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  1. Fulltext Methanolic Extract of Clinacanthus nutans Exerts Antinociceptive Activity via the Opioid/Nitric Oxide-Mediated, but cGMP-Independent, Pathways
    Abdul Rahim MH, Zakaria ZA, Mohd Sani MH, Omar MH, Yakob Y, Cheema MS, et al.
    Evid Based Complement Alternat Med, 2016;2016:1494981.
    PMID: 27190528 DOI: 10.1155/2016/1494981
    The objectives of the present study were to determine the mechanisms of antinociceptive effect of methanol extract of Clinacanthus nutans (Acanthaceae) leaves (MECN) using various animal nociceptive models. The antinociceptive activity of orally administered 10% DMSO, 100 mg/kg acetylsalicylic acid (ASA), 5 mg/kg morphine, or MECN (100, 250, and 500 mg/kg) was determined using the acetic acid-induced abdominal constriction (ACT), formalin-induced paw licking (FT), and hot plate tests (HPT). The role of opioid and nitric oxide/cyclic guanosine monophosphate (NO/cGMP) systems was also investigated. The results showed that MECN produced a significant (p < 0.05) antinociceptive response in all nociceptive models with the recorded ED50 value of 279.3 mg/kg for the ACT, while, for the early and late phases of the FT, the value was >500 mg/kg or 227.7 mg/kg, respectively. This antinociceptive activity was fully antagonized by naloxone (a nonselective opioid antagonist) but was partially reversed by l-arginine (l-arg; a nitric oxide [NO] precursor), Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME; an NO synthase inhibitor), or their combinations thereof. In contrast, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ; a soluble guanylyl cyclase inhibitor) enhanced the extract's antinociception. UHPLC analysis revealed the presence of several flavonoid-based compounds with antinociceptive action. In conclusion, MECN exerted the peripherally and centrally mediated antinociceptive activity via the modulation of the opioid/NO-mediated, but cGMP-independent, systems.
    Matched MeSH terms: Naloxone
  2. Fulltext Lack of reduction in buprenorphine injection after introduction of co-formulated buprenorphine/naloxone to the Malaysian market
    Bruce RD, Govindasamy S, Sylla L, Kamarulzaman A, Altice FL
    Am J Drug Alcohol Abuse, 2009;35(2):68-72.
    PMID: 19212931 DOI: 10.1080/00952990802585406
    Diversion of buprenorphine (BPN) has been described in settings where it is legally prescribed and has resulted in increasing concern. To address this concern, co-formulation of buprenorphine/naloxone (BPN/NLX) replaced buprenorphine alone in Malaysia in December 2006.
    Matched MeSH terms: Buprenorphine, Naloxone Drug Combination; Naloxone/administration & dosage; Naloxone/adverse effects*
  3. Fulltext Antinociceptive action of isolated mitragynine from Mitragyna Speciosa through activation of opioid receptor system
    Shamima AR, Fakurazi S, Hidayat MT, Hairuszah I, Moklas MA, Arulselvan P
    Int J Mol Sci, 2012;13(9):11427-42.
    PMID: 23109863 DOI: 10.3390/ijms130911427
    Cannabinoids and opioids systems share numerous pharmacological properties and antinociception is one of them. Previous findings have shown that mitragynine (MG), a major indole alkaloid found in Mitragyna speciosa (MS) can exert its antinociceptive effects through the opioids system. In the present study, the action of MG was investigated as the antinociceptive agent acting on Cannabinoid receptor type 1 (CB1) and effects on the opioids receptor. The latency time was recorded until the mice showed pain responses such as shaking, licking or jumping and the duration of latency was measured for 2 h at every 15 min interval by hot plate analysis. To investigate the beneficial effects of MG as antinociceptive agent, it was administered intraperitoneally 15 min prior to pain induction with a single dosage (3, 10, 15, 30, and 35 mg/kg b.wt). In this investigation, 35 mg/kg of MG showed significant increase in the latency time and this dosage was used in the antagonist receptor study. The treated groups were administered with AM251 (cannabinoid receptor-1 antagonist), naloxone (non-selective opioid antagonist), naltrindole (δ-opioid antagonist) naloxonazine (μ(1)-receptor antagonist) and norbinaltorpimine (κ-opioid antagonist) respectively, prior to administration of MG (35 mg/kg). The results showed that the antinociceptive effect of MG was not antagonized by AM251; naloxone and naltrindole were effectively blocked; and norbinaltorpimine partially blocked the antinociceptive effect of MG. Naloxonazine did inhibit the effect of MG, but it was not statistically significant. These results demonstrate that CB1 does not directly have a role in the antinociceptive action of MG where the effect was observed with the activation of opioid receptor.
