Caco-2 Cell Line Standardization with Pharmaceutical Requirements and In Vitro Model Suitability for Permeability Assays

Effects of co-exposure to microplastics and perfluorooctanoic acid on the Caco-2 cells

As plastics are produced and used, humans are inevitably exposed to microplastics (MPs) on a daily basis. The pollution of MPs has aroused widespread human concern. Perfluorooctanoic acid (PFOA), a persistent organic pollutant (POP), can be adsorbed by microplastics and may exacerbate human health hazards. In this study, we investigated the effects of co-exposure of PET MPs and PFOA on the human intestinal tract in terms of both cytotoxicity and intestinal barrier through in vitro experiments. The results showed that PFOA induced cellular oxidative stress, mitochondrial dysfunction exerted cytotoxic effects, and inhibited tight junction (TJ) protein expression causing intestinal barrier damage. PET MPs can synergize with PFOA to exacerbate the deleterious effects on the intestinal tract by decreasing cell membrane permeability to increase PFOA accumulation in the cell and enhancing the ability of PFOA to inhibit zonula occludens-1 (ZO-1) proteins.

Robust and reproducible human intestinal organoid-derived monolayer model for analyzing drug absorption

Predicting the absorption of orally administered drugs is crucial to drug development. Current in vitro models lack physiological relevance, robustness, and reproducibility, thus hindering reliable predictions. In this study, we developed a reproducible and robust culture method to generate a human intestinal organoid-derived monolayer model that can be applied to study drug absorption through a step-by-step approach. Our model showed similarity to primary enterocytes in terms of the drug absorption-related gene expression profile, tight barrier function, tolerability toward artificial bile juice, drug transporter and metabolizing enzyme function, and nuclear receptor activity. This method can be applied to organoids derived from multiple donors. The permeability of launched 19 drugs in our model demonstrated a correlation with human Fa values, with an R2 value of 0.88. Additionally, by combining the modeling and simulation approaches, the estimated FaFg values for seven out of nine drugs, including CYP3A substrates, fell within 1.5 times the range of the human FaFg values. Applying this method to the drug discovery process might bridge the gap between preclinical and clinical research and increase the success rates of drug development.

Selective activity of Tabebuia avellanedae against Giardia duodenalis infecting organoid-derived human gastrointestinal epithelia

Giardia duodenalis is a widespread intestinal protozoan that affects mammals, including humans. Symptoms can range from being subclinical to causing severe abdominal pain and diarrhoea. Giardiasis often requires repeated treatment with synthetic drugs like metronidazole. In recent years, treatment failures in clinical cases involving nitroimidazoles have been increasingly reported. Consequently, identifying therapeutic alternatives is necessary. Medicinal plants have traditionally been used as antiparasitic compounds, but systematic evaluation under controlled experimental conditions is often lacking. Here, we evaluated the in vitro efficacy of Tabebuia avellanedae dry and hydroalcoholic extracts, as well as one of its active compounds, β-lapachone, as potential treatment against G. duodenalis infection. We observed effective antigiardial activity for all tested compounds, with β-lapachone exhibiting lower IC50 values than metronidazole. Cytotoxic effects often limit therapeutic concentration windows of opportunity, and choosing an informative model to assess them is not straightforward. In the present case, only T. avellanedae hydroalcoholic extract showed no cytotoxicity on tumoral human intestinal Caco-2 cell line, and only a trend of inhibition when tested on canine epithelial kidney MDCK cells. To introduce a more physiological test system, we used in vitro G. duodenalis infection experiments in a trans-well set-up using organoid derived monolayers (ODM) to assess at the same time drug efficacy against the parasite and safety on primary human intestinal epithelia, a likely surrogate for in vivo conditions. Our studies using this model point towards the potential therapeutic opportunity for non-systemic applications of T. avellanedae extracts and a relevant ingredient of these, β-lapachone. The data suggest that ODM co-cultures with G. duodenalis are suitable for testing antigiardial compounds, providing a more informative in vitro model before progressing to in vivo tests.

Comparative analysis of Caco-2 cells and human jejunal and duodenal enteroid-derived cells in gel- and membrane-based barrier models of intestinal permeability

Intestinal absorption is a key toxicokinetics parameter. Although the colon carcinoma cell line Caco-2 is the most used in vitro model to estimate human drug absorption, models representing other intestinal segments are available. We characterized the morphology, tissue-specific markers, and functionality of 3 human intestinal cell types: Caco-2, primary human enteroid-derived cells from jejunum (J2), and duodenum (D109) when cultured in the OrganoPlate 3-lane 40 microphysiological system (MPS) or static 24-well Transwells. In both conditions, J2 and D109 formed dome-like structures; Caco-2 formed uniform monolayers. In MPS, only Caco-2 formed tubules. Cells grown on Transwells formed a thicker monolayer. All cells and conditions exhibited expression of ZO-1 (tight junctions). Polarization markers Ezrin and Villin were highest in J2 and D109 in MPS, highest expression of Mucin was observed with J2. However, J2 and D109 exhibited poor barrier (70 kDa TRITC-dextran) in MPS, whereas robust barrier was recorded in Transwells. Barrier function and drug transport were evaluated using caffeine, indomethacin, and propranolol. The gel lane in MPS acted as a blockade; only a small fraction crossed, even without cells. The permeability ratios were used to parameterize the probabilistic compartmental absorption model to determine whether in vitro data could reduce uncertainty. The most accurate prediction of the fraction absorbed was achieved with Transwell-derived data from Caco-2, combined with the experimentally derived segment-specific absorption ratios. The impact of this study includes demonstration that enteroid-derived cells cultured in MPS show most physiological morphology, but that studies of drug permeability in this MPS are challenging.

