Low Permeability Drugs Research Articles

Morphology-Mediated Tumor Deep Penetration for Enhanced Near Infrared II Photothermal and Chemotherapy of Colorectal Cancer.

The low permeability and heterogeneous distribution of drugs (including nanomedicines) have limited their deep penetration into solid tumors. Herein we report the design of gold nanoparticles with virus-like spikes (AuNVs) to mimic viral shapes and facilitate tumor penetration. Mechanistic studies revealed that AuNVs mainly entered cells through macropinocytosis, then transported to the Golgi/endoplasmic reticulum system via Rab11-regulated pathway, and finally exocytosed through recycling endosomes, leading to high cellular uptake, effective transcytosis, and deep tumor penetration compared to gold nanospheres (AuNPs) and gold nanostars (AuNSs). The high tumor accumulation and deep tumor penetration of mitoxantrone (MTO) facilitated by AuNVs endowed effective chemophotothermal therapy when exposed to a near-infrared II laser, significantly reducing tumor sizes in a mouse model of colorectal cancer. This study reveals a potent mechanism of viral-like structures in tissue penetration and highlights their potential as effective drug delivery carriers.

Old drugs, new tricks: Delivering pitavastatin-loaded nanostructured lipid carriers for glioblastoma treatment

Glioblastoma (GB) is the most common and lethal primary form of malignant brain cancers. Its intrinsic aggressiveness and the blood-brain barrier (BBB) are two major factors that limit the efficacy of standard therapies. In recent years, nanostructured lipid carriers (NLCs) have established themselves as a promising avenue for improving drug delivery to the brain, overcoming the challenges associated with the low drug permeability of the BBB.This work delves into the systematic development of a novel carrier for pitavastatin delivery by establishing a “get it right at the first time” quality by design perspective, supported by multivariate analysis, computational modelling, and molecular docking. The manufacturing process was comprehensively evaluated at each step, from raw material selection to NLC purification, thus leading to a carrier with optimal colloidal, encapsulation and stability properties. The cytotoxic behaviour of the carrier was assessed in a panel of GB cell lines, which includes a low, a medium and a highly sensitive cell line to pitavastatin, providing a better discriminatory power and addressing the different potential in the therapeutic responses. The results obtained reflect a strong antiglioblastoma activity in concentrations where the standard of care lacks activity, as well as a swift and prominent internalization by GB cells. Overall, this work positions these long-term stable parenteral systems in line with the hypothesis of providing more effective surrogate therapeutics in the field of GB.

Comparison of in vitro screening methods for evaluating the effects of pharmaceutical excipients on membrane permeability

The effects of pharmaceutical excipients on intestinal drug absorption have been highlighted and careful excipient selection is required to develop biologically equivalent formulations. This study aimed to evaluate the effects of excipients on drug permeability and compare the characteristics of in vitro screening methods. Three in vitro models, the commercial precoated parallel artificial membrane permeability assay (PAMPA), PermeaPadTM, and Caco-2 monolayer, were used to evaluate the effects of 14 excipients on the permeability of several drugs with different biopharmaceutical classification system classes. Concentration-dependent effects were analyzed to distinguish non-specific effects. The permeability of low-permeability drugs was increased by excipients such as hydroxypropyl cellulose and povidone K30 in the precoated PAMPA model, whereas PermeaPadTM maintained membrane integrity at higher concentrations. Conversely, croscarmellose sodium and sodium lauryl sulfate (SLS) decreased the permeability of highly permeable drugs in both precoated PAMPA and PermeaPadTM assays in a concentration-dependent manner. In Caco-2 monolayer assays, most excipients showed minimal effects on drug permeability. However, SLS significantly reduces the permeability of highly permeable drugs at concentrations above the critical micelle concentration, thereby compromising the integrity of the cell monolayer. Our results suggested that most of excipients, except SLS, did not affect the membrane permeation of drugs at clinically used concentrations. The pre-coated PAMPA model demonstrated high sensitivity to excipient effects, making it suitable for conservative evaluation. The PermeaPadTM and Caco-2 models allowed assessment at higher excipient concentrations, with PermeaPadTM being particularly useful for excipients that cause toxicity in Caco-2 cells.

