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Nesbit MO, Ahn S, Zou H, Floresco SB, Phillips AG. Potentiation of prefrontal cortex dopamine function by the novel cognitive enhancer d-govadine. Neuropharmacology 2024; 246:109849. [PMID: 38244888 DOI: 10.1016/j.neuropharm.2024.109849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/13/2023] [Accepted: 01/16/2024] [Indexed: 01/22/2024]
Abstract
Cognitive impairment is a debilitating feature of psychiatric disorders including schizophrenia, mood disorders and substance use disorders for which there is a substantial lack of effective therapies. d-Govadine (d-GOV) is a tetrahydroprotoberberine recently shown to significantly enhance working memory and behavioural flexibility in several prefrontal cortex (PFC)-dependent rodent tasks. d-GOV potentiates dopamine (DA) efflux in the mPFC and not the nucleus accumbens, a unique pharmacology that sets it apart from many dopaminergic drugs and likely contributes to its effects on cognitive function. However, specific mechanisms involved in the preferential effects of d-GOV on mPFC DA function remain to be determined. The present study employs brain dialysis in male rats to deliver d-GOV into the mPFC or ventral tegmental area (VTA), while simultaneously sampling DA and norepinephrine (NE) efflux in the mPFC. Intra-PFC delivery or systemic administration of d-GOV preferentially potentiated medial prefrontal DA vs NE efflux. This differential effect of d-GOV on the primary catecholamines known to affect mPFC function further underscores its specificity for the mPFC DA system. Importantly, the potentiating effect of d-GOV on mPFC DA was disrupted when glutamatergic transmission was blocked in either the mPFC or the VTA. We hypothesize that d-GOV acts in the mPFC to engage the mesocortical feedback loop through which prefrontal glutamatergic projections activate a population of VTA DA neurons that specifically project back to the PFC. The activation of a PFC-VTA feedback loop to elevate PFC DA efflux without affecting mesolimbic DA release represents a novel approach to developing pro-cognitive drugs.
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Affiliation(s)
- Maya O Nesbit
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Soyon Ahn
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Haiyan Zou
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Stan B Floresco
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Anthony G Phillips
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.
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Liu X, Ma Y, Bu J, Lian C, Ma R, Li Q, Jiao X, Hu Z, Chen Y, Chen S, Guo J, Huang L. Characterization of CYP82 genes involved in the biosynthesis of structurally diverse benzylisoquinoline alkaloids in Corydalis yanhusuo. PLANT MOLECULAR BIOLOGY 2024; 114:23. [PMID: 38453737 DOI: 10.1007/s11103-023-01397-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 10/27/2023] [Indexed: 03/09/2024]
Abstract
Benzylisoquinoline alkaloids (BIAs) represent a significant class of secondary metabolites with crucial roles in plant physiology and substantial potential for clinical applications. CYP82 genes are involved in the formation and modification of various BIA skeletons, contributing to the structural diversity of compounds. In this study, Corydalis yanhusuo, a traditional Chinese medicine rich in BIAs, was investigated to identify the catalytic function of CYP82s during BIA formation. Specifically, 20 CyCYP82-encoding genes were cloned, and their functions were identified in vitro. Ten of these CyCYP82s were observed to catalyze hydroxylation, leading to the formation of protopine and benzophenanthridine scaffolds. Furthermore, the correlation between BIA accumulation and the expression of CyCYP82s in different tissues of C. yanhusuo was assessed their. The identification and characterization of CyCYP82s provide novel genetic elements that can advance the synthetic biology of BIA compounds such as protopine and benzophenanthridine, and offer insights into the biosynthesis of BIAs with diverse structures in C. yanhusuo.
