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Stereoselective effects of the second-generation synthetic cathinone α-pyrrolidinopentiophenone (α-PVP): assessments of conditioned taste avoidance in rats. Psychopharmacology (Berl) 2019; 236:1067-1077. [PMID: 30334086 PMCID: PMC8328279 DOI: 10.1007/s00213-018-5070-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/04/2018] [Indexed: 12/19/2022]
Abstract
RATIONALE Work with α-pyrrolidinopentiophenone (α-PVP), a second-generation synthetic cathinone, has been generally limited to the racemate. Given that with other synthetic cathinones, there are behavioral and neurochemical differences between their enantiomers, differences may also be seen with α-PVP. OBJECTIVES The present study assessed the relative contribution of each enantiomer to the aversive effects of racemic-α-PVP by comparing their ability to induce a conditioned taste avoidance. METHODS Adult male Sprague-Dawley rats were exposed every other day for four exposures to a novel saccharin solution followed immediately by an injection of 0 (saline vehicle) or 1.5, 3, or 6 mg/kg of S-, R-, or racemic-α-PVP (IP). On alternating days, all subjects were given access to water to assess any unconditioned effects of α-PVP on general fluid consumption. RESULTS Rats injected with the racemate and S-isomer of α-PVP displayed avoidance of the drug-associated saccharin solution, although this avoidance was dose-dependent only for the subjects injected with the racemate. There was no evidence of taste avoidance in animals injected with the R-enantiomer at any dose tested. Animals injected with 3 mg/kg racemic-α-PVP did not differ in avoidance from those treated with 1.5 mg/kg of the S-enantiomer, but subjects treated with 6 mg/kg racemic-α-PVP displayed a significantly stronger avoidance than those treated with 3 mg/kg S-α-PVP. CONCLUSIONS The present work suggests that the aversive effects of racemic α-PVP are mediated primarily by its S-isomer. The fact that at the highest dose tested (6 mg/kg), the racemate induces an avoidance greater than the simple additive effects of the S- and R-isomers (at 3 mg/kg) suggests that while the R-isomer may not induce taste avoidance at this dose, it may interact synergistically with the S-isomer in mediating the effects of the racemic mixture. These results were discussed in terms of similar effects with other behavioral and physiological endpoints reported with a number of psychostimulants and suggest that the enantiomers of α-PVP are an important variable in characterizing its behavioral effects.
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Gannon BM, Williamson A, Suzuki M, Rice KC, Fantegrossi WE. Stereoselective Effects of Abused "Bath Salt" Constituent 3,4-Methylenedioxypyrovalerone in Mice: Drug Discrimination, Locomotor Activity, and Thermoregulation. J Pharmacol Exp Ther 2016; 356:615-23. [PMID: 26769917 DOI: 10.1124/jpet.115.229500] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/30/2015] [Indexed: 11/22/2022] Open
Abstract
3,4-Methylenedioxypyrovalerone (MDPV) is a common constituent of illicit "bath salts" products. MDPV is a chiral molecule, but the contribution of each enantiomer to in vivo effects in mice has not been determined. To address this, mice were trained to discriminate 10 mg/kg cocaine from saline, and substitutions with racemic MDPV, S(+)-MDPV, and R(-)-MDPV were performed. Other mice were implanted with telemetry probes to monitor core temperature and locomotor responses elicited by racemic MDPV, S(+)-MDPV, and R(-)-MDPV under a warm (28°C) or cool (20°C) ambient temperature. Mice reliably discriminated the cocaine training dose from saline, and each form of MDPV fully substituted for cocaine, although marked potency differences were observed such that S(+)-MDPV was most potent, racemic MDPV was less potent than the S(+) enantiomer, and R(-)-MDPV was least potent. At both ambient temperatures, locomotor stimulant effects were observed after doses of S(+)-MDPV and racemic MDPV, but R(-)-MDPV did not elicit locomotor stimulant effects at any tested dose. Interestingly, significant increases in maximum core body temperature were only observed after administration of racemic MDPV in the warm ambient environment; neither MDPV enantiomer altered core temperature at any dose tested, at either ambient temperature. These studies suggest that all three forms of MDPV induce biologic effects, but R(-)-MDPV is less potent than S(+)-MDPV and racemic MDPV. Taken together, these data suggest that the S(+)-MDPV enantiomer is likely responsible for the majority of the biologic effects of the racemate and should be targeted in therapeutic efforts against MDPV overdose and abuse.
