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Xiao JX, Li FX, Ren SJ, Qu J. Studies on the Biomimetic Synthesis of Marine Ladder Polyethers via Endo-Selective Epoxide-to-Epoxonium Ring-Opening Cascades. Angew Chem Int Ed Engl 2024; 63:e202403597. [PMID: 38752455 DOI: 10.1002/anie.202403597] [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: 02/21/2024] [Indexed: 07/16/2024]
Abstract
Marine ladder polyethers have attracted the attention of chemists and biologists because of their potent biological activities. Synthetic chemists have attempted to construct their polyether frameworks by epoxide ring-opening cascades, as Nakanishi hypothesis describes. However, Baldwin's rules of ring closure state that exo-selective intramolecular cyclization of epoxy alcohols is preferred over endo-selective cyclization. Herein, we investigated epoxide ring-opening cascades of polyepoxy alcohols in [EMIM]BF4/PFTB (1-ethyl-3-methylimidazolium tetrafluoroborate /perfluoro-tert-butyl alcohol) and found that all-endo products were formed via epoxide-to-epoxonium ring-opening cyclizations (not restricted by Baldwin's rules, which only apply to intramolecular hydroxyl-to-epoxide cyclizations). We determined that the key factor enabling polyepoxy alcohols to undergo a high proportion of all-endo-selective cyclization was inhibition of exo-selective hydroxyl-to-epoxide cyclization starting from the terminal hydroxyl group of a polyepoxy alcohol. By introducing a slow-release protecting group to the terminal hydroxyl group, we could markedly increase the cyclization yields of polyether fragments with hydrogen atoms at the ring junctions. For the first time, we constructed consecutively fused six-membered-ring and fused seven-, eight-, and nine-membered-ring polyether fragments by epoxide-to-epoxonium ring-opening cyclizations through the addition of a suitable Lewis acid. We also suggest that the biosynthesis of marine ladder polyethers may proceed via epoxide-to-epoxonium ring-opening cyclization of polyepoxide.
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Affiliation(s)
- Jia-Xi Xiao
- College of Chemistry, Nankai University, The State Key Laboratory and Institute of Elemento-Organic Chemistry, Tianjin, 300071, China
| | - Feng-Xing Li
- College of Chemistry, Nankai University, The State Key Laboratory and Institute of Elemento-Organic Chemistry, Tianjin, 300071, China
| | - Shu-Jian Ren
- College of Chemistry, Nankai University, The State Key Laboratory and Institute of Elemento-Organic Chemistry, Tianjin, 300071, China
| | - Jin Qu
- College of Chemistry, Nankai University, The State Key Laboratory and Institute of Elemento-Organic Chemistry, Tianjin, 300071, China
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2
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Genovese M, Galietta LJV. Anoctamin pharmacology. Cell Calcium 2024; 121:102905. [PMID: 38788257 DOI: 10.1016/j.ceca.2024.102905] [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: 03/21/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024]
Abstract
TMEM16 proteins, also known as anoctamins, are a family of ten membrane proteins with various tissue expression and subcellular localization. TMEM16A (anoctamin 1) is a plasma membrane protein that acts as a calcium-activated chloride channel. It is expressed in many types of epithelial cells, smooth muscle cells and some neurons. In airway epithelial cells, TMEM16A expression is particularly enhanced by inflammatory stimuli that also promote goblet cell metaplasia and mucus hypersecretion. Therefore, pharmacological modulation of TMEM16A could be beneficial to improve mucociliary clearance in chronic obstructive respiratory diseases. However, the correct approach to modulate TMEM16A activity (activation or inhibition) is still debated. Pharmacological inhibitors of TMEM16A could also be useful as anti-hypertensive agents given the TMEM16A role in smooth muscle contraction. In contrast to TMEM16A, TMEM16F (anoctamin 6) behaves as a calcium-activated phospholipid scramblase, responsible for the externalization of phosphatidylserine on cell surface. Inhibitors of TMEM16F could be useful as anti-coagulants and anti-viral agents. The role of other anoctamins as therapeutic targets is still unclear since their physiological role is still to be defined.
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Affiliation(s)
- Michele Genovese
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli (NA), Italy
| | - Luis J V Galietta
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli (NA), Italy; Department of Translational Medical Sciences (DISMET), University of Naples "Federico II", Italy.