    Matched MeSH terms: Naloxone/analogs & derivatives; Naloxone/pharmacology
  4. Impact of capillary flow hydrodynamics on carrier-mediated transport of opioid derivatives at the blood-brain barrier, based on pH-dependent Michaelis-Menten and Crone-Renkin analyses
    Yusof SR, Abbott NJ, Avdeef A
    Eur J Pharm Sci, 2017 Aug 30;106:274-286.
    PMID: 28614733 DOI: 10.1016/j.ejps.2017.06.016
    Most studies of blood-brain barrier (BBB) permeability and transport are conducted at a single pH, but more detailed information can be revealed by using multiple pH values. A pH-dependent biophysical model was applied to the mechanistic analysis of published pH-dependent BBB luminal uptake data from three opioid derivatives in rat: pentazocine (Suzuki et al., 2002a, 2002b), naloxone (Suzuki et al., 2010a), and oxycodone (Okura et al., 2008). Two types of data were processed: in situ brain perfusion (ISBP) and brain uptake index (BUI). The published perfusion data were converted to apparent luminal permeability values, Papp, and analyzed by the pCEL-X program (Yusof et al., 2014), using the pH-dependent Crone-Renkin equation (pH-CRE) to determine the impact of cerebrovascular flow on the Michaelis-Menten transport parameters (Avdeef and Sun, 2011). For oxycodone, the ISBP data had been measured at pH7.4 and 8.4. The present analysis indicates a 7-fold lower value of the cerebrovascular flow velocity, Fpf, than that expected in the original study. From the pyrilamine-inhibited data, the flow-corrected passive intrinsic permeability value was determined to be P0=398×10-6cm·s-1. The uptake data indicate that the neutral form of oxycodone is affected by a transporter at pH8.4. The extent of the cation uptake was less certain from the available data. For pentazocine, the brain uptake by the BUI method had been measured at pH5.5, 6.5, and 7.4, in a concentration range 0.1-40mM. Under similar conditions, ISBP data were also available. The pH-CRE determined values of Fpf from both methods were nearly the same, and were smaller than the expected value in the original publication. The transport of the cationic pentazocine was not fully saturated at pH5.5 at 40mM. The transport of the neutral species at pH7.4 appeared to reach saturation at 40mM pentazocine concentration, but not at 12mM. In the case of naloxone, a pH-dependent Michaelis-Menten equation (pH-MME) analysis of the data indicated a smooth sigmoidal transition from a higher capacity uptake process affecting cationic naloxone (pH5.0-7.0) to a lower capacity uptake process affecting the neutral drug (pH8.0-8.5), with cross-over point near pH7.4. Evidently, measurements at multiple pH values can reveal important information about both cerebrovascular flow and BBB transport kinetics.
    Matched MeSH terms: Naloxone/pharmacokinetics*
  5. Injection of buprenorphine and buprenorphine/naloxone tablets in Malaysia
    Vicknasingam B, Mazlan M, Schottenfeld RS, Chawarski MC
    Drug Alcohol Depend, 2010 Sep 1;111(1-2):44-9.
    PMID: 20478668 DOI: 10.1016/j.drugalcdep.2010.03.014
    Buprenorphine maintenance is efficacious for treating opioid dependence, but problems with diversion and misuse of buprenorphine (BUP) may limit its acceptability and dissemination. The buprenorphine/naloxone combination tablet (BNX) was developed to reduce potential problems with diversion and abuse. This paper provides data regarding the characteristics of BUP injection drug users in Malaysia and preliminary data regarding the impact of withdrawing BUP and introducing BNX. BUP was introduced in 2002 and subsequently withdrawn from the Malaysian market in 2006. BNX was introduced in 2007.
