Effects Of Hepatic Metabolism Research Articles

Drug Repurposing Patent Applications April–June 2021

Drug Repurposing Patent Applications April–June 2021

Metabolic Effects of Endoscopic Duodenal Mucosal Resurfacing: a Systematic Review and Meta-analysis.

Duodenal mucosal resurfacing (DMR) is an innovative endoscopic bariatric and metabolic therapy (EBMT) emerging in recent years. It uses the duodenum to achieve better glycemic and weight control. This study aimed to evaluate in a critical and systematic way the metabolic effects of this procedure. Electronic searches were performed evaluating the DMR procedure based on predefined inclusion and exclusion criteria. Changes in measured outcomes were evaluated using random-effects models by computing weighted mean differences (MD) and corresponding 95% CIs between pre-and post-procedure metabolic characteristics. Four studies were selected for qualitative and quantitative analysis. DMR demonstrated beneficial glycemic and hepatic metabolic effects among patients with non-insulin dependent type 2 diabetes (T2D) at 3 and 6months post-procedure.

A Phenotypic Screen for the Liver Stages of Plasmodium vivax

Control of malaria caused by Plasmodium vivax can be improved by the discovery and development of novel drugs against the parasite's liver stage, which includes relapse-causing hypnozoites. Several recent reports describe breakthroughs in the culture of the P. vivax liver stage in 384-well microtiter plates, with the goal of enabling a hypnozoite-focused drug screen. Herein we describe assay details, protocol developments, and different assay formats to interrogate the chemical sensitivity of the P. vivax liver stage in one such medium-throughput platform. The general assay protocol includes seeding of primary human hepatocytes which are infected with P. vivax sporozoites generated from the feeding of Anopheles dirus mosquitoes on patient isolate bloodmeals. This protocol is unique in that, after source drug plates are supplied, all culture-work steps have been optimized to preclude the need for automated liquid handling, thereby allowing the assay to be performed within resource-limited laboratories in malaria-endemic countries. Throughput is enhanced as complex culture methods, such as extracellular matrix overlays, multiple cell types in co-culture, or hepatic spheroids, are excluded as the workflow consists entirely of routine culture methods for adherent cells. Furthermore, installation of a high-content imager at the study site enables assay data to be read and transmitted with minimal logistical delays. Herein we detail distinct assay improvements which increase data quality, provide a means to limit the confounding effect of hepatic metabolism on assay data, and detect activity of compounds with a slow-clearance phenotype. Graphical abstract: Overview of P. vivax liver stage screening assay performed at the Institute Pasteur of Cambodia.

Investigation of the effect of hepatic metabolism on off-target cardiotoxicity in a multi-organ human-on-a-chip system

Regulation of cosmetic testing and poor predictivity of preclinical drug studies has spurred efforts to develop new methods for systemic toxicity. Current in vitro assays do not fully represent physiology, often lacking xenobiotic metabolism. Functional human multi-organ systems containing iPSC derived cardiomyocytes and primary hepatocytes were maintained under flow using a low-volume pumpless system in a serum-free medium. The functional readouts for contractile force and electrical conductivity enabled the non-invasive study of cardiac function. The presence of the hepatocytes in the system induced cardiotoxic effects from cyclophosphamide and reduced them for terfenadine due to drug metabolism, as expected from each compound's pharmacology. A computational fluid dynamics simulation enabled the prediction of terfenadine-fexofenadine pharmacokinetics, which was validated by HPLC-MS. This in vitro platform recapitulates primary aspects of the in vivo crosstalk between heart and liver and enables pharmacological studies, involving both organs in a single in vitro platform. The system enables non-invasive readouts of cardiotoxicity of drugs and their metabolites. Hepatotoxicity can also be evaluated by biomarker analysis and change in metabolic function. Integration of metabolic function in toxicology models can improve adverse effects prediction in preclinical studies and this system could also be used for chronic studies as well.