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Wu K, Kang K, Liu D, Zhang C, Wang X, Zhang M, Li Q. Gold-catalyzed endo-selective Ring-opening of Epoxides and its Application in Construction of Poly-ethers. Chemistry 2024; 30:e202400234. [PMID: 38273816 DOI: 10.1002/chem.202400234] [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: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 01/27/2024]
Abstract
Tetrahydropyran and tetrahydropyran-fused poly-ethers scaffolds are found in many classes of natural products and medicinally relevant small molecules. Here we describe a catalytic system for 6-endo selective ring-opening of epoxides by Au(I) or Au(III) catalyst that provides rapid access to various tetrahydropyran-derived motifs. It also could efficiently construct the subunits of marine ladder-like poly-ethers through emulating the Nakanishi's hypothesis on the biosynthesis of these toxins. The synthetic utility of this method is also demonstrated in the preparation of the tricyclic core of tetrahydropyran-containing macrolide natural products lituarines A-C.
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Affiliation(s)
- Kehuan Wu
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
| | - Kaiwen Kang
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dan Liu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Chiyue Zhang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Xinyu Wang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Miaocheng Zhang
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qi Li
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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4
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Minns LA, Sausman KT, Brown AP, York RA, McCall JR. Karenia brevis Extract Induces Cellular Entry through Distinct Mechanisms in Phagocytic RAW 264.7 Macrophages versus Non-Phagocytic Vero Cells. Mar Drugs 2023; 22:4. [PMID: 38276642 PMCID: PMC10820030 DOI: 10.3390/md22010004] [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: 11/28/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024] Open
Abstract
Marine algae extracts are an important area of potential drug discovery; however, nearly all studies to date have used non-fluorescent-based methods to determine changes in target cell activity. Many of the most robust immunological and cellular analyses rely on fluorescent probes and readouts, which can be problematic when the algae extract is fluorescent itself. In this study, we identified the fluorescent spectrum of an isolated extract from the marine dinoflagellate Karenia brevis, which included two fluorescing components: chlorophyll α and pheophytin α. When excited at 405 nm and 664 nm, the extract emitted fluorescence at 676 nm and 696 nm, respectively. The extract and its fluorescing components, chlorophyll α and pheophytin α, entered phagocytic RAW 264.7 macrophages and non-phagocytic Vero kidney cells through distinct mechanisms. When incubated with the extract and its main components, both the RAW 264.7 macrophages and the Vero cells accumulated fluorescence as early as 30 min and continued through 48 h. Vero kidney cells accumulated the K. brevis fluorescent extract through a dynamin-independent and acidified endosomal-dependent mechanism. RAW 264.7 macrophages accumulated fluorescent extract through a dynamin-independent, acidified endosomal-independent mechanism, which supports accumulation through phagocytosis. Furthermore, RAW 264.7 macrophages downregulated cell-surface expression of CD206 in response to extract stimulation indicating activation of phagocytic responses and potential immunosuppression of these immune cells. This study represents the first characterization of the cellular update of K. brevis extracts in phagocytic versus non-phagocytic cells. The data suggest the importance of understanding cellular uptake of fluorescing algae extracts and their mechanism of action for future drug discovery efforts.
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Affiliation(s)
- Laurie A. Minns
- School of Nursing, College of Health and Human Services, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (L.A.M.)
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
| | - Kathryn T. Sausman
- School of Nursing, College of Health and Human Services, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (L.A.M.)
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
| | - Ariel P. Brown
- School of Nursing, College of Health and Human Services, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (L.A.M.)
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
| | - Robert A. York
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
- Algal Resources Collection, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
| | - Jennifer R. McCall
- School of Nursing, College of Health and Human Services, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (L.A.M.)
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA
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Finol-Urdaneta RK, Zhorov BS, Baden DG, Adams DJ. Brevetoxin versus Brevenal Modulation of Human Nav1 Channels. Mar Drugs 2023; 21:396. [PMID: 37504927 PMCID: PMC10382042 DOI: 10.3390/md21070396] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/29/2023] Open
Abstract
Brevetoxins (PbTx) and brevenal are marine ladder-frame polyethers. PbTx binds to and activates voltage-gated sodium (Nav) channels in native tissues, whereas brevenal antagonizes these actions. However, the effects of PbTx and brevenal on recombinant Nav channel function have not been systematically analyzed. In this study, the PbTx-3 and brevenal modulation of tissue-representative Nav channel subtypes Nav1.2, Nav1.4, Nav1.5, and Nav1.7 were examined using automated patch-clamp. While PbTx-3 and brevenal elicit concentration-dependent and subtype-specific modulatory effects, PbTx-3 is >1000-fold more potent than brevenal. Consistent with effects observed in native tissues, Nav1.2 and Nav1.4 channels were PbTx-3- and brevenal-sensitive, whereas Nav1.5 and Nav1.7 appeared resistant. Interestingly, the incorporation of brevenal in the intracellular solution caused Nav channels to become less sensitive to PbTx-3 actions. Furthermore, we generated a computational model of PbTx-2 bound to the lipid-exposed side of the interface between domains I and IV of Nav1.2. Our results are consistent with competitive antagonism between brevetoxins and brevenal, setting a basis for future mutational analyses of Nav channels' interaction with brevetoxins and brevenal. Our findings provide valuable insights into the functional modulation of Nav channels by brevetoxins and brevenal, which may have implications for the development of new Nav channel modulators with potential therapeutic applications.
