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Nature Aug 2015Activation of the μ-opioid receptor (μOR) is responsible for the efficacy of the most effective analgesics. To shed light on the structural basis for μOR activation,...
Activation of the μ-opioid receptor (μOR) is responsible for the efficacy of the most effective analgesics. To shed light on the structural basis for μOR activation, here we report a 2.1 Å X-ray crystal structure of the murine μOR bound to the morphinan agonist BU72 and a G protein mimetic camelid antibody fragment. The BU72-stabilized changes in the μOR binding pocket are subtle and differ from those observed for agonist-bound structures of the β2-adrenergic receptor (β2AR) and the M2 muscarinic receptor. Comparison with active β2AR reveals a common rearrangement in the packing of three conserved amino acids in the core of the μOR, and molecular dynamics simulations illustrate how the ligand-binding pocket is conformationally linked to this conserved triad. Additionally, an extensive polar network between the ligand-binding pocket and the cytoplasmic domains appears to play a similar role in signal propagation for all three G-protein-coupled receptors.
Topics: Allosteric Regulation; Animals; Binding Sites; Crystallography, X-Ray; Heterotrimeric GTP-Binding Proteins; Mice; Models, Molecular; Molecular Dynamics Simulation; Morphinans; Protein Stability; Protein Structure, Tertiary; Pyrroles; Receptor, Muscarinic M2; Receptors, Adrenergic, beta-2; Receptors, Opioid, mu; Single-Chain Antibodies; Structure-Activity Relationship
PubMed: 26245379
DOI: 10.1038/nature14886 -
Anaesthesia Jun 1983
Topics: Anti-Anxiety Agents; Buprenorphine; Drug Interactions; Humans; Lorazepam; Male; Middle Aged; Morphinans; Sleep Stages; Time Factors
PubMed: 6135366
DOI: 10.1111/j.1365-2044.1983.tb14083.x -
Molecules (Basel, Switzerland) Jun 2021Sinomenine is a morphinan alkaloid with a variety of biological activities. Its derivatives have shown significant cytotoxic activity against different cancer cell lines...
Sinomenine is a morphinan alkaloid with a variety of biological activities. Its derivatives have shown significant cytotoxic activity against different cancer cell lines in many studies. In this study, two series of sinomenine derivatives were designed and synthesized by modifying the active positions C and C on the A ring of sinomenine. Twenty-three compounds were synthesized and characterized by spectroscopy (IR, H-NMR, C-NMR, and HRMS). They were further evaluated for their cytotoxic activity against five cancer cell lines, MCF-7, Hela, HepG2, SW480 and A549, and a normal cell line, Hek293, using MTT and CCK8 methods. The chlorine-containing compounds exhibited significant cytotoxic activity compared to the nucleus structure of sinomenine. Furthermore, we searched for cancer-related core targets and verified their interaction with derivatives through molecular docking. The chlorine-containing compounds , , , , , , and exhibited the best against four core targets AKT1, EGFR, HARS and KARS. The molecular docking results were consistent with the cytotoxic results. Overall, results indicate that chlorine-containing derivatives might be a promising lead for the development of new anticancer agents.
Topics: A549 Cells; Antineoplastic Agents; Apoptosis; Cell Line; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Design; Drug Screening Assays, Antitumor; HEK293 Cells; HeLa Cells; Hep G2 Cells; Humans; MCF-7 Cells; Molecular Docking Simulation; Morphinans
PubMed: 34200341
DOI: 10.3390/molecules26113466 -
Cell Jan 2018The κ-opioid receptor (KOP) mediates the actions of opioids with hallucinogenic, dysphoric, and analgesic activities. The design of KOP analgesics devoid of...
The κ-opioid receptor (KOP) mediates the actions of opioids with hallucinogenic, dysphoric, and analgesic activities. The design of KOP analgesics devoid of hallucinatory and dysphoric effects has been hindered by an incomplete structural and mechanistic understanding of KOP agonist actions. Here, we provide a crystal structure of human KOP in complex with the potent epoxymorphinan opioid agonist MP1104 and an active-state-stabilizing nanobody. Comparisons between inactive- and active-state opioid receptor structures reveal substantial conformational changes in the binding pocket and intracellular and extracellular regions. Extensive structural analysis and experimental validation illuminate key residues that propagate larger-scale structural rearrangements and transducer binding that, collectively, elucidate the structural determinants of KOP pharmacology, function, and biased signaling. These molecular insights promise to accelerate the structure-guided design of safer and more effective κ-opioid receptor therapeutics.