Caco2/HT-29 In Vitro Cell Co-Culture: Barrier Integrity, Permeability, and Tight Junctions' Composition During Progressive Passages of Parental Cells

Epithelial linings are crucial for the maintenance of physiological barriers. The intestinal epithelial barrier (IEB) consists of enterocytes through tight junctions and mucus-secreting cells and can undergo physiological modifications throughout life. To reproduce as closely as possible the IEB main features over time, in vitro co-cultures of Caco2/HT-29 70/30 formed by parental Caco2 and HT-29 cells sub-cultivated for more than 40 passages were set up. The measurements of the transepithelial electrical resistance (TEER) identified two populations: physiological TEER co-cultures (PC) with values > 50 Ωcm2 formed by parental cells with fewer than 40 passages, and leaky TEER co-cultures (LC) with values < 50 Ωcm2 formed by parental cells with more than 40 passages. In LC, paracellular permeability increased in parallel. By immunofluorescence and Western blot analysis, an increase in claudin 2 was observed in LC vs. PC, with no differences in occludin expression. MUC-2 immunoreactivity was stronger in PC than in LC. LC also showed an enhanced vulnerability to TNFα+IFN-γ. These results reproduce the main morpho-functional modifications reported in the human leaky/aged gut and support the usefulness of our in vitro cell model for studying the molecular processes underlying these modifications and testing drug/nutraceutical treatments to ameliorate leaky gut aging.

Identification and evaluation of bioactive compounds from Azadirachta indica as potential inhibitors of DENV-2 capsid protein: An integrative study utilizing network pharmacology, molecular docking, molecular dynamics simulations, and machine learning techniques

Background

Dengue fever is a viral disease caused by the dengue flavivirus and transmitted through mosquito bites in humans. According to the World Health Organization, severe dengue causes approximately 40,000 deaths annually, and nearly 4 billion people are at risk of dengue infection. The urgent need for effective treatments against the dengue virus has led to extensive research on potential bioactive compounds.

Objective

In this study, we utilized a network pharmacology approach to identify the DENV-2 capsid protein as an appropriate target for intervention. Subsequently, we selected a library of 537 phytochemicals derived from Azadirachta indica (Family: Meliaceae), known for their anti-dengue properties, to explore potential inhibitors of this protein.

Methods

The compound library was subjected to molecular docking to the capsid protein to identify potent inhibitors with high binding affinity. We selected 81 hits based on a thorough analysis of their binding affinities, particularly those exhibiting higher binding energy than the established inhibitor ST-148. After evaluating their binding characteristics, we identified two top-scored compounds and subjected them to molecular dynamics simulations to assess their stability and binding properties. Additionally, we predicted ADMET properties using in silico methods.

Results

One of the inhibitors, [(5S,7R,8R,9R,10R,13R,17R)-17-[(2R)-2-hydroxy-5-oxo-2H-furan-4-yl]-4,4,8,10,13-pentamethyl-3-oxo-5,6,7,9,11,12,16,17-octahydrocyclopenta[a]phenanthren-7-yl] acetate (AI-59), showed the highest binding affinity at -10.4 kcal/mol. Another compound, epoxy-nimonol (AI-181), demonstrated the highest number of H-bonds with a binding affinity score of -9.5 kcal/mol. During molecular dynamics simulation studies, both compounds have exhibited noteworthy outcomes. Through molecular mechanics employing Generalized Born surface area (MM/GBSA) calculations, AI-59 and AI-181 displayed negative ΔG_bind scores of -74.99 and -83.91 kcal/mol, respectively.

Conclusion

The hit compounds identified in the present investigation hold the potential for developing drugs targeting dengue virus infections. Furthermore, the knowledge gathered from this study serves as a foundation for the structure- or ligand-based exploration of anti-dengue compounds.

A Versatile and Modular Microfluidic System for Dynamic Cell Culture and Cellular Interactions

A versatile and modular microfluidic system for cell co-culture has been developed. Microfluidic chips, each featuring dual compartments separated by a porous membrane, have been fabricated and assembled within the system to facilitate fluidic interconnection and cell-cell communication through the chip assembly. A set of fluidic valves has been successfully integrated to regulate the flow through the chip assembly. The system allows for chip assembly in various arrangements, including in parallel, in series, and complex connections. Individual chips can be interconnected or disconnected within the system at any time. Moreover, the spatial order and orientation of the chips can be adjusted as needed, enabling the study of different cell-cell arrangements and the impact of the presence or absence of specific cell types. The utility of the system has been evaluated by culturing and interconnecting multi-monolayers of intestinal epithelial cells as a model of the complex cellular system. Epithelial monolayers were grown in multiple chips and interconnected in various configurations. The transepithelial electrical resistance and permeability profiles were investigated in detail for these configurations upon treatment of the cells with dextran sulfate sodium. Immune cells were stimulated through the epithelial layers and the expression of inflammatory cytokines was detected. This miniaturized platform offers controlled conditions for co-culturing key cellular components and assessing potential therapeutic agents in a physiologically relevant setting.