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Affiliation(s)
- Rocio K Finol-Urdaneta
- Illawarra Health & Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Boris S Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 Saint Petersburg, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Daniel G Baden
- Center for Marine Science, University of North Carolina Wilmington MARBIONC, Wilmington, NC 28409, USA
| | - David J Adams
- Illawarra Health & Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
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6
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Pesek JJ, Matyska MT, Hiltz T, McCall J. Application of a Cholesterol-Based Stationary Phase for the Analysis of Brevetoxins. J Sep Sci 2023; 46:e2200666. [PMID: 36369995 DOI: 10.1002/jssc.202200666] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/20/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
A high-performance liquid chromatography protocol for the analysis of brevetoxins has been developed using a silica hydride-based cholesterol column. Brevetoxins are neurotoxins produced by harmful algae that have additional potential as drugs for a number of illnesses/diseases. To develop the optimum conditions, a number of different experimental approaches were tested. These include isocratic and gradient elution, different organic mobile phase components, and temperature variations. A separate protocol was developed for the compounds brevenal and brevenol, also produced by the same algae that make brevetoxins. Brevenal is a natural product under investigation as a therapy for chronic respiratory diseases, such as cystic fibrosis or asthma. The goal of this study was to provide a protocol for the analysis of these compounds that could be further developed into a validated method depending on a particular laboratory's capabilities and to highlight some of the unique features of the cholesterol stationary phase.
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Affiliation(s)
- Joseph J Pesek
- Department of Chemistry, San Jose State University, San Jose, California, USA
| | - Maria T Matyska
- Department of Chemistry, San Jose State University, San Jose, California, USA
| | - Tanya Hiltz
- MicroSolv Technology Corporation, Leland, North Carolina, USA
| | - Jennifer McCall
- University of North Carolina Wilmington, College of Health and Human Services, Wilmington, North Carolina, USA
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7
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Sansone C, Balestra C, Pistelli L, Del Mondo A, Osca D, Brunet C, Crocetta F. A Comparative Analysis of Mucus Immunomodulatory Properties from Seven Marine Gastropods from the Mediterranean Sea. Cells 2022; 11:cells11152340. [PMID: 35954185 PMCID: PMC9367618 DOI: 10.3390/cells11152340] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/07/2022] [Accepted: 07/28/2022] [Indexed: 12/10/2022] Open
Abstract
The treatment of inflammatory and immune-related diseases due to dysfunctioning of the immune system necessitates modulation of the immune response through immunomodulatory compounds. Marine environments are considered as a new frontier for health benefit product implementations. Marine biodiversity is still a low explored resource, despite it is expected to represent an important platform for chemical bioactive compounds. Within the phylum Mollusca, gastropods are known to synthetize mucus, the latter presenting relevant bioactive properties, e.g., related to immunomodulant molecules able to activate the innate and acquired immune system. This study proposes a bioprospecting of the immunomodulant activity of mucus isolated from seven common gastropod species from the Gulf of Naples (Mediterranean Sea). Results showed that not all mucus displayed a significant cytotoxic activity on the two human cancer cell lines A549 and A2058. On the other hand, the mucus from Bolinus brandaris was strongly bioactive and was therefore thoroughly investigated at cellular, molecular, and protein levels on the human monocytes U937 line. It can conclusively induce monocyte differentiation in vitro and significantly stimulate natural immunity response.
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Affiliation(s)
- Clementina Sansone
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (C.B.); (L.P.); (A.D.M.); (C.B.)
- Institute of Biomolecular Chemistry, National Council of Reasearch, Via Campi Flegrei 34, I-80078 Pozzuoli, Italy
- Correspondence:
| | - Cecilia Balestra
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (C.B.); (L.P.); (A.D.M.); (C.B.)
- National Institute of Oceanography and Applied Geophysics—OGS, I-34100 Trieste, Italy
| | - Luigi Pistelli
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (C.B.); (L.P.); (A.D.M.); (C.B.)
| | - Angelo Del Mondo
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (C.B.); (L.P.); (A.D.M.); (C.B.)
| | - David Osca
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (D.O.); (F.C.)
| | - Christophe Brunet
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (C.B.); (L.P.); (A.D.M.); (C.B.)
| | - Fabio Crocetta
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Napoli, Italy; (D.O.); (F.C.)
