Caco-2 Cell Permeability Research Articles

Design, Synthesis, and Biological Evaluation of Covalently Mucoadhesive Derivatives as Nonsystemic Intestine-Targeted TGR5 Agonists.

Takeda G-protein-coupled receptor 5 (TGR5) is considered a promising therapeutic target for treating type 2 diabetes mellitus (T2DM), obesity, and other metabolism-related diseases. Although many TGR5 agonists have been identified, they might cause some side effects in the gallbladder and the heart. To reduce these side effects and improve glucose-lowering capability, we first designed and synthesized a series of 4-phenoxynicotinamide intestine-targeted TGR5 agonist derivatives containing maleimides in the side chains with different linker lengths. All of the target compounds demonstrated significant TGR5 agonistic activity, among which compound 22b displayed the best TGR5 agonistic activity. Additionally, compound 22b displayed low Caco-2 cell permeability and strong mucoadhesion to mucin and the rat intestine. In C57BL/6J, diet-induced obese, and db/db mice, compound 22b demonstrated a robust and prolonged hypoglycemic effect along with an acceptable safety profile.

Poly(2-Deoxy-2-Methacrylamido-D-Glucose)-Based Complex Conjugates of Colistin, Deferoxamine and Vitamin B12: Synthesis and Biological Evaluation.

Growing resistance to traditional antibiotics poses a global threat to public health. In this regard, modification of known antibiotics, but with limited applications due to side effects, is one of the extremely promising approaches at present. In this study, we proposed the synthesis of novel complex polymeric conjugates of the peptide antibiotic colistin (CT). A biocompatible and water-soluble synthetic glycopolymer, namely, poly(2-deoxy-2-methacrylamido-D-glucose) (PMAG), was used as a polymer carrier. In addition to monoconjugates containing CT linked to PMAG by hydrolyzable and stable bonds, a set of complex conjugates also containing the siderophore deferoxamine (DFOA) and vitamin B12 was developed. The structures of the conjugates were confirmed by 1H NMR and FTIR-spectroscopy, while the compositions of conjugates were determined by UV-Vis spectrophotometry and HPLC analysis. The buffer media with pH 7.4, corresponding to blood or ileum pH, and 5.2, corresponding to the intestinal pH after ingestion or pH in the focus of inflammation, were used to study the release of CT. The resulting conjugates were examined for cytotoxicity and antimicrobial activity. All conjugates showed less cytotoxicity than free colistin. A Caco-2 cell permeability assay was carried out for complex conjugates to simulate the drug absorption in the intestine. In contrast to free CT, which showed very low permeability through the Caco-2 monolayer, the complex polymeric conjugates of vitamin B12 and CT provided significant transport. The antimicrobial activity of the conjugates depended on the conjugate composition. It was found that conjugates containing CT linked to the polymer by a hydrolyzable bond were found to be more active than conjugates with a non-hydrolyzable bond between CT and PMAG. Conjugates containing DFOA complexed with Fe3+ were characterized by enhanced antimicrobial activity against Pseudomonas aeruginosa compared to other conjugates.

Improved preclinical drug metabolism and pharmacokinetics of pibothiadine (HEC121210), a novel hepatitis B virus capsid assembly modulator

Pibothiadine (PBD; HEC121120) is a novel hepatitis B virus capsid assembly modulator based on GLS4 (morphothiadine) and has inhibitory activities against resistant strains. To assess the overall preclinical drug metabolism and pharmacokinetics (DMPK) properties of PBD, in vivo pharmacokinetics studies in rats and dogs have been performed along with a series of in vitro metabolism assays. The oral bioavailability of PBD in rats and dogs might be related to its medium permeability in Caco-2 cells and largely be impacted by the pH-dependent solubility. PBD was highly distributed to the liver where the local exposure was 16.4 fold of the system exposure. PBD showed relatively low metabolic rate in recombinant human cytochrome P450 enzymes, whereas low to moderate in vitro clearance in liver microsomes and low (dog) to moderate (rat) in vivo clearance. Furthermore, β-oxidation and dehydrogenation were proposed as the primary metabolic pathways of PBD in rats. Compared to GLS4, the higher systemic exposure of PBD might be attributed to its improved oral absorption and metabolic stability. In addition, the enhanced liver/plasma exposure ratio could further increase the local exposure around the target. These improved DMPK properties might indicate better development of PBD in the clinical phase.

