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Pharmaceutical Biology Dec 2021Peimine and paeoniflorin can be combined for the treatment of cough in paediatrics. The interaction during the co-administration could dramatically affect the...
CONTEXT
Peimine and paeoniflorin can be combined for the treatment of cough in paediatrics. The interaction during the co-administration could dramatically affect the bioavailability of drugs.
OBJECTIVE
The interaction between peimine and paeoniflorin was investigated in this study.
MATERIALS AND METHODS
The pharmacokinetics of paeoniflorin (20 mg/kg) with or without the coadministration of peimine (5 mg/kg for 10 days before paeoniflorin) was orally investigated in Sprague-Dawley rats ( = 6). The group without the peimine was set as the control group. The metabolic stability of paeoniflorin was studied in rat liver with microsomes. The effect of peimine on the absorption of paeoniflorin was investigated with Caco-2 cell monolayers.
RESULTS
The (244.98 ± 10.95 vs. 139.18 ± 15.14 μg/L) and AUC (3295.92 ± 263.02 vs. 139.18 ± 15.14 h·μg/L) of paeoniflorin was increased by peimine. The was prolonged from 5.33 ± 1.65 to 14.21 ± 4.97 h and the clearance was decreased from 15.43 ± 1.75 to 4.12 ± 0.57 L/h/kg. Consistently, peimine increased the metabolic stability of paeoniflorin with rat liver microsomes with the increased (56.78 ± 2.62 vs. 26.33 ± 3.15 min) and the decreased intrinsic clearance (24.42 ± 3.78 vs. 52.64 ± 4.47 μL/min/mg protein). Moreover, the transportation of paeoniflorin was also inhibited by peimine as the efflux ratio decreased from 3.06 to 1.63.
DISCUSSION AND CONCLUSIONS
Peimine increased the systemic exposure of paeoniflorin through inhibiting the activity of CYP3A4 and P-gp. These results provide a reference for further studies in a broader population.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Animals; Area Under Curve; Caco-2 Cells; Cevanes; Cytochrome P-450 CYP3A; Drug Interactions; Glucosides; Half-Life; Humans; Male; Microsomes, Liver; Monoterpenes; Rats; Rats, Sprague-Dawley
PubMed: 33721550
DOI: 10.1080/13880209.2021.1875013 -
Cell Jul 2018The seven-transmembrane-spanning protein Smoothened is the central transducer in Hedgehog signaling, a pathway fundamental in development and in cancer. Smoothened is...
The seven-transmembrane-spanning protein Smoothened is the central transducer in Hedgehog signaling, a pathway fundamental in development and in cancer. Smoothened is activated by cholesterol binding to its extracellular cysteine-rich domain (CRD). How this interaction leads to changes in the transmembrane domain and Smoothened activation is unknown. Here, we report crystal structures of sterol-activated Smoothened. The CRD undergoes a dramatic reorientation, allosterically causing the transmembrane domain to adopt a conformation similar to active G-protein-coupled receptors. We show that Smoothened contains a unique inhibitory π-cation lock, which is broken on activation and is disrupted in constitutively active oncogenic mutants. Smoothened activation opens a hydrophobic tunnel, suggesting a pathway for cholesterol movement from the inner membrane leaflet to the CRD. All Smoothened antagonists bind the transmembrane domain and block tunnel opening, but cyclopamine also binds the CRD, inducing the active transmembrane conformation. Together, these results define the mechanisms of Smoothened activation and inhibition.