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8
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Pradhan B, Kim H, Abassi S, Ki JS. Toxic Effects and Tumor Promotion Activity of Marine Phytoplankton Toxins: A Review. Toxins (Basel) 2022; 14:397. [PMID: 35737058 PMCID: PMC9229940 DOI: 10.3390/toxins14060397] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/06/2022] [Indexed: 12/25/2022] Open
Abstract
Phytoplankton are photosynthetic microorganisms in aquatic environments that produce many bioactive substances. However, some of them are toxic to aquatic organisms via filter-feeding and are even poisonous to humans through the food chain. Human poisoning from these substances and their serious long-term consequences have resulted in several health threats, including cancer, skin disorders, and other diseases, which have been frequently documented. Seafood poisoning disorders triggered by phytoplankton toxins include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP), and azaspiracid shellfish poisoning (AZP). Accordingly, identifying harmful shellfish poisoning and toxin-producing species and their detrimental effects is urgently required. Although the harmful effects of these toxins are well documented, their possible modes of action are insufficiently understood in terms of clinical symptoms. In this review, we summarize the current state of knowledge regarding phytoplankton toxins and their detrimental consequences, including tumor-promoting activity. The structure, source, and clinical symptoms caused by these toxins, as well as their molecular mechanisms of action on voltage-gated ion channels, are briefly discussed. Moreover, the possible stress-associated reactive oxygen species (ROS)-related modes of action are summarized. Finally, we describe the toxic effects of phytoplankton toxins and discuss future research in the field of stress-associated ROS-related toxicity. Moreover, these toxins can also be used in different pharmacological prospects and can be established as a potent pharmacophore in the near future.
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Affiliation(s)
| | | | | | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (B.P.); (H.K.); (S.A.)
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Pradhan B, Ki JS. Phytoplankton Toxins and Their Potential Therapeutic Applications: A Journey toward the Quest for Potent Pharmaceuticals. Mar Drugs 2022; 20:md20040271. [PMID: 35447944 PMCID: PMC9030253 DOI: 10.3390/md20040271] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/12/2022] [Accepted: 04/16/2022] [Indexed: 02/04/2023] Open
Abstract
Phytoplankton are prominent organisms that contain numerous bioactive substances and secondary metabolites, including toxins, which can be valuable to pharmaceutical, nutraceutical, and biotechnological industries. Studies on toxins produced by phytoplankton such as cyanobacteria, diatoms, and dinoflagellates have become more prevalent in recent years and have sparked much interest in this field of research. Because of their richness and complexity, they have great potential as medicinal remedies and biological exploratory probes. Unfortunately, such toxins are still at the preclinical and clinical stages of development. Phytoplankton toxins are harmful to other organisms and are hazardous to animals and human health. However, they may be effective as therapeutic pharmacological agents for numerous disorders, including dyslipidemia, obesity, cancer, diabetes, and hypertension. In this review, we have focused on the properties of different toxins produced by phytoplankton, as well as their beneficial effects and potential biomedical applications. The anticancer properties exhibited by phytoplankton toxins are mainly attributed to their apoptotic effects. As a result, phytoplankton toxins are a promising strategy for avoiding postponement or cancer treatment. Moreover, they also displayed promising applications in other ailments and diseases such as Alzheimer’s disease, diabetes, AIDS, fungal, bacterial, schizophrenia, inflammation, allergy, osteoporosis, asthma, and pain. Preclinical and clinical applications of phytoplankton toxins, as well as future directions of their enhanced nano-formulations for improved clinical efficacy, have also been reviewed.
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Sem K, Jang M, Pierce R, Blum P, Yu Z. Characterization of Atmospheric Processes of Brevetoxins in Sea Spray Aerosols from Red Tide Events. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1811-1819. [PMID: 35050617 DOI: 10.1021/acs.est.1c05740] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Atmospheric processes can affect the longevity of harmful toxins in sea spray aerosols (SSA). This study characterized the degradation of brevetoxin (BTx) in SSA under different environmental conditions. The samples of seawater collected during a Karenia brevis bloom in Manasota, Florida, were nebulized into a large outdoor photochemical chamber to mimic the atmospheric oxidation of aerosolized toxins and then aged in the presence or absence of sunlight and/or O3. Aerosol samples were collected during the aging process using a Particle-Into-Liquid Sampler. Their BTx concentrations were measured using an enzyme-linked immuno-sorbent assay (ELISA) and high-performance liquid chromatography/tandem mass spectroscopy. The BTx ozonolysis rate constant measured by ELISA was 5.74 ± 0.21 × 103 M-1 s-1. The corresponding lifetime for decay of 87.5% BTx in the presence of 20 ppb of O3 was 7.08 ± 0.26 h, suggesting that aerosolized BTx can still travel long distances at night before SSA deposition. BTx concentrations in SSA decreased more rapidly in the presence of sunlight than in its absence due to oxidation with photochemically produced OH radicals.