Hepatic metabolic effects of Curcuma longa extract supplement in high-fructose and saturated fat fed rats

The metabolic effects of an oral supplementation with a Curcuma longa extract, at a dose nutritionally relevant with common human use, on hepatic metabolism in rats fed a high fructose and saturated fatty acid (HFS) diet was evaluated. High-resolution magic-angle spinning NMR and GC/MS in combination with multivariate analysis have been employed to characterize the NMR metabolite profiles and fatty acid composition of liver tissue respectively. The results showed a clear discrimination between HFS groups and controls involving metabolites such as glucose, glycogen, amino acids, acetate, choline, lysophosphatidylcholine, phosphatidylethanolamine, and β-hydroxybutyrate as well as an increase of MUFAs and a decrease of n-6 and n-3 PUFAs. Although the administration of CL did not counteract deleterious effects of the HFS diet, some metabolites, namely some n-6 PUFA and n-3 PUFA, and betaine were found to increase significantly in liver samples from rats having received extract of curcuma compared to those fed the HFS diet alone. This result suggests that curcuminoids may affect the transmethylation pathway and/or osmotic regulation. CL extract supplementation in rats appears to increase some of the natural defences preventing the development of fatty liver by acting on the choline metabolism to increase fat export from the liver.

Hepatic functions of GLP-1 and its based drugs: current disputes and perspectives.

GLP-1 and its based drugs possess extrapancreatic metabolic functions, including that in the liver. These direct hepatic metabolic functions explain their therapeutic efficiency for subjects with insulin resistance. The direct hepatic functions could be mediated by previously assumed "degradation" products of GLP-1 without involving canonic GLP-1R. Although GLP-1 analogs were created as therapeutic incretins, extrapancreatic functions of these drugs, as well as native GLP-1, have been broadly recognized. Among them, the hepatic functions are particularly important. Postprandial GLP-1 release contributes to insulin secretion, which represses hepatic glucose production. This indirect effect of GLP-1 is known as the gut-pancreas-liver axis. Great efforts have been made to determine whether GLP-1 and its analogs possess direct metabolic effects on the liver, as the determination of the existence of direct hepatic effects may advance the therapeutic theory and clinical practice on subjects with insulin resistance. Furthermore, recent investigations on the metabolic beneficial effects of previously assumed "degradation" products of GLP-1 in the liver and elsewhere, including GLP-128-36 and GLP-132-36, have drawn intensive attention. Such investigations may further improve the development and the usage of GLP-1-based drugs. Here, we have reviewed the current advancement and the existing controversies on the exploration of direct hepatic functions of GLP-1 and presented our perspectives that the direct hepatic metabolic effects of GLP-1 could be a GLP-1 receptor-independent event involving Wnt signaling pathway activation.

High Content Analysis of an In Vitro Model for Metabolic Toxicity: Results with the Model Toxicants 4-Aminophenol and Cyclophosphamide

In vitro models that accurately and rapidly assess hepatotoxicity and the effects of hepatic metabolism on nonliver cell types are needed by the U.S. Department of Defense and the pharmaceutical industry to screen compound libraries. Here, we report the first use of high content analysis on the Integrated Discrete Multiple Organ Co-Culture (IdMOC) system, a high-throughput method for such studies. We cultured 3T3-L1 cells in the presence and absence of primary human hepatocytes, and exposed the cultures to 4-aminophenol and cyclophosphamide, model toxicants that are respectively detoxified and activated by the liver. Following staining with calcein-AM, ethidium homodimer-1, and Hoechst 33342, high content analysis of the cultures revealed four cytotoxic endpoints: fluorescence intensities of calcein-AM and ethidium homodimer-1, nuclear area, and cell density. Using these endpoints, we observed that the cytotoxicity of 4-aminophenol in 3T3-L1 cells in co-culture was less than that observed for 3T3-L1 monocultures, consistent with the known detoxification of 4-aminophenol by hepatocytes. Conversely, cyclophosphamide cytotoxicity for 3T3-L1 cells was enhanced by co-culturing with hepatocytes, consistent with the known metabolic activation of this toxicant. The use of IdMOC plates combined with high content analysis is therefore a multi-endpoint, high-throughput capability for measuring the effects of metabolism on toxicity.

Fatty Acid Bile Acid Conjugate Inhibits Hepatic Stearoyl Coenzyme A Desaturase and Is Non-atherogenic

Suppression of stearoyl-coenzyme A desaturase (SCD) activity leads to reduction of obesity, fatty liver as well as of insulin resistance. It was, however, recently reported to enhance atherogenesis. The aim of the present study was to investigate whether inhibition of SCD by Aramchol, a fatty acid bile conjugate with known hypocholesterolemic effects, will affect atherogenesis and how. Aramchol was tested in vitro in cultured cells and in vivo in rodents. Aramchol, at very low concentrations, reduced SCD activity in liver microsomes of mice. Aramchol enhanced cholesterol efflux from macrophages more than twofold. In vivo it increased fecal sterol output and decreased markedly plasma cholesterol levels in mice. In ApoE(-/-), LDRL(-/-) and C57Bl6 mice, the effects of Aramchol on atherogenesis were non-atherogenic. Aramchol reduces SCD activity and is non-atherogenic. It may offer a means to obtain the desirable hepatic metabolic effects of SCD inhibition without the deleterious atherogenic effect.

