A fast screening model for drug permeability assessment based on native small intestinal extracellular matrix

Antiangiogenic potential of phytochemicals from Clerodendrum inerme (L.) Gaertn investigated through in silico and quantum computational methods

Suppressing vascular endothelial growth factor (VEGF), its receptor (VEGFR2), and the VEGF/VEGFR2 signaling cascade system to inhibit angiogenesis has emerged as a possible cancer therapeutic target. The present work was designed to discover and evaluate bioactive phytochemicals from the Clerodendrum inerme (L.) Gaertn plant for their anti-angiogenic potential. Molecular docking of twenty-one phytochemicals against the VEGFR-2 (PDB ID: 3VHE) protein was performed, followed by ADMET profiling and molecular docking simulations. These investigations unveiled two hit compounds, cirsimaritin (- 12.29 kcal/mol) and salvigenin (- 12.14 kcal/mol), with the highest binding energy values when compared to the reference drug, Sorafenib (- 15.14 kcal/mol). Furthermore, only nine phytochemicals (cirsimaritin and salvigenin included) obeyed Lipinski's rule of five and passed ADMET filters. Molecular dynamics simulations run over 100 ns revealed that the protein-ligand complexes remained stable with minimal backbone fluctuations. The binding free energy values of cirsimaritin (- 52.35 kcal/mol) and salvigenin (- 55.89 kcal/mol), deciphered by MM-GBSA analyses, further corroborated the docking interactions. The HOMO-LUMO band energy gap (ΔE) was calculated using density-functional theory (DFT) and substantiated using density of state (DOS) spectra. The chemical reactivity analyses revealed that salvigenin exhibited the highest chemical softness value (6.384 eV), the lowest hardness value (0.07831 eV), and the lowest ΔE value (0.1566 eV), which implies salvigenin was less stable and chemically more reactive than cirsimaritin and sorafenib. These findings provide further evidence that cirsimaritin and salvigenin have the ability to prevent angiogenesis and the development of cancer. Nevertheless, more in vitro and in vivo confirmation is necessary.

Postbiotic Metabolite Derived from Lactiplantibacillus plantarum PD18 Maintains the Integrity of Cell Barriers and Affects Biomarkers Associated with Periodontal Disease

Background/Objectives: Periodontal disease is caused by oral infections, biofilms, persistent inflammation, and degeneration of cell barrier integrity, allowing pathogens to invade host cells. Probiotics have been extensively studied for the treatment of periodontal disease. However, research on the involvement of beneficial substances produced by probiotics, called "postbiotics," in periodontal diseases remains in its early stages. The present study aimed to evaluate the effect of a postbiotic metabolite (PM) from Lactiplantibacillus plantarum PD18 on immunomodulation and maintenance of cell barrier integrity related to periodontal disease. Method: The main substance in PM PD18 was analyzed by GC-MS. The cytotoxic effect of PM PD18 was performed using the MTT assay, wound healing through the scratch assay, cell permeability through TEER value, modulation of inflammatory cytokines through ELISA, and gene expression of inflammatory cytokines and tight junction protein was determined using qRT-PCR. Results: The main substance found in PM PD18 is 2,3,5,6-tetramethylpyrazine. PM PD18 did not exhibit cytotoxic effects on RAW 264.7 cells but promoted wound healing and had an antiadhesion effect on Porphyromonas gingivalis concerning SF-TY cells. This postbiotic could maintain cell barrier integrity by balancing transepithelial electrical resistance (TEER) and alkaline phosphatase (ALP) activity. In addition, the gene and protein expression levels of zonula occludens-1 (ZO-1) increased. PM PD18 was found to have immunomodulatory properties, as demonstrated by regulated anti- and pro-inflammatory cytokines. Interleukin-10 (IL-10) increased, while IL-6 and IL-8 were reduced. Conclusions: This study demonstrated that PM PD18 is efficient as a natural treatment for maintaining cell barrier integrity and balancing inflammatory responses associated with periodontal disease.

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.

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.

Short Caco-2 model for evaluation of drug permeability: A sodium valerate-assisted approach

The human colorectal adenocarcinoma cell line Caco-2, widely used for studying intestinal drug permeability, is typically grown on permeable filter supports and matures in 21 days with frequent media changes. The process is labor-intensive, prone to contamination, and has low throughput, contributing to the overall high utilization cost. Efforts to establish a low-cost, high-throughput, and short-duration model have encountered obstacles, such as weaker tight junctions causing monolayer leaks, incomplete differentiation resulting in low transporter expression, intricate and challenging protocols, and cytotoxicity, limiting the usability. Hence, this study aimed to develop a low-cost, efficient, and short-duration model by addressing the aforementioned concerns by customizing the media and finding a safe differentiation inducer. We generated a new rapid model using sodium valerate, which demonstrated sufficient transporter activity, improved monolayer integrity, and higher levels of differentiation markers than the 21-day model. Furthermore, this model exhibited consistent and reliable results when used to evaluate drug permeability over multiple days of repeated use. This study demonstrates the potential of a sodium valerate-assisted abbreviated model for drug permeability assessment with economic and practical advantages.