IFN-β Overexpressing Adipose-Derived Mesenchymal Stem Cells Mitigate Alcohol-Induced Liver Damage and Gut Permeability.

Alcoholic liver disease (ALD) is a form of hepatic inflammation. ALD is mediated by gut leakiness. This study evaluates the anti-inflammatory effects of ASCs overexpressing interferon-beta (ASC-IFN-β) on binge alcohol-induced liver injury and intestinal permeability. In vitro, ASCs were transfected with a non-viral vector carrying the human IFN-β gene, which promoted hepatocyte growth factor (HGF) secretion in the cells. To assess the potential effects of ASC-IFN-β, C57BL/6 mice were treated with three oral doses of binge alcohol and were administered intraperitoneal injections of ASC-IFN-β. Mice treated with binge alcohol and administered ASC-IFN-β showed reduced liver injury and inflammation compared to those administered a control ASC. Analysis of intestinal tissue from ethanol-treated mice administered ASC-IFN-β also indicated decreased inflammation. Additionally, fecal albumin, blood endotoxin, and bacterial colony levels were reduced, indicating less gut leakiness in the binge alcohol-exposed mice. Treatment with HGF, but not IFN-β or TRAIL, mitigated the ethanol-induced down-regulation of cell death and permeability in Caco-2 cells. These results demonstrate that ASCs transfected with a non-viral vector to induce IFN-β overexpression have protective effects against binge alcohol-mediated liver injury and gut leakiness via HGF.

High-Throughput SFC-MS/MS Method to Measure EPSA and Predict Human Permeability.

Permeability is a key factor driving the absorption of orally administered drugs. In early discovery, the efficient evaluation of permeability, particularly for compounds violating Lipinski's Rule of 5, remains challenging. Addressing this, we established a high-throughput method to measure the experimental polar surface area (HT-EPSA) as an in vitro surrogate to measure permeability. Compared to earlier methods, HT-EPSA significantly reduces data acquisition time with enhanced sensitivity, selectivity, and data quality. In the effort of translating EPSA to human in vitro and in vivo passive permeability, we demonstrated the application of EPSA for predicting Caco-2 cell and human intestinal permeability, showing improvements over topological polar surface area and the parallel artificial membrane permeability assay for rank-ordering permeability in a proteolysis targeting chimera case study. The HT-EPSA method is expected to be highly beneficial in guiding early stage compound rank-ordering, faster decision-making, and in predicting in vitro and/or in vivo human intestinal permeability.

Bacteriocins attenuate Listeria monocytogenes–induced intestinal barrier dysfunction and inflammatory response

Bacteriocins have the potential to effectively improve food-borne infections or gastrointestinal diseases and hold promise as viable alternatives to antibiotics. This study aimed to explore the antibacterial activity of three bacteriocins (nisin, enterocin Gr17, and plantaricin RX-8) and their ability to attenuate intestinal barrier dysfunction and inflammatory responses induced by Listeria monocytogenes, respectively. Bacteriocins have shown excellent antibacterial activity against L. monocytogenes without causing any cytotoxicity. Bacteriocins inhibited the adhesion and invasion of L. monocytogenes on Caco-2 cells, lactate dehydrogenase (LDH), trans-epithelial electrical resistance (TEER), and cell migration showed that bacteriocin improved the permeability of Caco-2 cells. These results were attributed to the promotion of tight junction proteins (TJP) assembly, specifically zonula occludens-1 (ZO-1), occludin, and claudin-1. Furthermore, bacteriocins could alleviate inflammation by inhibiting the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathways and reducing the secretion of interleukin-6 (IL-6), interleukin-1 β (IL-1β) and tumor necrosis factor α (TNF-α). Among three bacteriocins, plantaricin RX-8 showed the best antibacterial activity against L. monocytogenes and the most pronounced protective effect on the intestinal barrier due to its unique structure. Based on our findings, we hypothesized that bacteriocins may inhibit the adhesion and invasion of L. monocytogenes by competing adhesion sites. Moreover, they may further enhance intestinal barrier function by inhibiting the expression of L. monocytogenes virulence factors, increasing the expression of TJP and decreasing the secretion of inflammatory factors. Therefore, bacteriocins will hopefully be an effective alternative to antibiotics, and this study provides valuable insights into food safety concerns.Key points• Bacteriocins show excellent antibacterial activity against L. monocytogenes• Bacteriocins improve intestinal barrier damage and inflammatory response• Plantaricin RX-8 has the best protective effect on Caco-2 cells damageGraphical