    Matched MeSH terms: Naloxone/administration & dosage*
  6. Buprenorphine/naloxone treatment practices in Malaysia: Results of national surveys of physicians and patients
    Vicknasingam B, Dazali MN, Singh D, Schottenfeld RS, Chawarski MC
    Drug Alcohol Depend, 2015 Jul 1;152:164-9.
    PMID: 25935736 DOI: 10.1016/j.drugalcdep.2015.04.007
    Medication assisted treatment with buprenorphine/naloxone (Bup/Nx), including prescribing and dispensing practices of general practitioners (GPs) in Malaysia and their patients' experiences with this treatment have not been systematically examined. The current study surveyed GPs providing Bup/Nx treatment and patients receiving office-based Bup/Nx treatment in Malaysia.
    Matched MeSH terms: Buprenorphine, Naloxone Drug Combination/therapeutic use*
  7. Fulltext Data on the mechanisms of antidiarrhoeal activity of methanol leaf extract of Combretum hypopilinum Diels (Combretaceae): Involvement of opioidergic and (α1 and β)-adrenergic pathways
    Ahmad MH, Zezi AU, Anafi SB, Alhassan Z, Mohammed M, Danraka RN
    Data Brief, 2021 Jun;36:107155.
    PMID: 34041327 DOI: 10.1016/j.dib.2021.107155
    This article describes the dataset for the elucidation of the possible mechanisms of antidiarrhoeal actions of methanol leaves extract of Combretum hypopilinum (Diels) Combretaceae in mice. The plant has been used in traditional medicine to treat diarrhoea in Nigeria and other African countries. We introduce the data for the antidiarrhoeal activity of the methanol leaf extract of Combretum hypopilinum at 1,000 mg/kg investigated using charcoal meal test in mice with loperamide (5 mg/kg) as the standard antidiarrhoeal agent. To elucidate the possible mechanisms of its antidiarrhoeal action, naloxone (2 mg/kg), prazosin (1 mg/kg), yohimbine (2 mg/kg), propranolol (1 mg/kg), pilocarpine (1 mg/kg) and isosorbide dinitrate (150 mg/kg) were separately administered to different groups of mice 30 minutes before administration of the extract. Each mouse was dissected using dissecting set, and the small intestine was immediately removed from pylorus to caecum, placed lengthwise on moist filter paper and measured the distance travelled by charcoal relative to the length of the intestine using a calibrated ruler in centimetre. Besides, the peristaltic index and inhibition of charcoal movement of each animal were calculated and recorded. The methods for the data collection is similar to the one used to investigate the possible pathways involved in the antidiarrhoeal action of Combretum hypopilinum in mice in the research article by Ahmad et al. (2020) "Mechanisms of Antidiarrhoeal Activity of Methanol Leaf Extract of Combretum hypopilinum Diels (Combretaceae): Involvement of Opioidergic and (α1 and β)-Adrenergic Pathways" (https://doi.org/10.1016/j.jep.2020.113750) [1]. Therefore, this datasets could form a basis for in-depth research to elucidate further the pharmacological properties of the plant Combretum hypopilinum and its bioactive compounds to develop standardized herbal product and novel compound for management of diarrhoea. It could also be instrumental for evaluating the plant's pharmacological potentials using other computational-based and artificial intelligence approaches, including predictive modelling and simulation.
    Matched MeSH terms: Naloxone
  8. Fulltext Boesenbergia rotunda ethanolic extract inhibits compound action potentials via opioid receptors
    Gopalsamy, Banulata, Chia, Jasmine Siew Min, Farihah Hanani Ghazali, Ammar Izzati Amir Ramadan, Wong, Siong Jun, Ahmad Akira Omar Farouk, et al.