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Affiliation(s)
- Brenda M Gannon
- Department of Pharmacology and Toxicology (B.M.G., W.E.F.), College of Medicine (A.W.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Drug Design and Synthesis Section, Chemical Biology Research Branch, National Institutes of Health National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (M.S., K.C.R.)
| | - Adrian Williamson
- Department of Pharmacology and Toxicology (B.M.G., W.E.F.), College of Medicine (A.W.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Drug Design and Synthesis Section, Chemical Biology Research Branch, National Institutes of Health National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (M.S., K.C.R.)
| | - Masaki Suzuki
- Department of Pharmacology and Toxicology (B.M.G., W.E.F.), College of Medicine (A.W.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Drug Design and Synthesis Section, Chemical Biology Research Branch, National Institutes of Health National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (M.S., K.C.R.)
| | - Kenner C Rice
- Department of Pharmacology and Toxicology (B.M.G., W.E.F.), College of Medicine (A.W.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Drug Design and Synthesis Section, Chemical Biology Research Branch, National Institutes of Health National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (M.S., K.C.R.)
| | - William E Fantegrossi
- Department of Pharmacology and Toxicology (B.M.G., W.E.F.), College of Medicine (A.W.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; and Drug Design and Synthesis Section, Chemical Biology Research Branch, National Institutes of Health National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (M.S., K.C.R.)
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Abstract
Khat chewing is deeply rooted in the every day life of people living in the Horn of Africa and in South Arabia, where Catha edulis is endemic. Considered little more than an exotic habit producing just mild pharmacological effects, systematic investigations on its active principles have instead lead to the isolation and chemical characterization of cathinone, a compound structurally related to amphetamine. Three decades of intense experimental and clinical research on khat have depicted a consistently clear picture of its pharmacological and toxicological effects.
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Affiliation(s)
- Manuela Graziani
- Department of Human Physiology and Pharmacology, University of Rome, La Sapienza, Rome, Italy
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Abstract
The habit of chewing fresh leaves and twigs of khat (Catha edulis) for their stimulating amphetamine-like effects is highly prevalent in East Africa and southwest on the Arabic peninsula. There is an extensive literature on khat providing information about its history, botany, production, geographical distribution, chemistry and pharmacology, and exploring the social, economic, medical, psychological and oral aspects related to its use. Some of this literature dates as early as the 11th century; however, most of it appeared after the first scientific description of khat by Peter Forskal in 1775. This review provides a panorama of khat and the various aspects of its use. A non-technical description of the plant chemistry and pharmacology is included. The medical, psychological and oral aspects are emphasized, and the current knowledge about the microbiological effects of khat is also presented.
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Affiliation(s)
- Nezar N Al-Hebshi
- Department of Oral Sciences-Oral Microbiology, Faculty of Dentistry, University of Bergen, Norway.
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Ho Hyun M, Tan G, Cho YJ. Liquid chromatographic enantioseparation of aryl?-amino ketones on a crown ether-based chiral stationary phase. Biomed Chromatogr 2005; 19:208-13. [PMID: 15515110 DOI: 10.1002/bmc.437] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A liquid chromatographic chiral stationary phase based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 covalently bonded to silica gel was applied in the resolution of aryl alpha-amino ketones including cathinone, the main psychoactive alkaloid found in the leaves of the khat plant. The resolution was excellent, the separation factors ranging between 1.72 and 8.58 and the resolution factors (R(S)) ranging between 2.60 and 11.10. The chromatographic resolution behaviour was dependent on the type and the content of organic and acidic modifiers and the ammonium acetate concentration in aqueous mobile phase and the column temperature.
