RNA-Seq Reveals Protective Mechanisms of Mongolian Medicine Molor-Dabos-4 on Acute Indomethacin-Induced Gastric Ulcers in Rats.

This study aimed to apply transcriptomics to determine how Molor-Dabos-4 (MD-4) protects healthy rats against indomethacin (IND)-induced gastric ulcers and to identify the mechanism behind this protective effect. Rats were pretreated with MD-4 (0.3, 1.5, or 3 g/kg per day) for 21 days before inducing gastric ulcers by oral administration with indomethacin (30 mg/kg). Unulcerated and untreated healthy rats were used as controls. Effects of the treatment were assessed based on the ulcer index, histological and pathological examinations, and indicators of inflammation, which were determined by enzyme-linked immunosorbent assay. Transcriptomic analysis was performed for identifying potential pharmacological mechanisms. Eventually, after identifying potential target genes, the latter were validated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). After pretreatment with MD-4, gastric ulcers, along with other histopathological features, were reduced. MD-4 significantly (p < 0.05) increased the superoxide dismutase (SOD) levels in ulcers and reduced pepsin, TNF-α, and IL-6 levels. RNA-seq analysis identified a number of target genes on which MD-4 could potentially act. Many of these genes were involved in pathways that were linked to anti-inflammatory and antioxidant responses, and other protective mechanisms for the gastric mucosa. qRT-PCR showed that altered expression of the selected genes, such as Srm, Ryr-1, Eno3, Prkag3, and Eef1a2, was consistent with the transcriptome results. MD-4 exerts protective effects against IND-induced gastric ulcers by reducing inflammatory cytokines and pepsin and increasing the expression of SOD levels. Downregulation of Srm, Ryr-1, Eno3, Prkag3, and Eef1a2 genes involved in regulating arginine and proline metabolism, calcium signaling pathway, HIF-1 signaling pathway, oxytocin signaling pathway, and legionellosis are possibly involved in MD-4-mediated protection against gastric ulcers.

Metabolomics investigation on antiobesity effects of Corydalis bungeana on high-fat high-sugar diet-induced obese rats.

Objective: Corydalis bungeana (CB) is a well-used medicinal herb in Mongolian folk medicine and has been traditionally applied as an antiobesity agent. However, the evidence-based pharmacological effects of CB and its specific metabolic alterations in the obese model are not entirely understood. This study aimed to utilize untargeted metabolomic techniques to identify biomarkers and gain mechanistic insight into the serum metabolite alterations associated with weight loss and lipid metabolism in obese rats. Methods: A high-fat high-sugar (HFHS) diet was used to induce obese models in rats. CB extract was orally gavaged at 0.18, 0.9 and 1.8 g/kg doses for six weeks, and feed intake, body weight, fat pad weight, and blood indexes were measured. Blood serum metabolites were evaluated by gas chromatography/quadrupole time-of-flight tandem mass spectrometry (GC-TOF/MS). Results: The results showed that compared with the obese group, the administration of CB extract caused significant decreases in body weight (P < 0.05), feed intake, Lee's index, and perirenal, mesenteric, epididymal fat weight. CB extract also reduced blood triglyceride and total cholesterol levels (P < 0.05) of obese rats. Metabolomic findings showed that nine differential metabolites, including pyruvic acid, D-glucuronic acid, malic acid, dimethylglycine, oxoglutaric acid, pantothenic acid, sorbitol acid, fumaric acid and glucose 6-phosphate were identified under CB treatment and altered metabolic pathways such as TCA cycle, pantothenate and CoA biosynthesis, and glycolysis/gluconeogenesis. Conclusion: This study demonstrated weight loss and lipid lowering effects of CB on HFHS diet-induced obese rats and identified nine metabolites as potential biomarkers for evaluating the favorable therapeutic mechanism of CB via regulation of lipid and glucose metabolism.

Usefulness of Noncontrast MRI-Based Radiomics Combined Clinic Biomarkers in Stratification of Liver Fibrosis.