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Affiliation(s)
- Karen Sem
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, Florida 32611, United States
| | - Myoseon Jang
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, Florida 32611, United States
| | - Richard Pierce
- Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, Florida 34326, United States
| | - Patricia Blum
- Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, Florida 34326, United States
| | - Zechen Yu
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, Florida 32611, United States
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11
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Hort V, Abadie E, Arnich N, Dechraoui Bottein MY, Amzil Z. Chemodiversity of Brevetoxins and Other Potentially Toxic Metabolites Produced by Karenia spp. and Their Metabolic Products in Marine Organisms. Mar Drugs 2021; 19:656. [PMID: 34940655 PMCID: PMC8709462 DOI: 10.3390/md19120656] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/14/2022] Open
Abstract
In recent decades, more than 130 potentially toxic metabolites originating from dinoflagellate species belonging to the genus Karenia or metabolized by marine organisms have been described. These metabolites include the well-known and large group of brevetoxins (BTXs), responsible for foodborne neurotoxic shellfish poisoning (NSP) and airborne respiratory symptoms in humans. Karenia spp. also produce brevenal, brevisamide and metabolites belonging to the hemi-brevetoxin, brevisin, tamulamide, gymnocin, gymnodimine, brevisulcenal and brevisulcatic acid groups. In this review, we summarize the available knowledge in the literature since 1977 on these various identified metabolites, whether they are produced directly by the producer organisms or biotransformed in marine organisms. Their structures and physicochemical properties are presented and discussed. Among future avenues of research, we highlight the need for more toxin occurrence data with analytical techniques, which can specifically determine the analogs present in samples. New metabolites have yet to be fully described, especially the groups of metabolites discovered in the last two decades (e.g tamulamides). Lastly, this work clarifies the different nomenclatures used in the literature and should help to harmonize practices in the future.
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Affiliation(s)
- Vincent Hort
- Laboratory for Food Safety, Pesticides and Marine Biotoxins Unit, ANSES (French Agency for Food, Environmental and Occupational Health and Safety), 94701 Maisons-Alfort, France
| | - Eric Abadie
- MARBEC (MARine Biodiversity, Exploitation and Conservation), Université de Montpellier, CNRS, Ifremer, IRD, 34200 Sète, France;
| | - Nathalie Arnich
- Risk Assessment Directorate, ANSES (French Agency for Food, Environmental and Occupational Health and Safety), 94701 Maisons-Alfort, France;
| | - Marie-Yasmine Dechraoui Bottein
- Université Côte d’Azur, CNRS, UMR 7035 ECOSEAS, 06103 Nice, France;
- Federative Research Institute—Marine Ressources, Université Côte d’Azur, CNRS, 06108 Nice, France
| | - Zouher Amzil
- Ifremer (French Research Institute for Exploitation of the Sea), 44311 Nantes, France
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Rabinowitz S, Solano JJ. When the Red Tide Rolls In: A Red Tide Associated Angioedema Case Report. Clin Pract Cases Emerg Med 2021; 5:222-225. [PMID: 34437010 PMCID: PMC8143816 DOI: 10.5811/cpcem.2021.3.51920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/12/2021] [Indexed: 12/02/2022] Open
Abstract
Introduction Histamine-mediated angioedema is a potentially life-threatening reaction following exposures that incite mast cell activation. In Florida, red tides are a frequent phenomenon caused by overgrowth of the harmful algae species Karenia brevis, which contain environmentally detrimental brevetoxins. Even in low concentrations, brevetoxins can cause disease in humans through inducing histamine release. We report the first documented case of angioedema associated with red tide exposure. Case Report A 52-year-old-male presented with severe angioedema encompassing both lips within a few hours after exposure to red tide algae. Other symptoms included voice changes and difficulty swallowing. Laboratory findings revealed complement factors that were within reference range, which ruled out a bradykinin-mediated pathology and supported the diagnosis of histaminergic angioedema. Symptoms resolved after 24 hours in the intensive care unit under management with epinephrine, diphenhydramine, methylprednisolone, and famotidine. Conclusion In coastal regions, red tide algae should be recognized as a rare cause of acute angioedema. Emergency management of histamine-mediated angioedema should focus on preventing respiratory compromise with frequent airway monitoring and treatment with steroids, antihistamines, and epinephrine.
