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Liu X, Xiang J, Fan S, Chen X, Peng C, Xu Z. 20S-Ginsenoside Rh2, the major bioactive saponin in Panax notoginseng flowers, ameliorates cough by inhibition of NaV1.7 and TRPV1 channel currents and downregulation of TRPV1 expression. JOURNAL OF ETHNOPHARMACOLOGY 2025; 336:118716. [PMID: 39179055 DOI: 10.1016/j.jep.2024.118716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 08/13/2024] [Accepted: 08/19/2024] [Indexed: 08/26/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Panax notoginseng flowers, which are the buds of the traditional Chinese medicinal herb Sanqi, are widely used in China for their cough-ameliorating properties, with demonstrated therapeutic effects in the treatment of both acute and chronic coughs. However, both the antitussive mechanism and active compound basis of P. notoginseng flowers remain poorly understood. AIM OF THE STUDY We investigated the antitussive effects of P. notoginseng flowers, identified the bioactive constituents responsible for alleviating cough symptoms, and elucidated the underlying pharmacological mechanisms. MATERIALS AND METHODS We analyzed the major chemical constituents of aqueous extracts of P. notoginseng flowers using liquid chromatography-mass spectrometry and quantitatively analyzed the key component, 20S-ginsenoside Rh2, using high-performance liquid chromatography. Using a cough reflex model in healthy mice and an ovalbumin-induced, highly sensitive guinea pig cough model, we verified the suppressive effects of P. notoginseng flowers and their saponin constituents on coughing. Furthermore, we explored the mechanisms of action of the key ion channels, NaV1.7 and TRPV1, using whole-cell patch-clamp techniques and molecular docking. Finally, the therapeutic mechanisms of P. notoginseng flowers on pathological cough were revealed using hematoxylin and eosin staining, immunohistochemistry, and western blotting. RESULTS The active components of P. notoginseng flowers were primarily protopanaxadiol-type saponins, among which 20S-ginsenoside Rh2 had the highest content (51.46 mg/g). In the mouse model, P. notoginseng flowers exhibited antitussive effects comparable to those of pentoxyverine citrate. Although its main saponin component, 20S-ginsenoside Rh2, showed slightly weaker effects, it still demonstrated concentration-dependent inhibition of channel activity. The whole-cell patch-clamp technique and virtual molecular docking showed that Rh2 might exert its effects by directly binding to the NaV1.7 and TRPV1 channels. In the guinea pig model, P. notoginseng flowers and their saponin components not only reduced cough frequency and prolonged the latency period before cough onset, but also significantly inhibited tracheal and pulmonary inflammation and the overexpression of TRPV1. CONCLUSIONS 20S-Ginsenoside Rh2, the major bioactive saponin in P. notoginseng flowers, exhibits potent antitussive effects. The potential mechanism of action of 20S-Ginsenoside Rh2 in the treatment of cough may involve inhibiting NaV1.7 and TRPV1 channel currents through direct binding to core protein active sites and downregulating TRPV1 expression.
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Affiliation(s)
- Xiao Liu
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Jie Xiang
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Shuyuan Fan
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Xumin Chen
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Chengzhan Peng
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Zhengxin Xu
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou, 225009, China; Jiangsu Key Laboratory of Experimental & Translational Non-Coding RNA Research, Yangzhou, 225009, China; Yeda Institute of Gene and Cell Therapy, Taizhou, 318000, China.