Topics: Allosteric Regulation; Animals; Binding Sites; Cell Line; Cholesterol; Crystallography, X-Ray; Flow Cytometry; Hedgehog Proteins; Humans; Mice; Molecular Dynamics Simulation; Protein Binding; Protein Domains; Protein Structure, Tertiary; Signal Transduction; Small Molecule Libraries; Smoothened Receptor; Veratrum Alkaloids; Xenopus Proteins; Xenopus laevis
PubMed: 29804838
DOI: 10.1016/j.cell.2018.04.029 -
British Journal of Pharmacology Nov 2003The endocannabinoids N-arachidonylethanolamine (AEA or anandamide) and 2-arachidonylglycerol (2-AG) are hypothesized to function in the brain as interneuronal signaling... (Review)
Review
The endocannabinoids N-arachidonylethanolamine (AEA or anandamide) and 2-arachidonylglycerol (2-AG) are hypothesized to function in the brain as interneuronal signaling molecules. Prevailing models of the actions of these molecules require that they traverse cellular plasma membranes twice; first, following cellular synthesis and second, prior to enzymatic hydrolysis. The transmembrane movement of AEA has been studied in multiple laboratories with a primary focus on its cellular accumulation following extracellular administration. Although there are areas of consensus among laboratories regarding AEA accumulation, several aspects are very unclear. In particular, there is a lack of consensus in the literature regarding the importance of AEA hydrolysis by fatty acid amide hydrolase in maintaining the driving force for accumulation. Furthermore, evidence for and against a transmembrane carrier protein has been published. We have reviewed the available literature and present a working model of the processes that are involved in the cellular accumulation of AEA. It is our hypothesis that transmembrane movement of AEA is regulated by concentration gradient between extracellular and intracellular free AEA. Furthermore, it is our view that a significant portion of the intracellular AEA in most cells is sequestered either by a protein or lipid compartment and that AEA sequestered in this manner does not equilibrate directly with the extracellular pool. Finally, we discuss the available data that have been presented in support of a transmembrane carrier protein for AEA.
Topics: Animals; Arachidonic Acids; Biological Transport; Cell Membrane; Endocannabinoids; Humans; Polyunsaturated Alkamides; Veratridine
PubMed: 12970089
DOI: 10.1038/sj.bjp.0705468 -
Bioorganic & Medicinal Chemistry Aug 2016Veratrum californicum, commonly referred to as corn lily or Californian false hellebore, grows in high mountain meadows and produces the steroidal alkaloid cyclopamine,...
Veratrum californicum, commonly referred to as corn lily or Californian false hellebore, grows in high mountain meadows and produces the steroidal alkaloid cyclopamine, a potent inhibitor of the Hedgehog (Hh) signaling pathway. The Hh pathway is a crucial regulator of many fundamental processes during vertebrate embryonic development. However, constitutive activation of the Hh pathway contributes to the progression of various cancers. In the present study, a direct correlation was made between the extraction efficiency for cyclopamine from root and rhizome by eight methods, and the associated biological activity in Shh-Light II cells using the Dual-Glo® Luciferase Assay System. Alkaloid recovery ranged from 0.39 to 8.03mg/g, with ethanol soak being determined to be the superior method for obtaining biologically active cyclopamine. Acidic ethanol and supercritical extractions yielded degraded or contaminated cyclopamine with lower antagonistic activity towards Hh signaling.
Topics: Biomass; Cell Line; Chromatography, High Pressure Liquid; Hedgehog Proteins; Signal Transduction; Veratrum; Veratrum Alkaloids
PubMed: 27338657
DOI: 10.1016/j.bmc.2016.06.017 -
Proceedings of the National Academy of... Jan 2018Many ion channels, including Nav1.7, Cav1.3, and Kv1.3, are linked to human pathologies and are important therapeutic targets. To develop efficacious and safe drugs,...
Many ion channels, including Nav1.7, Cav1.3, and Kv1.3, are linked to human pathologies and are important therapeutic targets. To develop efficacious and safe drugs, subtype-selective modulation is essential, but has been extremely difficult to achieve. We postulate that this challenge is caused by the poor assay design, and investigate the Nav1.7 membrane potential assay, one of the most extensively employed screening assays in modern drug discovery. The assay uses veratridine to activate channels, and compounds are identified based on the inhibition of veratridine-evoked activities. We show that this assay is biased toward nonselective pore blockers and fails to detect the most potent, selective voltage-sensing domain 4 (VSD4) blockers, including PF-05089771 (PF-771) and GX-936. By eliminating a key binding site for pore blockers and replacing veratridine with a VSD-4 binding activator, we directed the assay toward non-pore-blocking mechanisms and discovered Nav1.7-selective chemical scaffolds. Hence, we address a major hurdle in Nav1.7 drug discovery, and this mechanistic approach to assay design is applicable to Cav3.1, Kv1.3, and many other ion channels to facilitate drug discovery.