    Life Sciences, Medicine and Biomedicine, 2018;2(2):7-12.
    MyJurnal
    Boesenbergia rotunda, traditionally used to relieve stomach, abdomen, joint, muscle, and rheumatic pain was also reported for its antinociceptive effect on a mouse model. However, the possible pain relief effect of Boesenbergia rotunda ethanolic extract (BREE) via the inhibition to the neural pain pathway remains to be elucidated. This study investigated the inhibitory effect of BREE on compound action potentials (CAPs) and the possible involvement of the opioid receptors. The changes in the CAPs amplitudes of the frog’s sciatic nerves were evaluated following the exposure to three different dosages of BREE (1, 3 and 10 mg/ml and morphine (3 mg/ml). In another set of experiment, the nerves were pretreated with a non-selective opioid receptor antagonist, naloxone (0.1 mg/ml), before exposing the nerve to BREE (1 mg/ml) to investigate the involvement of opioid receptors in the CAPs inhibitory mechanism. The outcome showed a reduction in the CAPs amplitudes when treated with BREE (1, 3 and 10 mg/ml) whereby the effect was reversible. The CAPs inhibition by BREE was absent when the opioid receptors were blocked. Taken together, these findings suggest that BREE-induced CAPs amplitude reduction involves the activation of opioid receptors.
    Matched MeSH terms: Naloxone
  9. Fulltext Central Antinociceptive and Mechanism of Action of Pereskia bleo Kunth Leaves Crude Extract, Fractions, and Isolated Compounds
    Guilhon CC, Abdul Wahab IR, Boylan F, Fernandes PD
    Evid Based Complement Alternat Med, 2015;2015:915927.
    PMID: 26273315 DOI: 10.1155/2015/915927
    Pereskia bleo (Kunth) DC. (Cactaceae) is a plant commonly used in popular medicine in Malaysia. In this work, we evaluate the antinociceptive effect of P. bleo leaf extracts and isolated compounds in central antinociceptive model. Ethanol extract (E), hexane (H), ethyl acetate (EA), or butanol (B) fractions (30, 50, or 100 mg/kg, p.o.), sitosterol (from hexane) and vitexin (from ethyl acetate), were administered to mice. Antinociceptive effect was evaluated in the hot plate and capsaicin- or glutamate-induced licking models. Morphine (1 mg/kg, p.o.) was used as reference drug. Naloxone (1 mg/kg, i.p.), atropine (1 mg/kg, i.p.), and L-nitro arginine methyl ester (L-NAME, 3 mg/kg, i.p.) were administered 30 min earlier (100 mg/kg, p.o.) in order to evaluate the mechanism of the antinociceptive action. Higher dose of B developed an effect significantly superior to morphine-treated group. Naloxone prevented the antinociceptive effect of all fractions. L-NAME demonstrated effect against E, EA, and B. In all fractions, sitosterol and vitexin reduced the licking time after capsaicin injection. Glutamate-induced licking response was blocked by H, EA, and B. Our results indicate that Pereskia bleo fractions, sitosterol and vitexin, possessed a central antinociceptive effect. Part of this effect is mediated by opioid receptors and nitrergic pathway.
    Matched MeSH terms: Naloxone
  10. Outcomes from the Malaysian Arm of The International Survey Informing Greater Insights in Opioid Dependence Treatment (INSIGHT) Project
    George P
    Med J Malaysia, 2015 Apr;70(2):117-24.
    PMID: 26162395 MyJurnal
    BACKGROUND: Opioid dependence (OD) is a chronic, relapsing condition representing a significant societal burden in Asia. Opioid maintenance treatment (OMT) in combination with psychosocial treatment is considered to be the most effective strategy to treat opioid dependence. In Malaysia, about 52,000 patients reported receiving OMT in December 2012.

    OBJECTIVE: The International Survey Informing Greater Insights in Opioid Dependence Treatment (INSIGHT) project aimed to assess aspects of OMT access and quality of care by surveying patients and users with opioid dependence, and healthcare professionals treating opioid-dependent patients.