Cryopreservation and Rapid Recovery of Differentiated Intestinal Epithelial Barrier Cells at Complex Transwell Interfaces Is Enabled by Chemically Induced Ice Nucleation

Cell-based models, such as organ-on-chips, can replace and inform in vivo (animal) studies for drug discovery, toxicology, and biomedical science, but most cannot be banked "ready to use" as they do not survive conventional cryopreservation with DMSO alone. Here, we demonstrate how macromolecular ice nucleators enable the successful cryopreservation of epithelial intestinal models supported upon the interface of transwells, allowing recovery of function in just 7 days post-thaw directly from the freezer, compared to 21 days from conventional suspension cryopreservation. Caco-2 cells and Caco-2/HT29-MTX cocultures are cryopreserved on transwell inserts, with chemically induced ice nucleation at warmer temperatures resulting in increased cell viability but crucially retaining the complex cellular adhesion on the transwell insert interfaces, which other cryoprotectants do not. Trans-epithelial electrical resistance measurements, confocal microscopy, histology, and whole-cell proteomics demonstrated the rapid recovery of differentiated cell function, including the formation of tight junctions. Lucifer yellow permeability assays confirmed that the barrier functions of the cells were intact. This work will help solve the long-standing problem of transwell tissue barrier model storage, facilitating access to advanced predictive cellular models. This is underpinned by precise control of the nucleation temperature, addressing a crucial biophysical mode of damage.

An Improved In Vitro Blood-Brain Barrier Model for the Evaluation of Drug Permeability Using Transwell with Shear Stress

The development of drugs targeting the central nervous system (CNS) is challenging because of the presence of the Blood-Brain barrier (BBB). Developing physiologically relevant in vitro BBB models for evaluating drug permeability and predicting the activity of drug candidates is crucial. The transwell model is one of the most widely used in vitro BBB models. However, this model has limitations in mimicking in vivo conditions, particularly in the absence of shear stress. This study aimed to overcome the limitations of the transwell model using immortalized human endothelial cells (hCMEC/D3) by developing a novel dish design for an orbital shaker, providing shear stress. During optimization, we assessed cell layer integrity using trans-endothelial electrical resistance measurements and the % diffusion of lucifer yellow. The efflux transporter activity and mRNA expression of junctional proteins (claudin-5, occludin, and VE-cadherin) in the newly optimized model were verified. Additionally, the permeability of 14 compounds was evaluated and compared with published in vivo data. The cell-layer integrity was substantially increased using the newly designed annular shaking-dish model. The results demonstrate that our model provided robust conditions for evaluating the permeability of CNS drug candidates, potentially improving the reliability of in vitro BBB models in drug development.

Apple juice relieves loperamide-induced constipation in rats by downregulating the intestinal apical sodium-dependent bile acid transporter ASBT

Apples are known to exhibit various beneficial effects on human health. In the present study, we investigated the effect of continuous intake of apple juice (AJ) on constipation status. A single dose of loperamide in rats as the constipation model markedly decreased the weight and number of fecal pellets compared to saline-administered rats as a control. After the administration of AJ twice a day for seven days, recovery of defecation close to that of the control was observed in loperamide-treated rats. In addition, the total bile acid content in the feces increased from day 4 after the administration of AJ. Among hepatic and intestinal transporters and enzymes that regulate bile acids, the mRNA expression of the apical sodium-dependent bile acid transporter (Asbt, slc10a2) was decreased by AJ in rats. Furthermore, the Asbt-mediated bile acid transport activity in the rat ileum decreased after AJ administration. Moreover, in human colonic cancer-derived Caco-2 cells, AJ exposure for 24 and 48 h decreased the expressions of ASBT mRNA and protein, and the uptake activity of taurocholic acid in both 7- and 21-d cultures. Several components of AJ, such as procyanidins, decreased the expression of ASBT in Caco-2 cells. In conclusion, ASBT downregulation is a possible mechanism responsible for the constipation-relieving effect of apples, and procyanidins may play a role in downregulating ASBT, which leads to the beneficial effects of apples against constipation. Although it is generally agreed that the common dietary compositions play a role in constipation relief, the novel specific mechanism of apples found in this study would facilitate understanding food functions.

Oral bioavailability of bioactive compounds; modulating factors, in vitro analysis methods, and enhancing strategies