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Affiliation(s)
- Xiuyu Liu
- School of Pharmaceutical Sciences, Henan University of Chinese Medicine, No. 156 Jinshuidong Road, Zhengzhou, 450046, China
| | - Ying Ma
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China
| | - Junling Bu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China
| | - Conglong Lian
- School of Pharmaceutical Sciences, Henan University of Chinese Medicine, No. 156 Jinshuidong Road, Zhengzhou, 450046, China
| | - Rui Ma
- School of Pharmaceutical Sciences, Henan University of Chinese Medicine, No. 156 Jinshuidong Road, Zhengzhou, 450046, China
| | - Qishuang Li
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China
| | - Xiang Jiao
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Zhimin Hu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China
| | - Yun Chen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Suiqing Chen
- School of Pharmaceutical Sciences, Henan University of Chinese Medicine, No. 156 Jinshuidong Road, Zhengzhou, 450046, China.
| | - Juan Guo
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China.
| | - Luqi Huang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinan Academy of Chinese Medical Sciences, Beijing, 100000, China.
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Namballa HK, Decker AM, Dorogan M, Gudipally A, Goclon J, Harding WW. Fluoroalkoxylated C-3 and C-9 (S)-12-bromostepholidine analogues with D1R antagonist activity. Bioorg Chem 2023; 141:106862. [PMID: 37722267 PMCID: PMC10872833 DOI: 10.1016/j.bioorg.2023.106862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/10/2023] [Accepted: 09/11/2023] [Indexed: 09/20/2023]
Abstract
To illuminate the tolerance of fluoroalkoxylated groups at the C-3 and C-9 positions of tetrahydroprotoberberines (THPBs) on D1R activity, C-3 and C-9 fluoroalkoxylated analogues of (S)-12-bromostepholidine were prepared and evaluated. All compounds examined were D1R antagonists as measured by a cAMP assay. Our structure-activity studies herein indicate that the C-3 position tolerates a 1,1-difluoroethoxy substituent for D1R antagonist activity. Compound 13a was the most potent cAMP-based D1R antagonist identified and was also found to antagonize β-arrestin translocation in a TANGO assay. Affinity assessments at other dopamine receptors revealed that 13a is selective for D1R and unlike other naturally-occurring THPBs such as (S)-stepholidine, lacks D2R affinity. In preliminary biopharmaceutical assays, excellent BBB permeation was observed for 13a. Further pharmacological studies are warranted on (S)-stepholidine congeners to harvest their potential as a source of novel, druggable D1R-targeted agents.
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Affiliation(s)
- Hari K Namballa
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, NY 10065, United States
| | - Ann M Decker
- Center for Drug Discovery, RTI International, Research Triangle Park, NC 27709, United States
| | - Michael Dorogan
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, NY 10065, United States
| | - Ashok Gudipally
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, NY 10065, United States; Program in Chemistry, CUNY Graduate Center 365 5th Avenue, New York, NY 10016, United States
| | - Jakub Goclon
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, NY 10065, United States
| | - Wayne W Harding
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, NY 10065, United States; Program in Chemistry, CUNY Graduate Center 365 5th Avenue, New York, NY 10016, United States; Program in Biochemistry, CUNY Graduate Center 365 5th Avenue, New York, NY 10016, United States.