Nanostructured lipid carriers as a strategy to enhance oral levosulpiride delivery: An in vitro and ex vivo assessment

Oral absorption is limited for many small-molecule drugs due to their poor aqueous solubility as well as, for some, poor membrane permeation. One such is levosulpiride (LSP), used to treat psychotic and other conditions. The present study aims to explore the effect of nanostructured lipid carriers (NLCs) for the delivery of LSP. The permeation of LSP in vitro and ex vivo as well as effects on the epithelium and mucosa was monitored. In vitro and ex vivo permeation studies exhibited an 8-fold and 1.6-fold increase in the Papp of LSP respectively, as compared to unformulated LSP applied as a suspension. Transepithelial electrical resistance (TEER) measured in real-time by impedance spectroscopy decreased during exposure yet recovered upon removal of the NLCs. Together with the increased passage of the paracellular markers [14C]-mannitol and FD4 applied together with blank NLCs, but not the transcellular marker [3H]-metoprolol, this indicates permeation of LSP via the paracellular pathway. The reversible effect on integrity was associated with altered cell morphology confirmed by occludin and f-actin localization with insignificant effect on metabolic activity. These results suggest that the NLCs and/or components thereof can mediate improved absorption of drugs by increasing the permeability of the intestinal epithelial membrane, further facilitated by increased drug solubilization.

Human organotypic colon in vitro microtissue: unveiling a new window into colonic drug disposition

The purpose of this study was to evaluate EpiColon, a novel human organotypic 3D colon microtissue prototype, developed to assess colonic drug disposition, with a particular focus on permeability ranking, and compare its performance to Caco-2 monolayers. EpiColon was characterized for barrier function using transepithelial electrical resistance (TEER), morphology via histology and immunohistochemistry, and functionality through drug transport studies measuring apparent permeability (Papp). Cutoff thresholds for the permeability of FITC-dextran 4 kDa (FD4), FITC-dextran 10 kDa (FD10S), and [14C]mannitol were established to monitor microtissue integrity. Permeability of EpiColon for 20 benchmark drugs was compared with Caco-2 data, and the activity of pivotal efflux transporters, including multidrug resistance protein 1/P-glycoprotein (MDR1/P-gp), along with multidrug resistance protein 2 (MRP2) and breast cancer resistance protein (BCRP), was evaluated using selective substrates. EpiColon exhibited a physiological barrier function (272.0 ± 53.05 Ω x cm2) and effectively discriminated between high (e.g., budesonide and [3H]metoprolol) and low permeable compounds (e.g., [3H]atenolol and [14C]mannitol). The model demonstrated functional activity for key efflux transporters, with efflux ratios of 2.32 for [3H]digoxin (MDR1/P-gp) and 3.34 for sulfasalazine (MRP2 and BCRP). Notably, EpiColon showed an enhanced dynamic range in the low permeability range, differentiating Papp between FD4 and FD10S, in contrast to Caco-2 monolayers. Significant positive correlations were observed between human fraction absorbed (fabs) and logarithmically transformed Papp [AP-BL] values for both EpiColon (rs = 0.68) and Caco-2 (rs = 0.68). Furthermore, EpiColon recapitulates some essential phenotypic and cellular features of the human colon, including the expression of critical marker genes (Pan-Cytokeratin+: epithelial/colonocytes, Vimentin+: mesenchymal/fibroblast, and Alcian Blue+: goblet cell/mucus). In conclusion, EpiColon is a promising platform that offers a valuable complement to conventional Caco-2 monolayers for studying colonic drug disposition. However, the presence of flat and some cuboidal cells, along with low throughput, must be addressed to improve its applicability in both academic research and pharmaceutical industry.

Novel 2-Thiazolylhydrazone with Druggable Properties for Antifungal Application

Fungal infections have become a growing concern in healthcare, particularly in immunocompromised individuals, with species like Candida, Cryptococcus, and Sporothrix posing significant challenges due to rising resistance and limited treatment options. In response, novel antifungal agents are being explored, including thiazolyl hydrazones. This study focuses on the development of a novel thiazolylhydrazone derivative, RW3. RW3 was synthesized to improve its water solubility and pharmacokinetic properties. The compound demonstrated a broad antifungal spectrum, particularly effective against Cryptococcus neoformans and Candida auris, with minimal irritant potential and low cytotoxicity. RW3 showed favorable solubility and high intestinal permeability, indicating potential for oral administration. The results suggest RW3 as a promising lead for further development as a therapeutic agent for systemic fungal infections. These findings underscore the importance of optimizing drug properties to enhance efficacy and safety profiles, opening the path for the development of innovative antifungal treatments.