Pyridopyrimidinones as a new chemotype of calcium dependent protein kinase 1 (CDPK1) inhibitors for Cryptosporidium

The protozoan protein kinase calcium-dependent protein kinase 1 (CDPK1) has emerged as a potential therapeutic target for the treatment of cryptosporidiosis. A focused screen of known kinase inhibitors identified a pyridopyrimidinone as a new chemotype of Cryptosporidium parvum (Cp) CDPK1 inhibitors. Structural comparison of CpCDPK1 to two representative human kinases, RIPK2 and Src, revealed differences in the positioning of the αC-helix that was used in the design of a potent pyridopyrimidinone-based CpCDPK1 inhibitor 7 (a.k.a. UH15–16, IC50 = 10 nM), which blocked the growth of three C. parvum strains (EC50 = 12–40 nM) as well as C. hominis (EC50 = 85 nM) in HCT-8 host cells. Pharmacokinetic and tissue distribution analyses indicated that 7 had low systemic exposure after oral administration, but high gastrointestinal concentration, as well as good Caco-2 cell permeability. Finally, 7 demonstrated partial efficacy in an IL-12 knock-out mouse model of acute cryptosporidiosis.

A Machine Learning Approach for Predicting Caco-2 Cell Permeability in Natural Products from the Biodiversity in Peru.

Peru is one of the most biodiverse countries in the world, which is reflected in its wealth of knowledge about medicinal plants. However, there is a lack of information regarding intestinal absorption and the permeability of natural products. The human colon adenocarcinoma cell line (Caco-2) is an in vitro assay used to measure apparent permeability. This study aims to develop a quantitative structure-property relationship (QSPR) model using machine learning algorithms to predict the apparent permeability of the Caco-2 cell in natural products from Peru. A dataset of 1817 compounds, including experimental log Papp values and molecular descriptors, was utilized. Six QSPR models were constructed: a multiple linear regression (MLR) model, a partial least squares regression (PLS) model, a support vector machine regression (SVM) model, a random forest (RF) model, a gradient boosting machine (GBM) model, and an SVM-RF-GBM model. An evaluation of the testing set revealed that the MLR and PLS models exhibited an RMSE = 0.47 and R2 = 0.63. In contrast, the SVM, RF, and GBM models showcased an RMSE = 0.39-0.40 and R2 = 0.73-0.74. Notably, the SVM-RF-GBM model demonstrated superior performance, with an RMSE = 0.38 and R2 = 0.76. The model predicted log Papp values for 502 natural products falling within the applicability domain, with 68.9% (n = 346) showing high permeability, suggesting the potential for intestinal absorption. Additionally, we categorized the natural products into six metabolic pathways and assessed their drug-likeness. Our results provide insights into the potential intestinal absorption of natural products in Peru, thus facilitating drug development and pharmaceutical discovery efforts.

Himatanthus bracteatus stem bark ethanolic extract obtained by sequential pressurized liquid extraction: Chromatographic characterization and profiling of cytotoxic, antitumoral and immunopharmacological properties

This study aims to characterize the cytotoxic, antitumoral and immunopharmacological profile of the ethanolic extract of Himatanthus bracteatus (EEHB) stem bark. Chromatographic analysis revealed the major EEHB composition in dimethyl isoplumerideo acid, 13-deoxyplumerido, isoplumeride, and plumeride. Cytotoxicity was performed on MCF-7 and MCF-10A cell lines using MTT assay. The antitumor activity was assessed using sarcoma 180 tumor cells subcutaneously implanted in mice. After seven days, hematological and biochemical analysis, and pathological evaluation of tumors and visceral organs were carried out. The IC50 value was 28.49 ± 2.05 μg/mL on MCF7 cells, but over 320 μg/mL on MCF-10A cells. Molecular docking was predicted using the caspase 3 molecular target with plumeride and isoplumeride ligands. Both compounds were also analyzed by PreADMET. The tumor growth inhibition was comparable to 5-FU. EEHB reduced the proliferative index (Ki67 immunoexpression) but increased the expression of apoptotic markers in a sarcoma 180 model. The ligands showed interaction with Caspase 3 with a binding energy between −7.2 and −6.6 kcal/mol for isoplumeride and −7.8 to −7.0 kcal/mol for plumeride. Hydrogen interactions were present between the ligands and caspase 3. Both phytochemicals showed low or no permeability in blood-brain barrier and medium permeability in Caco-2 cells and only isoplumeride showed mutagenic potential and carcinogenic. EEHB presented no toxicological effect either on the hematological parameters or average weight and histological features of liver, kidneys, and spleen. Our data suggest that EEHB has antitumor activity in S-180 tumor-bearing mice by blocking cell cycle and increasing apoptosis.