Topics: Analgesics; Animals; Binding Sites; HEK293 Cells; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Morphinans; Protein Binding; Protein Stability; Receptors, Opioid, kappa; Sf9 Cells; Spodoptera
PubMed: 29307491
DOI: 10.1016/j.cell.2017.12.011 -
International Journal of Clinical... Oct 2015To characterize the absorption, distribution, metabolism, and excretion of naloxegol, a PEGylated derivative of the µ-opioid antagonist naloxone, in healthy male...
OBJECTIVE
To characterize the absorption, distribution, metabolism, and excretion of naloxegol, a PEGylated derivative of the µ-opioid antagonist naloxone, in healthy male subjects.
MATERIALS AND METHODS
[14C]-Labeled naloxegol (27 mg, 3.43 MBq) was administered as an oral solution to 6 fasted subjects. Blood, fecal, and urine samples were collected predose and at various intervals postdose. Naloxegol and its metabolites were quantified or identified by liquid chromatography with radiometric or mass spectrometric detection. Pharmacokinetic parameters were calculated for each subject, and metabolite identification was performed by liquid chromatography with parallel radioactivity measurement and mass spectrometry.
RESULTS
Naloxegol was rapidly absorbed, with a maximum plasma concentration (geometric mean) of 51 ng/mL reached before 2 hours after dosing. A second peak in the observed naloxegol and [14C] plasma concentration-time profiles was observed at ~3 hours and was likely due to enterohepatic recycling of parent naloxegol. Distribution to red blood cells was negligible. Metabolism of [14C]-naloxegol was rapid and extensive and occurred via demethylation and oxidation, dealkylation, and shortening of the polyethylene glycol chain. Mean cumulative recovery of radioactivity was 84.2% of the total dose, with ~68.9% recovered within 96 hours of dosing. Fecal excretion was the predominant route of elimination, with mean recoveries of total radioactivity in feces and urine of 67.7% and 16.0%, respectively. Unchanged naloxegol accounted for ~1/4 of the radioactivity recovered in feces.
CONCLUSIONS
Naloxegol was rapidly absorbed and cleared via metabolism, with predominantly fecal excretion of parent and metabolites.
Topics: Aged; Carbon Radioisotopes; Humans; Male; Middle Aged; Morphinans; Narcotic Antagonists; Polyethylene Glycols; Tissue Distribution
PubMed: 26329350
DOI: 10.5414/CP202276 -
International Journal of Nanomedicine 2021Transarterial chemoembolization is the preferred treatment for patients with middle and advanced-stage hepatocellular carcinoma (HCC); however, most hepatic artery...
PURPOSE
Transarterial chemoembolization is the preferred treatment for patients with middle and advanced-stage hepatocellular carcinoma (HCC); however, most hepatic artery embolization agents have various disadvantages. The purpose of this study was to evaluate phytantriol-based liquid crystal injections for potential use in treatment of HCC.
METHODS
Using sinomenine (SN) and 5-fluorouracil (5-FU) as model drugs, three precursor in situ liquid crystal injections based on phytantriol (P1, P2, and P3) were prepared, and their in vitro biocompatibility, anticancer activity, and drug release investigated, to evaluate their feasibility for use in treatment of HCC. The properties of the precursor injections and subsequent cubic liquid crystal gels were observed by visual and polarizing microscopy, in an in vitro gelation experiment. Biocompatibility was evaluated by in vitro hemolysis, histocompatibility, and cytotoxicity assays.
RESULTS
Precursor injections were colorless liquids that formed transparent cubic liquid crystal gels on addition of excess water. The three precursor injections all caused slight hemolysis, without agglutination, and were mildly cytotoxic. Histocompatibility experiments showed that P1 had good histocompatibility, while P2 and P3 resulted in strong inflammatory responses, which subsequently resolved spontaneously. In vitro anti-cancer testing showed that SN and 5-FU inhibited HepG2 cells in a time- and concentration-dependent manner and had synergistic effects. Further, in vitro release assays indicated that all three preparations had sustained release effects, with cumulative release of >80% within 48 h.
CONCLUSION
These results indicate that SN and 5-FU have synergistic inhibitory effects on HepG2 cells, which has not previously been reported. Moreover, we describe a biocompatible precursor injection, useful as a drug carrier for the treatment of liver cancer, which can achieve targeting, sustained release, synergistic chemotherapy, and embolization. These data indicate that precursor injections containing SN and 5-FU have great potential for use in therapy for liver cancer.
Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Death; Drug Carriers; Drug Liberation; Drug Synergism; Fatty Alcohols; Fluorouracil; Gels; Hemolysis; Hep G2 Cells; Humans; Injections; Liquid Crystals; Liver Neoplasms; Morphinans; Rats, Sprague-Dawley; Water; Rats
PubMed: 34103913
DOI: 10.2147/IJN.S207607 -
Neuropharmacology Mar 2021Effective treatments for chronic pain without abuse liability are urgently needed. One in 5 adults suffer chronic pain and half of these patients report inefficient...
Effective treatments for chronic pain without abuse liability are urgently needed. One in 5 adults suffer chronic pain and half of these patients report inefficient treatment. Mu opioid receptor agonists (MOP), including oxycodone, tramadol and morphine, are often prescribed to treat chronic pain, however, use of drugs targeting MOP can lead to drug dependency, tolerance and overdose deaths. Kappa opioid receptor (KOP) agonists have antinociceptive effects without abuse potential; however, they have not been utilised clinically due to dysphoria and sedation. We hypothesise that mixed opioid receptor agonists targeting the KOP and delta opioid receptor (DOP) would have a wider therapeutic index, with the rewarding effects of DOP negating the negative effects of KOP. MP1104, an analogue of 3-Iodobenzoyl naltrexamine, is a novel mixed opioid receptor agonist with potent antinociceptive effects mediated via KOP and DOP in mice without rewarding or aversive effects. In this study, we show MP1104 has potent, long-acting antinociceptive effects in the warm-water tail-withdrawal assay in male and female mice and rats; and is longer acting than morphine. In the paclitaxel-induced neuropathic pain model in mice, MP1104 reduced both mechanical and cold allodynia and unlike morphine, did not produce tolerance when administered daily for 23 days. Moreover, MP1104 did not induce sedative effects in the open-field locomotor activity test, respiratory depression in mice using whole-body plethysmography, or have cross-tolerance with morphine. This data supports the therapeutic development of mixed opioid receptor agonists, particularly mixed KOP/DOP agonists, as non-addictive pain medications with reduced tolerance.
Topics: Analgesics, Opioid; Animals; Antineoplastic Agents; Dose-Response Relationship, Drug; Female; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Morphinans; Neuralgia; Rats; Rats, Sprague-Dawley; Receptors, Opioid, delta; Receptors, Opioid, kappa
PubMed: 33383089
DOI: 10.1016/j.neuropharm.2020.108445 -
Molecular Medicine Reports Mar 2016Asthma is an inflammatory disease that involves airway inflammation and remodeling. Sinomenine (SIN) has been demonstrated to have immunosuppressive and...
Asthma is an inflammatory disease that involves airway inflammation and remodeling. Sinomenine (SIN) has been demonstrated to have immunosuppressive and anti‑inflammatory properties. The aim of the present study was to investigate the inhibitory effects of SIN on airway inflammation and remodeling in an asthma mouse model and observe the effects of SIN on the transforming growth factor‑β1 (TGF‑β1)/connective tissue growth factor (CTGF) pathway and oxidative stress. Female BALB/c mice were sensitized by repetitive ovalbumin (OVA) challenge for 6 weeks in order to develop a mouse model of asthma. OVA‑sensitized animals received SIN (25, 50 and 75 mg/kg) or dexamethasone (2 mg/kg). A blank control group received saline only. The area of smooth muscle and collagen, levels of mucus secretion and inflammatory cell infiltration were evaluated 24 h subsequent to the final OVA challenge. mRNA and protein levels of TGF‑β1 and CTGF were determined by reverse transcription‑quantitative polymerase chain reaction and immunohistology, respectively. The indicators of oxidative stress were detected by spectrophotometry. SIN significantly reduced allergen‑induced increases in smooth muscle thickness, mucous gland hypertrophy, goblet cell hyperplasia, collagen deposition and eosinophilic inflammation. The levels of TGF‑β1 and CTGF mRNA and protein were significantly reduced in the lungs of mice treated with SIN. Additionally, the total antioxidant capacity was increased in lungs following treatment with SIN. The malondialdehyde content and myeloperoxidase activities in the lungs from OVA‑sensitized mice were significantly inhibited by SIN. In conclusion, SIN may inhibit airway inflammation and remodeling in asthma mouse models, and may have therapeutic efficacy in the treatment of asthma.