Purpose: To develop and validate a radiomic nomogram based on texture features from out-of-phase T1W images and clinical biomarkers in prediction of liver fibrosis. Materials and Methods: Patients clinically diagnosed with chronic liver fibrosis who underwent liver biopsy and noncontrast MRI were enrolled. All patients were assigned to the nonsignificant fibrosis group with fibrosis stage <2 and the significant fibrosis group with stage ≥2. Texture parameters were extracted from out-of-phase T1-weighted (T1W) images and calculated using the Artificial Intelligent Kit (AK). Boruta and LASSO regressions were used for feature selection and a multivariable logistic regression was used for construction of a combinational model integrating radiomics and clinical biomarkers. The performance of the models was assessed by using the receiver operator curve (ROC) and decision curve. Results: ROC analysis of the radiomics model that included the most discriminative features showed AUCs of the training and test groups were 0.80 and 0.78. A combinational model integrating RADscore and fibrosis 4 index was established. ROC analysis of the training and test groups showed good to excellent performance with AUC of 0.93 and 0.86. Decision curves showed the combinational model added more net benefit than radiomic and clinical models alone. Conclusions: The study presents a combinational model that incorporates RADscore and clinical biomarkers, which is promising in classification of liver fibrosis.

[Anti-obesity and lipid-lowering mechanism of Corydalis Bungeanae Herba: based on intestinal microflora and metabolomics].

This study aims to explore anti-obesity and lipid-lowering mechanism of Corydalis Bungeanae Herba(CB) based on intestinal microflora and metabolomics. Specifically, high-fat high-sugar diet(HFHS, 10 weeks) was used to induce obesity in rats. Then the model rats were randomized into the model group, low-dose(0.18 g·kg~(-1)), medium-dose(0.9 g·kg~(-1)), and high-dose(1.8 g·kg~(-1)) CBH groups, and orlistat group(0.03 g·kg~(-1)), 12 in each group. Rats which received normal diet were used as control. The body weight and feed intake of rats were recorded every week. After 6 weeks of administration, rats were killed and gastric emptying and small intestinal propulsion were examined. Enzyme-linked immunosorbent assay(ELISA) was employed to analyze serum indexes, and liver and perirenal fat were collected for haematoxilin-eosin(HE) staining. Rat feces and serum were gathered for 16 S rDNA sequencing and metabolomics analysis and Spearman's correlation analysis was performed to explore the correlation between differential microflora and differential metabolites. The result showed that CBH extract decreased body weight, feed intake, and serum cholecystokinin(CCK), triglyceride(TG), and total cholesterol(TC), delayed gastric emptying, and reduced fat accumulation in liver and perirenal adiposity as compared with rats in the model group. In addition, Lachnospiraceae and Sutterellaceaecan significantly decreased in the model group, but CBH extract up-regulated their abundance. Moreover, the abundance of Prevotellaceae was significantly raised by HFHS, but CBH decreased it. Glutaric acid, glyceric acid, hippuric acid, malic acid, glyceric acid, oxoglutaric acid, fumaric acid/succinic acid, oxoglutaric acid/isocitric acid, D-glucuronic acid, cholic acid were the main deferentially expressed metabolites and significantly correlated with Sutterellaceae and Prevotellaceae. These key metabolites and microbiota mainly involved in tricarboxylic acid(TCA) cycle, glucose metabolism, amino acid metabolism, and energy metabolism. This study proved that CBH can efficiently improve body weight and blood lipids, reduce adipocyte volume, and positively regulate the intestinal microflora and serum metabolites, thereby achieving the anti-obesity and lipid-owering effect.

Hepatoprotective Effects of Ixeris chinensis on Nonalcoholic Fatty Liver Disease Induced by High-Fat Diet in Mice: An Integrated Gut Microbiota and Metabolomic Analysis.