Fabrication of porous poly(L-lactide-co-ε-caprolactone) micropowder for microbubble effect and ultrasound-mediated drug delivery.

Biodegradable elastic poly(L-lactide-co-ε-caprolactone) (PLCL) copolymer (50:50, lactide:caprolactone molar ratio) was synthesized and porous PLCL micropowders was fabricated by a simple method involving rapid cooling of 0.1, 0.5, and 1% (wt/vol) PLCL/dioxane spray into liquid nitrogen. The physicochemical properties of the porous PLCL micropowders were examined by measuring their pore size, pore morphology, and microbead size using a scanning electron microscopy (SEM) and dye and temozolomide (TMZ)-release testing under ultrasound. Human U-87MG, glioblastoma (GBM) cell culture tests were performed to evaluate cell cytotoxicity by released drug from PLCL micropowders. In this study, the porous PLCL micropowders prepared from 1 wt%/vol% PLCL solutions showed a highly porous structure, satisfactory mechanical properties, and optimal drug release efficiency compared with those produced from 0.1 or 0.5 wt%/vol% solutions. The results of the accumulated release test with the results of the absorbance of the dye initially applied, it was confirmed that more than 80% of the added dye was trapped inside the micropowder, and clearly GBM cytotoxicity effect could be observed by the released TMZ. The drug release system using micropowders and ultrasound can be applied as a drug supply system for various diseases such as brain tumors with low drug permeability.

Hydrogel: a new material for intravesical drug delivery after bladder cancer surgery.

The standard treatment for non-muscle invasive bladder cancer (NMIBC) is transurethral resection of bladder tumor (TURBT). However, this procedure may miss small lesions or incompletely remove them, resulting in cancer recurrence or progression. As a result, intravesical instillation of chemotherapy or immunotherapy drugs is often used as an adjunctive treatment after TURBT to prevent cancer recurrence. In the traditional method, drugs are instilled into the patient's bladder through a urinary catheter under sterile conditions. However, this treatment exposes the bladder mucosa to the drug directly, leading to potential side effects like chemical cystitis. Furthermore, this treatment has several limitations, including a short drug retention period, susceptibility to urine dilution, low drug permeability, lack of targeted effect, and limited long-term clinical efficacy. Hydrogel, a polymer material with a high-water content, possesses solid elasticity and liquid fluidity, making it compatible with tissues and environmentally friendly. It exhibits great potential in various applications. One emerging use of hydrogels is in intravesical instillation. By employing hydrogels, drug dilution is minimized, and drug absorption, retention, and persistence in the bladder are enhanced due to the mucus-adhesive and flotation properties of hydrogel materials. Furthermore, hydrogels can improve drug permeability and offer targeting capabilities. This article critically examines the current applications and future prospects of hydrogels in the treatment of bladder cancer.

Magnitude of Fruit Juice-Drug Interactions Due to Osmolality-Dependent Fluid Secretion: Differences among Apple, Orange, and Grapefruit Juices.

We recently reported that the gastrointestinal (GI) fluid volume is influenced by the solution osmolality, and proposed that this effect may play a role in beverage-drug interactions. Here, we investigated whether osmolality-dependent fluid secretion can explain the difference in the magnitudes of fruit juice-drug interactions depending on the type of fruit juice (grapefruit juice (GFJ), orange juice (OJ), and apple juice (AJ)). The osmolality of GFJ, OJ, and AJ used in this study was found to be 552, 686, and 749 mOsm/kg, respectively. Measurements of intestinal fluid movement following beverage administration by the in situ closed-loop technique revealed the following rank order for fluid volume in rat ileum: AJ > OJ > GFJ > purified water, suggesting that water movement is dependent on the osmolality of these beverages. Such changes in GI fluid volume are expected to alter the luminal drug concentration, potentially contributing to the magnitude of beverage-drug interactions. Indeed, in vivo pharmacokinetic study in rats revealed that the plasma concentration of atenolol, a low-permeability drug, was the highest after oral administration in purified water, followed by GFJ and OJ, and was the lowest after administration in AJ. In contrast, antipyrine, a high-permeability drug, showed no significant difference in plasma concentration after administration in purified water and fruit juices, suggesting that the absorption of high-permeability drugs is less affected by solution osmolality. Our findings indicate that differences in the magnitude of beverage-drug interactions can be at least partly explained by differences in the osmolality of the beverages ingested.