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Yang L, Zou H, Gao Y, Luo J, Xie X, Meng W, Zhou H, Tan Z. Insights into gastrointestinal microbiota-generated ginsenoside metabolites and their bioactivities. Drug Metab Rev 2020; 52:125-138. [PMID: 31984805 DOI: 10.1080/03602532.2020.1714645] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The gastrointestinal microbiota and host co-evolve into a complex 'super-organism,' and this relationship plays a vital role in many physiological processes, such as drug metabolism. Ginseng is an important medicinal resource and the main ingredients are ginsenosides, which are less polar, difficult to absorb, and have low bioavailability. However, studies have shown that the biological activity of ginsenosides such as compound K (CK), ginsenoside Rg3 (Rg3), ginsenoside Rh2 (Rh2), 20(S)-protopanaxatriol (20(S)-PPT), and 20(S)-protopanaxadiol (20(S)-PPD) is closely related to the gastrointestinal microbiota. In this paper, the metabolic pathway of gastrointestinal microbiota-generated ginsenosides and the main pharmacological effects of these metabolites are discussed. Furthermore, our study provides a new insight into the discovery of novel drugs. Specifically, in new drug screening process, candidates with low biological activity and bioavailability should not be excluded. Because their metabolites may exhibit good pharmacological effects due to the involvement of the gastrointestinal microbiota. In addition, in further research studies to develop probiotics, a combination of agents could exert greater efficacy than single agents. Moreover, differences in lifestyle and diet lead to differences in the gastrointestinal microbiota in the human body. Therefore, administration of the same drug dose to different individuals could elicit different therapeutic effects, owing to the involvement of the gastrointestinal microbiota. Thus, treatment accuracy could be achieved by detecting the gastrointestinal microbiota before drug treatment.HighlightsGastrointestinal microbiota plays a decisive role in bioactivities of ginsenosides.The metabolic pathway and main pharmacological effects of ginsenoside metabolites are discussed.It provides new insights into novel drug discovery and further research to find probiotic, combinations to exert greater efficacy.Differences in lifestyle and diet, varies the gastrointestinal microbiota in the human body. However, the same dose of a drug producing different therapeutic effects may involve gastrointestinal microbiota.
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Affiliation(s)
- Li Yang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Hecun Zou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China.,Institute of Life Sciences, Chongqing Medical University, Chongqing, Hunan, PR China
| | - Yongchao Gao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Junjia Luo
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Xiaonv Xie
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Wenhui Meng
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Honghao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
| | - Zhirong Tan
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, PR China.,Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha, PR China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, Changsha, PR China.,National Clinical Research Center for Geriatric Disorders, Changsha, Hunan, PR China
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Jakaria M, Kim J, Karthivashan G, Park SY, Ganesan P, Choi DK. Emerging signals modulating potential of ginseng and its active compounds focusing on neurodegenerative diseases. J Ginseng Res 2018; 43:163-171. [PMID: 30976157 PMCID: PMC6437449 DOI: 10.1016/j.jgr.2018.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 01/08/2018] [Accepted: 01/12/2018] [Indexed: 02/08/2023] Open
Abstract
Common features of neurodegenerative diseases (NDDs) include progressive dysfunctions and neuronal injuries leading to deterioration in normal brain functions. At present, ginseng is one of the most frequently used natural products. Its use has a long history as a cure for various diseases because its extracts and active compounds exhibit several pharmacological properties against several disorders. However, the pathophysiology of NDDs is not fully clear, but researchers have found that various ion channels and specific signaling pathways might have contributed to the disease pathogenesis. Apart from the different pharmacological potentials, ginseng and its active compounds modulate various ion channels and specific molecular signaling pathways related to the nervous system. Here, we discuss the signal modulating potential of ginseng and its active compounds mainly focusing on those relevant to NDDs.