Ixeris chinensis (Thunb.) Nakai (IC) is a folk medicinal herb used in Mongolian medical clinics for the treatment of hepatitis and fatty liver diseases even though its pharmacological mechanism has not been well characterized. This study investigated the hepatoprotective mechanism of IC on mice with nonalcoholic fatty liver disease (NAFLD) by integrating gut microbiota and metabolomic analysis. A high-fat diet (HFD) was used to develop nonalcoholic fatty liver disease, after which the mice were treated with oral IC (0.5, 1.5 and 3.0 g/kg) for 10 weeks. HFD induced NAFLD and the therapeutic effects were characterized by pathological and histological evaluations, and the serum indicators were analyzed by ELISA. The gut microbial and metabolite profiles were studied by 16S rRNA sequencing and untargeted metabolomic analysis, respectively. The results showed that the administration of IC resulted in significant decreases in body weight; liver index; serum biomarkers such as ALT, TG, and LDL-C; and the liver inflammatory factors IL-1ß, IL-6, and TNF-α. The 16S rRNA sequencing results showed that administration of IC extract altered both the composition and abundance of the gut microbiota. Untargeted metabolomic analysis of liver samples detected a total of 212 metabolites, of which 128 were differentially expressed between the HFD and IC group. IC was found to significantly alter the levels of metabolites such as L-glutamic acid, pyridoxal, ornithine, L-aspartic acid, D-proline, and N4-acetylaminobutanal, which are involved in the regulation of glutamine and glutamate, Vitamin B6 metabolism, and arginine and proline metabolic pathways. Correlation analysis indicated that the effects of the IC extract on metabolites were associated with alterations in the abundance of Akkermansiaceae, Lachnospiraceae, and Muribaculaceae. Our study revealed that IC has a potential hepatoprotective effect in NAFLD and that its function might be linked to improvements in the composition of gut microbiota and their metabolites.

A rare case of duodenal spindle cell lipoma with gastrointestinal bleeding.

The manuscript reports a rare case of duodenal spindle cell lipoma (SCL), which is a rarely reported benign lipomatous neoplasm of the gastrointestinal tract. It is less commonly observed within the duodenum. Our patient presented with gastrointestinal bleeding, which is a rare symptom of lipomas. This report describes the appearance of the neoplasm on endoscopy as well as endoscopic ultrasonography. The ulcer on the surface of the neoplasm is another rare feature. The correct diagnosis of SCL was based on its microscopic features and immunohistochemical findings. We believe that our study makes a significant contribution to the literature because this information will be of practical use to clinicians for the management of similar conditions and encourage other researchers to validate our findings.

Use of Texture Analysis on Noncontrast MRI in Classification of Early Stage of Liver Fibrosis.

Purpose. To compare the diagnostic value of texture analysis- (TA-) derived parameters from out-of-phase T1W, in-phase T1W, and T2W images in the classification of the early stage of liver fibrosis. Methods. Patients clinically diagnosed with hepatitis B infection, who underwent liver biopsy and noncontrast MRI scans, were enrolled. TA parameters were extracted from out-of-phase T1-weighted (T1W), in-phase T1W, and T2-weighted (T2W) images and calculated using Artificial Intelligent Kit (AK). Features were extracted including first-order, shape, gray-level cooccurrence matrix, gray-level run-length matrix, neighboring gray one tone difference matrix, and gray-level differential matrix. After statistical analyses, final diagnostic models were constructed. Receiver operating curves (ROCs) and areas under the ROC (AUCs) were used to assess the diagnostic value of each final model and 100-time repeated cross-validation was applied to assess the stability of the logistic regression models. Results. A total of 57 patients were enrolled in this study, with 27 in the fibrosis stage < 2 and 30 in stages ≥ 2. Overall, 851 features were extracted per ROI. Eight features with high correlation were selected by the maximum relevance method in each sequence, and all had a good diagnostic performance. ROC analysis of the final models showed that all sequences had a preferable performance with AUCs of 0.87, 0.90, and 0.96 in T2W and in-phase and out-of-phase T1W, respectively. Cross-validation results reported the following values of mean accuracy, specificity, and sensitivity: 0.98 each for out-of-phase T1W; 0.90, 0.89, and 0.90 for in-phase T1W; and 0.86, 0.88, 0.84 for T2W in the training set, and 0.76, 0.81, and 0.72 for out-of-phase T1W; 0.74, 0.72, and 0.75 for in-phase T1W; and 0.63, 0.64, and 0.63 for T2W for the test group, respectively. Conclusion. Noncontrast MRI scans with texture analysis are viable for classifying the early stages of liver fibrosis, exhibiting excellent diagnostic performance.