Novel biaryloxazolidinone derivatives with broad-spectrum antibacterial activity, favorable drug-like profiles and in vivo efficacy against linezolid-resistant Staphylococcusaureus

The emergence of multidrug-resistant bacteria along with a declining pipeline of clinically useful antibiotics has led to the urgent need for the development of more effective antibacterial agents to treat drug-resistant bacteria. We previously discovered compound OB-158 with potent antibacterial activity but exhibited poor oral bioavailability. Herein, a systematic structural optimization of OB-158 to improve pharmacokinetic profiles yielded 26 novel biaryloxazolidinone analogues, and their activities against Gram-positive S. aureus, multidrug resistant S. aureus and Enterococcus faecalis were evaluated. Remarkably, compound 8b was identified with potent antibacterial activity against S. aureus (MIC=0.06μg/mL), MSSA (MIC=0.125μg/mL), MRSA (MIC=0.06μg/mL), LRSA (MIC=0.125μg/mL) and LREFa (MIC=0.5μg/mL). Compound 8b was demonstrated as a promising candidate through druglikeness evaluation including metabolism in microsomes and plasma, Caco-2cell permeability, plasma protein binding, cytotoxicity, and inhibition of CYP450 and human monoamine oxidase. Notably, compound 8b displayed excellent PK profile with appropriate T1/2 of 1.49h, high peak plasma concentration (Cmax=2320ng/mL), high plasma exposure (AUC0-t=8310hng/mL), and superior oral bioavailability (F=68.1%) in Sprague-Dawley rats. Ultimately, in vivo efficacy of compound 8b in a mouse model of LRSA systemic infection was also demonstrated. Taken together, compound 8b represents a promising drug candidate for the treatment of linezolid-resistant Gram-positive bacterial strains infection.

Biological activity an in silico toxicity of phenolic compounds found in cupuaçu seed (Theobroma grandiflorum)

Cupuaçu (Theobroma grandiflorum) from the Malvaceae family, has seeds rich in flavonoids. The biological activities of seeds are diverse, however, there are scarce data on these metabolites. The study aimed to evaluate, through in silico methods, the biological, toxicological, and pharmacokinetic potential of metabolites present in the cupuaçu seed. The metabolites hypolaetina 3'-methylether 8-O-β-D glucuronide, theograndin II, hypolaetina 3'-methylether 8-O-β-D 3”-sulfated glucuronide, isoscutellarein 8-0-β-D glucuronide and theograndin I were analysed through Pubchem to search for structures, and PreADMET (pharmacokinetics and toxicity) and PASS online for biological activities (PA >98%). The results demonstrated low human intestinal absorption, in addition to weak to moderate distribution across the blood-brain barrier. All phenolic compounds showed weak to moderate binding to plasma proteins and low permeability in CaCo2 cells, except for isoscutelarein 8-0-β-D glucuronide and hypolaetina 3'-methylether 8-O-β-D glucuronide with moderate permeability, being non-mutagenic. Furthermore, they had the potential to inhibit CYPs, such as CYP-2C9 and CYP-3A4. Also, the structures showed toxicity in Medaka fish, but they did not present toxicity in algae and Daphnia sp. Finally, the molecules presented the following main properties: hemostatic, cardioprotective, and antioxidant action, among others. The compounds presented varied biological activity profiles, but their pharmacokinetic and toxicity were not promising, limiting the potential for developing new drugs. The use of technologies is suggested to transform them into prodrugs, carriers, and the use of molecular modeling.