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Affiliation(s)
- Sarah Rabinowitz
- Charles E. Schmidt College of Medicine, Department of Emergency Medicine, Boca Raton, Florida
| | - Joshua J Solano
- Charles E. Schmidt College of Medicine, Department of Emergency Medicine, Boca Raton, Florida
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13
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Pinto MC, Silva IAL, Figueira MF, Amaral MD, Lopes-Pacheco M. Pharmacological Modulation of Ion Channels for the Treatment of Cystic Fibrosis. J Exp Pharmacol 2021; 13:693-723. [PMID: 34326672 PMCID: PMC8316759 DOI: 10.2147/jep.s255377] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Cystic fibrosis (CF) is a life-shortening monogenic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, an anion channel that transports chloride and bicarbonate across epithelia. Despite clinical progress in delaying disease progression with symptomatic therapies, these individuals still develop various chronic complications in lungs and other organs, which significantly restricts their life expectancy and quality of life. The development of high-throughput assays to screen drug-like compound libraries have enabled the discovery of highly effective CFTR modulator therapies. These novel therapies target the primary defect underlying CF and are now approved for clinical use for individuals with specific CF genotypes. However, the clinically approved modulators only partially reverse CFTR dysfunction and there is still a considerable number of individuals with CF carrying rare CFTR mutations who remain without any effective CFTR modulator therapy. Accordingly, additional efforts have been pursued to identify novel and more potent CFTR modulators that may benefit a larger CF population. The use of ex vivo individual-derived specimens has also become a powerful tool to evaluate novel drugs and predict their effectiveness in a personalized medicine approach. In addition to CFTR modulators, pro-drugs aiming at modulating alternative ion channels/transporters are under development to compensate for the lack of CFTR function. These therapies may restore normal mucociliary clearance through a mutation-agnostic approach (ie, independent of CFTR mutation) and include inhibitors of the epithelial sodium channel (ENaC), modulators of the calcium-activated channel transmembrane 16A (TMEM16, or anoctamin 1) or of the solute carrier family 26A member 9 (SLC26A9), and anionophores. The present review focuses on recent progress and challenges for the development of ion channel/transporter-modulating drugs for the treatment of CF.
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Affiliation(s)
- Madalena C Pinto
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Iris A L Silva
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miriam F Figueira
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
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14
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Mucus Release and Airway Constriction by TMEM16A May Worsen Pathology in Inflammatory Lung Disease. Int J Mol Sci 2021; 22:ijms22157852. [PMID: 34360618 PMCID: PMC8346050 DOI: 10.3390/ijms22157852] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022] Open
Abstract
Activation of the Ca2+ activated Cl− channel TMEM16A is proposed as a treatment in inflammatory airway disease. It is assumed that activation of TMEM16A will induce electrolyte secretion, and thus reduce airway mucus plugging and improve mucociliary clearance. A benefit of activation of TMEM16A was shown in vitro and in studies in sheep, but others reported an increase in mucus production and airway contraction by activation of TMEM16A. We analyzed expression of TMEM16A in healthy and inflamed human and mouse airways and examined the consequences of activation or inhibition of TMEM16A in asthmatic mice. TMEM16A was found to be upregulated in the lungs of patients with asthma or cystic fibrosis, as well as in the airways of asthmatic mice. Activation or potentiation of TMEM16A by the compounds Eact or brevenal, respectively, induced acute mucus release from airway goblet cells and induced bronchoconstriction in mice in vivo. In contrast, niclosamide, an inhibitor of TMEM16A, blocked mucus production and mucus secretion in vivo and in vitro. Treatment of airway epithelial cells with niclosamide strongly inhibited expression of the essential transcription factor of Th2-dependent inflammation and goblet cell differentiation, SAM pointed domain-containing ETS-like factor (SPDEF). Activation of TMEM16A in people with inflammatory airway diseases is likely to induce mucus secretion along with airway constriction. In contrast, inhibitors of TMEM16A may suppress pulmonary Th2 inflammation, goblet cell metaplasia, mucus production, and bronchoconstriction, partially by inhibiting expression of SPDEF.
