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Hu M, Xu M, Chen Y, Ye Z, Zhu S, Cai J, Zhang M, Zhang C, Huang R, Ye Q, Ao H. Therapeutic potential of toosendanin: Novel applications of an old ascaris repellent as a drug candidate. Biomed Pharmacother 2023; 167:115541. [PMID: 37738795 DOI: 10.1016/j.biopha.2023.115541] [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: 08/08/2023] [Revised: 09/13/2023] [Accepted: 09/17/2023] [Indexed: 09/24/2023] Open
Abstract
Toosendanin (TSN), extracted from Melia. toosendan Sieb.et Zucc. and Melia. azedarach L., has been developed into an ascaris repellent in China. However, with the improvement of public health protection, the incidence of ascariasis has been reduced considerably, resulting in limited medical application of TSN. Therefore, it is questionable whether this old ascaris repellent can develop into a drug candidate. Modern studies have shown that TSN has strong pharmacological activities, including anti-tumor, anti-botulinum, anti-viral and anti-parasitic potentials. It also can regulate fat formation and improve inflammation. These researches indicate that TSN has great potential to be developed into a corresponding medical product. In order to better development and application of TSN, the availability, pharmacodynamics, pharmacokinetics and toxicology of TSN are summarized systematically. In addition, this review discusses shortcomings in the current researches and provides useful suggestions about how TSN developed into a drug candidate. Therefore, this paper illustrates the possibility of developing TSN as a medical product, aimed to provide directions for the clinical application and further research of TSN.
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Affiliation(s)
- Minghao Hu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Min Xu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Yuchen Chen
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Zhangkai Ye
- Xinjiang Normal University, Urumqi 830017, Xinjiang, China
| | - Shunpeng Zhu
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Jia Cai
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Mengxue Zhang
- First School of Clinical Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Chi Zhang
- School of health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China
| | - Ruizhen Huang
- Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610072, China.
| | - Qiang Ye
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China.
| | - Hui Ao
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China; Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, Sichuan, China.
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Dissanayake KN, Margetiny F, Whitmore CL, Chou RCC, Roesl C, Patel V, McArdle JJ, Webster R, Beeson D, Tattersall JEH, Wyllie DJA, Eddleston M, Ribchester RR. Antagonistic postsynaptic and presynaptic actions of cyclohexanol on neuromuscular synaptic transmission and function. J Physiol 2021; 599:5417-5449. [PMID: 34748643 DOI: 10.1113/jp281921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/01/2021] [Indexed: 01/20/2023] Open
Abstract
Intentional ingestion of agricultural organophosphorus insecticides is a significant public health issue in rural Asia, causing thousands of deaths annually. Some survivors develop a severe, acute or delayed myasthenic syndrome. In animal models, similar myasthenia has been associated with increasing plasma concentration of one insecticide solvent metabolite, cyclohexanol. We investigated possible mechanisms using voltage and current recordings from mouse neuromuscular junctions (NMJs) and transfected human cell lines. Cyclohexanol (10-25 mM) reduced endplate potential (EPP) amplitudes by 10-40% and enhanced depression during repetitive (2-20 Hz) stimulation by up to 60%. EPP decay was prolonged more than twofold. Miniature EPPs were attenuated by more than 50%. Cyclohexanol inhibited whole-cell currents recorded from CN21 cells expressing human postjunctional acetylcholine receptors (hnAChR) with an IC50 of 3.74 mM. Cyclohexanol (10-20 mM) also caused prolonged episodes of reduced-current, multi-channel bursting in outside-out patch recordings from hnAChRs expressed in transfected HEK293T cells, reducing charge transfer by more than 50%. Molecular modelling indicated cyclohexanol binding (-6 kcal/mol) to a previously identified alcohol binding site on nicotinic AChR α-subunits. Cyclohexanol also increased quantal content of evoked transmitter release by ∼50%. In perineurial recordings, cyclohexanol selectively inhibited presynaptic K+ currents. Modelling indicated cyclohexanol binding (-3.8 kcal/mol) to voltage-sensitive K+ channels at the same site as tetraethylammonium (TEA). TEA (10 mM) blocked K+ channels more effectively than cyclohexanol but EPPs were more prolonged in 20 mM cyclohexanol. The results explain the pattern of neuromuscular dysfunction following ingestion of organophosphorus insecticides containing cyclohexanol precursors and suggest that cyclohexanol may facilitate investigation of mechanisms regulating synaptic strength at NMJs. KEY POINTS: Intentional ingestion of agricultural organophosphorus insecticides is a significant public health issue in rural Asia, causing thousands of deaths annually. Survivors may develop a severe myasthenic syndrome or paralysis, associated with increased plasma levels of cyclohexanol, an insecticide solvent metabolite. Analysis of synaptic transmission at neuromuscular junctions in isolated mouse skeletal muscle, using isometric tension recording and microelectrode recording of endplate voltages and currents, showed that cyclohexanol reduced postsynaptic sensitivity to acetylcholine neurotransmitter (reduced quantal size) while simultaneously enhancing evoked transmitter release (increased quantal content). Patch recording from transfected cell lines, together with molecular modelling, indicated that cyclohexanol causes selective, allosteric antagonism of postsynaptic nicotinic acetylcholine receptors and block of presynaptic K+ -channel function. The data provide insight into the cellular and molecular mechanisms of neuromuscular weakness following intentional ingestion of agricultural organophosphorus insecticides. Our findings also extend understanding of the effects of alcohols on synaptic transmission and homeostatic synaptic function.