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Zhao W, Liu M, Liu K, Liu H, Liu X, Liu J. An Enzymatic Strategy for the Selective Methylation of High-Value-Added Tetrahydroprotoberberine Alkaloids. Int J Mol Sci 2023; 24:15214. [PMID: 37894895 PMCID: PMC10607743 DOI: 10.3390/ijms242015214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Tetrahydroprotoberberines (THPBs) are plant-specific alkaloids with significant medicinal value. They are present in trace amounts in plants and are difficult to chemically synthesize due to stereoselectivity and an unfavorable environment. In this study, a selective methylation strategy was developed for the biocatalysis of seven high-value-added THPB compounds using 4'-O-methyltransferase (Cj4'OMT), norcoclaurine 6-O-methyltransferase (Cj6OMT), and (S)-scoulerine 9-O-methyltransferase (SiSOMT and PsSOMT) in engineered E. coli. The methyltransferases Cj4'OMT, Cj6OMT, PsSOMT, and SiSOMT were expressed heterologously in E. coli. Compound 1 (10-methoxy-2,3,9-tetrahydroxyberbine) was synthesized using the recombinant E. coli strain Cj4'OMT and the substrate 2,3,9,10-tetrahydroxyberbine. Compound 2 (9-methoxy-2,3,10-tetrahydroxyberbine) was produced in the recombinant Escherichia coli (E. coli) strain PsSOMT, and compounds 2 and 3 (discretamine) were produced in the recombinant E. coli strain SiSOMT. Compounds 4 (9,10-methoxy-2,3-tetrahydroxyberbine) and 5 (corypalmine) were obtained by co-culturing the recombinant strains Cj4'OMT and SiSOMT with substrate. Compounds 6 (scoulerine) and 7 (isoscoulerine) were produced by co-culturing the substrate with the recombinant strains Cj4'OMT and Cj6OMT. To increase the yield of novel compound 2, the flask culture conditions of the engineered SiSOMT strain were optimized, resulting in the production of 165.74 mg/L of this compound. This study thus presents an enzymatic approach to the synthesis of high-value-added THPBs with minimum environmental wastage.
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Affiliation(s)
- Wanli Zhao
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
| | - Manyu Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
| | - Kemeng Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
| | - Hanqing Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
| | - Xiufeng Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
| | - Jihua Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China; (W.Z.)
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China
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Namballa HK, Dorogan M, Gudipally AR, Okafor S, Gadhiya S, Harding WW. Discovery of Selective Dopamine Receptor Ligands Derived from (-)-Stepholidine via C-3 Alkoxylation and C-3/C-9 Dialkoxylation. J Med Chem 2023. [PMID: 37421373 DOI: 10.1021/acs.jmedchem.3c00976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2023]
Abstract
We evaluated C-3 alkoxylated and C-3/C-9 dialkoxylated (-)-stepholidine analogues to probe the tolerance at the C-3 and C-9 positions of the tetrahydroprotoberberine (THPB) template toward affinity for dopamine receptors. A C-9 ethoxyl substituent appears optimal for D1R affinity since high D1R affinities were observed for compounds that contain an ethyl group at C-9, with larger C-9 substituents tending to decrease D1R affinity. A number of novel ligands were identified, such as compounds 12a and 12b, with nanomolar affinities for D1R and no affinity for either D2R or D3R, with compound 12a being identified as a D1R antagonist for both G-protein- and β-arrestin-based signaling. Compound 23b was identified as the most potent and selective D3R ligand containing a THPB template to date and functions as an antagonist for both G-protein- and β-arrestin-based signaling. Molecular docking and molecular dynamics studies validated the D1R and D3R affinity and selectivity of 12a, 12b, and 23b.
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Affiliation(s)
- Hari K Namballa
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, New York 10065, United States
| | - Michael Dorogan
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, New York 10065, United States
| | - Ashok R Gudipally
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, New York 10065, United States
- Ph.D. Program in Chemistry, CUNY Graduate Center, 365 5th Avenue, New York, New York 10016, United States
| | - Sunday Okafor
- Department of Pharmaceutical and Medicinal Chemistry, University of Nigeria, 410011 Nsukka, Enugu State, Nigeria
- Center for Biomedical Research, New York, New York 10065, United States
| | - Satishkumar Gadhiya
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, New York 10065, United States
- Ph.D. Program in Chemistry, CUNY Graduate Center, 365 5th Avenue, New York, New York 10016, United States
