Insights in opiates toxicity: impairment of human vascular mesenchymal stromal cells.

The most common pulmonary findings in opiate-related fatalities are congestion and oedema, as well as acute and/or chronic alveolar haemorrhage, the cause of which is thought to be a damage to the capillary endothelium related to ischemia. Human vascular mesenchymal stromal cells (vMSCs) play a fundamental role in tissue regeneration and repair after endothelial cell injury, and they express opioid receptors. The aim of this study was to assess the effect of in vitro morphine exposure on the physiological activity and maintenance of human vMSCs. vMSCs were obtained from abdominal aorta fragments collected during surgery repair and were exposed to incremental doses (0.1 mM, 0.4 mM, 0.8 mM and 1 mM) of morphine sulphate for 7 days. The effect was investigated through cell viability assessment, proliferation assay, reactive oxygen species (ROS) detection assay, senescence-associated ß-galactosidase assay, senescent-related markers (p21WAF1/CIP1 and p16INK4) and the apoptosis-related marker caspase 3. Moreover, an ultrastructural analysis by transmission electron microscopy and in vitro vascular differentiation were evaluated. Results showed a decrease of the cellular metabolic activity, a pro-oxidant and pro-senescence effect, an increase in intracellular ROS and the activation of the apoptosis signalling, as well as ultrastructural modifications and impairment of vascular differentiation after morphine treatment of vMSC. Although confirmation studies are required on real fatal opiate intoxications, the approach based on morphological and immunofluorescence methodologies may have a high potential also as a useful tool or as a complementary method in forensic pathology. The application of these techniques in the future may lead to the identification of new markers and morphological parameters useful as complementary investigations for drug-related deaths.

Alvimopan retains efficacy in patients undergoing colorectal surgery within an established ERAS program.

BACKGROUND: Post-operative ileus and delayed return of gastrointestinal function are complications seen frequently in patients undergoing colorectal surgery. Many enhanced recovery after surgery protocols include alvimopan to inhibit the effects of opiates in the gastrointestinal tract and lidocaine to augment analgesics. Limited data exist regarding alvimopan's efficacy in opiate-sparing regimens. METHODS: This single-center, retrospective cohort analysis was conducted in a randomly selected population of adult patients undergoing colorectal resection between February 2018 and October 2019. Patients meeting inclusion criteria were divided into four groups dependent upon whether or not they received alvimopan (A or a) and/or lidocaine (L or l). The primary endpoint in this study was median time to first bowel movement or discharge, whichever came first. Our secondary endpoint was length of stay. RESULTS: Of the 430 patients evaluated, a total of 192 patients were included in the final evaluation in the following groups: AL (n = 93), Al (n = 34), aL (n = 44), and al (n = 21). A significant difference was found among the groups for the primary outcome of median time to bowel movement or discharge (p = 0.001). Three subsequent pair-wise comparisons resulted in a significant difference in the primary outcome: group AL 39.4 h vs. group aL 54.0 h (p = 0.003), group AL 39.4 h vs. group al 55.4 h (p = 0.001), and group Al 44.9 h vs. group al 55.4 h (p = 0.01). Length of stay was significantly reduced by 1.8 days in groups AL and Al compared to group aL (p < 0.001). CONCLUSION: Treatment with alvimopan resulted in a significant improvement in time to GI recovery and decreased length of stay in an established ERAS program. While lidocaine's reduction in opiates was minimal, the group receiving both alvimopan and lidocaine had the greatest reduction in time to GI recovery and length of stay.

Pharmacologic Profile of Naloxegol, a Peripherally Acting µ-Opioid Receptor Antagonist, for the Treatment of Opioid-Induced Constipation.