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Affiliation(s)
- Kosala N Dissanayake
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Pharmacology, Toxicology and Therapeutics, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Filip Margetiny
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Robert C-C Chou
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Cornelia Roesl
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Vishwendra Patel
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, State University of New Jersey, Newark, NJ, USA
| | - Joseph J McArdle
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, State University of New Jersey, Newark, NJ, USA
| | - Richard Webster
- Weatherall Institute for Molecular Medicine, Radcliffe Infirmary, Oxford, UK
| | - David Beeson
- Weatherall Institute for Molecular Medicine, Radcliffe Infirmary, Oxford, UK
| | | | - David J A Wyllie
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Michael Eddleston
- Pharmacology, Toxicology and Therapeutics, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
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Fang XF, Cui ZJ. The anti-botulism triterpenoid toosendanin elicits calcium increase and exocytosis in rat sensory neurons. Cell Mol Neurobiol 2011; 31:1151-62. [PMID: 21656151 DOI: 10.1007/s10571-011-9716-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 05/20/2011] [Indexed: 02/07/2023]
Abstract
Toosendanin, a triterpenoid from Melia toosendan Sieb et Zucc, has been found before to be an effective anti-botulism agent, with a bi-phasic effect at both motor nerve endings and central synapse: an initial facilitation followed by prolonged depression. Initial facilitation may be due to activation of voltage-dependent calcium channels plus inhibition of potassium channels, but the depression is not fully understood. Toosendanin has no effect on intracellular calcium or secretion in the non-excitable pancreatic acinar cells, ruling out general toosendanin inhibition of exocytosis. In this study, toosendanin effects on sensory neurons isolated from rat nodose ganglia were investigated. It was found that toosendanin stimulated increases in cytosolic calcium and neuronal exocytosis dose dependently. Experiments with membrane potential indicator bis-(1,3-dibutylbarbituric acid)trimethine oxonol found that toosendanin hyperpolarized capsaicin-insensitive but depolarized capsaicin-sensitive neurons; high potassium-induced calcium increase was much smaller in hyperpolarizing neurons than in depolarizing neurons, whereas no difference was found for potassium-induced depolarization in these two types of neurons. In neurons showing spontaneous calcium oscillations, toosendanin increased the oscillatory amplitude but not frequency. Toosendanin-induced calcium increase was decreased in calcium-free buffer, by nifedipine, and by transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine. Simultaneous measurements of cytosolic and endoplasmic reticulum (ER) calcium showed an increase in cytosolic but a decrease in ER calcium, indicating that toosendanin triggered ER calcium release. These data together indicate that toosendanin modulates sensory neurons, but had opposite effects on membrane potential depending on the presence or absence of capsaicin receptor/TRPV 1 channel.
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Affiliation(s)
- Xiao Feng Fang
- Institute of Cell Biology, Beijing Normal University, Beijing 100875, China
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Affiliation(s)
- Qin-Gang Tan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, P.R.China
- Guilin Medical University, Guilin, 541004, P.R.China
| | - Xiao-Dong Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, P.R.China
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Larsen JC. U.S. Army Botulinum Neurotoxin (BoNT) Medical Therapeutics Research Program: past accomplishments and future directions. Drug Dev Res 2009. [DOI: 10.1002/ddr.20304] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Shi YL, Li MF. Biological effects of toosendanin, a triterpenoid extracted from Chinese traditional medicine. Prog Neurobiol 2007; 82:1-10. [PMID: 17363132 DOI: 10.1016/j.pneurobio.2007.02.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 11/27/2006] [Accepted: 02/06/2007] [Indexed: 11/21/2022]
Abstract
Toosendanin (TSN) is a triterpenoid extracted from Melia toosendan Sieb et Zucc, which was used as a digestive tract-parasiticide and agricultural insecticide in ancient China. TSN was demonstrated to be a selective presynaptic blocker and an effective antibotulismic agent. By interfering with neurotransmitter release through an initial facilitation followed by a subsequent depression, TSN eventually blocks synaptic transmission at both the neuro-muscular junction and central synapses. Despite sharing some similar actions with botulinum neurotoxin (BoNT), TSN has a marked antibotulismic effect in vivo and in vitro. Studies suggest that the antibotulismic effect of TSN is achieved by preventing BoNT from approaching its enzymatic substrate, the SNARE protein. It is also found that TSN can induce differentiation and apoptosis in several cell lines, and suppress proliferation of various human cancer cells. TSN inhibits various K(+)-channels, selectively facilitates Ca(2+)-influx via L-type Ca(2+) channels and increases intracellular Ca(2+) concentration ([Ca(2+)](i)). The TSN-induced [Ca(2+)](i) increase and overload could be responsible for the TSN-induced biphasic effect on transmitter release, cell differentiation, apoptosis as well as the cytoxicity of TSN.