Investigation of cellulose acetate electrospun films for controlled drug permeability

The current work examined the capability of electrospun film to act as a membrane for controlling drug permeability for its intended application in local drug delivery systems. Electrospun films of cellulose acetate were chosen as the model to utilize Taguchi design of experiment (DoE) that took into account the independent input variables (applied voltage, flow rate, collector distance and polymer concentration). Drug permeability and tensile strength were chosen as the response parameters. Applied voltage of 27 kV, flow rate of 1.25 mL/h, collector distance of 12.5 cm and polymer concentration of 19 % were found to be the ideal combination for higher tensile strength and lower drug permeability. The results of the analysis of variance (ANOVA) revealed that, among the input parameters examined, polymer concentration was the most influencing for both the response parameters. The analysis of fiber morphology, fiber orientation and porosity of electrospun was also performed. The results indicated the ability of electrospun fiber to achieve drug permeability as low as 31.7 % (in initial 24 h) and highest tensile strength of 3.81 MPa.

Approaches to Account for Colon Absorption in Physiologically Based Biopharmaceutics Modeling of Extended-Release Drug Products.

The rate and extent of colon absorption are important determinants of the in vivo performance of extended-release (ER) drug products. The ability to appropriately predict this at different stages of development using mechanistic physiologically based biopharmaceutic modeling (PBBM) is highly desirable. This investigation aimed to evaluate the prediction performance of three different approaches to account for colon absorption in predictions of the in vivo performance of ER drug product variants with different in vitro release profiles. This was done by mechanistic predictions of the absorption and plasma exposure of the ER drug products using GastroPlus and GI-Sim for five drugs with different degrees of colon absorption limitations in humans. Colon absorption was accounted for in the predictions using three different approaches: (1) by an a priori approach using the default colon models, (2) by fitting the colon absorption scaling factors to the observed plasma concentration-time profiles after direct administration to the colon in humans, or (3) from the ER drug product variant with the slowest in vitro release profile. The prediction performance was evaluated based on the percentage prediction error and the average absolute prediction error (AAPE). Two levels of acceptance criteria corresponding to highly accurate (AAPE ≤ 20%) and accurate (AAPE 20-50%) predictions were defined prior to the evaluation. For the a priori approach, the relative bioavailability (Frel), AUC0-t, and Cmax of the ER drug product variants for the low to medium colon absorption limitation risk drugs was accurately predicted with an AAPE range of 11-53 and 8-59% for GastroPlus and GI-Sim, respectively. However, the prediction performance was poor for the high colon absorption limitation risk drugs. Moreover, accounting for the human regional colon absorption data in the models did not improve the prediction performance. In contrast, using the colon absorption scaling factors derived from the slowest ER variant significantly improved the prediction performance regardless of colon absorption limitation, with a majority of the predictions meeting the high accuracy criteria. For the slowest ER approach, the AAPE ranges were 5-24 and 5-32% for GastroPlus and GI-Sim, respectively, excluding the low permeability drug. In conclusion, the a priori PBBM can be used during candidate selection and early product design to predict the in vivo performance of ER drug products for low to medium colon absorption limitation risk drugs with sufficient accuracy. The results also indicate a limited value in performing human regional absorption studies in which the drug is administered to the colon as a bolus to support PBBM development for ER drug products. Instead, by performing an early streamlined relative bioavailability study with the slowest relevant ER in vitro release profile, a highly accurate PBBM suitable for ER predictions for commercial and regulatory applications can be developed, except for permeability-limited drugs.