Opioid-induced constipation (OIC) is a common side effect of opioid pharmacotherapy for the management of pain because opioid agonists bind to µ-opioid receptors in the enteric nervous system (ENS). Naloxegol, a polyethylene glycol derivative of naloxol, which is a derivative of naloxone and a peripherally acting µ-opioid receptor antagonist, targets the physiologic mechanisms that cause OIC. Pharmacologic measures of opioid activity and pharmacokinetic measures of central nervous system (CNS) penetration were employed to characterize the mechanism of action of naloxegol. At the human µ-opioid receptor in vitro, naloxegol was a potent inhibitor of binding (Ki = 7.42 nM) and a neutral competitive antagonist (pA2 - 7.95); agonist effects were <10% up to 30 µM and identical to those of naloxone. The oral doses achieving 50% of the maximal effect in the rat for antagonism of morphine-induced inhibition of gastrointestinal transit and morphine-induced antinociception in the hot plate assay were 23.1 and 55.4 mg/kg for naloxegol and 0.69 and 1.14 mg/kg by for naloxone, respectively. In the human colon adenocarcinoma cell transport assay, naloxegol was a substrate for the P-glycoprotein transporter, with low apparent permeability in the apical to basolateral direction, and penetrated the CNS 15-fold slower than naloxone in a rat brain perfusion model. Naloxegol-derived radioactivity was poorly distributed throughout the rat CNS and was eliminated from most tissues within 24 hours. These findings corroborate phase 3 clinical studies demonstrating that naloxegol relieves OIC-associated symptoms in patients with chronic noncancer pain by antagonizing the µ-opioid receptor in the ENS while preserving CNS-mediated analgesia.

Opiate receptor blockade on human granulosa cells inhibits VEGF release.

The objectives of this study were to determine whether the main opioid receptor (OPRM1) is present on human granulosa cells and if exogenous opiates and their antagonists can influence granulosa cell vascular endothelial growth factor (VEGF) production via OPRM1. Granulosa cells were isolated from women undergoing oocyte retrieval for IVF. Complementary to the primary cells, experiments were conducted using COV434, a well-characterized human granulosa cell line. Identification and localization of opiate receptor subtypes was carried out using Western blot and flow cytometry. The effect of opiate antagonist on granulosa cell VEGF secretion was assessed by enzyme-linked immunosorbent assay. For the first time, the presence of OPRM1 on human granulosa cells is reported. Blocking of opiate signalling using naloxone, a specific OPRM1 antagonist, significantly reduced granulosa cell-derived VEGF levels in both COV434 and granulosa-luteal cells (P < 0.01). The presence of opiate receptors and opiate signalling in granulosa cells suggest a possible role in VEGF production. Targeting this signalling pathway could prove promising as a new clinical option in the prevention and treatment of ovarian hyperstimulation syndrome.

Effects of drugs of abuse on the central neuropeptide Y system.

Neuropeptide Y (NPY), which is widely expressed in the central nervous system is involved in several neuropathologies including addiction. Here we comprehensively and systematically review alterations on the central NPY system induced by several drugs. We report on the effects of psychostimulants [cocaine, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and nicotine], ethanol, and opioids on NPY protein levels and expression of different NPY receptors. Overall, expression and function of NPY and its receptors are changed under conditions of drug exposure, thus affecting several physiologic behaviors, such as feeding, stress and anxiety. Drugs of abuse differentially affect the components of the NPY system. For example methamphetamine and nicotine lead to a consistent increase in NPY mRNA and protein levels in different brain sites whereas ethanol and opioids decrease NPY mRNA and protein expression. Drug-induced alterations on the different NPY receptors show more complex regulation pattern. Manipulation of the NPY system can have opposing effects on reinforcing and addictive properties of drugs of abuse. NPY can produce pro-addictive effects (nicotine and heroin), but can also exert inhibitory effects on addictive behavior (AMPH, ethanol). Furthermore, NPY can act as a neuroprotective agent in chronically methamphetamine and MDMA-treated rodents. In conclusion, manipulation of the NPY system seems to be a potential target to counteract neural alterations, addiction-related behaviors and cognitive deficits induced by these drugs.

Non-addictive opium alkaloids selectively induce apoptosis in cancer cells compared to normal cells.