A Comparative Study of the In Vitro Intestinal Permeability of Pinnatoxins and Portimine

The pinnatoxins (PnTXs) and portimines, produced by Vulcanodinium rugosum, have been detected in several countries, raising concerns for human health. Although no human poisoning from these toxins has been reported so far, they have been shown to distribute throughout the rodent body after oral administration. Therefore, we investigated the impact of PnTX analogs (PnTX-A, -E, -F, -G, and -H) and portimine (8, 16, and 32 ng/mL) on intestinal barrier integrity and their oral bioavailability using human Caco-2 cell monolayers treated for 2, 6, and 24 h. Our results demonstrated that all of the toxins could impair barrier integrity after 24 h, with differences observed for PnTX-A, -E, and -F, as well as portimine, the most potent of all. While PnTX-A and -E exhibited poor permeability, the other PnTXs were more penetrative, with a Papp > 1.5 × 10-6 cm·s-1. Portimine was the only toxin displaying both a time- and concentration-dependent passage, likely involving a passive diffusion process. The experimental results were compared to predictions obtained by QSAR tools. Although only qualitative, our results suggest that some of these compounds may be more likely to be distributed throughout the body. Further in vivo studies are required to estimate oral bioavailability and potential public health concerns.

Fiber and polyphenol enriched biscuits using date palm byproduct: Physiochemical characteristics, sensory properties, in vitro digestion, and storage stability

Functional biscuit was formulated by fortifying them with polyphenolic extract and fiber-rich residue of defatted date seed powder (DDSP) obtained through microwave-assisted extraction. Effect of particle size (small, medium, and large) and substitution level (2.5%, 5%, and 7.5%) of fiber-rich residue, along with the phenolic extract, on bioactive, physical, textural, and gastrointestinal digestion of fortified biscuits was studied followed by sensory and shelf-life studies. The total phenolic content (TPC) and antioxidant properties of biscuits increased with increasing substitution levels and particle size. DDSP residue fortification increased the fiber content in biscuits. Large particles of the residue-fortified biscuits showed significantly higher (p < 0.05) hardness compared to the control biscuits. Diameter of the biscuits decreased with increasing substitution level and particle size of fiber-rich residue with the lowest value of 50.66 mm in 7.5% substitution of large particles. The 7.5% substitution level of small particles resulted in the lowest spread ratio of 8.97 and the highest thickness of 5.79 mm. Consumer perceptions were at an acceptable level after the fortification, with an average sensory score of 6.02 out of 9 for overall acceptability. After 24 weeks storage, TPC decreased in biscuits, but TPC retention increased with increasing substitution level and particle size of residue. Thiobarbituric acid reactive substances (TBARS) value of biscuits increased with storage. The highest phenolic recovery was observed in the intestinal phase of the gastrointestinal digestion with the highest recovery of 102.33 at 2.5% level of large particles. Thus, phenolic extract and fiber-rich residue incorporation was effective to enhance the nutritional and functional properties of biscuits. PRACTICAL APPLICATION: Date seeds are rich in bioactive components and fiber. This study demonstrated the feasibility of utilizing date seeds to improve nutritional and functional properties of bakery products. The incorporation of the microwave-assisted polyphenolic extract and the fiber-rich residue of defatted date seed powder into biscuit enhanced the bioactive, nutritional, and functional characteristics while maintaining the consumer acceptance. This research contributes to the valorization of byproducts in the agriculture and food industries, promoting sustainability and a bio-circular economy.

Hypotensive effect of potent angiotensin-I-converting enzyme inhibitory peptides from corn gluten meal hydrolysate: Gastrointestinal digestion and transepithelial transportation modifications

The study examined the antihypertensive effect of peptides derived from pepsin-hydrolyzed corn gluten meal, namely KQLLGY and PPYPW, and their in silico gastrointestinal tract digested fragments, KQL and PPY, respectively. KQLLGY and PPYPW showed higher angiotensin I-converting enzyme (ACE)-inhibitory activity and lower ACE inhibition constant (Ki) values when compared to KQL and PPY. Only KQL showed a mild antihypertensive effect in spontaneously hypertensive rats with -7.83 and - 5.71 mmHg systolic and diastolic blood pressure values, respectively, after 8 h oral administration. During passage through Caco-2 cells, KQL was further degraded to QL, which had reduced ACE inhibitory activity. In addition, molecular dynamics revealed that the QL-ACE complex was less stable compared to the KQL-ACE. This study reveals that structural transformation during peptide permeation plays a vital role in attenuating antihypertensive effect of the ACE inhibitor peptide.

Valorizing date seeds through ultrasonication to enhance quality attributes of dough and biscuit: Part 2 - Study on bioactive properties, sensory acceptance, in vitro gastrointestinal digestion and shelf life of biscuits

Aligning with sustainable food system development, in this study, date seeds derived compounds were utilized as functional ingredient to formulate value-added biscuits. Ultrasound-assisted extraction (UAE) was employed as a non-thermal method to extract polyphenolic compounds from small, medium and large particles of defatted date seed powder (DDSP). The remaining fiber-rich fraction (residue) was further utilized. Water content in biscuit formulation was replaced by the extract, and the fiber-rich fraction was substituted at three substitution levels; 2.5 %, 5 % and 7.5 %. Effects of baking on bioactive properties of dough, nutrient composition, sensory analysis, bioaccessibility of polyphenols, and shelf-life of biscuits were analyzed. Total phenolic content (TPC) increased in dough and biscuit with incorporated fiber-rich fraction. TPC of dough decreased with increasing particle size of fiber-rich fraction while biscuits exhibited an opposite trend. Similar tendency was observed with antioxidant activity of dough and biscuit. TPC was higher in biscuits than dough, with the highest values of 0.46 mg gallic acid equivalents (GAE)/g and 2.26 mg GAE/g in dough and biscuit, respectively. Fiber and moisture contents in biscuits increased while protein content decreased with fortification. Consumers showed moderate acceptance of fortified biscuits with overall acceptability comparable with the control biscuits. Bioaccessibility index of polyphenols upon gastrointestinal digestion was high in biscuits with 5 % and 7.5 % substitution of small and medium sized particles of fiber-rich fraction. Phenolic retention increased with fiber fortification and at the end of 6 months the lowest thiobarbituric acid reactive substances (TBARS) value of 18.23 nmol malondialdehyde (MDA)/g sample, was observed in 7.5 % large particle substituted biscuit. Thus, utilizing date seeds in the form of green extracted polyphenols and fiber-rich fraction, as functional and bioactive ingredients highlight sustainable processing and utilization of date-fruit processing by-products which is in line with the circular economy approach.