Innovative Aqueous Nanoemulsion Prepared by Phase Inversion Emulsification with Exceptional Homogeneity.

Formulating low-solubility or low-permeability drugs is a challenge, particularly with the low administration volumes required in intranasal drug delivery. Nanoemulsions (NE) can solve both issues, but their production and physical stability can be challenging, particularly when a high proportion of lipids is necessary. Hence, the aim of the present work was to develop a NE with good solubilization capacity for lipophilic drugs like simvastatin and able to promote the absorption of drugs with low permeability like fosphenytoin. Compositions with high proportion of two lipids were screened and characterized. Surprisingly, one of the compositions did not require high energy methods for high droplet size homogeneity. To better understand formulation factors important for this feature, several related compositions were evaluated, and their relative cytotoxicity was screened. Optimized compositions contained a high proportion of propylene glycol monocaprylate NF, formed very homogenous NE using a low-energy phase inversion method, solubilized simvastatin at high drug strength, and promoted a faster intranasal absorption of the hydrophilic prodrug fosphenytoin. Hence, a new highly homogeneous NE obtained by a simple low-energy method was successfully developed, which is a potential alternative for industrial application for the solubilization and protection of lipophilic actives, as well as (co-)administration of hydrophilic molecules.

Enzyme-triggered transcytosis of drug carrier system for deep penetration into hepatoma tumors

In recent years, nano-drug delivery systems have made considerable progress in the direction of tumor treatment, but the low permeability of drugs has restricted the development of nano drugs. To solve this problem, we constructed a nano-drug delivery system with the dual effects of γ-glutamyltransferase (GGT) reaction and high nuclear targeting in tumor microenvironment to promote the deep penetration of drugs. Over-expression of GGT in tumor cells can specifically recognize γ-glutamyl substrate and release amino group from the hydrolysis reaction, which makes the whole system change from negative or neutral to positive charge system. The conjugated complex with positive charge rapidly endocytosis through electrostatic interaction, enhancing its permeability in tumor parenchyma. At the same time, the cell penetrating TAT contains a large amount of lysine, which can be identified by the nuclear pore complexes (NPCs) on the surface of the nuclear membrane, showing excellent nuclear localization function. The active DOX is released in the nucleus, which inhibits the mitosis of cancer cells and enhances the active transport ability of drugs in tumor cells. Therefore, this drug delivery system actively transports adriamycin into the tumor to achieve deep penetration of drugs through enzyme response and nuclear targeting, showing high anti-tumor activity and can be effectively applied to the treatment of liver cancer.

A method for improving the properties of famotidine

According to crystal engineering, the pharmaceutical intermediate m-nitrobenzoic acid (MNBA), which contains a carboxylic acid group, was selected as a coformer (CCF) for drug cocrystallization with famotidine (FMT), and a new stable FMT salt cocrystal was synthesized. The salt cocrystals were characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, powder X-ray diffraction and X-ray single crystal diffraction. A single crystal structure of FMT–MNBA (1:1) was successfully obtained, and then the solubility and permeability of the newly synthesized salt cocrystal were studied. The results showed that, compared with free FMT, the FMT from the FMT–MNBA cocrystal showed improved permeability. This study provides a synthetic method to improve the permeability of BCS III drugs, which will contribute to the development of low-permeability drugs.