Topics: Animals; Drug Discovery; High-Throughput Screening Assays; Humans; Insect Proteins; Membrane Potentials; Molecular Targeted Therapy; NAV1.7 Voltage-Gated Sodium Channel; Rats; Veratridine; Voltage-Gated Sodium Channel Blockers; Wasp Venoms
PubMed: 29311306
DOI: 10.1073/pnas.1713701115 -
International Journal of Molecular... Feb 2019The present study aimed to investigate the effects of astragaloside IV on osteoblast‑like cell proliferation and migration, in addition to the underlying signaling...
The present study aimed to investigate the effects of astragaloside IV on osteoblast‑like cell proliferation and migration, in addition to the underlying signaling pathway. In order to observe the effect on proliferation, a Cell Counting Kit‑8 assay and flow cytometry were used. To detect cell migration ability, cell scratch and Transwell cell migration assays were performed. The RNA and protein expression levels of hedgehog signaling molecules, including Sonic hedgehog (SHH) and GLI family zinc finger 1 (GLI1), were examined by reverse transcription‑quantitative polymerase chain reaction and western blot analyses. To inhibit the hedgehog signaling pathway, cyclopamine was used. Astragaloside IV, at a dosage of 1x10‑2 µg/ml in MG‑63 cells and 1x10‑3 µg/ml in U‑2OS cells, resulted in the enhanced proliferation and migration of cells, and the gene expression levels of the SHH and GLI1 were significantly increased. The combination of astragaloside IV and cyclopamine reduced MG‑63 and U‑2OS cell proliferation and migration, and inhibited the gene expression of SHH and GLI1. Astragaloside IV enhanced the proliferation and migration of human osteoblast‑like cells through activating the hedgehog signaling pathway. The results of the present study provide a rational for the mechanistic link in astragaloside IV promoting the proliferation and migration of osteoblasts via the hedgehog signaling pathway.
Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Drug Antagonism; Drugs, Chinese Herbal; Hedgehog Proteins; Humans; Molecular Targeted Therapy; Osseointegration; Osteoblasts; Osteogenesis; Saponins; Signal Transduction; Triterpenes; Veratrum Alkaloids; Zinc Finger Protein GLI1
PubMed: 30535481
DOI: 10.3892/ijmm.2018.4013 -
The Journal of Biological Chemistry 1945
Topics: Alkaloids; Veratrine; Veratrum; Veratrum Alkaloids
PubMed: 21004565
DOI: No ID Found -
Virus Research Jan 2024Porcine epidemic diarrhea (PED) is a contagious intestinal disease caused by α-coronavirus porcine epidemic diarrhea virus (PEDV). At present, no effective vaccine is...
Porcine epidemic diarrhea (PED) is a contagious intestinal disease caused by α-coronavirus porcine epidemic diarrhea virus (PEDV). At present, no effective vaccine is available to prevent the disease. Therefore, research for novel antivirals is important. This study aimed to identify the antiviral mechanism of Veratramine (VAM), which actively inhibits PEDV replication with a 50 % inhibitory concentration (IC) of ∼5 µM. Upon VAM treatment, both PEDV-nucleocapsid (N) protein level and virus titer decreased significantly. The time-of-addition assay results showed that VAM could inhibit PEDV replication by blocking viral entry. Importantly, VAM could inhibit PEDV-induced phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) activity and further suppress micropinocytosis, which is required for PEDV entry. In addition, PI3K inhibitor LY294002 showed anti-PEDV activity by blocking viral entry as well. Taken together, VAM possessed anti-PEDV properties against the entry stage of PEDV by inhibiting the macropinocytosis pathway by suppressing the PI3K/Akt pathway. VAM could be considered as a lead compound for the development of anti-PEDV drugs and may be used during the viral entry stage of PEDV infection.