- Ph.D. Program in Biochemistry, CUNY Graduate Center, 365 5th Avenue, New York, New York 10016, United States
| | - Wayne W Harding
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, New York 10065, United States
- Ph.D. Program in Chemistry, CUNY Graduate Center, 365 5th Avenue, New York, New York 10016, United States
- Ph.D. Program in Biochemistry, CUNY Graduate Center, 365 5th Avenue, New York, New York 10016, United States
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Oleinichenko D, Ahn S, Song R, Snutch TP, Phillips AG. Morphine Withdrawal-Induced Hyperalgesia in Models of Acute and Extended Withdrawal Is Attenuated by l-Tetrahydropalmatine. Int J Mol Sci 2023; 24:ijms24108872. [PMID: 37240217 DOI: 10.3390/ijms24108872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
Effective pain control is an underappreciated aspect of managing opioid withdrawal, and its absence presents a significant barrier to successful opioid detoxification. Accordingly, there is an urgent need for effective non-opioid treatments to facilitate opioid detoxification. l-Tetrahydropalmatine (l-THP) possesses powerful analgesic properties and is an active ingredient in botanical formulations used in Vietnam for the treatment of opioid withdrawal syndrome. In this study, rats receiving morphine (15 mg/kg, i.p.) for 5 days per week displayed a progressive increase in pain thresholds during acute 23 h withdrawal as assessed by an automated Von Frey test. A single dose of l-THP (5 or 7.5 mg/kg, p.o.) administered during the 4th and 5th weeks of morphine treatment significantly improves pain tolerance scores. A 7-day course of l-THP treatment in animals experiencing extended withdrawal significantly attenuates hyperalgesia and reduces the number of days to recovery to baseline pain thresholds by 61% when compared to vehicle-treated controls. This indicates that the efficacy of l-THP on pain perception extends beyond its half-life. As a non-opioid treatment for reversing a significant hyperalgesic state during withdrawal, l-THP may be a valuable addition to the currently limited arsenal of opioid detoxification treatments.
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Affiliation(s)
- Daria Oleinichenko
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Djavad Mowafaghian Centre for Brain Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Soyon Ahn
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Djavad Mowafaghian Centre for Brain Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ru Song
- Djavad Mowafaghian Centre for Brain Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Terrance P Snutch
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Djavad Mowafaghian Centre for Brain Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anthony G Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2A1, Canada
- Djavad Mowafaghian Centre for Brain Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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7
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Characterization of two microalgae consortia grown in industrial wastewater for biomass valorization. ALGAL RES 2022. [DOI: 10.1016/j.algal.2021.102628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Akaberi T, Shourgashti K, Emami SA, Akaberi M. Phytochemistry and pharmacology of alkaloids from Glaucium spp. PHYTOCHEMISTRY 2021; 191:112923. [PMID: 34454171 DOI: 10.1016/j.phytochem.2021.112923] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 06/13/2023]
Abstract
Glaucium Mill. comprising 28 species with 78 synonyms, 3 subspecies, and 3 varieties worldwide belongs to the Papaveraceae family. The plants are well known for their different types of alkaloids. In the present study, we attempted to review the chemistry and pharmacology of the alkaloids from the genus Glaucium. For this purpose, the relevant data were collected from different scientific databases including, "Google Scholar", "ISI Web of Knowledge", "PubMed", "Scopus", and available books and e-books. Our results showed that aporphine alkaloids are dominated in the species; however, other types of alkaloids including protopines, benzophenanthridines, benzylisoquinolines, protoberberines, and morphinanes have also been reported from the genus. The pharmacological studies have shown that the alkaloids from Glaucium species have several biological activities of which anti-cancer and anti-cholinesterase effects have been highly reported. Besides, the data indicated that most of the species have been investigated neither phytochemically nor pharmacologically. Glaucium flavum, known as yellow horn poppy, is the most studied species. According to the reports, the plants from this genus have anti-cancer and anti-cholinesterase potentials and can be used as a source for aporphine alkaloids.