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Affiliation(s)
- Myung Ho Hyun
- Department of Chemistry, Pusan National University, Pusan 609-735, Republic of Korea.
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Banjaw MY, Mayerhofer A, Schmidt WJ. Anticataleptic activity of cathinone and MDMA (Ecstasy) upon acute and subchronic administration in rat. Synapse 2003; 49:232-8. [PMID: 12827642 DOI: 10.1002/syn.10236] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
It was recently demonstrated that acute administration of 3,4-methylenedioxymethamphet-amine (MDMA, "Ecstasy") is capable of counteracting haloperidol-induced catalepsy in rats. The present study was done with another psychostimulant, S-(-)-cathinone. In these experiments, 32 male Sprague-Dawley rats, 225 +/- 25 g, were used. They were divided into three groups. All groups received 0.5 mg/kg haloperidol in normal saline (s.c.) as a first injection. Then 30 min later each group received either isotonic phosphate-buffered saline, 1 mg/kg S-(-)-cathinone, or 2.5 mg/kg (RS)-MDMA (s.c.) as a second injection. The results of descent latency on both the horizontal bar and vertical grid showed that S-(-)-cathinone or (RS)-MDMA upon acute administration induces a strong anticataleptic activity (P < 0.0001) compared to rats treated with haloperidol plus vehicle. The effect of both drugs was later masked upon subchronic administration (days 2-7, 26-29). This is probably due to sensitization of cataleptic behavior. However, when the same groups of rats were tested on day 8 in a different task, i.e., open-field, they showed a significant difference (P < 0.05). The detailed mechanism of the observed strong anticataleptic activity of S-(-)-cathinone (which is considered a potent dopamine releaser) requires further investigation.
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Affiliation(s)
- Mehret Yerdaw Banjaw
- Zoological Institute, Department of Neuropharmacology, University of Tübingen, Auf der Morgenstelle 28E, 72076 Tübingen, Germany
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Aboul-Enein HY, Serignese V. Direct enantiomeric separation of cathinone and one major metabolite on cellobiohydrolase (CBH-I) chiral stationary phase. Biomed Chromatogr 1997; 11:47-9. [PMID: 9051217 DOI: 10.1002/(sici)1099-0801(199701)11:1<47::aid-bmc626>3.0.co;2-m] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A direct, isocratic high-performance liquid chromatographic (HPLC) method is described for the enantiomeric separation of racemic cathinone and one of its metabolites (+/-)-norephedrine, on a protein-based chiral stationary phase (CSP), cellobiohydrolase, known as CBH-I, under reversed-phase conditions. It was determined that the S-(-)-enantiomer eluted first for cathinone while the 1S,2R-(+)-enantiomer eluted first for norephedrine. The procedure is simple with no sample derivatization required and a short assay time.
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Affiliation(s)
- H Y Aboul-Enein
- Bioanalytical and Drug Development Laboratory, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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Abstract
Cathinone is an alkaloid that has been discovered some fifteen years ago in the leaves of the khat bush. This plant grows in East Africa and in southern Arabia, and the inhabitants of these regions frequently chew khat because of its stimulating properties. Cathinone, which is S(-)-alpha-aminopropiophenone, was soon found to have a pharmacological profile closely resembling that of amphetamine; indeed, in a wide variety of in vitro and in vivo experiments it was demonstrated that cathinone shares the action of amphetamine on CNS as well as its sympathomimetic effects; thus, for example, drug-conditioned animals will not distinguish between cathinone and amphetamine. These various observations were confirmed by a clinical experiment showing that cathinone also in humans produces amphetamine-like objective and subjective effects. Finally, it was demonstrated that cathinone operates through the same mechanism as amphetamine, i.e. it acts by releasing catecholamines from presynaptic storage sites. Thus, much experimental evidence indicates that cathinone is the main psychoactive constituent of the khat leaf and that, in fact, this alkaloid is a natural amphetamine.