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Affiliation(s)
- Yu-Liang Shi
- Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, PR China.
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Li MF, Shi YL. Toosendanin, a triterpenoid derivative, acts as a novel agonist of L-type Ca2+ channels in neonatal rat ventricular cells. Eur J Pharmacol 2004; 501:71-8. [PMID: 15464064 DOI: 10.1016/j.ejphar.2004.08.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 08/05/2004] [Accepted: 08/10/2004] [Indexed: 10/26/2022]
Abstract
Toosendanin, a triterpenoid derivative extracted from Melia toosendan Sieb et Zucc, was demonstrated to be potentially useful in medical and scientific researches. Here, we investigated the effects of toosendanin on L-type voltage-dependent Ca(2+) channels in cultured neonatal rat ventricular cells, using whole-cell patch-clamp method. Toosendanin irreversibly increased L-type Ca(2+) current (I(Ca(L))) in a concentration-dependent manner and shifted the maximum of the current/voltage relationship from 8.3+/-3.7 to 1.7+/-3.7 mV, without modifying the threshold potential of the current. Toosendanin shifted the steady-state activation and inactivation curves to the left. The deactivation kinetics of the I(Ca(L)) was significantly slowed by toosendanin while the activation kinetics was not affected. The cells pretreated with 100 nM 1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-3-pyridinecarboxylic acid methyl ester (S(-)-BayK8644) still respond to further addition of 87 microM toosendanin, and vice versa. These results prove toosendanin to be a novel L-type Ca(2+) channel agonist, which possesses a distinct binding site from BayK8644.
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Affiliation(s)
- Mu-Feng Li
- Key Laboratory of Neurobiology, Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, P.R. China
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Xu TH, Ding J, Shi YL, Li MF, Lu CZ, Qiao J. Effects of myasthenia gravis patients' sera with different autoantibodies on slow K+ current at mouse motor nerve terminals. Neurol Res 2003; 25:58-62. [PMID: 12564127 DOI: 10.1179/016164103101200932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The antibodies against pre-synaptic membrane receptor (PsmR) and acetylcholine receptor (AChR) in serum samples of myasthenia gravis (MG) patients and healthy donors were tested by enzyme-linked immunosorbent assays (ELISA). The serum samples of eight MG patients with different autoantibodies and those of six healthy donors without these two kinds of autoantibodies were collected to investigate their effects on the peri-neurially recorded membrane currents at mouse motor nerve terminals. After inhibition of both fast and Ca(2+)-dependent K+ currents by tetra-ethylammonium (TEA), a positive wave was revealed, which was a balance of the slow K+(Ik,s) and Ca2+ currents (ICa). Application of anti-PsmR antibody negative MG sera and healthy donor sera, whether anti-AChR antibody positive or negative, did not affect the positive wave. However, the positive wave shifted to prolonged Ca(2+)-plateau when adding two of four anti-PsmR antibody positive serum samples from MG patients, indicating an inhibition of Ik,s by anti-PsmR antibody positive sera. Meanwhile, all serum samples derived from either patients or healthy donors did not affect INa.
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Affiliation(s)
- Tong-Hui Xu
- Key Laboratory of Neurobiology, Institute of Physiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P.R. China
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Abstract
AIM Toosendanin is a pre-synaptic blocker at the neuromuscular junction and its inhibitory effect is divided into an initial facilitative/stimulatory phase followed by a prolonged inhibitory phase. The present study investigated whether the subsequent inhibitory phase was due to exhaustion of the secretory machinery as a result of extensive stimulation during the initial facilitative phase. More specifically, this paper examined whether toosendanin could directly inhibit the secretory machinery in exocrine cells. METHODS Rat pancreatic acinar cells were isolated by collagenase digestion. Secretion was assessed by measuring the amount of amylase released into the extracellular medium as a percentage of the total present in the cells before stimulation. Cholecystokinin (CCK)-induced increases in intracellular calcium in single cells were measured with fura-2 microfluorometry. RESULTS Effects of toosendanin on CCK-induced amylase secretion and calcium oscillations were investigated. Toosendanin of 87-870 microM had no effect on 10 pM-100 nM CCK-stimulated amylase secretion, nor did 8.7-870 microM toosendanin inhibit 5 pM CCK-induced calcium oscillations. In contrast, 10 nM CCK(1) receptor antagonist FK 480 completely blocked 5 pM CCK-induced calcium oscillations. CONCLUSION The pre-synaptic "blocker" toosendanin is a selective activator of the voltage-dependent calcium channels, but does not interfere with the secretory machinery itself.
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Affiliation(s)
- Zong-Jie Cui
- Institute of Cell Biology, Beijing Normal University, Beijing 100875, China.
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