Anti-inflammatory effects of heat-killed Lactiplantibacillus argentoratensis BBLB001 on a gut inflammation co-culture cell model and dextran sulfate sodium-induced colitis mouse model

Dysbiosis caused by dietary changes can alter the intestinal bacterial species and is closely associated with inflammatory bowel disease (IBD). Among the possible treatment options, postbiotics, which act to balance the constituent intestinal microflora, have gained substantial attention. Herein, we investigated the anti-inflammatory effects of heat-killed Lactiplantibacillus argentoratensis (hk-LA) BBLB001 isolated from a marine environment using both cell (Caco2/RAW264.7 cell co-culture) and animal (dextran sodium sulfate [DSS]-induced colitis in mice) models. hk-LA BBLB001 markedly reduced IL-8 secretion in Caco-2 cell culture medium after lipopolysaccharide-mediated stimulation of RAW264.7 cells by enhancing the expression of cell adhesion factors.The body weight loss, reduced inflammatory cytokine levels in the serum and colon tissues, colon shortening, and myeloperoxidase activation caused by DSS in mice were alleviated by hk-LA BBLB001. Similar to that in the intestinal cell model, the gene and protein expressions of cell adhesion molecules in the colon tissue were increased upon hk-LA BBLB001 treatment in DSS-induced colitis mice. We observed increased mucin expression and secretory IgA concentration in colon tissues, suggesting that hk-LA BBLB001 intake may benefit pathogen defense and the regulation of intestinal commensal bacteria. Thus, hk-LA BBLB001 may serve as an instrumental postbiotic material in IBD treatment.

Bioengineering the Human Intestinal Mucosa and the Importance of Stromal Support for Pharmacological Evaluation In Vitro

Drug discovery is associated with high levels of compound elimination in all stages of development. The current practices for the pharmacokinetic testing of intestinal absorption combine Transwell® inserts with the Caco-2 cell line and are associated with a wide range of limitations. The improvement of pharmacokinetic research relies on the development of more advanced in vitro intestinal constructs that better represent human native tissue and its response to drugs, providing greater predictive accuracy. Here, we present a humanized, bioengineered intestinal construct that recapitulates aspects of intestinal microanatomy. We present improved histotypic characteristics reminiscent of the human intestine, such as a reduction in transepithelial electrical resistance (TEER) and the formation of a robust basement membrane, which are contributed to in-part by a strong stromal foundation. We explore the link between stromal-epithelial crosstalk, paracrine communication, and the role of the keratinocyte growth factor (KGF) as a soluble mediator, underpinning the tissue-specific role of fibroblast subpopulations. Permeability studies adapted to a 96-well format allow for high throughput screening and demonstrate the role of the stromal compartment and tissue architecture on permeability and functionality, which is thought to be one of many factors responsible for unexpected drug outcomes using current approaches for pharmacokinetic testing.

Functionalisation of chitosan with methacryloyl and crotonoyl groups as a strategy to enhance its mucoadhesive properties

Mucoadhesive polymers are crucial for prolonging drug retention on mucosal surfaces. This study focuses on synthesising and characterising novel derivatives by reacting chitosan with crotonic and methacrylic anhydrides. The structure of the resulting derivatives was confirmed using proton-nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectroscopy. It was established that the degree of substitution plays a crucial role in the pH-dependent solubility profiles and electrophoretic mobility of the chitosan derivatives. Spray-drying chitosan solutions enabled preparation of microparticles, whose mucoadhesive properties were evaluated using fluorescence flow-through studies and tensile test, demonstrating improved retention on sheep nasal mucosa for modified derivatives. Acute toxicity studies conducted in vivo using planaria and in vitro using MTT assay with the Caco-2 cell line, a model of the mucosal epithelium in vitro, showed that the novel derivatives are not cytotoxic. These findings emphasise the potential of tailored chitosan chemical modifications for enhancing transmucosal drug delivery.