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15
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Hofbauer WK. Toxic or Otherwise Harmful Algae and the Built Environment. Toxins (Basel) 2021; 13:465. [PMID: 34209446 PMCID: PMC8310063 DOI: 10.3390/toxins13070465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022] Open
Abstract
This article gives a comprehensive overview on potentially harmful algae occurring in the built environment. Man-made structures provide diverse habitats where algae can grow, mainly aerophytic in nature. Literature reveals that algae that is potentially harmful to humans do occur in the anthropogenic environment in the air, on surfaces or in water bodies. Algae may negatively affect humans in different ways: they may be toxic, allergenic and pathogenic to humans or attack human structures. Toxin-producing alga are represented in the built environment mainly by blue green algae (Cyanoprokaryota). In special occasions, other toxic algae may also be involved. Green algae (Chlorophyta) found airborne or growing on manmade surfaces may be allergenic whereas Cyanoprokaryota and other forms may not only be toxic but also allergenic. Pathogenicity is found only in a special group of algae, especially in the genus Prototheca. In addition, rare cases with infections due to algae with green chloroplasts are reported. Algal action may be involved in the biodeterioration of buildings and works of art, which is still discussed controversially. Whereas in many cases the disfigurement of surfaces and even the corrosion of materials is encountered, in other cases a protective effect on the materials is reported. A comprehensive list of 79 taxa of potentially harmful, airborne algae supplemented with their counterparts occurring in the built environment, is given. Due to global climate change, it is not unlikely that the built environment will suffer from more and higher amounts of harmful algal species in the future. Therefore, intensified research in composition, ecophysiology and development of algal growth in the built environment is indicated.
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Affiliation(s)
- Wolfgang Karl Hofbauer
- Umwelt, Hygiene und Sensorik, Fraunhofer-Institut für Bauphysik, 83626 Valley, Bavaria, Germany
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16
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Fuwa H. Synthesis-Driven Stereochemical Assignment of Marine Polycyclic Ether Natural Products. Mar Drugs 2021; 19:257. [PMID: 33947080 PMCID: PMC8145320 DOI: 10.3390/md19050257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 01/11/2023] Open
Abstract
Marine polycyclic ether natural products have gained significant interest from the chemical community due to their impressively huge molecular architecture and diverse biological functions. The structure assignment of this class of extraordinarily complex natural products has mainly relied on NMR spectroscopic analysis. However, NMR spectroscopic analysis has its own limitations, including configurational assignment of stereogenic centers within conformationally flexible systems. Chemical shift deviation analysis of synthetic model compounds is a reliable means to assign the relative configuration of "difficult" stereogenic centers. The complete configurational assignment must be ultimately established through total synthesis. The aim of this review is to summarize the indispensable role of organic synthesis in stereochemical assignment of marine polycyclic ethers.
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Affiliation(s)
- Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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17
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Li FX, Ren SJ, Li PF, Yang P, Qu J. An Endo-Selective Epoxide-Opening Cascade for the Fast Assembly of the Polycyclic Core Structure of Marine Ladder Polyethers. Angew Chem Int Ed Engl 2020; 59:18473-18478. [PMID: 32666578 DOI: 10.1002/anie.202007980] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Indexed: 12/13/2022]
Abstract
The rapid synthesis of marine ladder polyethers from polyepoxide precursors (in analogy with the biosynthetic pathway hypothesized by Nakanishi) is hampered by the fact that the exo-selective epoxide-opening cyclization cascade that gives THF-type polyethers is preferred over the endo-selective cascade that gives the desired products. We found that perfluoro-tert-butanol (PFTB) cooperating with 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4 ) can promote endo-selective epoxide-opening cyclization reactions of trisubstituted epoxy alcohols. Starting from readily accessible homochiral polyepoxy alcohols with a methyl group at all the endo-cyclization sites, we were able to construct polyethers up to five consecutive fused 6-, 7-, and/or 8-membered rings in one step. Notably, molecules with the 7/7/6/6 and 7/7/6/7/6 polyether frameworks of hemibrevetoxin B and brevenal, respectively, could be synthesized in 40 % and 17 % chemical yields.