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Affiliation(s)
- Md Jakaria
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, Republic of Korea
| | - Joonsoo Kim
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, Republic of Korea
| | - Govindarajan Karthivashan
- Research Institute of Inflammatory Disease, and Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea
| | - Shin-Young Park
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, Republic of Korea
| | - Palanivel Ganesan
- Research Institute of Inflammatory Disease, and Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.,Nanotechnology Research Center, Konkuk University, Chungju, Republic of Korea
| | - Dong-Kug Choi
- Department of Applied Life Science, Graduate School, Konkuk University, Chungju, Republic of Korea.,Research Institute of Inflammatory Disease, and Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.,Nanotechnology Research Center, Konkuk University, Chungju, Republic of Korea
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Jiang S, Fang DF, Chen Y. Involvement of N-Methyl-D-Aspartic Acid Receptor and DL-α-Amino-3-Hydroxy-5- Methyl-4-Isoxazole Propionic Acid Receptor in Ginsenosides Rb1 and Rb3 against Oxygen-Glucose Deprivation-Induced Injury in Hippocampal Slices from Rat. Pharmacology 2017; 101:133-139. [PMID: 29207398 DOI: 10.1159/000481710] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/22/2017] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Ginsenosides, Rb1 and Rb3, are the major protopanaxadiol components of ginseng saponin. In the present study, the influences of ginsenosides Rb1 and Rb3 on N-methyl-D-aspartic acid (NMDA) receptor or DL-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor-mediated synaptic transmission after oxygen-glucose deprivation (OGD) were investigated. METHODS NMDA receptor population spike (NMDA-PS) or AMPA receptor-mediated population spike (AMPA-PS) was recorded in the CA1 pyramidal cell layer of rat hippocampal slices by electrophysiological techniques. RESULTS Under normal conditions, ginsenosides Rb3 and Rb1 depressed glutamate receptors-mediated synaptic transmission. Fourteen min of OGD resulted in a poor recovery amplitude of NMDA-PS or AMPA-PS after reoxygenation. Ginsenoside Rb3 significantly delayed the appearance of transient recovery of PS during OGD, and improved the recovery amplitudes of NMDA-PS and AMPA-PS after reoxygenation. However, the similar protective effects of ginsenoside Rb1 were observed only on NMDA-PS but not AMPA-PS. CONCLUSION These results suggest that ginsenosides Rb1 and Rb3 have the different inhibitions on NMDA and AMPA receptors-mediated response, which may partially explain the different protective effects of these agents on ischemic neuronal death.
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Affiliation(s)
- Shan Jiang
- Department of Anatomy and Physiology, Lianyungang Branch of Traditional Chinese Medicine, Jiangsu Union Technical Institute, Lianyungang, China
| | - De-Fang Fang
- Department of Anatomy and Physiology, Lianyungang Branch of Traditional Chinese Medicine, Jiangsu Union Technical Institute, Lianyungang, China
| | - Ying Chen
- Department of Anesthesiology, The First People's Hospital of Lianyungang, Lianyungang, China
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Liu ZY, Zhang HY, Bi Y, Liu XX, Lu J, Zhang XC, Xu JY, Wang CZ, Yuan CS. Design and synthesis of 28-hydroxy protopanaxadiol as a novel probe template. Nat Prod Res 2017; 31:1523-1528. [PMID: 28107791 DOI: 10.1080/14786419.2017.1280488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
To explore the antitumour mechanism of 20(S)-protopanaxadiol (PPD) while maintaining its uncovered pharmacological active site 3-hydroxyl, 28-hydroxy protopanaxadiol (17), a small molecular probe template of PPD was first designed and synthesised based on the Baldwin's reaction. Thus, 28-hydroxyl of 17 was built successfully as a derivatized site of molecular probe's functional and report groups. The important intermediates and final product were confirmed by ESI-MS and nuclear magnetic resonance spectra with good yield. These studies provided a valuable basis for probe research of PPD.