Clinical Study of the Prediction of Malignancy in Thyroid Nodules: Modified Score versus 2017 American College of Radiology's Thyroid Imaging Reporting and Data System Ultrasound Lexicon.

The clinical importance of thyroid nodules rests with the need to exclude thyroid cancer. In the present study, we developed a modified Thyroid Imaging Reporting and Data System (TI-RADS) score using gray-scale ultrasound, contrast-enhanced ultrasound (CEUS) and shear-wave elastography (SWE) images to predict malignancy of thyroid nodules and compared this modified score system with the subjective scoring criteria based on the Thyroid Imaging Reporting and Data System (TI-RADS, 2017 edition). The results revealed that by using SWE and CEUS (enhanced pattern) to downgrade TI-RADS category 4 and 5 nodules, the malignancy rate for TI-RADS category 4 and 5 nodules increased from 47.6% with American College of Radiology (ACR) TI-RADS assessment alone to 49.4% with ACR TI-RADS combined with shear wave elastography (SWE) and CEUS (enhanced pattern). Likewise, by using the modified TI-RADS to adjust TI-RADS category 3 nodules, the malignancy rate for TI-RADS category 3 nodules increased from 13.9%-20.0%. The discriminating power for detection of malignancy of the variable score 2 (ACR TI-RADS + SWE + CEUS), with an area under the curve (AUC) of 0.899 (95% confidence interval [CI]: 86.1%-93.6%), was higher than that of score 1 (ACR TI-RADS), with an AUC of 0.862 (95% CI: 81.9%-90.6%; p > 0.05). With a point 4.5 as the optimal cutoff value, a score of 1 predicted malignancy with an accuracy of 75.6%, sensitivity of 85.0% and specificity of 71.6%. However, with a point 5.5 as the optimal cutoff value, a score of 2 predicted malignancy with an accuracy of 84.9%, sensitivity of 81.0% and specificity of 86.6%. The modified TI-RADS based on ACR TI-RADS + SWE + CEUS (enhanced pattern) could contribute to a reduction in the number of biopsies performed on benign nodules and the implementation of consistent follow-up in clinical practice.

Depletion of H3K79 methyltransferase Dot1L promotes cell invasion and cancer stem-like cell property in ovarian cancer.

DOT1-like protein (Dot1L) is the sole methyltransferase for methylation of lysine 79 in histone H3. Dot1L-dependent H3K79 methylation is involved in many biological processes, including telomeric silencing, cell cycle regulation, transcriptional activation and DNA repair. Genome-wide sequencing studies have revealed recurrent deletion and mutations of Dot1L gene in many types of human malignancies including ovarian cancer, however the role of Dot1L in ovarian cancer are largely unknown. To demonstrate the role of Dot1L in ovarian cancer, the expression of Dot1L was knocked out in ovarian cancer cells using CRISPR/Cas9 technology in the present study. Dot1L loss showed minimal effect on cell growth, but significantly promoted cell invasion and induced cancer stem-like cell property in ovarian cancer cells. Mechanistically, loss of Dot1L downregulated the expression of tight junction makers E-Cadherin and TJP1 and upregulated the expression of ALDH1A1 through Wnt signaling activation. Our data indicate potential tumor suppressor function of Dot1L in ovarian cancer, which is correlated with observed deletion of Dot1L gene in ovarian cancer patients, further study is granted to elucidate the function of Dot1L in tumorigenesis and progression in ovarian cancer.