Combined novel approach to enhance the solubility and Intestinal absorption: A recent review

For oral pharmaceutical products to achieve high bioavailability and minimal variability, the API must dissolve and be stable in the GI media as well as sufficiently absorb at pertinent sites in the large intestine and small intestine. The possibility for API absorption from any dosage form is determined by an important biopharmaceutical parameter known as regional intestine effective permeability. For effective estimation of the manufacturing potential of a dosage form, it is especially crucial to understand the quantity of drug absorption from the human large intestine. Drug development is difficult because enhancing a drug's solubility, dissolution, and bioavailability is challenging. Among the four classes of the biopharmaceutical classification system (BCS) major work has been done on the low soluble drugs. In recent years poor solubility has been a major challenge for pharmaceutical scientists and a lot of experimental works are ongoing. Changing polymorphic forms by different new approaches and increase in the surface area is a widely used and comparatively simple method for increasing solubility and making the drug more bioavailable. For achieving the desired effects, permeability (intestinal absorption) is also playing an important role like solubility, but the focus of scientists is less on the permeability enhancement of low permeable drugs in respect of solubility. Sometimes it has been tried but with very limited success. The objective of this paper to provide a comprehensive review on improving solubility, release and intestinal absorption of low soluble and low permeable drugs with a combined novel approach of solubility and absorption enhancement. The ability to produce high soluble and high permeable drugs will grow significantly in the coming years and this will help to grow the revenue of the innovators as well as generic pharmaceutical companies. Keywords: Absorption, Bioavailability, Dissolution, Duodenum, Gastrointestinal tract, Gastrointestinal transit time, Gastroretention, Milling, Permeability, Poorly water-soluble drug(s), Polymer(s), Solvent evaporation, Spray drying

Physiologically based biopharmaceutics modeling of regional and colon absorption in humans

Colon absorption is a key determinant for successful development of extended release and colon targeted drug products. This is the first systematic evaluation of the ability to predict in vivo regional differences in absorption and the extent of colon absorption in humans using mechanistic physiologically based biopharmaceutics modeling (PBBM). A new dataset, consisting of 19 drugs with a wide range of biopharmaceutics properties and extent of colon absorption in humans, was established. Mechanistic predictions of the extent of absorption and plasma exposure after oral, or jejunal and direct colon administration were performed in GastroPlus and GI-Sim using an a priori approach. Two new colon models developed in GI-Sim, were also evaluated to assess if the prediction performance could be improved. Both GastroPlus and GI-Sim met the pre-defined criteria for accurate predictions of regional and colon absorption for high permeability drugs irrespective of formulation type, while the prediction performance was poor for low permeability drugs. For solutions, the two new GI-Sim colon models improved the colon absorption prediction performance for the low permeability drugs while maintaining the accurate prediction performance for the high permeability drugs. In contrast, the prediction performance decreased for non-solutions using the two new colon models. In conclusion, PBBM can be used with sufficient accuracy to predict regional and colon absorption in humans for high permeability drugs in candidate selection as well as early design and development of extended release or colon targeted drug products. The prediction performance of the current models needs to be improved to allow high accuracy predictions for commercial drug product applications including highly accurate predictions of the entire plasma concentration–time profiles as well as for low permeability drugs.

Polyols Permeability on Caco-2 Cells and Their Effects on Transport of Low-Permeability Drugs

Some pharmaceutical excipients are able to modify intestinal permeability, thus influencing drug absorption and bioavailability. The effect of four polyols (mannitol, maltitol, sorbitol and xylitol) on the permeability of seven active pharmaceutical ingredients (API), representing different BCS classes (furosemide, amiloride, atenolol, ranitidine, nadolol, L-thyroxine and acyclovir), was investigated using the Caco-2 cell permeability model. Analytical methods for the sensitive polyol and API quantification were developed using Ultra High Performance Liquid Chromatography coupled to triple-quadrupole Mass Spectrometry (UHPLC-QqQ). Apparent permeability coefficients (Papp) were calculated from the measured concentrations in the apical and basolateral compartments. The cell monolayer remained intact throughout the experiment in all trials, neither significant Lucifer Yellow (LY) passage, nor modification of the electrical resistance was detected, demonstrating that no active principle or excipient (or combinations thereof) modulated the paracellular transport. The Papp values for apical to basolateral and basolateral to apical directions of drug + excipient combinations were compared with the Papp values for the drug substance alone. Our results show that mannitol, maltitol, sorbitol and xylitol did not modify the permeability of furosemide, amiloride, atenolol, ranitidine, nadolol, acyclovir and L-thyroxine APIs. Moreover, the presence of polyols did not alter the efflux of the active principle (basolateral to apical).