    MATERIALS AND METHODS: Using a structured questionnaire, 50 patients who were currently receiving OMT (or had received OMT in the past 3 months) and 77 physicians were surveyed in Malaysia regarding the provision and quality of OMT.

    RESULTS: Patients were predominately male and in their thirties. Nearly all patients (98%) reported currently receiving methadone liquid; almost half (48%) reported ever having received psychosocial counselling and only 14% had ever received buprenorphine-naloxone in the past. Most physicians reported they were treating their patients with OMT (77% on methadone and 15% on buprenorphine-naloxone), and 3% used psychosocial counselling alone. Although methadone maintenance doses were close to levels recommended by WHO guidelines, induction doses of methadone, and both induction and maintenance doses of buprenorphine were well below these levels in Malaysia.

    CONCLUSIONS: The findings suggest that OMT implementation in Malaysia can be improved by providing patients with more education on treatment options, better access to available treatments, including abuse-deterrent formulations, and psychosocial support.

    Matched MeSH terms: Buprenorphine, Naloxone Drug Combination
  11. Antinociceptive activity of a synthetic oxopyrrolidine-based compound, ASH21374, and determination of its possible mechanisms
    Zakaria ZA, Sani MH, Mohammat MF, Mansor NS, Shaameri Z, Kek TL, et al.
    Can J Physiol Pharmacol, 2013 Dec;91(12):1143-53.
    PMID: 24289087 DOI: 10.1139/cjpp-2013-0099
    This study was carried out to determine the antinociceptive activity of a novel synthetic oxopyrrolidine-based compound, (2R,3R,4S)-ethyl 4-hydroxy-1,2-dimethyl-5-oxopyrrolidine-3-carboxylate (ASH21374), and to elucidate the involvement of the opioid, vanilloid, glutamate, and nitric oxide - cyclic guanosine monophosphate (NO/cGMP) systems in modulating the observed antinociception. ASH21374, in the doses of 2, 10, and 100 mg/kg body mass, was administered orally to mice 60 mins prior to exposure to various antinociceptive assays. From the results obtained, ASH21374 exhibited significant (P < 0.05) antinociceptive activity in the abdominal constriction, hot-plate, and formalin tests that was comparable with 100 mg/kg acetylsalicylic acid or 5 mg/kg morphine, respectively. ASH21374 also attenuated capsaicin- and glutamate-induced paw licking. Pre-treatment with 5 mg/kg naloxone significantly (P < 0.05) inhibited the activity in all assays, while pretreatment with 10 mg/kg β-funaltraxamine, 1 mg/kg naltrindole, or 1 mg/kg nor-binaltorphimine significantly (P < 0.05) reversed the activity in the abdominal constriction test. l-Arginine, N(G)-nitro-l-arginine methyl esters (l-NAME), methylene blue, and their combinations, failed to inhibit the ASH21374 antinociceptive activity. In conclusion, ASH21374 demonstrated antinociceptive activities on the peripheral and central nervous systems, mediated through the activation of opioid receptors, inhibition of the glutamatergic system, and attenuation of vanilloid-mediated nociceptive transmission. Further studies have been planned to determine the pharmacological potential of ASH21374.
    Matched MeSH terms: Naloxone/pharmacology
  12. Opioid receptors mediate the acquisition, but not the expression of mitragynine-induced conditioned place preference in rats
    Yusoff NHM, Mansor SM, Müller CP, Hassan Z
    Behav Brain Res, 2017 08 14;332:1-6.
