL→AP ratio of close to 1.0.@*CONCLUSION@#Trolline is moderately absorbed through an associative mechanism involving active and passive transport, and veratric acid is well-absorbed mainly through passive diffusion. These factors should be taken into account when chemically assessing the pharmacodynamic material basis of the flowers of T. chinensis.

Transport characteristics of hydroxysafflor yellow A across Caco-2 cell monolayer model / 中草药

Objective: To investigate the transport characteristics of hydroxysafflor yellow A (HSYA) in Danhong Injection across Caco-2 cell monolayer. Methods: Safe concentration range of HSYA against Caco-2 cell monolayer model was selected by MTT method; The effects of time, drug concentration, temperature, pH, P-gp inhibitor (Verapamil), and energy metabolism inhibitor (sodium azide) on the absorption of HSYA were observed by Caco-2 cell monolayer model; The multidrug resistance (MDR1) gene expression in Caco-2 cells was analyzed by the RT-PCR method. Results: The Papp of HSYA transport from apical (AP) side to basolateral (BL) side was in 2 × 10-6-5 × 10-6 cm/s, which showed a medium absorption. The transport of HSYA was positively correlated with time and concentration. The Papp of HSYA transport at 37°C has significant differences with those at 4 and 25°C (P < 0.01). The Papp of HSYA transport under pH 9.0 has significant differences with those under pH 5.0 and 7.4 (P < 0.01). The gene expression of MDR1 was significantly reduced by Verapamil, but the transport of HSYA was not influenced by Verapamil and sodium azide, the number of Papp(BL→AP)/Papp(AP→BL) was between 1 and 1.5, so the absorption of HSYA was basically in line with the passive diffusion. Conclusion: The transport of HSYA across Caco-2 cell monolayer model is passive diffusion, and is not influenced by the change of P-gp and energy metabolism. Low temperature and alkaline environment are not conducive to the absorption of HSYA.

Transport characteristics of ligustrazine across Caco-2 cell monolayer model and its effect on P-glycoprotein expression / 中草药

Objective: To investigate the transport characteristics of ligustrazine across Caco-2 cell monolayer and the effect on P-glycoprotein (P-gp) expression. Methods: Safe concentration range of ligustrazine against Caco-2 cell monolayer model was selected by the MTT method. The mechanism of ligustrazine bidirectional transport was investigated by Caco-2 cell monolayer model. The influences of time, concentration, and P-gp inhibitor Verapamil on the transport of ligustrazine were studied using apparent permeability coefficient (Papp) as index. P-gp expression in Caco-2 cells was analyzed by the Western blotting method. Results: The Papp of transport from apical (AP) side to basolateral (BL) side was over 10-6 cm/s, which showed a good absorption. In the Caco-2 cell model, the transport amount of ligustrazine was positively correlated with time and concentration, and the transport amount from AP side to BL side was higher than that from BL to AP. The absorption of ligustrazine was not only rejected by P-gp, but also the P-gp expression was inhibited by ligustrazine. Conclusion: The transport of ligustrazine across Caco-2 cell monolayer model is deduced as passive transport, ligustrazine is rejected by P-gp, and there is an inhibition of ligustrazine on the expression of P-gp.

Absorption mechamism of dehydroandrographolide in human caco-2 cell monolayer model / 中草药

Objective: To study the absorption mechanism of dehydroandrographolide (DAL) in human Caco-2 cell monolayer model. Methods: Caco-2 cell monolayer model was applied to investigate the bidirectional transport of DAL. The effects of time, drug concentration, temperature, and P-gp inhibitor (Verapamil) on the absorption of DAL were observed. Drug concentration was measured by LC/MS/MS and the apparent permeability coefficients (Papp) were calculated. Results: With the time and concentration increasing, the bidirection transport of DAL in Caco-2 cell monolayer model was of time and concentration dependence, without saturation. And it was not influenced by the change of temperature and the presence of Verapamil. Conclusion: The absorption and transport of DAL are passive diffusion as the dominating process in Caco-2 cell monolayer model.

Transcytosis mechanism of chlorogenic acid across cell monolayer model / 中国药理学通报

Aim To investigate the transcytosis mechanism of chlorogenic acid(CGA)by using Caco-2 and MDCK(Madin Darby canine kidney) monolayers models.Method ① Caco-2 and MDCK cell models:Caco-2 cell(105 cells/cm2) and MDCK cell(5?104 cells/cm2) were inoculated in Millicell-CM culture plate inserts,and the TEER of cell monolayer were detected to make sure the models are available for experiments.② Permeating experiments: to measure the value of OD of CGA and calculate the cumulative amount.Result CGA could be Absorbed and secreted on two monolayer models.Verapamil could inhibit the secretion at lower concentration of CGA on MDCK monolayer model.P-pg could partly act on the secretion of CGA on Caco-2 and MDCK cell models.Conclusion CGA can secrete and Absorb at the same time across Caco-2 and MDCK cell monolayers,P-pg partly involving in the secretion of CGA.