Topics: Animals; Chlorocebus aethiops; Coronavirus Infections; Phosphatidylinositol 3-Kinases; Porcine epidemic diarrhea virus; Proto-Oncogene Proteins c-akt; Swine; Swine Diseases; Veratrum Alkaloids; Vero Cells; Virus Internalization
PubMed: 37923169
DOI: 10.1016/j.virusres.2023.199260 -
Cancer Biology & Therapy Jun 2006The hedgehog pathway regulates epithelial-mesenchymal interactions, differentiation, proliferation and survival during development. Stimulation of hedgehog signaling...
The hedgehog pathway regulates epithelial-mesenchymal interactions, differentiation, proliferation and survival during development. Stimulation of hedgehog signaling induces carcinogenesis or promotes cell survival in cancers of multiple organs. Using real-time, quantitative PCR, laser capture microdissection, and immunohistochemistry, distinctive patterns of expression of the hedgehog pathway members patched 1 (PTCH1), smoothened, GLI1, GLI2 and the 3 hedgehog ligands were identified for epithelial cells and stromal fibroblasts in benign breast and breast cancer. Hedgehog ligands were expressed at higher levels in some cancer epithelial cell lines compared to noncancerous epithelial cells. Correspondingly, expression of GLI1, a transcription factor and transcriptional product of hedgehog signaling, was increased 8-fold in cancer epithelial cell lines; however, PTCH1, also a transcriptional target of hedgehog signaling in many cell types, was not increased. GLI1 protein and mRNA, and PTCH1 and sonic hedgehog (SHH) proteins were elevated in 3 of 10 breast cancers; however, PTCH1 transcripts were not consistently increased. Hedgehog-mediated transcription, as indicated by a reporter of GLI-dependent promoter activity and by expression of GLI1 transcripts, was reduced by the hedgehog pathway inhibitor cyclopamine in both MDA-MB-435 cancer epithelial cells and MCF10AT epithelial cells, a cell line derived from benign breast. However, cyclopamine reduced viability of cancer epithelial cell lines, including MDA-MB-435, but did not specifically affect fibroblasts or epithelial cells from benign breast, including MCF10AT. Treatment with sonic hedgehog ligand diminished the cyclopamine-induced reduction in GLI-dependent promoter activity in MCF10AT and MDA-MB-435 and viability of MDA-MB-435. These results demonstrate modulation of GLI-mediated transcription in both cancer and benign-derived epithelial cells by cyclopamine and sonic hedgehog, and further suggest that hedgehog signaling contributes to the survival of only the cancer epithelial cells. Determination as to whether the increase in GLI1 and SHH expression in breast cancer indicates a significant increase in hedgehog signaling will require further evaluation.
Topics: Base Sequence; Breast; Breast Neoplasms; Cell Line, Tumor; DNA Primers; Epithelial Cells; Female; Fibroblasts; Hedgehog Proteins; Humans; RNA, Neoplasm; Stromal Cells; Veratrum Alkaloids
PubMed: 16855373
DOI: 10.4161/cbt.5.6.2906 -
Evidence-based Complementary and... 2014The eighteen incompatible medicaments is an important theory in traditional Chinese medicine. The theory suggests that drugs in the eighteen incompatible medicaments can...
The eighteen incompatible medicaments is an important theory in traditional Chinese medicine. The theory suggests that drugs in the eighteen incompatible medicaments can be toxic when used together. Veratrum nigrum L. and Radix paeoniae alba belong to the eighteen incompatible medicaments and have been prohibited for thousands of years. This study offers preliminary insight into the mechanism and chemical constituents responsible for the incompatibility and toxicity of these two agents. Specifically, we performed toxicology studies to identify and quantify the constituent substances of the two agents. Experiments revealed that acute toxicity increases when the dose of V. nigrum L. is higher than, or equal to, RPA. UPLC-TOF-MS analysis showed that, although the volumes of V. nigrum L. were the same, the content of some veratrum alkaloids changed significantly and had a trend toward a highly positive correlation (|r| ≥ 0.8) with toxicity. This suggests that the increased toxicity of the V. nigrum L. and RPA combination was due mainly to increased content of the special veratrum alkaloids. The cytotoxicity of veratridine in SH-SY5Y cells was decreased with increasing paeoniflorin concentrations. This study provides insight into the mechanism behind the incompatibility theory of TCM.
PubMed: 25024734
DOI: 10.1155/2014/892797