In Silico Approach for Assessment of the Anti-Tumor Potential of Cannabinoid Compounds by Targeting Glucose-6-Phosphate Dehydrogenase Enzyme

Glucose-6-phosphate dehydrogenase (G6PD) is a pentose phosphate pathway (PPP) enzyme that generates NADPH, which is required for cellular redox equilibrium and reductive biosynthesis. It has been demonstrated that abnormal G6PD activation promotes cancer cell proliferation and metastasis. To date, no G6PD inhibitor has passed clinical testing successfully enough to be launched as a medicine. As a result, in this investigation, cannabinoids were chosen to evaluate their anticancer potential by targeting G6PD. Molecular docking indicated that three molecules, Tetrahydrocannabinolic acid (THCA), Cannabichromenic acid (CBCA), and tetrahydrocannabivarin (THCV), have the highest binding affinities for G6PD of -8.61, -8.39, and 8.01 Kcal mol. ADMET analysis found that all of them were safe prospective drug candidates. Molecular dynamics (MD) simulation and MM-PBSA analysis confirm the structural compactness and lower conformational variation of protein-ligand complexes, thereby maintaining structural stability and rigidity. Thus, our in silico investigation exhibited all three cannabinoids as potential competitive inhibitors of G6PD.

Design and optimization of chitosan-coated solid lipid nanoparticles containing insulin for improved intestinal permeability using piperine

The objective of this research was to optimize the composition and performance of chitosan-coated solid lipid nanoparticles carrying insulin (Ch-In-SLNs) and to assess the potential of piperine in enhancing the intestinal permeability of insulin from these SLNs in vitro. The SLNs were formulated from glyceryl behenate (GB), soya lecithin, and poloxamer® 407, and then coated with a combination of chitosan and piperine to facilitate insulin penetration across the gastrointestinal (GI) mucosa. A Box-Behnken Design (BBD) was utilized to optimize the Ch-In-SLNs formulations, with PDI, particle size, zeta potential, and association efficiency (AE) serving as the response variables. The resulting Ch-In-SLNs exhibited excellent monodispersity (PDI = 0.4), optimal particle size (654.43 nm), positive zeta potential (+36.87 mV), and low AE values. The Ch-In-SLNs demonstrated sustained release of insulin for 12 h in simulated gastric fluid (SGF) and intestinal fluid (SIF), with increased release in the latter. After incubation in SGF and SIF for 12 h, the insulin SLNs retained 54 and 41 % of their initial insulin load, respectively, indicating effective protection from gastric enzymes. Permeation studies using goat intestine and Caco-2 cell lines indicated improved insulin permeation in the presence of piperine. Additionally, cell uptake studies confirmed the role of piperine in enhancing insulin permeation.

Rebamipide nanocrystal with improved physicomechanical properties and its assessment through bio-mimicking 3D intestinal permeability model

This study investigated the formulation and characterization of rebamipide nanocrystals (REB-NCs) to enhance the solubility and permeability of rebamipide, an anti-ulcer medication known for its low aqueous solubility and permeability, classified as BCS class IV. Employing high-pressure homogenization and wet milling techniques, we successfully achieved nanonization of rebamipide, resulting in stable nanosuspensions that were subsequently freeze-dried to produce REB-NCs with an average particle size of 223 nm. Comprehensive characterization techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) confirmed the crystalline nature of the nanocrystals and their compatibility with the selected excipients. The saturation solubility study revealed a remarkable three-fold enhancement in PBS pH 7.4 compared to rebamipide API, indicating the effectiveness of the nanocrystal formulation in improving drug solubility. Furthermore, 3D in-vitro permeability assessments conducted on Caco-2 cell monolayers demonstrated an noticeable increase in the permeability of REB-NCs relative to the pure active pharmaceutical ingredient (API), highlighting the promise of this formulation to enhance drug absorption. The dissolution profile of the nanocrystal tablets exhibited immediate release characteristics, significantly outperforming conventional formulations in terms of the dissolution rate. This research underscores the potential of nanomilling as a scalable, environment-friendly, and less toxic approach to significantly enhance the bioavailability of rebamipide. By addressing the challenges associated with the solubility and permeability of poorly water-soluble drugs, our outcome offers insightful information into developing efficient nanomedicine strategies for enhancing therapeutic outcomes.

Identification of novel drug targets for Helicobacter pylori: structure-based virtual screening of potential inhibitors against DAH7PS protein involved in the shikimate pathway

Background

Helicobacter pylori, a bacterium associated with severe gastrointestinal diseases and malignancies, poses a significant challenge because of its increasing antibiotic resistance rates. This study aimed to identify potential drug targets and inhibitors against H. pylori using a structure-based virtual screening (SBVS) approach.

Methods

Core-proteome analysis of 132 H. pylori genomes was performed using the EDGAR database. Essential genes were identified and human and gut microbiota homolog proteins were excluded. The DAH7PS protein involved in the shikimate pathway was selected for the structure-based virtual screening (SBVS) approach. The tertiary structure of the protein was predicted through homology modeling (based on PDB ID: 5UXM). Molecular docking was performed to identify potential inhibitors of DAH7PS among StreptomeDB compounds using the AutoDock Vina tool. Molecular dynamics (MD) simulations assessed the stability of DAH7PS-ligand complexes. The complexes were further evaluated in terms of their binding affinity, Lipinski's Rule of Five, and ADMET properties.

Results

A total of 54 novel drug targets with desirable properties were identified. DAH7PS was selected for further investigation, and virtual screening of StreptomeDB compounds yielded 36 high-affinity binding of the ligands. Two small molecules, 6,8-Dihydroxyisocoumarin-3-carboxylic acid and Epicatechin, also showed favorable RO5 and ADMET properties. MD simulations confirmed the stability and reliability of DAH7PS-ligand complexes, indicating their potential as inhibitors.