    PMID: 28559179 DOI: 10.1016/j.bbr.2017.05.059
    Mitragynine is the main psychoactive ingredient of the herbal drug preparation Kratom (Ketum), derived from the plant Mitragyna speciosa. Kratom is a widely abused drug in Southeast Asian and has a psychostimulant profile at low-medium doses, while high doses have opioidergic effects. Mitragynine was shown to possess opiate receptor affinity. However, its role in the behavioural effects of mitragynine is unclear. Here we asked whether the reinforcing effects of mitragynine are mediated by opiate receptors using a conditioned place preference (CPP) paradigm in rats. In the first experiment we tested the effects of the opiate receptor antagonist naloxone (0.1, 0.3 and 1.0mg/kg) on the acquisition of mitragynine (10mg/kg)-induced CPP. In the second experiment, we tested the involvement of opiate receptors in the expression of mitragynine-induced CPP in rats. We found that naloxone suppresses the acquisition of mitragynine-induced CPP. This effect was already evident at a dose of naloxone (0.1mg/kg) which, by itself, had no conditioned place aversion (CPA) effect. Higher doses of naloxone induced a CPA and blocked mitragynine-induced CPP. In contrast, naloxone had no effect on the expression of mitragynine-induced CPP. These findings suggest that the acquisition, but not the expression of the reinforcing effects of mitragynine is mediated by opiate receptors.
    Matched MeSH terms: Naloxone/pharmacology
  13. Antinociceptive and anti-inflammatory activities of the aqueous extract of Kaempferia galanga leaves in animal models
    Sulaiman MR, Zakaria ZA, Daud IA, Ng FN, Ng YC, Hidayat MT
    J Nat Med, 2008 Apr;62(2):221-7.
    PMID: 18404328 DOI: 10.1007/s11418-007-0210-3
    This study was performed to determine the antinociceptive and anti-inflammatory activities of aqueous extract of Kaempferia galanga leaves using various animal models. The extract, in the doses of 30, 100, and 300 mg/kg, was prepared by soaking (1:10; w/v) the air-dried powdered leaves (40 g) in distilled water (dH(2)O) for 72 h and administered subcutaneously in mice/rats 30 min prior to the tests. The extract exhibited significant (P < 0.05) antinociceptive activity when assessed using the abdominal constriction, hot-plate and formalin tests, with activity observed in all tests occurring in a dose-dependent manner. Furthermore, the antinociceptive activity of K. galanga extract was significantly (P < 0.05) reversed when prechallenged with 10 mg/kg naloxone. The extract also produced a significantly (P < 0.05) dose-dependent anti-inflammatory activity when assessed using the carrageenan-induced paw-edema test. In conclusion, this study demonstrated that K. galanga leaves possessed antinociceptive and anti-inflammatory activities and thus supports the Malay's traditional uses of the plant for treatments of mouth ulcer, headache, sore throat, etc.
    Matched MeSH terms: Naloxone/pharmacology
  14. Preliminary analysis of the antinociceptive activity of zerumbone
    Sulaiman MR, Perimal EK, Zakaria ZA, Mokhtar F, Akhtar MN, Lajis NH, et al.
    Fitoterapia, 2009 Jun;80(4):230-2.
    PMID: 19535012 DOI: 10.1016/j.fitote.2009.02.002
    We have investigated the antinociceptive activity of zerumbone (1), a natural cyclic sesquiterpene isolated from Zingiber zerumbet Smith, in acetic acid-induced abdominal writhing test and hot plate test in mice. 1 given by intraperitoneal route produced significant dose-dependent antinociceptive effect in all the test models used. In addition, the antinociceptive effect of 1 in the hot plate test was reversed by the non-selective opioid receptor antagonist naloxone, suggesting that the opioid system is involved in its analgesic mechanism of action.
    Matched MeSH terms: Naloxone/pharmacology
  15. Evaluation of the antinociceptive activity of Ficus deltoidea aqueous extract
    Sulaiman MR, Hussain MK, Zakaria ZA, Somchit MN, Moin S, Mohamad AS, et al.
    Fitoterapia, 2008 Dec;79(7-8):557-61.
    PMID: 18672036 DOI: 10.1016/j.fitote.2008.06.005
    The aqueous extract of Ficus deltoidea leaves was evaluated for possible antinociceptive activity in three models of nociception, namely, acetic acid-induced abdominal writhing, formalin and hot plate test. The results of the present study showed that intraperitoneal administration of the F. deltoidea leaves aqueous extract at the dose of 1, 50 and 100 mg/kg, 30 min prior to pain induction produced significant dose-dependent antinociceptive effect in all the models used, which indicating the presence of both central and peripherally mediated activities. Furthermore, the antinociceptive effect of the extract in the formalin and hot plate test was reversed by the non-selective opioid receptor antagonist naloxone suggesting that the endogenous opioid system is involved in its analgesic mechanism of action. Thus, the present results demonstrated that F. deltoidea leaves aqueous extract contains pharmacologically active constituents which possess antinociceptive activity justifying its popular therapeutic use in treating conditions associated with the painful conditions.