Evaluation of Solubility and Membrane Permeability of Middle-Molecule Compounds Using Artificial Membranes and Living Cells

In contrast to small molecules, middle molecules present a promising therapeutic modality owing to their elevated specificity, minimal adverse effects, capacity to target protein-protein interactions, and, unlike antibody-based drugs, their suitability for oral administration and intracellular target engagement. Post-oral administration, the paramount considerations encompass solubility and membrane permeability during the initial phase until the drug attains systemic circulation. Furthermore, penetration of the cell membrane is essential to accessing intracellular targets. We evaluated the solubility and membrane permeability of 965 compounds sourced from middle molecule libraries affiliated with Hokkaido University, Kitasato University, and the University of Tokyo. To gauge membrane permeability, we employed both the parallel artificial membrane permeability assay (PAMPA) and Caco-2 cell monolayers. Notably, while membrane permeability in Caco-2 cells exhibited an approximate threefold increase in comparison to PAMPA measurements, certain compounds demonstrated permeability levels less than one-third of those observed in Caco-2 cells. Recognizing the potential involvement of efflux transporters expressed in Caco-2 cells in these variations, we conducted additional assessments involving directional transport in the presence of a transporter inhibitor. Our findings suggest that nearly 80% of these compounds serve as substrates for efflux transporters. Considering the relevance of intracellular targets, we shifted our focus from membrane permeation to intracellular uptake, conducting simulations tailored to assess cellular uptake.

Increasing the bioavailability of curcumin using a green supercritical fluid technology-assisted approach based on simultaneous starch aerogel formation-curcumin impregnation

A green approach based on simultaneous starch aerogel formation-curcumin impregnation via supercritical fluid technology was used to increase the bioavailability of curcumin. The loading amounts of curcumin were 16.4, 21.4, and 24.9 mg/g of aerogel for the 25% Amyl-loaded, 55% Amyl-loaded, and 72% Amyl-loaded samples, respectively. Curcumin-loaded aerogels showed the eventual distribution of curcumin in the hydrophobic area of the internal structure of the aerogels. In vitro gastrointestinal release profiles demonstrated the enhanced curcumin release from the curcumin-loaded aerogel formulations produced by the SC-CO2 technology over free curcumin. After intestinal digestion, the percentage of released curcumin from 25% Amyl-loaded, 55% Amyl-loaded, and 72% Amyl-loaded was 7.2, 12.1, and 12.1%, respectively, while the release of native curcumin was only 0.5%. Caco-2 cell permeation studies revealed superior bioavailability of curcumin from the curcumin-loaded aerogels. Curcumin-loaded aerogels exhibited improved storage stability than free curcumin.

Use of in vitro ADME methods to identify suitable analogs of homosalate and octisalate for use in a read-across safety assessment.

Case studies are needed to demonstrate the use of human-relevant New Approach Methodologies in cosmetics ingredient safety assessments. For read-across assessments, it is crucial to compare the target chemical with the most appropriate analog; therefore, reliable analog selection should consider physicochemical properties, bioavailability, metabolism, as well as the bioactivity of potential analogs. To complement in vitro bioactivity assays, we evaluated the suitability of three potential analogs for the UV filters, homosalate and octisalate, according to their in vitro ADME properties. We describe how technical aspects of conducting assays for these highly lipophilic chemicals were addressed and interpreted. There were several properties that were common to all five chemicals: they all had similar stability in gastrointestinal fluids (in which no hydrolysis to salicylic occurred); were not substrates of the P-glycoprotein efflux transporter; were highly protein bound; and were hydrolyzed to salicylic acid (which was also a major metabolite). The main properties differentiating the chemicals were their permeability in Caco-2 cells, plasma stability, clearance in hepatic models, and the extent of hydrolysis to salicylic acid. Cyclohexyl salicylate, octisalate, and homosalate were identified suitable analogs for each other, whereas butyloctyl salicylate exhibited ADME properties that were markedly different, indicating it is unsuitable. Isoamyl salicylate can be a suitable analog with interpretation for octisalate. In conclusion, in vitro ADME properties of five chemicals were measured and used to pair target and potential analogs. This study demonstrates the importance of robust ADME data for the selection of analogs in a read-across safety assessment.