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Affiliation(s)
- Toktam Akaberi
- Department of Organic Chemistry, Ferdowsi University, Mashhad, Iran.
| | - Kamran Shourgashti
- Department of Pharmacognosy, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Seyed Ahmad Emami
- Department of Pharmacognosy, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Traditional Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Maryam Akaberi
- Department of Pharmacognosy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Differential effects of d- and l-enantiomers of govadine on distinct forms of cognitive flexibility and a comparison with dopaminergic drugs. Psychopharmacology (Berl) 2021; 238:1069-1085. [PMID: 33432392 DOI: 10.1007/s00213-020-05754-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/21/2020] [Indexed: 10/22/2022]
Abstract
RATIONALE There is an urgent need for novel drugs for treating cognitive deficits that are defining features of schizophrenia. The individual d- and l-enantiomers of the tetrahydroprotoberberine (THPB) d,l-govadine have been proposed for the treatment of cognitive deficiencies and positive symptoms of schizophrenia, respectively. OBJECTIVES We examined the effects of d-, l-, or d,l-govadine on two distinct forms of cognitive flexibility perturbed in schizophrenia and compared them to those induced by a selective D1 receptor agonist and D2 receptor antagonist. METHODS Male rats received d-, l-, or d,l-govadine (0.3, 0.5, and 1.0 mg/kg), D1 agonist SKF81297(0.1, 0.3, and 1.0 mg/kg), or D2 antagonist haloperidol (0.1-0.2 mg/kg). Experiment 1 used a strategy set-shifting task (between-subjects). In experiment 2, well-trained rats were tested on a probabilistic reversal task (within-subjects). RESULTS d-Govadine improved set-shifting across all doses, whereas higher doses of l-govadine impaired set-shifting. SKF81297 reduced perseverative errors at the lowest dose. Low/high doses of haloperidol increased/decreased set-shifting errors, the latter "improvement" attributable to impaired retrieval of a previous acquired rule. Probabilistic reversal performance was less affected by these drugs, but d-govadine reduced errors during the first reversal, whereas l-govadine impaired initial discrimination learning. d,l-Govadine had no reliable cognitive effects but caused psychomotor slowing like l-govadine and haloperidol. CONCLUSIONS These findings further highlight differences between two enantiomers of d,l-govadine that may reflect differential modulation of D1 and D2 receptors. These preclinical findings give further impetus to formal clinical evaluation of d-govadine as a treatment for cognitive deficiencies related to schizophrenia.
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Ahn S, Nesbit MO, Zou H, Vacca G, Axerio-Cilies P, Van Sung T, Phillips AG. Neural bases for attenuation of morphine withdrawal by Heantos-4: role of l-tetrahydropalmatine. Sci Rep 2020; 10:21275. [PMID: 33277581 PMCID: PMC7718916 DOI: 10.1038/s41598-020-78083-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/17/2020] [Indexed: 11/24/2022] Open
Abstract
Severe withdrawal symptoms triggered by cessation of long-term opioid use deter many individuals from seeking treatment. Opioid substitution and α2-adrenergic agonists are the current standard of pharmacotherapy for opioid use disorder in western medicine; however, each is associated with significant complications. Heantos-4 is a non-opioid botanical formulation used to facilitate opioid detoxification in Vietnam. While ongoing clinical use continues to validate its safety and effectiveness, a mechanism of action accounting for these promising effects remains to be specified. Here, we assess the effects of Heantos-4 in a rat model of morphine-dependence and present evidence that alleviation of naloxone-precipitated somatic withdrawal signs is related to an upregulation of mesolimbic dopamine activity and a consequent reversal of a hypodopaminergic state in the nucleus accumbens, a brain region implicated in opioid withdrawal. A central dopaminergic mechanism is further supported by the identification of l-tetrahydropalmatine as a key active ingredient in Heantos-4, which crosses the blood–brain barrier and shows a therapeutic efficacy comparable to its parent formulation in attenuating withdrawal signs. The anti-hypodopaminergic effects of l-tetrahydropalmatine may be related to antagonism of the dopamine autoreceptor, thus constituting a plausible mechanism contributing to the effectiveness of Heantos-4 in facilitating opioid detoxification.
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Affiliation(s)
- Soyon Ahn
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada
| | - Maya O Nesbit
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada
| | - Haiyan Zou
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada
| | - Giada Vacca
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada
| | - Peter Axerio-Cilies
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada
| | - Tran Van Sung
- Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Anthony G Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, V6T 2A1, Canada.
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