A potential biomarker hsa-miR-200a-5p distinguishing between benign thyroid tumors with papillary hyperplasia and papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is the most common endocrine cancer with a significantly increase of the incidence recently. Several cytokines, such as thyroid peroxidase (TPO), cluster of differentiation 56 (CD56), Galectin-3, mesothelial cell (MC), cytokeratin 19 (CK19) and BRAF (B-raf) were recommended to be tested by immunohistochemistry (IHC) for a definitive diagnosis, but were still limited in clinical use because of their relative lower sensitivity and specificity. MicroRNA (miRNA), as a new molecular biomarkers, however, has not been reported yet so far. To address this, hsa-miR-200a-5p, a miRNA, was selected and detected in PTC patients by in situ hybrization with benign thyroid tumor with papillary hyperplasia as a control, and the differential expression of hsa-miR-200a-5p between fresh PTC tissues and control was detected by qRT-PCR. Expressive levels of cytokines of TPO, CD56, Galectin-3, MC, CK19 and B-raf were also detected by immunohistochemistry. The correlation was analyzed by SPSS software using Spearman methods. As expected, the hsa-miR-200a-5p expressive level was significantly increased in PTC patients, compared to that of control, and was consistent with that of TPO, CD56, Galectin-3, MC, CK19 and B-raf. In addition, expression of hsa-miR-200a-5p showed negative correlation to that of TPO (rs = - 0.734; **: P < 0.01) and CD56 (rs = - 0.570; **: P < 0.01), but positive correlation to that of Galectin-3 (rs = 0.601; **: P < 0.01), MC (rs = 0.508; **: P < 0.01), CK19 (rs = 0.712; **: P < 0.01) and B-raf (rs = 0.378; **: P < 0.01). PTC and papillary benign thyroid papillary hyperplasia are difficult to distinguish in morphology, so requiring immunohistochemistry to further differentiate the diagnosis, however, for the existing clinical common diagnostic marker for immunohistochemistry, the sensitivity and accuracy are low, it is easy to miss diagnosis. Therefore, there is an urgent need for a rapid and sensitive molecular marker. So miR-200a-5p can be used to assist in the diagnosis of PTC at the molecular level, and as a biomarker, can be effectively used to distinguish between PTC and benign thyroid tumor with papillary hyperplasia.

Supersaturated polymeric micelles for oral cyclosporine A delivery: The role of Soluplus-sodium dodecyl sulfate complex.

Our previous study demonstrated that the retention of drug in the hydrophobic core of Soluplus micelle greatly impeded drug absorption from gastrointestinal tract. Using supersaturated polymeric micelles can improve drug release, however, insufficient maintaining of supersaturation of drug is still unfavorable for drug absorption. Here, we report adding small amount of small molecule, sodium dodecyl sulfate (SDS), to Soluplus solution can form a Soluplus-SDS complex. This complex not only showed a higher solubilization capability for the model drug cyclosporine A (CsA), but also maintained a longer period of and higher supersaturation than was achieved with Soluplus alone. The Soluplus-SDS interactions were characterized by analyzing surface tension, small-angle X-ray scattering (SAXS), fluorescence spectra, and nuclear magnetic resonance spectroscopy. The results demonstrated that the formation of Soluplus-SDS complex via SDS adsorption on hydrophobic segments of Soluplus, which have more hydrophobic domain than that of Soluplus micelle, contributed significantly to the solubilization and stabilization of supersaturated CsA. Using this amphiphilic copolymer-small molecule surfactant system, the cellular uptake and rat in vivo absorption of CsA were more effectively achieved than pure Soluplus. The area under the plasma concentration-time curve (AUC) and the maximal plasma concentration (Cmax) achieved by CsA-loaded Soluplus-SDS complex were 1.58- and 1.8-times higher than the corresponding values for CsA-loaded pure Soluplus, respectively. This study highlighted the benefits of Soluplus-SDS complex for optimizing the solubilization and oral absorption of a drug with low aqueous solubility.

Lipid-Based Formulations for Oral Drug Delivery: Effects on Drug Absorption and Metabolism.

The application of lipid-based drug delivery systems on the industrial scale has successfully demonstrated their therapeutic and manufacturing advantages. Recently, various lipid-based formulations were successfully prepared for oral delivery of compounds that are difficult to administer. Nevertheless, an improved understanding of how these formulations affect drug absorption and metabolism is required to support the rapid and successful completion of drug development programs. In this review, we report the detailed mechanisms whereby lipids and lipid-based excipients affect drug absorption and metabolism, and summarize the capacity of lipids and lipid-based formulations to improve drug absorption by improving drug solubility, mucosa penetration, lymphatic transport, and hepatic metabolism. Finally, we discuss the progress made toward the use of novel lipid formulations to enhance oral absorption by surmounting specific absorption barriers.

Supersaturated polymeric micelles for oral cyclosporine A delivery.