Foods are complex biosystems made up of a wide variety of compounds. Some of them, such as nutrients and bioactive compounds (bioactives), contribute to supporting body functions and bring important health benefits; others, such as food additives, are involved in processing techniques and contribute to improving sensory attributes and ensuring food safety. Also, there are antinutrients in foods that affect food bioefficiency and contaminants that increase the risk of toxicity. The bioefficiency of food is evaluated with bioavailability which represents the amount of nutrients or bioactives from the consumed food reaching the organs and tissues where they exert their biological activity. Oral bioavailability is the result of some physicochemical and biological processes in which food is involved such as liberation, absorption, distribution, metabolism, and elimination (LADME). In this paper, a general presentation of the factors influencing oral bioavailability of nutrients and bioactives as well as the in vitro techniques for evaluating bioaccessibility and is provided. In this context, a critical analysis of the effects of physiological factors related to the characteristics of the gastrointestinal tract (GIT) on oral bioavailability is discussed, such as pH, chemical composition, volumes of gastrointestinal (GI) fluids, transit time, enzymatic activity, mechanical processes, and so on, and the pharmacokinetics factors including BAC and solubility of bioactives, their transport across the cell membrane, their biodistribution and metabolism. The impact of matrix and food processing on the BAC of bioactives is also explained. The researchers' recent concerns for improving oral bioavailability of nutrients and food bioactives using both traditional techniques, for example, thermal treatments, mechanical processes, soaking, germination and fermentation, as well as food nanotechnologies, such as loading of bioactives in different colloidal delivery systems (CDSs), is also highlighted.

The case for cancer-associated fibroblasts: essential elements in cancer drug discovery?

Although cancer-associated fibroblasts (CAFs) have gained increased attention for supporting cancer progression, current CAF-targeted therapeutic options are limited and failing in clinical trials. As the largest component of the tumor microenvironment (TME), CAFs alter the biochemical and physical structure of the TME, modulating cancer progression. Here, we review the role of CAFs in altering drug response, modifying the TME mechanics and the current models for studying CAFs. To provide new perspectives, we highlight key considerations of CAF activity and discuss emerging technologies that can better address CAFs; and therefore, increase the likelihood of therapeutic efficacy. We argue that CAFs are crucial components of the cancer drug discovery pipeline and incorporating these cells will improve drug discovery success rates.

All layers matter: Innovative three-dimensional epithelium-stroma-endothelium intestinal model for reliable permeability outcomes

Drug development is an ever-growing field, increasingly requesting reliable in vitro tools to speed up early screening phases, reducing the need for animal experiments. In oral delivery, understanding the absorption pattern of a new drug in the small intestine is paramount. Classical two-dimensional (2D) in vitro models are generally too simplistic and do not accurately represent native tissues. The main goal of this work was to develop an advanced three-dimensional (3D) in vitro intestinal model to test absorption in a more reliable manner, by better mimicking the native environment. The 3D model is composed of a collagen-based stromal layer with embedded fibroblasts mimicking the intestinal lamina propria and providing support for the epithelium, composed of enterocytes and mucus-secreting cells. An endothelial layer, surrogating the absorptive capillary network, is also present. The cellular crosstalk between the different cells present in the model is unveiled, disclosing key players, namely those involved in the contraction of collagen by fibroblasts. The developed 3D model presents lower levels of P-glycoprotein (P-gp) and Multidrug Resistance Protein 2 (MRP2) efflux transporters, which are normally overexpressed in traditional Caco-2 models, and are paramount in the absorption of many compounds. This, allied with transepithelial electrical resistance (TEER) values closer to physiological ranges, leads to improved and more reliable permeability outcomes, which are observed when comparing our results with in vivo data.

QSPR model for Caco-2 cell permeability prediction using a combination of HQPSO and dual-RBF neural network

The Caco-2 cell model is widely used to evaluate the in vitro human intestinal permeability of drugs due to its morphological and functional similarity to human enterocytes. Although it is safe and relatively economic, it is time-consuming. A rapid and accurate quantitative structure-property relationship (QSPR) model of Caco-2 permeability is helpful to improve the efficiency of oral drug development. The aim of our study is to explore the predictive ability of the QSPR model, to study its permeation mechanism, and to develop a potential permeability prediction model, for Caco-2 cells. In our study, a relatively large data set was collected and the abnormal data were eliminated using the Monte Carlo regression and hybrid quantum particle swarm optimization (HQPSO) algorithm. Then, the remaining 1827 compounds were used to establish QSPR models. To generate multiple chemically diverse training and test sets, we used a combination of principal component analysis (PCA) and self-organizing mapping (SOM) neural networks to split the modeling data set characterized by PaDEL-descriptors. After preliminary selection of descriptors by the mean decrease impurity (MDI) method, the HQPSO algorithm was used to select the key descriptors. Six different methods, namely, multivariate linear regression (MLR), support vector machine regression (SVR), xgboost, radial basis function (RBF) neural networks, dual-SVR and dual-RBF were employed to develop QSPR models. The best dual-RBF model was obtained finally with R 2 = 0.91, and R cv5 2 = 0.77, for the training set, and R T 2 = 0.77, for the test set. A series of validation methods were used to assess the robustness and predictive ability of the dual-RBF model under OECD principles. A new application domain (AD) definition method based on the descriptor importance-weighted and distance-based (IWD) method was proposed, and the outliers were analyzed carefully. Combined with the importance of the descriptors used in the dual-RBF model, we concluded that the "H E-state" and hydrogen bonds are important factors affecting the permeability of drugs passing through the Caco-2 cell. Compared with the reported studies, our method exhibits certain advantages in data size, transparency of modeling process and prediction accuracy to some extent, and is a promising tool for virtual screening in the early stage of drug development.