Hydrophobic modification improves the delivery of cell-penetrating peptides to eliminate intracellular pathogens in animals.

Infections induced by intracellular pathogens are difficult to eradicate due to poor penetration of antimicrobials into cell membranes. It is of great importance to develop a new generation of antibacterial agents with dual functions of efficient cell penetration and bacterial inhibition. In this study, the association between hydrophobicity and cell-penetrating peptide delivery efficiency was investigated by fragment interception and hydrophobicity modification of natural porcine antimicrobial peptide PR-39 and the combination of cationic cell-penetrating peptide (R6) with antimicrobial peptide fragments modified with hydrophobic residues. The chimeric peptides P3I7 and P3L7, obtained through biofunctional screening, exhibited potent broad-spectrum antibacterial activity and low cytotoxicity. Moreover, P3I7 and P3L7 can effectively penetrate cells to eliminate intracellular pathogens mainly through endocytosis. The membrane destruction mechanism makes the peptides fast sterilizers and less prone to developing drug resistance. Finally, their good biocompatibility and antibacterial infection effects were verified in mice and piglets. To conclude, the chimeric peptides P3I7 and P3L7 show great potential as affordable and effective antimicrobial agents and may serve as ideal candidates for the treatment of intracellular bacterial infections. STATEMENT OF SIGNIFICANCE: The low permeability of antibacterial drugs makes infections induced by intracellular bacteria extremely difficult to treat. To address this issue, we designed chimeric peptides with dual cell-penetrating and antibacterial functions. The active peptides P3I7 and P3L7, acquired through functional screening have strong broad-spectrum antibacterial activity and powerful bactericidal effects against intracellular Staphylococcus aureus. The membrane permeation mechanism of P3I7 and P3L7 against bacteria endows fast bactericidal activity with low drug resistance. The biosafety and antibacterial activity of P3I7 and P3L7 were also validated by in vivo trials. This study provides an ideal drug candidate against intracellular bacterial infections.

A Review on Different Solubility Enhancement Techniques of Ticagrelor

Ticagrelor is a BCS class IV drug that inhibits platelet action by reversibly binding to the P2Y12 receptor. One of the major challenges faced by the class IV (low solubility, low permeability) drug is the lower dissolution rate leading to low bioavailability. The bioavailability of the marketed formulation of ticagrelor is approximately 36%. Researchers have come up with various techniques to improve the BCS class II and IV drug formulations as an integral part of the development of the pharmaceutical sciences. An increase in solubility can be achieved by various methods such as Salt formation, Complexation, Micronization, Solid Dispersion, altering the pH, Co-solvency, co-crystals, polymeric micelles, etc. A highly efficacious technique is converting a crystalline drug to its amorphous form. An extensive literature search was conducted using various databases like science direct, Taylor and Francis, Springer to extract relevant articles. Keywords like “Ticagrelor”, “low permeability”, “P2Y12 receptor inhibitor” were used for the literature search. Relevant articles were screened and referred for further study. This article discusses the techniques employed to increase the solubility of ticagrelor, thus highlighting the research conducted and reported. The increase in bioavailability of ticagrelor could be seen when formulated as nanoparticles, co-crystals, ticagrelor loaded self-micro emulsifying and nano emulsifying drug delivery system, solid dispersion, etc. the conversion of the crystalline drug into amorphous drug is a highly recommended approach to increase the solubility of ticagrelor which can be seen in cases of co-crystals and solid dispersion formulation.