Metabolomics combined with network pharmacology reveals anti-asthmatic effects of Nepeta bracteata on allergic asthma rats

ObjectiveTo investigate the mechanisms that underlie the anti-asthmatic effects of Nepeta bracteata (DBJJ, Dabao Jingjie in Chinese) in rats by integrating metabolomics and network pharmacology. MethodsIn this study, the rat model of asthma was induced by using ovalbumin (OVA), and subsequently, the rats were treated with a decoction of N. bracteata. Pathological changes in lung tissue were observed, and the quantification of eosinophils (EOS) and white blood cells (WBC) in bronchoalveolar lavage fluid (BALF) was performed. Furthermore, the serum levels of asthma-related factors induced by OVA were assessed. The proton nuclear magnetic resonance (1H NMR) spectroscopy serum metabolomics method was utilized to identify differential metabolites and their associated metabolic pathways. Moreover, UPLC-QE-MS/MS combined with network pharmacology was employed to predict the core targets and pathways of DBJJ in its action against asthma. Furthermore, the anti-asthmatic properties of DBJJ were investigated using an integrated approach of metabolomics and network pharmacology. Subsequently, the findings were validated through molecular docking and Western blotting analysis of the key targets. ResultsThe findings indicated that the administration of DBJJ effectively alleviated OVA-induced lung histopathological changes and decreased the number of EOS and WBC in BALF. Additionally, DBJJ inhibited the OVA-induced elevation of TNF-α, IL-18, Ig-E, EOS, IL-1β, MDA, VEGF-A, and TGF-β1. A total of 21 biomarkers and 10 pathways were found by metabolomics analysis. The 29 compounds were identified by UPLC-QE-MS/MS and 13 active components were screened by oral availability and Caco-2 cell permeability, the 120 targets and 173 KEGG pathways were predicted. The integration of metabolomics and network pharmacological analysis revealed that DBJJ's primary constituents, including ferulic acid and ursolic acid, exerted their effects on four targets, namely DAO and NOS2, as well as their associated metabolites and pathways. The active constituents of DBJJ demonstrated a high binding affinity towards DAO and NOS2. Furthermore, DBJJ was observed to decrease the protein expression and phosphorylation levels of NOS2, MAPK, and STAT3. ConclusionThe administration of DBJJ demonstrates notable anti-asthma properties in rats with allergic asthma. This effect can be attributed to the modulation of various targets, including NOS2, MAPK, and STAT3, by primary constituents such as ferulic acid and ursolic acid.

Hit-to-Lead Identification and Validation of a Triaromatic Pleuromutilin Antibiotic Candidate.

Herein, we report the hit-to-lead identification of a drug-like pleuromutilin conjugate 16, based on a triaromatic hit reported in 2020. The lead arose as the clear candidate from a hit-optimization campaign in which Gram-positive antibacterial activity, solubility, and P-gp affinity were optimized. Conjugate 16 was extensively evaluated for its in vitro ADMET performance which, apart from solubility, was overall on par with lefamulin. This evaluation included Caco-2 cell permeability, plasma protein binding, hERG inhibition, cytotoxicity, metabolism in microsomes and CYP3A4, resistance induction, and time-kill kinetics. Intravenous pharmacokinetics of 16 proved satisfactory in both mice and pigs; however, oral bioavailability was limited likely due to insufficient solubility. The in vivo efficacy was evaluated in mice, systemically infected with Staphylococcus aureus, where 16 showed rapid reduction in blood bacteriaemia. Through our comprehensive studies, lead 16 has emerged as a highly promising and safe antibiotic candidate for the treatment of Gram-positive bacterial infections.

Multitask learning for predicting pulmonary absorption of chemicals

Pulmonary absorption is an important route for drug delivery and chemical exposure. To streamline the chemical assessment process for the reduction of animal experiments, several animal-free models were developed for pulmonary absorption research. While Calu-3 and Caco-2 cells and their derived computational models were used in estimating pulmonary permeability, the ex vivo isolated perfused lung (IPL) models are considered more clinically relevant measurements. However, the IPL experiments are resource-consuming making it infeasible for the large-scale screening of potential inhaled toxicants and drugs. In silico models are desirable for estimating pulmonary absorption. This study presented a novel machine learning method that employed an extratrees-based multitask learning approach to predict the IPL absorption rate constant (kaIPL) of various chemicals. The shared permeability knowledge was extracted by simultaneously learning three relevant tasks of Caco-2 and Calu-3 cell permeability and IPL absorption rate. Seven informative physicochemical descriptors were identified. A rigorous evaluation of the developed prediction model showed good performance with a high correlation between predictions and observations (r = 0.84) in the independent test dataset. Two case studies of inhalation drugs and respiratory sensitizers revealed the potential application of this model, which may serve as a valuable tool for predicting pulmonary absorption of chemicals.