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Affiliation(s)
- P Kalix
- Department of Pharmacology, University of Geneva, Switzerland
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Schechter MD, McBurney D. Effect of repeated administrations upon cathinone discrimination and conditioned place preference. GENERAL PHARMACOLOGY 1991; 22:779-82. [PMID: 1761180 DOI: 10.1016/0306-3623(91)90204-j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. Eight male rats were trained to discriminate the interoceptive cues produced by 0.8 mg/kg l-cathinone in a two-lever, food-motivated operant task and they were, subsequently, tested for preference to cathinone in a conditioned place preference (CPP)-test. 2. Once trained, the rats were placed on a 10 day regimen of twice-a-day non-contingent administrations of saline followed by a similar regimen of multiple injections of 0.8 mg/kg cathinone. 3. After each series of non-contingent administrations, the rats' ability to discriminate (0.2-0.8 mg/kg) cathinone, as well as their preference for it, was determined. 4. Results indicate that tolerance tends to develop to the effect of cathinone in its ability to control discriminative behavior as indicated by deficits in discriminative performance and a two-fold shift of the dose-response curve to the right. 5. In contrast, preference for cathinone, in the CPP-tests, was not significantly affected by the multiple cathinone administration regimen. 6. The possibility that tolerance to some behavioral effects may occur in habitual users of the cathinone-containing Khat shrub is discussed.
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Affiliation(s)
- M D Schechter
- Department of Pharmacology, Northeastern Ohio Universities College of Medicine, Rootstown 44272
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Abstract
The effects of the psychostimulant (+)cathine (norpseudoephedrine) were examined in a two-choice, food-motivated, drug-discrimination paradigm. Rats were able to discriminate cathine from vehicle and this effect was dose- and time-dependent. Prior administration of cathine resulted in a diminished response (tolerance) to subsequent cathine and this effect developed and dissipated rapidly. Thus, different dose-response curves were generated depending upon whether cathine or vehicle was administered the day before testing. The development of tolerance also shortened cathine's time course of action and enhanced the ability of haloperidol to antagonize the cathine cue. These results suggest caution in interpreting effects produced by intermittent drug injection schedules.
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Affiliation(s)
- E A Pehek
- Department of Pharmacology, Northeastern Ohio Universities College of Medicine, Rootstown 44272
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Abstract
The chewing of the stimulant leaf khat is a habit that is widespread in certain countries of East Africa and the Arabian peninsula. During the last decade, important progress has been made in understanding the pharmacological basis for the effects of khat. It is now known that the CNS action of this drug is due to the presence of the alkaloid cathinone, and the results of various in vitro and in vivo experiments indicate that this substance must be considered a natural amphetamine. It is the purpose of the present review to describe briefly the khat habit and to summarize the pharmacology of khat and of its active constituents.
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Abstract
The present review deals with the considerable body of evidence gathered in the last ten years on the clinical and experimental pharmacology of Khat. Khat effects are generally agreed to be of amphetamine-like type. In particular, Khat ingestion, like amphetamine ingestion, produces sympathetic activation, anorexia, euphoria, increased intellectual efficiency and alertness. These effects are mainly mediated by phenylalkylamines, such as cathinone and cathine, because the pharmacological actions of these agents and those produced by amphetamine almost overlap. In infra-human species cathinone is an effective positive reinforcer (i.e., it maintains self-administration). However, it would be inappropriate to infer from cathinone and cathine effects assessed in animals a high potential of abuse for Khat in humans; apart from other reasons the bulk volume of Khat leaves, limits the ingestion of high quantities of the active principles. Accordingly, in habitual consumers Khat dependence is probably mild, because craving and tolerance to the sympathomimetic and neuroendocrine effects of Khat are present, but there is no definite abstinence syndrome. Therefore, in our opinion, policies restricting the use of Khat should be adopted with caution, lest they simply change the pattern of drug abuse and increase the spread of more dangerous drugs.