    Matched MeSH terms: Naloxone/pharmacology
  16. Effect of acetylcholine and morphine on bronchial smooth muscle contraction and its modulation by steroid hormones
    Nabishah BM, Morat PB, Khalid BA, Kadir BA
    Clin Exp Pharmacol Physiol, 1990 Dec;17(12):841-7.
    PMID: 2092952
    1. The effects of corticosteroid pretreatment on acetylcholine (ACH)-induced contraction of bronchial smooth muscle (BSM) were studied. 2. ACH dose-response curves for dexamethasone (DM)- and corticosterone (B)-treated but not deoxycorticosterone (DOC)-treated BSM were significantly shifted to the right; this provides evidence that glucocorticoid treatment reduced the sensitivity of BSM to ACH. 3. Morphine enhanced BSM contraction in response to ACH by 20%. DM suppressed this enhancement. 4. These findings correlated well with the reduction of muscarinic receptor numbers in BSM by glucocorticoids in our previous study. In addition, glucocorticoids reduced the sensitivity of BSM to opioids.
    Matched MeSH terms: Naloxone/pharmacology
  17. Naloxone and vitamin E block stress-induced reduction of locomotor activity and elevation of plasma corticosterone
    Ainsah O, Nabishah BM, Osman CB, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 1999;107(7):462-7.
    PMID: 10595599
    Normal rats, on being repetitively stressed by being restrained in a tight container for two hours, had higher levels of plasma corticosterone compared to pre stress values. These rats also reacted to the stress by a behavioral response in which there was marked decrease in locomotor activity assessed by the open field test (pre stress: 71.3 +/- 2.6 squares crossed versus post stress: 14.3 +/- 2.5 squares crossed) by counting the number of squares entered by the rat over 5 minutes. By the 6th to 7th exposures to the repetitive stress, the rats adapted to the stress and had normal plasma corticosterone levels and locomotor activity scores comparable to the pre stress values. These responses to stress were completely blocked by the administration of 0.32 microg/100 g BW of naloxone i.p at 10 minutes prior to the stress. In rats fed with rat chow supplemented with 90 mg/kg rat chow or 150 mg/kg rat chow of vitamin E, there was significant reduction of the plasma corticosterone levels and improvement in the locomotor activity. Stress thus caused opioid mediated increase in plasma corticosterone and reduction in locomotor activity which could be blocked by naloxone. These stress responses probably also involved generation of oxygen free radicals which were scavenged by the vitamin E, thus reducing the effects of repetitive stress on locomotor activity and serum corticosterone levels.
    Matched MeSH terms: Naloxone/pharmacology*
  18. Effects of naloxone, glycyrrhizic acid, dexamethasone and deoxycorticosterone in repetitive stress
    Ainsah O, Nabishah BM, Osman CB, Khalid BA
    Clin Exp Pharmacol Physiol, 1999 7 1;26(5-6):433-7.