BACKGROUND: Cytotoxic effects of some of the members of papaveraceae family have been reported in Iranian folk medicine. Recent reports has indicated that alkaloids fraction of opium may be responsible for its cytotoxic effect; however, the mechanism of this effect is not fully understood. This study has been designed to investigate the selective cytotoxic, genotoxic and also apoptosis induction effects of noscapine, papaverine and narceine, three non-addictable opium alkaloids, on HT29, T47D and HT1080 cancer cell lines. Mouse NIH3T3 cell line was chosen to present non-cancerous cells and Doxorubicin was selected as the positive control. METHODS: Cells were treated by different concentrations of Noscapine, Papaverine, Narceine and doxorubicin; viability was assessed by MTT assay. The genotoxicity and apoptosis induction were tested with comet assay and Annexin-V affinity when the concentration of each these drugs is less than its IC50. In addition, the DNA damage and caspase activity of the T47D cells were examined and the results were compared. RESULTS: This study noted the cytotoxicity and genotoxicity of noscapine and papaverine, specifically on cancerous cell lines. Furthermore, papaverine induces apoptosis in all studied cancer cell lines and noscapine showed this effect in T47D and HT29 cells but not in NIH-3 T3 cells as noncancerous cell line. narceine also showed genototoxicity in the studied cell lines at its IC50 concentration. CONCLUSIONS: This experiment suggests that noscapine and papaverine may be of use in cancer treatment due to their specific cytotoxicity and genotoxicity. However, further in vivo studies are needed to confirm its usefulness in cancer treatment.

The effects of opioids and opioid analogs on animal and human endocrine systems.

Opioid abuse has increased in the last decade, primarily as a result of increased access to prescription opioids. Physicians are also increasingly administering opioid analgesics for noncancer chronic pain. Thus, knowledge of the long-term consequences of opioid use/abuse has important implications for fully evaluating the clinical usefulness of opioid medications. Many studies have examined the effect of opioids on the endocrine system; however, a systematic review of the endocrine actions of opioids in both humans and animals has, to our knowledge, not been published since 1984. Thus, we reviewed the literature on the effect of opioids on the endocrine system. We included both acute and chronic effects of opioids, with the majority of the studies done on the acute effects although chronic effects are more physiologically relevant. In humans and laboratory animals, opioids generally increase GH and prolactin and decrease LH, testosterone, estradiol, and oxytocin. In humans, opioids increase TSH, whereas in rodents, TSH is decreased. In both rodents and humans, the reports of effects of opioids on arginine vasopressin and ACTH are conflicting. Opioids act preferentially at different receptor sites leading to stimulatory or inhibitory effects on hormone release. Increasing opioid abuse primarily leads to hypogonadism but may also affect the secretion of other pituitary hormones. The potential consequences of hypogonadism include decreased libido and erectile dysfunction in men, oligomenorrhea or amenorrhea in women, and bone loss or infertility in both sexes. Opioids may increase or decrease food intake, depending on the type of opioid and the duration of action. Additionally, opioids may act through the sympathetic nervous system to cause hyperglycemia and impaired insulin secretion. In this review, recent information regarding endocrine disorders among opioid abusers is presented.

Challenging small human hepatocytes with opiates: further characterization of a novel prototype bioartificial liver.

Bioartificial liver (BAL) systems can take over liver functions in patients undergoing liver failure until transplantation. Recently, a novel prototype rotary BAL has been developed using small human hepatocytes (SH). This study investigated the metabolism of opiates morphine and methadone in the BAL and their influence on the basic cell culture parameters, viability, and growth of SH. Opiates may be present in patients due to pain therapy, anticancer treatment, or drug abuse. Cells were cultivated in the BAL for a total of 12 days and exposed twice to 100 microg/L of morphine or methadone. Morphine and methadone concentrations were analyzed using gas chromatography with a mass spectrometry detector. Further, the production of albumin, lactate dehydrogenase release, lactate release, urea production, and glucose consumption were measured. Cell viability and growth were determined by confocal microscopy. Cytochrome P 3A4 and uridindiphosphat (UDP) glucuronosyl transferase 2B7 in SH were analyzed by western blot. The mean cell density during treatment was 5.5 +/- 0.7 x 10(6) cells/mL (n = 6) and was not altered significantly by the opiates. Cell viability stayed above 90%. Morphine was not reduced by SH and was a stress factor as determined by decreased metabolic activity. On the other hand, SH metabolized methadone showing first-order kinetics: the first-order rate constant k = 0,019, half-life t(1/2) = 36 h. Methadone metabolism led to decreased urea and albumin production. The expression of cytochrome P 3A4, mainly responsible for methadone metabolism, was proved in SH. The prototype BAL is basically suited to support liver functions, provided patients receive therapy with methadone.