RESUMEN

Objective: A remarkably sensitive, accurate, and efficient ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach was developed as a facile and expeditious method for measuring cilofexor concentration in beagle dogs, the herb-drug interactions between silybinin and cilofexor was explored based on pharmacokinetics. Methods: The plasma sample protein of the beagles were rapidly sedimented with acetonitrile, and cilofexor and tropifexor (internal standard, ISTD) were separated by gradient elution using a 0.1% formic acid aqueous solution and acetonitrile as the mobile phase. The concentrations were detected using positive ion multiple reaction monitoring (MRM) mode. Mass transfer pairs were m/z 587.91→267.91 for cilofexor and m/z 604.08→228.03 for ISTD, respectively. A two-period self-controlled experimental design was adopted for the HDIs experiment. In the first period (Group A), six beagle dogs were orally administered cilofexor at a dose of 1 mg/kg. In the second period (Group B), silybinin (3 mg/kg) was orally administered to the six beagle dogs twice a day for seven consecutive days, after which cilofexor was orally administered. The cilofexor concentration in beagle dogs was determined, and HDIs were evaluated based on their pharmacokinetics. Results: The accuracy and precision of cilofexor were both less than 15%, and the recoveries, matrix effects, and stability met the relevant requirements. The Cmax of cilofexor in group B was 49.62% higher than that in group A, whereas the AUC(0-t) and AUC(0-∞) of cilofexor in group B were 47.85% and 48.52% higher, respectively, than those in group A. Meanwhile, the t1/2 extended from 7.84 h to 9.45 h, CL and Vz decreased in Group B. Conclusion: A novel UPLC-MS/MS approach was successfully applied for the measurement of cilofexor in beagle dog plasma. Silybinin can alter the pharmacokinetics of cilofexor in beagle dogs, thereby increasing plasma exposure to cilofexor.

RESUMEN

The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as KV11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called "Torsades de Pointes". Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented.

Asunto(s)

RESUMEN

BACKGROUND: Oil-in-water drug nanoemulsion forms drug delivery systems with high oral bioavailability. The conventional fabrication methods of nanoemulsion are low energy emulsification methods and high energy emulsification methods. However, both two methods are not ideal for industrial production. The problem of low energy emulsification methods is the high dosage of surfactant and co-surfactant which has potential biosecurity issues. What is more, high energy emulsification methods have some disadvantages, like the destruction of drug components, the price of equipment and the difficulties of industrial production. Hence, there have been a few commercial drug nanoemulsions so far. METHODS: In this work, we reported a novel method for the fabrication of stable and transparent drug nanoemulsion which contains hydrophilic drug rosuvastatin (ROS) calcium or hydrophobic drug silybinin (SYN) by using high-gravity rotating packed bed (RPB). The drug nanoemulsion was systematically characterized by droplet size, size distribution, stability and in vitro drug release as well as Caco-2 cells permeability. RESULTS: Compared with the self-emulsification method (SE), high-gravity technology could reduce 75% amount of mixed surfactants. The as-prepared nanoemulsion exhibited a very narrow droplet size distribution with a size of 13.53 ± 0.53 nm and a polydispersity index of 0.073 ± 0.018. Meanwhile, the drug nanoemulsion was physicochemically stable at 25°C and 4°C for one-year storage. Furthermore, both ROS and SYN nanoemulsion displayed higher cell permeability and in vitro dissolution than that of commercial formulations. CONCLUSION: These results demonstrate that RPB can be a potential device to facilitate the industrial production of drug nanoemulsion.

Asunto(s)