Topics: Animals; Anti-Asthmatic Agents; Anti-Inflammatory Agents; Asthma; Connective Tissue Growth Factor; Dexamethasone; Drug Evaluation, Preclinical; Female; Lung; Mice, Inbred BALB C; Morphinans; Oxidative Stress
PubMed: 26820806
DOI: 10.3892/mmr.2016.4816 -
Acta Pharmacologica Sinica Jun 2022SLL-039 (N-cyclopropylmethyl-7α-4'-(N'-benzoyl) amino-phenyl-6,14-endoethano-tetrahydronorthebaine) and SLL-1206 (N-cyclopropylmethyl-7α-3'-(p-methoxybenzyl)...
SLL-039 (N-cyclopropylmethyl-7α-4'-(N'-benzoyl) amino-phenyl-6,14-endoethano-tetrahydronorthebaine) and SLL-1206 (N-cyclopropylmethyl-7α-3'-(p-methoxybenzyl) amino-phenyl-6,14-endoethano-tetrahydronorthebaine) are two 4,5-epoxymorphinan-based high selective κ receptor agonists that we recently discovered. In the present study we characterized their pharmacological properties in comparison with arylacetamide-based typical κ agonist U50,488H. We showed that both SLL-039 and SLL-1206 produced potent and long-lasting antinociceptive actions in three different rodent models of pain via activation of κ opioid receptor. In hot-plate assay, the antinociceptive potency of SLL-039 and SLL-1206 increased about 11-and 17.3-fold compared to U50,488H and morphine, respectively, with ED values of 0.4 mg/kg. Following repeated administration, SLL-1206, SLL-039, and U50,488H all developed analgesic tolerance tested in hot-plate assay. U50,488H and SLL-039 produced antipruritic effects in a dose-dependent manner, whereas SLL-1206 displayed some antipruritic effects only at very low doses. In addition, SLL-1206 was capable of decreasing morphine-induced physical dependence. More importantly, SLL-039 and SLL-1206 at effective analgesic doses did not cause sedation and conditioned place aversion (CPA), whereas U50,488H did. In comparison with SLL-039, SLL-1206 caused similar antinociceptive responses, but fewer sedation and CPA. In conclusion, our results suggest that SLL-039 and SLL-1206 have potential to be developed as novel analgesic agents, and 4,5-expoxymorphinan scaffold is an attractive structure for the development of selective κ agonists with fewer side effects.
Topics: 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; Analgesics; Antipruritics; Benzylamines; Morphinans; Morphine; Receptors, Opioid, kappa; Thebaine
PubMed: 34493813
DOI: 10.1038/s41401-021-00761-x -
Clinical Chemistry and Laboratory... Aug 2017Oxycodone is a narcotic drug widely used to alleviate moderate and severe acute and chronic pain. Variability in analgesic efficacy could be explained by inter-subject...
Determination of oxycodone and its major metabolites noroxycodone and oxymorphone by ultra-high-performance liquid chromatography tandem mass spectrometry in plasma and urine: application to real cases.
BACKGROUND
Oxycodone is a narcotic drug widely used to alleviate moderate and severe acute and chronic pain. Variability in analgesic efficacy could be explained by inter-subject variations in plasma concentrations of parent drug and its active metabolite, oxymorphone. To evaluate patient compliance and to set up therapeutic drug monitoring (TDM), an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay was developed and validated for the parent drug and its major metabolites noroxycodone and oxymorphone.
METHODS
Extraction of analytes from plasma and urine samples was obtained by simple liquid-liquid extraction. The chromatographic separation was achieved with a reversed phase column using a linear gradient elution with two solvents: acetic acid 1% in water and methanol. The separated analytes were detected with a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI).
RESULTS
Separation of analytes was obtained in less than 5 min. Linear calibration curves for all the analytes under investigation in urine and plasma samples showed determination coefficients (r2) equal or higher than 0.990. Mean absolute analytical recoveries were always above 86%. Intra- and inter-assay precision (measured as coefficient of variation, CV%) and accuracy (measured as % error) values were always better than 13%. Limit of detection at 0.06 and 0.15 ng/mL and limit of quantification at 0.2 and 0.5 ng/mL for plasma and urine samples, respectively, were adequate for the purpose of the present study.
CONCLUSIONS
Rapid extraction, identification and quantification of oxycodone and its metabolites both in urine and plasma by UHPLC-MS/MS assay was tested for its feasibility in clinical samples and provided excellent results for rapid and effective drug testing in patients under oxycodone treatment.
Topics: Aged; Aged, 80 and over; Chromatography, High Pressure Liquid; Female; Humans; Male; Middle Aged; Morphinans; Oxycodone; Oxymorphone; Tandem Mass Spectrometry
PubMed: 28080998
DOI: 10.1515/cclm-2016-0990