Conclusion

This study identified 54 novel drug targets against H. pylori. The DAH7PS protein as a promising drug target was evaluated using a computer-aided drug design. 6,8-Dihydroxyisocoumarin-3-carboxylic acid and Epicatechin demonstrated desirable properties and stable interactions, highlighting their potential to inhibit DAH7PS as an essential protein. Undoubtedly, more experimental validations are needed to advance these findings into practical therapies for treating drug-resistant H. pylori.

A 3D in-vitro biomimicking Caco-2 intestinal permeability model-based assessment of physically modified telmisartan towards an alkalizer-free formulation development

Efficient telmisartan delivery for hypertension management requires the incorporation of meglumine and/or sodium hydroxide as an alkalizer in the formulation. Long-term use of powerful alkalis with formulation as part of chronic therapy can cause metabolic alkalosis, ulcers, diarrhea, and body pain. Here, we aimed to design a telmisartan formulation without alkalizers. Telmisartan properties were tailor-made by microfluidizer-based physical modification. After microfluidization, telmisartan nanosuspension was lyophilized to obtain telmisartan premix powder. The optimized telmisartan nanosuspension had an average particle size of 579.85 ± 32.14 nm. The lyophilized premix was characterized by FT-IR, DSC, and PXRD analysis to ensure its physicochemical characteristics. The solubility analysis of premix showed 2.2 times, 2.3 times, and 6 times solubility improvement in 0.1 N HCl, phosphate buffer pH 7.5, and pH 6.8 compared to pure telmisartan. A 3D in-vitro Caco-2 model was developed to compare apparent permeability of API and powder premix. It showed that the powder premix was more permeable than pure API. The tablet formulation prepared from the telmisartan premix showed a dissolution profile comparable to that of the marketed formulation. The technique present herein can be used as a platform technology for solubility and permeability improvement of similar classes of molecules.

Synthesis of Acetaminophen-Based Coumarins as Selective COX-2 Inhibitors: An in vitro-in silico Study

Acetaminophen, a centrally-acting old analgesic drug, is a weak inhibitor of cyclooxygenase (COX) isoforms with some selectivity toward COX-2. This compound was used in this work as a precursor to create nine acetaminophen based coumarins (ACFs). To satisfy the aim of this work, which states the synthesis of acetaminophen-based coumarins as selective COX-2 inhibitors, the ACFs were subjected to two types of investigation: in vitro and in silico. Given the former type, the ACFs capacity to block COX-1 and COX-2 was investigated in lab settings. On the other hand, the in silico investigation included docking the chemical structures of ACFs into the active sites of these enzymes, predicting their anticipated toxicities, and determining the ADME characteristics. The results of the in vitro study revealed that the synthesized ACFs demonstrated good-to-excellent inhibitory properties against the enzymes under study. Also, these ACFs exhibited a high level of COX-2 selectivity, which improved as the capacity of the aromatic substitute for withdrawing electrons was enhanced. Results of docking were comparable to the in vitro investigation in case of COX-2. On the other hand, the in silico investigations indicated that the synthesized ACFs are safer than their precursor, acetaminophen, with a high potential to consider oral-administrated candidates.

Set Up and Utilization of a Three-Dimensional In Vitro Bioreactor System for Human Intestinal Studies and Microbial Co-Cultures

The study of human intestinal physiology and host-microbe interactions is crucial for understanding gastrointestinal health and disease. Traditional two-dimensional cell culture models lack the complexity of the native intestinal environment, limiting their utility in studying intestinal biology. Here, we present a detailed protocol for the set up and utilization of a three-dimensional (3D) in vitro bioreactor system for human intestinal studies and bacterial co-culture. This article outlines the design and assembly of the bioreactor system, scaffold fabrication, bacterial culture techniques, analysis methods, and troubleshooting tips. By providing step-by-step instructions, the goal is to enable other laboratories to utilize physiologically relevant tissue models of the human intestine, incorporating key features, such as nutrient flow, multiple human cell types, 3D architecture, and microbial communities. The incorporation of commensal bacteria into the bioreactor system allows for the investigation of complex host-microbe interactions, providing insight into gastrointestinal health and pathology. This article serves as a comprehensive resource for scientists seeking to advance their understanding of intestinal biology toward the development of novel therapeutic strategies for gastrointestinal disorders. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Scaffold design Basic Protocol 2: Intestinal cell culture: Caco2 cells Basic Protocol 3: Intestinal cell culture: organoids Basic Protocol 4: Bioreactor design and set up Basic Protocol 5: Bacteria in 3D bioreactor set up Basic Protocol 6: Bacteria and drug dosing.