Polymeric micelles provide a promising platform for improving oral absorption of poorly soluble drugs. However, improved understanding of how drug retention within the hydrophobic micelle core can reduce drug absorption is required. We designed supersaturated polymeric micelles (Super-PMs) to increase molecularly dissolved drug concentration and gain an insight into the effect of the degree of supersaturation on oral absorption of cyclosporine A (CsA) in rats. The drug release from Super-PMs increased with an increase in initial supersaturation degrees in micelles. The cellular uptake of coumarin-6 was reduced by the retention of drug in polymer micelles. The transport flux of CsA across Caco-2 monolayer was increased with initial supersaturation degrees of 0.81-3.53 (p < 0.05). However, increase in supersaturation to 5.64 actually resulted in decreased CsA transport. The same trend was observed in a rat in vivo absorption study, in which the highest bioavailability of 134.6 ± 24.7% (relative to a commercial product, Sandimmun Neoral®, p<0.01) was achieved when the supersaturation degree was 3.53. These results demonstrated that Super-PMs were a promising drug delivery system for compounds with low aqueous solubility. This study also provided an experimental proof for the hypothesis that moderately supersaturated formulations are valuable alternative to high supersaturation formulations, resulting in optimal in vivo performance, and the degree of supersaturation should be carefully controlled to optimize drug absorption.

Comparative study of Pluronic(®) F127-modified liposomes and chitosan-modified liposomes for mucus penetration and oral absorption of cyclosporine A in rats.

Liposomes modified using cationic and hydrophilic nonionic polymers are 2 popular carriers for improving oral drug absorption. Cationic polymer-modified liposomes can adhere to the intestinal wall mucus (mucoadhesive type), while liposomes modified using hydrophilic nonionic polymers can penetrate across the mucus barrier (mucus-penetrating type). Chitosan-modified liposomes (CS-Lip, mucoadhesive type) and Pluronic(®) F127-modified liposomes (PF127-Lip, mucus-penetrating type) were engineered to investigate the differences between these mucoadhesive and mucus-penetrating systems in oral absorption of a poorly soluble drug, cyclosporine A (CyA). Stability of CS-Lip and PF127-Lip was studied in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The intestinal mucus adhesion or penetration of liposomes was studied by confocal laser scanning microcopy and fluorophotometry using coumarin 6 as the fluorescent probe. The oral absorption of CyA-loaded liposomes was also studied in Sprague-Dawley rats. In vitro and in vivo studies revealed that CS-Lip tended to aggregate in SIF, to be trapped by mucus, to remain mainly in the upper portion of the intestinal tract, and to show limited penetration ability. In contrast, PF127-Lip were more stable in the SIF and SGF, were found throughout the intestinal tract, and were able to penetrate the mucus layers to reach the epithelial surface. Pharmacokinetic analysis in rats showed that the Cmax and AUC0-t of PF127-Lip were 1.73- and 1.84-fold higher than those of CS-Lip, respectively (P<0.05). In conclusion, the stability and mucus-penetrating ability of PF127-Lip in the gastrointestinal tract rendered it more suitable than the mucoadhesive CS-Lip for oral delivery CyA.

An examination of the potential effect of lipids on the first-pass metabolism of the lipophilic drug anethol trithione.

In this study, an examination of the potential effect of lipids on the first-pass metabolism of anethol trithione (ATT) was investigated. ATT is metabolized rapidly and extensively in liver into 4-hydroxy-anethole trithione (ATX), which was confirmed using the rat intestinal perfusion with the mesenteric cannulation model. Male Sprague-Dawley rats were orally administered of the lipid-based formulations (prepared by medium chain triglycerides (MCT)), the cyclodextrin formulation and the suspension formulation, respectively. For 6.75 mg/kg groups, ATX/ATT area under the plasma concentration-time curve (AUC) ratio decreased by 87% and 76% after administration of the MCT-based formulations and the cyclodextrin formulation, when compared with the suspension formulation (p < 0.05), respectively; for 2.25 mg/kg groups, it decreased by 53% in the MCT group when compared with the cyclodextrin group (p < 0.05). The saturation of pre-system metabolism of ATT was observed after administration of the MCT-based formulations and the cyclodextrin formulation, likely as a result of enhanced absorption and therefore presentation of higher drug concentrations to liver, when compared with the suspension formulation. A trend toward lower systemic metabolite to parent ratios was evident after administration of the lipid formulations, when compared with the cyclodextrin formulation; however, this was not statistically significant. Further studies on the potential for lipids to inhibit hepatic metabolism are therefore warranted.