    PMID: 10386234
    1. The present study examined the effect of naloxone (NAL), glycyrrhizic acid (GCA), deoxycorticosterone (DOC) and dexamethasone (DEX) on daily repeated 2 h chronic restrained stress (RS) on the locomotor activity (LA) of rats tested in the open field arena to elucidate the possible roles of opioids, glucocorticoids and mineralocorticoids in response to stress. 2. Intact and adrenalectomized (ADX) rats were either injected with 0.1 mL of NAL (0.32 microgram/100 g BW), 2.4 mg/kg DOC or 120 micrograms/kg DEX or had 1.0 mg/mL GCA dissolved in their drinking water or normal saline (for the ADX group) dissolved in their drinking water. 3. In intact groups, treatment with NAL completely blocked the stress response and treatment with GCA, DOC and DEX partially prevented the stress response. Adaptation occurred on either days 4, 5, 6 or 7 for intact rats treated with DEX, DOC, GCA or control rats, respectively. All ADX control rats died following the first 2 h RS. Adrenalectomized rats treated with DEX or DOC adapted later compared with intact rats, while rats given either GCA or NAL were unable to block or adapt to chronic RS. 4. These findings demonstrate that the stress response is primarily mediated by endogenous opioids, in that it is blocked by NAL. Both mineralocorticoids and glucocorticoids, which can act centrally to inhibit endorphins, partially blocked the stress response. The effect of GCA in intact rats was similar to that of both DEX and DOC in intact rats. Adrenalectomized rats treated with GCA (despite their lack of endogenous corticosterone) showed a stress response that was significantly different from the other ADX groups, implying that GCA had effects independent of endogenous corticosterone.
    Matched MeSH terms: Naloxone/pharmacology*; Naloxone/therapeutic use
  19. Mineralocorticoid and glycyrrhizic acid block stress induced hypotension in rats
    Ruszymah BH, Nabishah BM, Aminuddin S, Khalid BA
    Clin Exp Pharmacol Physiol, 1995 Jan;22(1):35-9.
    PMID: 7768032
    1. The aim of this study was to investigate the effect of repeated exposure to stress on tail blood pressure (TBP) of normal as well as GCA (glycyrrhizic acid) and steroid treated rats. Male Sprague-Dawley rats (250 g) were exposed to ether vapour to achieve light anaesthesia prior to TBP recording. Rats were injected with either normal saline or naloxone prior to exposure to stress. Tail blood pressure was recorded daily for 2 weeks. 2. We found that ether stress caused a transient drop in TBP in control as well as in dexamethasone (DEX) treated rats. The stress-induced fall in blood pressure was reduced by naloxone in control rats but not in DEX treated rats. However the transient drop in TBP following stress was not seen in either GCA or deoxycorticosterone (DOC) treated rats. 3. We conclude that first, the reduction in TBP was due to the release of endogenous opioids caused by stress. Second, DOC may block the release of such endogenous opioids, preventing the drop in TBP in response to stress, while DEX did not. Third, GCA caused a similar mineralocorticoid effect on reversing stress induced hypotension.
    Matched MeSH terms: Naloxone/pharmacology
  20. Antinociceptive activity of the essential oil of Zingiber zerumbet
    Sulaiman MR, Tengku Mohamad TA, Shaik Mossadeq WM, Moin S, Yusof M, Mokhtar AF, et al.
    Planta Med, 2010 Feb;76(2):107-12.
    PMID: 19637111 DOI: 10.1055/s-0029-1185950
    In the present study, the rhizome essential oil from Zingiber zerumbet (Zingiberaceae) was evaluated for antinociceptive activity using chemical and thermal models of nociception, namely, the acetic acid-induced abdominal writhing test, the hot-plate test and the formalin-induced paw licking test. It was demonstrated that intraperitoneal administration of the essential oil of Z. zerumbet (EOZZ) at the doses of 30, 100 and 300 mg/kg produced significant dose-dependent inhibition of acetic acid-induced abdominal writhing, comparable to that of obtained with acetylsalicylic acid (100 mg/kg). At the same doses, the EOZZ produced significant dose-dependent increases in the latency time in the hot-plate test with respect to controls, and in the formalin-induced paw licking test, the EOZZ also significantly reduced the painful stimulus in both neurogenic and inflammatory phase of the test. In addition, the antinociceptive effect of the EOZZ in the formalin-induced paw licking test as well as hot-plate test was reversed by the nonselective opioid receptor antagonist, naloxone suggesting that the opioid system was involved in its analgesic mechanism of action. On the basis of these data, we concluded that the EOZZ possessed both central and peripheral antinociceptive activities which justifying its popular folkloric use to relieve some pain conditions.
    Matched MeSH terms: Naloxone/pharmacology
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