Bioaccessibility and Antioxidant Activity of Faba Bean Peptides in Comparison to those of Pea and Soy after In Vitro Gastrointestinal Digestion and Transepithelial Transport across Caco-2 and HT29-MTX-E12 Cells

In this study, the transepithelial transport of bioactive peptides derived from faba bean flour gastrointestinal digestates was investigated, in vitro, using a Caco-2 and HT29-MTX-E12 coculture monolayer, in comparison to those of pea and soy. The profile of transported peptides was determined by mass spectrometry, and the residual antioxidant activity was assessed. The ORAC value significantly (p < 0.05) decreased after transepithelial transport (24-36% reduction) for all legumes, while the antioxidant activity in ABTS assay significantly (p < 0.05) increased, as shown by the EC50 decrease of 26-44%. Five of the nine faba bean peptides that crossed the intestinal cell monolayer exhibited antioxidant activity. Two of these peptides, TETWNPNHPEL and TETWNPNHPE, were further hydrolyzed by the cells' brush border peptidases to smaller fragments TETWNPNHP and TWNPNHPE. These metabolized peptides were synthesized, and both maintained high antioxidant activity in both ABTS (EC50 of 1.2 ± 0.2 and 0.4 ± 0.1 mM, respectively) and ORAC (2.5 ± 0.1 and 3.4 ± 0.2 mM of Trolox equivalent/mM, respectively) assays. These results demonstrated for the first time the bioaccessibility of faba bean peptides produced after in vitro gastrointestinal digestion and how their bioactive properties can be modulated during transepithelial transport.

In Vitro Inhibition of Colorectal Cancer Gene Targets by Withania somnifera L. Methanolic Extracts: A Focus on Specific Genome Regulation

An approach that shows promise for quickening the evolution of innovative anticancer drugs is the assessment of natural biomass sources. Our study sought to assess the effect of W. somnifera L. (WS) methanolic root and stem extracts on the expression of five targeted genes (cyclooxygenase-2, caspase-9, 5-Lipoxygenase, B-cell lymphoma-extra-large, and B-cell lymphoma 2) in colon cancer cell lines (Caco-2 cell lines). Plant extracts were prepared for bioassay by dissolving them in dimethyl sulfoxide. Caco-2 cell lines were exposed to various concentrations of plant extracts, followed by RNA extraction for analysis. By explicitly relating phytoconstituents of WS to the dose-dependent overexpression of caspase-9 genes and the inhibition of cyclooxygenase-2, 5-Lipoxygenase, B-cell lymphoma-extra-large, and B-cell lymphoma 2 genes, our novel findings characterize WS as a promising natural inhibitor of colorectal cancer (CRC) growth. Nonetheless, we recommend additional in vitro research to verify the current findings. With significant clinical benefits hypothesized, we offer WS methanolic root and stem extracts as potential organic antagonists for colorectal carcinogenesis and suggest further in vivo and clinical investigations, following successful in vitro trials. We recommend more investigation into the specific phytoconstituents in WS that contribute to the regulatory mechanisms that inhibit the growth of colon cancer cells.

Development of an in vitro co-culture model using Caco-2 and J774A.1 cells to mimic intestinal inflammation

In vitro models that mimic the pathophysiology in vivo are important tools to study mechanisms of disease and assess the pharmacology and toxicity of drugs. In this work, we report the development of a novel model of intestinal inflammation. This model is based on the co-culture of intestinal epithelial Caco-2 cells and murine J774A.1 macrophages. The model is shown to mimic the intestinal barrier in both healthy and inflamed state. In the healthy state, without external stimulation, Caco-2 and J774A.1 cells were co-cultured in one system without affecting the barrier integrity of intestinal epithelial cells and without inducing release of cytokines from macrophages. To mimic the inflamed intestine, Caco-2 cells were primed with an optimised cytokine cocktail (TNF-⍺, IFN-γ and IL-1β) and J774A.1 cells were pre-exposed to lipopolysaccharide (LPS) and IFN-γ for 24 h before combining the two cell lines into co-culture. In these conditions, a significant disruption of the epithelial barrier and an increase in pro-inflammatory cytokine (TNF-⍺ and IL-6) levels released from macrophages were detected. The data also show that inflammation in the co-culture model was temporary and reversible upon the removal of the inflammatory stimulus. This new in vitro model could be a valuable tool for investigating the safety and efficacy of drugs in the context of intestinal inflammation and provides advantages over other reported co-culture models of intestinal inflammation in terms of cost and simplicity.

An Apple and Acáchul Berry Snack Rich in Bioaccessible Antioxidants and Folic Acid: A Healthy Alternative for Prenatal Diets

A fruit leather (apple and acáchul berry) oriented toward women of reproductive age was developed. The snack was supplemented with an ingredient composed of folic acid (FA) and whey proteins (WPI) to ensure the required vitamin intake to prevent fetal neural tube defects. In order to generate a low-calorie snack, alternative sweeteners were used (stevia and maltitol). The fruit leather composition was determined. Also, an in vitro digestion process was carried out to evaluate the bioaccessibility of compounds with antioxidant capacity (AC), total polyphenols (TPCs), total monomeric anthocyanins (ACY), and FA. The quantification of FA was conducted by a microbiological method and by HPLC. The leather contained carbohydrates (70%) and antioxidant compounds, mainly from fruits. Bioaccessibility was high for AC (50%) and TPCs (90%), and low for ACY (17%). Regarding FA, bioaccessibility was higher for WPI-FA (50%) than for FA alone (37%), suggesting that WPI effectively protected the vitamin from processing and digestion. Furthermore, the product was shown to be non-cytotoxic in a Caco-2 cell model. The developed snack is an interesting option due to its low energy intake, no added sugar, and high content of bioactive compounds. Also, the supplementation with WPI-FA improved the conservation and bioaccessibility of FA.