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Kumarihamy M, León F, Pettaway S, Wilson L, Lambert JA, Wang M, Hill C, McCurdy CR, ElSohly MA, Cutler SJ, Muhammad I. In vitro opioid receptor affinity and in vivo behavioral studies of Nelumbo nucifera flower. JOURNAL OF ETHNOPHARMACOLOGY 2015; 174:57-65. [PMID: 26260436 PMCID: PMC4636954 DOI: 10.1016/j.jep.2015.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/09/2015] [Accepted: 08/06/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nelumbo nucifera Geartn., known as sacred lotus, has been used traditionally in South East Asia as a traditional medicine for various CNS disorders including stress, fever, depression, insomnia, and cognitive conditions. AIM OF THE STUDY To investigate the in vitro cannabinoid and opioid receptor binding affinities, and in vivo behavioral actions of Nelumbo flower extracts and to isolate the potential compounds to treat CNS associated disorders. MATERIALS AND METHODS The white and pink flowers of N. nucifera were extracted with 95% EtOH, followed by acid-base partitioning using CHCl3 to give acidic and basic partitions. These partitions were subjected to Centrifugal Preparative TLC (CPTLC) to yield benzyltetrahydroisoquinoline (BTIQ) alkaloids and long chain fatty acids, identified by physical and spectroscopic methods. In addition, EtOH extracts and partitions were analyzed for chemical markers by UHPLC/MS and GC/MS. In vitro neuropharmacological effects were evaluated by cannabinoid (CB1 and CB2) and opioid [delta (δ), kappa (ĸ), and mu (µ)] competitive radioligand binding and GTPγS functional assays. The in vivo behavioral effect was studied through the use of the mouse tetrad assay at 10, 30, 75 and 100mg/kg/ip doses that revealed the effect on locomotion, catalepsy, body temperature, and nociception of acidic and basic CHCl3 partitions, fractions, and compounds. RESULTS Three aporphines, nuciferine (1), N-nor-nuciferine (2), asimilobine (3), and five BTIQs, armepavine (4), O-methylcoclaurine (5), N-methylcoclaurine (6), coclaurine (7), neferine (10), and a mixture of linoleic and palmitic acids (LA and PA), were identified and evaluated for cannabinoid and opioid receptor displacement activities. Compounds 5-7 showed binding affinities for the ĸ opioid receptor with equilibrium dissociation constant (Ki) values of 3.5 ± 0.3, 0.9 ± 0.1, 2.2 ± 0.2 μM, respectively. Compound 10 displayed affinities for δ-and µ- opioid receptors with Ki values of 0.7 ± 0.1 and 1.8 ± 0.2 μM, respectively, and was determined to be a weak δ agonist by GTPγS functional assay. The mixture of LA and PA (1:1) showed an affinity for δ opioid receptor with a Ki value of 9.2 ± 1.1 μM. The acidic and basic CHCl3 partitions, compounds 1 and 7, and 5-7 mixture were subjected to the tetrad assay, of which the acidic partition displayed decreased locomotion and increased catalepsy, antinociception, and hypothermia in animal at doses of 75-100 mg/kg/ip, and also showed clonic-tonic seizures upon touch at 100mg/kg. CONCLUSION Bioassay-guided isolation revealed compounds 5-7, 10, and the mixture of LA and PA displayed various degrees of opioid receptor radioligand displacement affinities. The in vivo tetrad assay of acidic CHCl3 partition, enriched with aporphines 1 and 2, displayed actions on all four points of behavioral parameters. It can be concluded that the in vivo mild canabimimetic-type effect observed for the CHCl3 partition is likely mediated through other CNS mechanisms since the extracts, partitions, and isolated compounds had no affinity for the in vitro CB1 and CB2 receptors. This work, along with traditional use and the reported bioactivities of the BTIQ alkaloids, suggested further studies on N. nucifera are needed to understand the roles that the extracts and/or individual compounds might contribute to the behavioral effects.
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Affiliation(s)
- Mallika Kumarihamy
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Francisco León
- Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Sara Pettaway
- Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Lisa Wilson
- Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Janet A Lambert
- Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Mei Wang
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Christopher Hill
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Christopher R McCurdy
- Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Mahmoud A ElSohly
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA; Department of Pharmaceutics and Drug Delivery, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Stephen J Cutler
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA; Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA
| | - Ilias Muhammad
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA.
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Bisson J, McAlpine JB, Friesen JB, Chen SN, Graham J, Pauli GF. Can Invalid Bioactives Undermine Natural Product-Based Drug Discovery? J Med Chem 2015; 59:1671-90. [PMID: 26505758 PMCID: PMC4791574 DOI: 10.1021/acs.jmedchem.5b01009] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
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High-throughput biology has contributed
a wealth of data on chemicals,
including natural products (NPs). Recently, attention was drawn to
certain, predominantly synthetic, compounds that are responsible for
disproportionate percentages of hits but are false actives. Spurious
bioassay interference led to their designation as pan-assay interference
compounds (PAINS). NPs lack comparable scrutiny,
which this study aims to rectify. Systematic mining of 80+ years of
the phytochemistry and biology literature, using the NAPRALERT database,
revealed that only 39 compounds represent the NPs most reported by
occurrence, activity, and distinct activity. Over 50% are not explained
by phenomena known for synthetic libraries, and all had manifold ascribed
bioactivities, designating them as invalid metabolic panaceas (IMPs). Cumulative
distributions of ∼200,000 NPs uncovered that NP research follows
power-law characteristics typical for behavioral phenomena. Projection
into occurrence–bioactivity–effort space produces the
hyperbolic black hole of NPs, where IMPs populate the high-effort
base.
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Affiliation(s)
| | | | - J Brent Friesen
- Physical Sciences Department, Rosary College of Arts and Sciences, Dominican University , River Forest, Illinois 60305, United States
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