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Affiliation(s)
- Ze-Yun Liu
- a School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong , Yantai University , Yantai , China
| | - Heng-Yuan Zhang
- b State Key Laboratory of Natural Medicines and Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing , China
| | - Yi Bi
- a School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong , Yantai University , Yantai , China
| | - Xian-Xuan Liu
- a School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong , Yantai University , Yantai , China
| | - Jing Lu
- a School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong , Yantai University , Yantai , China
| | - Xiao-Chen Zhang
- a School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong , Yantai University , Yantai , China
| | - Jin-Yi Xu
- b State Key Laboratory of Natural Medicines and Department of Medicinal Chemistry , China Pharmaceutical University , Nanjing , China
| | - Chong-Zhi Wang
- c Tang Center for Herbal Medicine Research , University of Chicago , Chicago , IL , USA.,d Department of Anesthesia and Critical Care , University of Chicago , Chicago , IL , USA
| | - Chun-Su Yuan
- c Tang Center for Herbal Medicine Research , University of Chicago , Chicago , IL , USA.,d Department of Anesthesia and Critical Care , University of Chicago , Chicago , IL , USA
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Smith I, Williamson EM, Putnam S, Farrimond J, Whalley BJ. Effects and mechanisms of ginseng and ginsenosides on cognition. Nutr Rev 2014; 72:319-33. [DOI: 10.1111/nure.12099] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Imogen Smith
- School of Chemistry; Food and Nutritional Sciences and Pharmacy; University of Reading; Reading Berkshire UK
| | - Elizabeth M Williamson
- School of Chemistry; Food and Nutritional Sciences and Pharmacy; University of Reading; Reading Berkshire UK
| | | | | | - Benjamin J Whalley
- School of Chemistry; Food and Nutritional Sciences and Pharmacy; University of Reading; Reading Berkshire UK
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Nah SY. Ginseng ginsenoside pharmacology in the nervous system: involvement in the regulation of ion channels and receptors. Front Physiol 2014; 5:98. [PMID: 24678300 PMCID: PMC3958645 DOI: 10.3389/fphys.2014.00098] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 02/27/2014] [Indexed: 01/05/2023] Open
Abstract
Ginseng, the root of Panax ginseng C.A. Meyer, is one of the oldest traditional medicines and is thought to be a tonic. It has been claimed that ginseng may improve vitality and health. Recent studies have advanced ginseng pharmacology and shown that ginseng has various pharmacological effects in the nervous system. Ginsenosides, steroid glycosides extracted from ginseng, were one of the first class of biologically active plant glycosides identified. The diverse pharmacological effects of ginsenosides have been investigated through the regulation of various types of ion channels and receptors in neuronal cells and heterologous expression systems. Ginsenoside Rg3 regulates voltage-gated ion channels such as Ca(2+), K(+), and Na(+) channels, and ligand-gated ion channels such as GABAA, 5-HT3, nicotinic acetylcholine, and N-methyl-D-aspartate (NMDA) receptors through interactions with various sites including channel blocker binding sites, toxin-binding sites, channel gating regions, and allosteric channel regulator binding sites when the respective ion channels or receptors are stimulated with depolarization or ligand treatment. Treatment with ginsenoside Rg3 has been found to stabilize excitable cells by blocking influxes of cations such as Ca(2+) and Na(+), or by enhancing Cl(-) influx. The aim of this review is to present recent findings on the pharmacological functions of the ginsenosides through the interactions with ion channels and receptors. This review will detail the pharmacological applications of ginsenosides as neuroprotective drugs that target ion channels and ligand-gated ion channels.
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Affiliation(s)
- Seung-Yeol Nah
- Ginsentology Research Laboratory, Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University Seoul, South Korea
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Bao Y, Wang Q, Tang P. Lithium adduct as precursor ion for sensitive and rapid quantification of 20 (S)-protopanaxadiol in rat plasma by liquid chromatography/quadrupole linear ion trap mass spectrometry and application to rat pharmacokinetic study. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:399-405. [PMID: 23494798 DOI: 10.1002/jms.3174] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/17/2013] [Accepted: 01/20/2013] [Indexed: 06/01/2023]
Abstract
A novel, rapid and sensitive liquid chromatography/quadrupole linear ion trap mass spectrometry [LC-ESI-(QqLIT)MS/MS] method was developed and validated for the quantification of protopanaxadiol (PPD) in rat plasma. Oleanolic acid (OA) was used as internal standard (IS). A simple protein precipitation based on acetonitrile (ACN) was employed. Chromatographic separation was performed on a Sepax GP-C18 column (50 × 2.1 mm, 5 μM) with a mobile phase consisting of ACN-water and 1.5 μM formic acid and 25 mM lithium acetate (90 : 10, v/v) at a flow rate of 0.4 ml/min for 3.0 min. Multiple-reaction-monitoring mode was performed using lithium adduct ion as precursor ion of m/z 467.5/449.4 and 455.6/407.4 for the drug and IS, respectively. Calibration curve was recovered over a concentration range of 0.5-100 ng/ml with a correlation coefficient >0.99. The limit of detection was 0.2 ng/ml in rat plasma for PPD. The results of the intraday and interday precision and accuracy studies were well within the acceptable limits. The validated method was successfully applied to investigate the pharmacokinetic study of PPD after intravenous and gavage administration to rat.