Absorption and transport mechanism of ursolic acid across Caco-2 monolayer model / 中草药

Objective To study the absorption and transport mechanism of ursolic acid(UA) by using Caco-2 monolayer model.Methods Evaluating the transport characteristic through studying whether P-glycoprotein(P-gp) transporter inhibitor Verapamil(VER) exists or not by using Caco-2 cell monolayer as an intestinal epithelial cell model and investigating the effects of uptake time,drug concentration,system temperature,and pH value of culture media on the uptake of UA.The drug concentration was measured by HPLC coupled with UV detector.Transport parameters and apparent permeability coefficients (P_(app)) were then calculated.Results In the concentration range of 10—40?mol/L,the uptake of UA by Caco-2 cell all linearly increased.The P_(app) of UA transported on Caco-2 cell monolayer model significantly changed when the specificity inhibitory of P-gp was added to model and the apparent permeability ratio decreased from 3.445 to 1.386.Conclusion The intestinal absorption of UA is passive diffusion as the dominating process and active transportation mediated by P-gp transporter in Caco-2 cell monolayer model.

Absorption and transportation of flavonoids in Herb Epimedii across Caco-2 monolayer model / 中草药

Objective To study the absorption and transportation of flavonoids in Herb Epimedii by using Caco-2 monolayer model. Methods Caco-2 cell monolayer model was used to study the bi-direction transport of icariin, epimedin A, epimedin B, epimedin C, and baohuoside Ⅰ. The concentration of the five flavonoids in cell culture medium was measured by UPLC and the apparent permeability coefficients (Papp) were calculated. Results The absorptive permeability coefficients (PAB) of icariin, epimedin A, epimedin B, epimedin C, and baohuoside Ⅰ were 5.91?10-7, 3.22?10-7, 2.76?10-7, 4.23?10-7, and 1.46?10-6 cm/s, respectively. Except baohuoside Ⅰ, the other four flavonodes had lower permeabilities, and the secretive permeabilities (PBA) of all the flavonoids were larger than their absorptive permeabilities. Among them, the PBA of baohuoside Ⅰ was 9.8 times as much as the PAB. Conclusion The results suggest that the intestinal absorption of the five flavonoids is lower, which might have efflux mechanism by transporters, and the absorption of monloglycoside (e.g. baohuoside Ⅰ) is better than that of diglycoside (e.g. icariin) and triglycoside (e.g. epimedin A, epimedin B, and epimedin C).

Absorptive Characteristics of Ginsenoside Rb_3 in Caco-2 Cell Monolayer Model / 中国药房

OBJECTIVE:To study the absorptive characteristics of ginsenoside Rb3 in Caco-2 cell monolayer model. METHO-DS:The ginsenoside Rb3 cell samples underwent high speed centrifugation, then the supernatant was collected and determined by LC-ESI-MS/MS method in which the mobile phase consisted of acetonitrile-1 mmol?L-1 ammonium formate water solution (34 ∶ 66) with ginsenoside Rg2 as internal standard, and the tandem mass spectrometry was operated in negative electrospray ionization in a multiple reaction monitoring (MRM) mode, with detection ions m/z1077.7→m/z 783.4 for ginsenoside Rb3 and m/z 783.6→m/z 475.1 for ginsenoside Rg2.The concentration of ginsenoside Rb3 across the Caco-2 cell monolayer model was determined and the apparent permeability coefficient(Papp) of ginsenoside Rb3 was calculated. RESULTS: The calibration curve for ginsenoside Rb3 was linear in the range of 50～2 000 ng?mL-1,with intra-day precision and inter-day precision at less than 15%. P(AP-BL) from apical side (AP) to basolateral side (BL) was 3.22?10-6 cm?s-1, whereas P(BL-AP) from BL to AP was 6.0?10-6 cm?s-1,and the ratio of P(BL-AP)/P(AP-BL) was 1.86.CONCLUSION:The LC-ESI/MS/MS method is simple and sensitive, and it is applicable for the study of the absorptive characteristics of ginsenoside Rb3 in Caco-2 cell monolayer model.

Transport and uptake of ecdysterone in Caco-2 cell monolayers / 中国药理学通报

Aim This study examined the uptake and transport of ecdysterone(EDS) using Caco-2 cell monolayers as a model of human intestinal mucosa.Methods Two kinds of Caco-2 cell monolayer model(Caco-2 cell monolayers;CYP3A4 expressing Caco-2 cell monolayers) were set up to study the uptake and transport of EDS.Results Compared bi-directional charaterizaton of Caco-2 cell,the apparent permeability coefficients(Papp) values of EDS were between 0.1?10-6 cm?s-1 and 1?10-6 cm?s-1.EDS absorption was 1%~10% for two kinds of Caco-2 models.The RPapp values were all less than 1.5 for 4 h.Conclusions The uptake and transport of EDS was a passive transcellular diffusion mechanism.Ecdysterone was not influenced by CYP3A4 mediate mechanism.