What is the evidence for the safety and efficacy of using ketamine in children?

What is the evidence for the safety and efficacy of using ketamine in children?

Side effects of budesonide in liver cirrhosis due to chronic autoimmune hepatitis: effect of hepatic metabolism versus portosystemic shunts on a patient complicated with HCC

To investigate the systemic availability of budesonide in a patient with Child A cirrhosis due to autoimmune hepatitis (AIH) and primary hepatocellular carcinoma, who developed serious side effects. Serum levels of budesonide, 6beta-OH-budesonide and 16alpha-OH-prednisolone were measured by HPLC/MS/MS; portosystemic shunt-index (SI) was determined by 99mTc nuclear imaging. All values were compared with a matched control patient without side effects. Serum levels of budesonide were 13-fold increased in the index patient. The ratio between serum levels of the metabolites 6beta-OH-budesonide and 16alpha-OH-prednisolone, respectively, and serum levels of budesonide was diminished (1.0 vs. 4.0 for 6beta-OH-budesonide, 4.2 vs. 10.7 for 16alpha-OH-prednisolone). Both patients had portosystemic SI (5.7% and 3.1%) within the range of healthy subjects. Serum levels of budesonide vary up to 13-fold in AIH patients with Child A cirrhosis in the absence of relevant portosystemic shunting. Reduced hepatic metabolism, as indicated by reduced metabolite-to-drug ratio, rather than portosystemic shunting may explain systemic side effects of this drug in cirrhosis.

The effect of hepatic metabolism on the production and toxicity of reactive metabolites in extrahepatic organs.

The effect of hepatic metabolism on the production and toxicity of reactive metabolites in extrahepatic organs.

Drug interactions with cimetidine

Drug-drug interactions of cimetidine and possible mechanisms of interaction are discussed. Cimetidine has several actions in vivo that may result in drug-drug interactions. By decreasing acid secretion into the stomach, cimetidine increases the pH of the gastric contents. This may lead to decreased absorption of drugs that require a lower pH for dissolution, or increased absorption of drugs whose absorption is normally decreased by acid inactivation in the stomach. Cimetidine also reduces hepatic blood flow significantly and inhibits microsomal metabolism of drugs inactivated by this system. Both of these actions impair inactivation of numerous drugs. Cimetidine's increase of gastric pH has not been shown to result in clinically important drug-drug interactions. Cimetidine's effects of hepatic metabolism and blood flow are clinically relevant, and several interactions are attributable to them.

On the obligatory role of the hypophysis in sexual differentiation hepatic metabolism in rats.

The hepatic metabolism of 4-[4-14C]androstene-3,17-dione and 5alpha-[4-14C]androstane-3alpha,17beta-diol was studies in castrated and hypophysectomized male rats with a transplanted pituitary under the kidney capsule. The effects of testosterone propionate and estradiol benzoate on liver metabolism were also studied in these experimental animals. It was found that the autonomous pituitary secreted a "feminizing factor" that transformed the male type of steroid metabolism characteristic of hypophysectomized rats into a female type of metabolism Hypophysectomized rats were unresponsive towards androgen action on the liver and did not respond with feminized hepatic metabolism after treatment with estradiol benzoate. It is concluded that estrogenic action on liver enzymes is mediated via modulation of the secretion of a central (probably hypothalamic) "feminizing factor inhibiting factor" and the sex hormonal effects of hepatic metabolism only occur in the presence of a pituitary in situ.

Uptake and distribution of thiopental after oral, rettal, and intramuscular administration: effect of hepatic metabolism and injection site blood flow.

The effects of hepatic metabolism and iniection site blood flow on blood and brain thiopental concentrations following oral, rectal, and intramuscular administration were evaluated using a digital computer programmed with input data from an idealized electrical model. Peak drug levels were increased with high injection site flow rates and decreased with high rates of metabolism. The position of the liver relative to the iniection site was important in decreasing drug levels approximately twice as much after oral than after intramuscular administration. Altered hepatic function (increased or decreased) will affect blood and tissue thiopental levels more after oral or rectal administration than after intramuscular or intravenous administration.