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Affiliation(s)
- Yuanwu Bao
- Sundia MediTech Company Ltd., 388 Jialilue Road Building 9, Zhangjiang High-Tech Park, Shanghai 201203, China
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Wang ZJ, Sun L, Peng W, Ma S, Zhu C, Fu F, Heinbockel T. Ginseng derivative ocotillol enhances neuronal activity through increased glutamate release: a possible mechanism underlying increased spontaneous locomotor activity of mice. Neuroscience 2011; 195:1-8. [PMID: 21864652 DOI: 10.1016/j.neuroscience.2011.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 06/06/2011] [Accepted: 08/02/2011] [Indexed: 10/17/2022]
Abstract
Ginsenosides are the main active ingredients in ginseng and have recently been reported to have beneficial effects on the CNS. Ocotillol is a derivate of pseudoginsenoside-F11, which is an ocotillol-type ginsenoside found in American ginseng. We examined the effects of ocotillol (a) on neuronal activity of projection neurons, mitral cells (MC), in a mouse olfactory bulb brain slice preparation using whole-cell patch-clamp recording, and (b) on animal behavior by measuring locomotor activity of mice in vivo. Ocotillol displayed an excitatory effect on spontaneous action potential firing and depolarized the membrane potential of MCs. The effect was concentration-dependent, with an EC(50) of 4 μM. In the presence of blockers of ionotropic glutamatergic and GABAergic synaptic transmission (6-cyano-7-nitroquinoxaline-2,3-dione [CNQX], 10 μM; D-AP5, 50 μM; gabazine, 5 μM), the excitatory effect of ocotillol on firing was abolished. Further experiments showed that the ocotillol-induced neuronal excitation persisted in the presence of GABA(A) receptor antagonist gabazine but was eliminated by applying AMPA/kainate receptor antagonist CNQX and N-methyl-d-aspartate (NMDA) receptor antagonist D-AP5, suggesting that ionotropic glutamate transmission was involved in mediating the effects of ocotillol. Bath application of ocotillol evoked an inward current as well as an increased frequency of spontaneous glutamatergic excitatory postsynaptic currents (EPSCs). Both the inward current and sEPSCs could be blocked by ionotropic glutamate receptor antagonists CNQX and D-AP5. These results indicate that the excitatory action of ocotillol on MCs was mediated by enhanced glutamate release. Behavioral experiments demonstrated that ocotillol increased locomotor activities of mice. Our results suggest that ocotillol-evoked neuronal excitability was mediated by increased release of glutamate, which may be responsible for the increased spontaneous locomotor activities in vivo.
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Affiliation(s)
- Z-J Wang
- Department of Anatomy, Howard University College of Medicine, 520 W Street North West, Washington, DC 20059, USA
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Abstract
Ginsenosides are a special group of triterpenoid saponins attributed to medical effects of ginseng. Therefore, they have been research targets over the last three decades to explain ginseng actions and a wealth of literature has been presented reporting on ginsenosides' effects on the human body. Recently, there is increasing evidence on beneficial effects of ginsenosides to the central nervous system (CNS). Using a wide range of in vitro and in vivo models, researchers have attributed these effects to specific pharmacological actions of ginsenosides on cerebral metabolism, oxidative stress and radical formation, neurotransmitter imbalance and membrane stabilizing effects, and even antiapoptotic effects. Modulating these particular mechanisms by ginsenosides has thus been reported to exert either general stimulatory effects on the brain functions or protecting the CNS against various disease conditions. In this review, we try to address the recently reported ginsenosides' actions on different CNS targets particularly those supporting possible therapeutic efficacies in CNS disorders and neurodegenerative diseases.
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Affiliation(s)
- Khaled Radad
- Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
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