Ethyl lauroyl arginate-based hydrophobic ion pair complex in lipid nanocapsules: A novel oral delivery approach of rosmarinic acid for enhanced permeability and bioavailability

Limited oral bioavailability due to high hydrophilicity restricts the beneficial use of Rosmaranic acid (RM) that is characterized by many biological and pharmacological effects. The present work was addressed to extract RM from Rosmarinus officinalis L. leaves and then increase its lipophilicity and permeability through the application of hydrophobic ion pair (HIP) approach using ethyl lauroyl arginate (ELA) as a novel counter-ion. Different RM:ELA ratios were screened to optimize HIP formation process. The encapsulation of the optimized HIP into lipid nanocapsules (LNCs) was then achieved to facilitate oral administration. The results of % transmittance, % complexation efficiency (87.32 ± 0.19%) and partition coefficient revealed the successful formation of the HIP complex occurred at RM:ELA molar ratio of 1:2. The formed HIP was successfully loaded into spherical small sized (39.32 ± 0.18 nm) LNCs. The ex vivo permeability studies across porcine intestine showed that the cumulative RM amount permeated/area after 6 h from HIP and LNCs were 3.79 ± 0.57 and 5.71 ± 0.32 µg/cm2, respectively. Pharmacokinetic study results showed that the maximum RM concentrations in plasma (Cmax) can be arranged in a descending manner as follows; 61.33 ± 8.89 < 42.13 ± 11.22 < 20.96 ± 3.12 ng/ml attained after 4.80, 8.00 and 10.40 h in case of LNC, HIP and solution, respectively. Moreover, the HIP and LNC formulae showed higher total drug amounts in plasma reaching 1.46 and 1.88-fold relative to RM solution, respectively. In conclusion, the HIP complex and HIP loaded LNCs prosper in enhancing the permeability and absorption of the low permeable drugs.

Tianhuang formula reduces the oxidative stress response of NAFLD by regulating the gut microbiome in mice

BackgroundThe gut microbiome affects the occurrence and development of NAFLD, but its mechanism has not yet been fully elucidated. Chinese medicine is a new treatment strategy to improve NAFLD by regulating the gut microbiome. Tianhuang formula (TH) has been proved to have a lipid-lowering effect in which constituents of ginsenoside Rb1, ginsenoside Rg1, ginsenoside Rb, ginsenoside Re, and ginsenoside R1 from Panax notoginseng and berberine, palmatine, and coptisine from Coptis chinensis have low drug permeability, which results in poor intestinal absorption into the human body, and are thus able to come into contact with the gut microflora for a longer time. Therefore, it might be able to influence the gut microbial ecosystem, but it still needs to be investigated.MethodThe characteristics of the gut microbiome were represented by 16S rRNA sequencing, and the metabolites in intestinal contents and liver were discovered by non-targeted metabolomics. Correlation analysis and fermentation experiments revealed the relationship between the gut microbiome and metabolites. Blood biochemical indicators, liver function indicators, and oxidation-related indicators were assayed. H&E staining and Oil Red O staining were used to analyze the characteristics of hepatic steatosis. RT-qPCR and western blotting were used to detect the expression of genes and proteins in liver tissues, and fecal microbial transplantation (FMT) was performed to verify the role of the gut microbiome.ResultsGut microbiome especially Lactobacillus reduced, metabolites such as 5-Methoxyindoleacetate (5-MIAA) significantly reduced in the liver and intestinal contents, the level of hepatic GSH and SOD reduced, MDA increased, and the protein expression of Nrf2 also reduced in NAFLD mice induced by high-fat diet (HFD). The normal diet mice transplanted with NAFLD mice feces showed oxidative liver injury, indicating that the NAFLD was closely related to the gut microbiome. TH and TH-treated mice feces both can reshape the gut microbiome, increase the abundance of Lactobacillus and the content of 5-MIAA in intestinal contents and liver, and improve oxidative liver injury. This indicated that the effect of TH improving NAFLD was related to the gut microbiome, especially Lactobacillus. 5-MIAA, produced by Lactobacillus, was proved with fermentation experiments in vitro. Further experiments proved that 5-MIAA activated the Nrf2 pathway to improve oxidative stress in NAFLD mice induced by HFD. TH reshaped the gut microbiome, increased the abundance of Lactobacillus and its metabolite 5-MIAA to alleviate oxidative stress, and improved NAFLD.ConclusionThe study has demonstrated a mechanism by which the gut microbiome modulated oxidative stress in NAFLD mice induced by HFD. The traditional Chinese medicine TH improved NAFLD by regulating the gut microbiome, and its mechanism was related to the “Lactobacillus-5-MIAA-Nrf2” pathway. It provided a promising way for the intervention of NAFLD.