Evaluation of Intestinal Permeability of the Antifungal Compound PD76: Comparison of in silico Platforms and in vitro Assay in Caco-2 Cell Model

The compound 2-hydrazinyl-4-(4-methoxyphenyl)thiazole (PD76) is a novel thiazolyl hydrazine derivative with proven antifungal activity against different fungal species, mainly Candida and Cryptococcus. Considering the advantages of oral route for clinical therapy, the aim of this work was to evaluate the potential intestinal permeability of this new antifungal drug. For the quantitation of PD76, a high-performance liquid chromatography method was developed and fully validated. The cytotoxicity of the compound in Caco-2 cells was analyzed and intestinal permeability of PD76 was assessed by means of the comparison of in vitro assay in Caco-2 cells and in silico platforms ADMETlab and admetSAR. Cell viability above 70% was obtained at all PD76 studied concentrations. Using Caco-2 cell model, the compound showed apparent permeability coefficients (Papp) of 5.25 × 10-6 and 23.28 × 10-6 cm s-1 in apical-basolateral and basolateral-apical directions, respectively. Experiments performed using verapamil as P-gp inhibitor demonstrated that PD76 is slightly susceptible to active efflux. Both in silico platforms inferred that PD76 presents permeability in Caco-2 cells, with Log P values of 2.82 (ADMETlab) and 2.10 (admetSAR). The results obtained in permeability studies showed that PD76 presents moderate intestinal permeability and a promising profile for clinical application.

Wheat peptides inhibit the activation of MAPK and NF-κB inflammatory pathways and maintain epithelial barrier integrity in NSAID-induced intestinal epithelial injury.

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has negative effects on the gastrointestinal tract, but the proton pump inhibitors currently in use only protect against gastrointestinal disease and may even make NSAID-induced enteropathy worse. Therefore, new approaches to treating enteropathy are required. This study aimed to investigate the protective effect of wheat peptides (WPs) against NSAID-induced intestinal damage in mice and their mechanism. Here, an in vivo mouse model was built to investigate the protective and reparative effects of different concentrations of WPs on NSAID-induced intestinal injury. WPs ameliorated NSAID-induced weight loss and small intestinal tissue damage in mice. WP treatment inhibited NSAID-induced injury leading to increased levels of oxidative stress and expression levels of inflammatory factors. WPs protected and repaired the integrity and permeability injury of the intestinal tight junction induced by NSAIDs. An in vitro Caco-2 cell model was built with lipopolysaccharide (LPS). WP pretreatment inhibited LPS-induced changes in the Caco-2 cell permeability and elevated the levels of oxidative stress. WPs inhibited LPS-induced phosphorylation of NF-κB p65 and mitogen-activated protein kinase (MAPK) signaling pathways and reduced the expression of inflammatory factors. In addition, WPs increased tight junction protein expression, which contributed to improved intestinal epithelial dysfunction. Our results suggest that WPs can ameliorate NSAID-induced impairment of intestinal barrier functional integrity by improving intestinal oxidative stress levels and reducing inflammatory factor expression through inhibition of NF-κB p65 and MAPK signaling pathway activation. WPs can therefore be used as potential dietary supplements to reduce NSAID-induced injury of the intestine.

Tuning Caco-2 permeability by cocrystallization: Insights from molecular dynamics simulation

Emerging evidence suggests that intestinal permeability can be potentially enhanced through cocrystallization. However, a mechanism for this effect remains to be established. In this study, we first demonstrate the enhancement in intestinal permeability, evaluated by the Caco-2 cell permeability assay, of acetazolamide (ACZ) in the presence of a conformer, p-aminobenzoic acid (PABA), delivered in the form of a 1:1 cocrystal. The binding strength of ACZ and PABA with the Pgp efflux transporter, either alone or as a mixture, was calculated using molecular dynamics simulation. Results show that PABA weakens the binding of ACZ with Pgp, which leads to a lower efflux ratio and elevated permeability of ACZ. This work provides molecular-level insights into a potentially effective strategy to improve the intestinal permeability of drugs. If the same cocrystal also exhibits higher solubility, oral bioavailability of BCS IV drugs can likely be improved by forming a cocrystal with a Pgp inhibitor.