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Affiliation(s)
- P Nencini
- Institute of Medical Pharmacology, University La Sapienza, Rome, Italy
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Abstract
Using a two-lever, food-motivated discrimination procedure, eight male rats were trained to discriminate 1.5 mg/kg of racemic 3,4-methylenedioxymethamphetamine (MDMA) from its vehicle, distilled water. Once trained, the rats demonstrated a dose-related decrease in discriminative performance after administration of lower doses of MDMA (ED50 = 0.27 mg/kg). Racemic MDMA-stimulus generalization occurred with both isomers of MDMA with the ED50 of the (+) isomer calculated as 0.50 mg/kg and for the (-) isomer being 1.07. Time-course data indicate that racemic MDMA has a peak effect from 20-60 min post-injection with a declining effect from 120-240 min. This time-course closely resembles that observed by subjective reports in human abusers and, together with previous data, would indicate that the discriminative paradigm would be useful in investigations as to the neurochemical effects of MDMA.
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Abstract
Ten male rats were trained to discriminate between the stimulus properties of 0.6 mg/kg l-cathinone and saline in a two-lever food-motivated operant task. Once trained, rats showed a dose-dependent increase in discrimination over a dosage range of 0.15-1.2 mg/kg l-cathinone. Analysis of this dose-response relationship indicated an ED50 of 0.27 mg/kg. Pretreatment with 0.2 mg/kg of the specific dopamine blocking drug haloperidol increased this ED50 to 0.47 mg/kg and significantly decreased discriminative performance when co-administered with either 0.15, 0.3, or 0.6 mg/kg l-cathinone. Since the dose-effect curves for cathinone with and without haloperidol pre-treatment were parallel, it is suggested that l-cathinone, the active constituent in khat, produces its discriminative properties, in part, by mediation of dopaminergic neuronal systems.
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Schechter MD. Induction of and recovery from tolerance to the discriminative stimulus properties of l-cathinone. Pharmacol Biochem Behav 1986; 25:13-6. [PMID: 3749220 DOI: 10.1016/0091-3057(86)90222-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Rats previously trained to discriminate between 0.6 mg/kg l-cathinone and saline in a two-lever, food-motivated operant task were administered l-cathinone at the same dose, every 8 hours for 10 days. Discrimination testing during this chronic administration phase of experimentation indicated that the animals' ability to discriminate both 0.3 and 0.6 mg/kg l-cathinone decreased when compared to their discriminative ability prior to chronic administration. In contrast, discrimination of the non-drug state, i.e., saline, was not affected. Comparison of dose-response curves prior to and during chronic cathinone administration indicated a 3-4 fold shift to the right for the latter curve. Continued testing after termination of chronic treatment resulted in a return to pre-chronic discriminative performance by the fifteenth day after cessation. These results indicate that tolerance to the discriminative effects of l-cathinone can be produced within 10 days of chronic administration and recovery from this observed tolerance occurs within 15 days of cessation of chronic administration.
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Abstract
Groups of rats were trained to discriminate the stimulus properties of dopaminergically and/or serotonergically active drugs, viz., apomorphine, fenfluramine, tetrahydro-beta-carboline (THBC) and l-cathinone. Once trained, these animals were given several doses of drugs used in training and dose-response relationships and ED50 values were generated. Subsequently, each group of trained rats was administered various doses of 3,4-methylenedioxymethamphetamine (MDMA) to test generalization of the interoceptive cue of the drug used for training to MDMA. Rats trained to fenfluramine, THBC, and l-cathinone were observed to discriminate MDMA in a manner similar to the drug state to which they had been trained. Analysis of dose-response curves suggested that MDMA may be acting both as an indirect dopaminergic agonist and as a serotonergic receptor agonist. This duality of effect of MDMA has been evidenced by other studies and may account for its present abuse potential.
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