NIR light-powered halloysite-based nanomotors for CT imaging diagnosis and synergistic chemo-photothermal cancer therapy

Near-infrared (NIR) light-powered nanomotors with active motion have attracted extensive attention in the chemo-photothermal therapy of cancer. However, there are also some limitations such as complicated synthesis process, low permeability of drugs and viscous physiological environment. Herein, we developed a facile route to synthesize novel NIR light-powered DOX/Au-m-HTAS nanomotor based on natural halloysite (HNTs) for active chemo-photothermal therapy. Such nanomotor exhibited NIR light controlled on/off motion with a maximum speed of 64.5 μm/s. Owing to the synergetic NIR light-powered motion and chemo-photothermal therapy, DOX/Au-m-HTAS nanomotor could effectively adhere tumor cells, leading to deeper cell penetration, higher cellular uptake, and better ablation of tumor cells. Meanwhile, DOX/Au-m-HTAS nanomotors also had enhanced ability for CT imaging of local tumor, demonstrating the enhanced anticancer efficiency. This strategy provided a new insight into the chemo-photothermal synergistic therapy of tumors.

Astragaloside IV ameliorates diet-induced hepatic steatosis in obese mice by inhibiting intestinal FXR via intestinal flora remodeling

BackgroundNonalcoholic fatty liver disease (NAFLD) is a major clinical and public health burden worldwide with no established pharmacological therapy. Changes in the intestinal flora and associated metabolite bile acids (BAs) have been described in NAFLD. Astragaloside IV (AS-IV) is a low drug permeability saponin with protective effects against multiple diseases. However, the specific mechanism underlying the involvement of AS-IV in the regulation of NAFLD is yet to be clarified. PurposeThis study aimed to investigate the effect of AS-IV on NAFLD and explore whether intestinal flora was involved. MethodsThe effect of AS-IV was evaluated on high-fat diet-fed mice. Real-time PCR, immunohistochemistry, immunofluorescence, and biochemical analyses were performed. 16S rRNA gene sequencing and UPLC-TQMS were used to determine the alterations in the intestinal flora and concentration of BAs. Fecal microbiota transplantation (FMT) and intestine-specific farnesoid X receptor (FXR) knockout were also performed. ResultsAS-IV treatment alleviated diet-induced metabolic impairments, particularly hepatic steatosis. These changes occurred in the setting of decreased intestinal bile salt hydrolase (BSH)-expressing flora. Further analysis showed that the reduced BSH activity increased intestinal tauro-β-muricholic acid levels, an inhibitor of intestinal FXR. Inhibition of intestinal FXR signaling by AS-IV was accompanied by decreased expression of intestinal fibroblast growth factor 15 and subsequent hepatic FXR activation as well as increased glucagon-like peptide-1 and decreased ceramide production, all of which contribute to the inhibition of sterol regulatory element-binding protein-1c-mediated hepatic steatosis. Furthermore, intestine-specific Fxr knockout and FMT further demonstrated an FXR- and intestinal flora-dependent preventive effect of AS-IV on hepatic steatosis. ConclusionThese results show that the changes in intestinal flora and BAs serve an essential role in the remission of hepatic steatosis by AS-IV, thereby suggesting that AS-IV may be used as a prebiotic agent to provide viable treatment for NAFLD.