RESUMEN

BACKGROUND: In vitro bioassays are important in the evaluation of plants with possible hepatoprotective effects. The aims of this study were to evaluate the pretreatment of HepG2 cells with hepatoprotective agents against the damage induced by carbon tetrachloride (CCl4) and paracetamol (APAP). METHODS: Antioxidative activity was measured using an assay to measure 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The in vitro hepatotoxicity of CCl4 and APAP, and the cytotoxic and hepatoprotective properties of silymarin (SLM), silybinin (SLB), and silyphos (SLP) were evaluated by measuring cell viability; activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH); total antioxidant capacity (TAOxC); and reduced glutathione (GSH), superoxide dismutase (SOD), and lipid peroxidation (malondialdehyde (MDA) levels). RESULTS: Only SLB and SLM showed strong antioxidative activity in the DPPH assay (39.71 ± 0.85 µg/mL and 14.14 ± 0.65 µg/mL, respectively). CCl4 induced time- and concentration-dependent changes. CCl4 had significant effects on cell viability, enzyme activities, lipid peroxidation, TAOxC, and SOD and GSH levels. These differences remained significant up to an exposure time of 3 h. APAP induced a variety of dose- and time-dependent responses up to 72 h of exposure. SLM, SLB, and SLP were not cytotoxic. Only SLB at a concentration of 100 µg/mL or 150 µg/mL significantly decreased the enzyme activities and MDA level, and prevented depletion of total antioxidants compared with CCl4. CONCLUSIONS: CCl4 was more consistent than APAP in inducing cell injury. Only SLB provided hepatoprotection. AST, LDH, and MDA levels were good markers of liver damage.

Asunto(s)

RESUMEN

Jasmonate and its methyl derivative, methyl jasmonate (MeJA), are naturally occurring compounds that mediate several plant physiological processes in response to pathogen attack, wounding, and ozone. Exogenous application of jasmonates triggers defense responses that resemble those initiated by pathogen infection and also modulates the production of certain secondary metabolites in a variety of plant species. In this study, we treated the hairy root cultures of Silybum marianum L. with 100 µM MeJA and then measured the content of Silymarin (SLM). We observed that the SLM content increased significantly after 48 h of MeJA treatment and remained constant for 120 h. However, MeJA treatment caused a significant growth reduction after 96 h incubation. The activity of lipoxygenase as a key enzyme in the jasmonate biosynthesis pathway and anti-oxidative enzymes; peroxidase and ascorbate peroxidase was also significantly increased after MeJA treatment. To elucidate the global effect of jasmonate on gene expression of S. marianum, we employed high resolution two-dimensional gel electrophoresis coupled with tandem mass spectrometry. Out of 670 reproducibly detected protein spots which were analyzed on each given gel, 32 spots were up- or down regulated upon MeJA treatment. Of them, ten proteins such as ER binding protein, glutamine synthetase, pathogenesis-related protein, caffeoyl CoA O-methyltransferase, and profilin-1 could be identified by mass spectrometry analysis. The possible implications of the identified proteins on physiological outcome of MeJA application in S. marianum hairy root culture will be discussed.

Asunto(s)

RESUMEN

Objective To explore the effects of silybin-phosphatidylcholine compound (SPC )on lipopolysaccharide (LPS)-induced activation of nuclear factor-?B (NF-?B) and phosphorylation and degradation of inhibitors of NF-?B?(I?B?).Methods Phagocyte were collected in abdominal cavity of Kunming mousse aged 6 to 8 weeks,cultured phagocyte(2?105 mL-1) were divided into control, LPS and SPC groups randomly, phagocyte in control group were added into the same volume of 9 g/L sodium chloride.Phagocyte in LPS group were added into a single bolus of LPS(10 ?g/mL LPS) for 24 hours, phagocyte in SPC groups were preincubated with different concentration of SPC for 2 hours followed by a 24 hours incubation with 10 ?g/mL LPS. Immunocytochemistry were used to measure the contents of NF-?B, phosphorylated I?B? in phagocyte.Results The content of NF-?B p65 located in the nuclear in control group was little. The content of NF-?B p65 located in the nuclear in LPS group markly higher than that in control group(P

RESUMEN

Objective To investigate the effects of silybin-phosphatidylcholine compound (SPC) on H2O2-induced the production of nitric oxide (NO) and reactive oxygen species (ROS) in mouse macrophage.Methods Macrophage were collected in abdominal cavity of 6-8 week Kunming mouse,and cultured macrophage(2?108 L-1) were divided into control and SPC group randomly.Macrophage in control group were added into the same volume(0.1 mL) of 9 g/L sodium chloride.Macrophage in H2O2 group were added into a single bolus of H2O2 (1 mmol/L H2O2) for 30 min,while macrophage in SPC group were preincubated with different concentration of SPC for 2 h followed by a 30 min incubation with 1 mmol/L H2O2.Immunocytochemistry were used to measure the contents of inducible nitric-oxide synthase(iNOS),NO production was determined by Griess reactive, ROS was determined by DCFH-DA Fluorescence probe.Results The production of NO in H2O2 group markedly higher than that in control group(P