Absorption enhancement of adefovir dipivoxil by incorporating MCT and ethyl oleate complex oil phase in emulsion.

AIM: To improve the oral absorption of adefovir dipivoxil (ADV) by employing MCT and the esterase inhibitor ethyl oleate (EO) as a complex oil phase in emulsion. METHODS: EO was used as the esterase inhibitor, and its inhibitory effect on esterase activity was assessed in rat intestinal homogenates. ADV emulsions with or without EO were prepared. The emulsions' protective effect against intestinal metabolism was evaluated in rat luminal contents, ex vivo, as well as in vivo. RESULTS: The IC(50) of EO in intestinal mucosal homogenates was 2.2 mg/mL. The emulsions exhibited significant protective effects in rat luminal contents compared to a simple suspension (98.7%, 96.3%, 95.7% vs 74.7%, P<0.01). The permeability calculated from the emulsion containing EO was significantly different (11.4 x 10(-6) vs 7.4/8.0 x 10(-6), P<0.05) from the simple suspension or the emulsion without EO in an ex vivo assay. A bioavailability study in vivo revealed that emulsions containing both EO and MCT as a complex oil phase demonstrated 1.6- and 1.5-fold enhancements in area under the curve (AUC(0-12)) values (5358 vs 3386/3618, P<0.05), respectively, when compared with emulsions containing EO or MCT as a single oil phase. CONCLUSION: Heterotic lipid formulations (emulsions) with an esterase inhibitor (ie, EO) may be useful in protecting ester prodrugs from intestinal metabolism and increasing their oral bioavailability.

Reversible inhibitory effects of saturated and unsaturated alkyl esters on the carboxylesterases activity in rat intestine.

This study was conducted to investigate the relationship between the carbon chain length/double bonds of alkyl esters and their inhibitory potency/mechanism on carboxylesterases (CESs). CESs activity was evaluated by inhibition of adefovir dipivoxil (ADV) metabolism in rat intestinal homogenates. Furthermore, the inhibitory effect of BNPP and ethyl (E)-hex-2-enoate (C8:1) on drug absorption was evaluated in situ intestinal perfusion model. The results showed that the rank order of the inhibitory potency on CESs was C10:0 > C8:0 > C6:0 > C4:0 > C12:0, C8:1 > C8:0, C6:1 > C6:0, while the esters (C14:0, C13:1, C16:0, C18:0, C17:1, C20:0) were found to have no inhibitory effect at investigated concentrations. However, the unsaturated esters (C20:1, C20:2, C20:3) displayed the inhibitory effect on CESs. Moreover, the double reciprocal plots indicated that alky esters inhibited the CESs in competitive and mixed competitive ways which were reversible. In addition, the result of most effective CESs inhibitor C8:1 from in situ experiment showed that C8:1 can inhibit the CESs-mediated intestinal metabolism and improve the drug absorption. And the inhibition had no time-dependent effect, compared with that of BNPP groups. The study suggested that alkyl esters can be served as effective and reversible CESs inhibitors, besides that their inhibitory potency/mechanism can be affected by their carbon chain length/double bonds.

Lipid-based formulations to enhance oral bioavailability of the poorly water-soluble drug anethol trithione: effects of lipid composition and formulation.

This study has explored the use of lipid-based formulations to enhance the oral bioavailability of the poorly water-soluble drug anethol trithione (ATT), and compared the performance of different formulations. Two groups of lipid-based formulations, sub-microemulsion (SME) and oil solution, were prepared using short (SCT), medium (MCT) and long (LCT) chain triglycerides respectively; aqueous suspension was used as the reference formulation. In vitro and in vivo studies were conducted to investigate the impact of lipid composition and formulation on drug absorption. In vitro digestion was used to analyze lipid digestion rates and drug distribution/solubilization. After in vitro digestion, the performance rank order for drug solubilization was SCT