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Affiliation(s)
- Feng-Xing Li
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Shu-Jian Ren
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Pei-Fang Li
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Peng Yang
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Jin Qu
- The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
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18
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Li F, Ren S, Li P, Yang P, Qu J. An
Endo
‐Selective Epoxide‐Opening Cascade for the Fast Assembly of the Polycyclic Core Structure of Marine Ladder Polyethers. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Feng‐Xing Li
- The State Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 China
| | - Shu‐Jian Ren
- The State Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 China
| | - Pei‐Fang Li
- The State Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 China
| | - Peng Yang
- The State Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 China
| | - Jin Qu
- The State Key Laboratory and Institute of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 China
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19
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Olson NE, Cooke ME, Shi JH, Birbeck JA, Westrick JA, Ault AP. Harmful Algal Bloom Toxins in Aerosol Generated from Inland Lake Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4769-4780. [PMID: 32186187 DOI: 10.1021/acs.est.9b07727] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Harmful algal blooms (HABs) caused by cyanobacteria in freshwater environments produce toxins (e.g., microcystin) that are harmful to human and animal health. HAB frequency and intensity are increasing with greater nutrient runoff and a warming climate. Lake spray aerosol (LSA) released from freshwater lakes has been identified on lakeshores and after transport inland, including from lakes with HABs, but little is known about the potential for HAB toxins to be incorporated into LSA. In this study, freshwater samples were collected from two lakes in Michigan: Mona Lake during a severe HAB with microcystin concentrations (>200 μg/L) well above the Environmental Protection Agency (EPA) recommended "do not drink" level (1.6 μg/L) and Muskegon Lake without a HAB (<1 μg/L microcystin). Microcystin toxins were identified in freshwater, as well as aerosol particles generated in the laboratory from Mona Lake water by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at atmospheric concentrations up to 50 ± 20 ng/m3. Enrichment of hydrophobic microcystin congeners (e.g., microcystin-LR) was observed in aerosol particles relative to bulk freshwater, while enrichment of hydrophilic microcystin (e.g., microcystin-RR) was lower. As HABs increase in a warming climate, understanding and quantifying the emissions of toxins into the atmosphere is crucial for evaluating the health consequences of HABs.
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Affiliation(s)
- Nicole E Olson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Madeline E Cooke
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jia H Shi
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Johnna A Birbeck
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Judy A Westrick
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Andrew P Ault
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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20
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Fire SE, Miller GA, Wells RS. Explosive exhalations by common bottlenose dolphins during Karenia brevis red tides. Heliyon 2020; 6:e03525. [PMID: 32181395 PMCID: PMC7063161 DOI: 10.1016/j.heliyon.2020.e03525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 09/11/2019] [Accepted: 02/28/2020] [Indexed: 11/30/2022] Open
Abstract
Harmful algal blooms (HABs) such as those produced by Karenia brevis have acute negative impacts on common bottlenose dolphins (Tursiops truncatus) in Florida coastal waters, frequently causing illness and death. However, much less is known about chronic, sub-acute effects on these important sentinel species. This study investigates whether bottlenose dolphin behavior in Sarasota Bay, Florida is influenced by the presence of severe red tide events, focusing on respiratory and other behaviors likely affected by abundant toxin aerosols produced during these blooms. Through focal animal behavioral follows, we observed free-ranging dolphin respiratory behavior, activity budgets, and movement patterns relative to K. brevis abundance in the study area. We compared behavior from dolphins observed during a 2005 K. brevis bloom to those observed during inter-bloom conditions where K. brevis was present at background concentrations. We found that the rate of “chuffing”, an explosive type of exhalation, was significantly greater in dolphins observed during the bloom. No apparent effect on respiratory rate, heading change rate or activity budgets was observed. We propose that this chuffing behavior is analogous to symptoms of respiratory irritation observed in humans exposed to such red tide events, and suggest that this may be a type of disturbance response. With an observed increase in both the frequency and severity of HABs, such disturbance responses may have large-scale chronic impacts to the health and fitness of bottlenose dolphins in regions where such HABs are common.
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Affiliation(s)
- Spencer E Fire
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA.,Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150 W. University Blvd., Melbourne, FL, 32901, USA
| | - Glenn A Miller
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150 W. University Blvd., Melbourne, FL, 32901, USA
| | - Randall S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA
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21
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Keeler DM, Grandal MK, McCall JR. Brevenal, a Marine Natural Product, is Anti-Inflammatory and an Immunomodulator of Macrophage and Lung Epithelial Cells. Mar Drugs 2019; 17:md17030184. [PMID: 30897777 PMCID: PMC6470468 DOI: 10.3390/md17030184] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/14/2019] [Accepted: 03/17/2019] [Indexed: 12/13/2022] Open
Abstract
Chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), cystic fibrosis, and asthma, are some of the leading causes of illness and fatalities worldwide. The search for novel treatments led to the exploration of marine natural products as drug candidates to combat the debilitating effects of mucus accumulation and chronic inflammation. Previous research showed that an alga-derived compound, brevenal, could attenuate the effects of inflammatory agents, but the mechanisms by which it exerted its effects remained unclear. We investigated the effects of brevenal on lipopolysaccharide (LPS) induced cytokine/chemokine production from murine macrophages and human lung epithelial cells. It was found that brevenal reduces proinflammatory mediator secretion while preserving anti-inflammatory secretion from these cells. Furthermore, we found that brevenal does not alter cell surface Toll-like receptor 4 (TLR4) expression, thereby maintaining the cells' ability to respond to bacterial infection. However, brevenal does alter macrophage activation states, as demonstrated by reduced expression of both M1 and M2 phenotype markers, indicating this putative anti-inflammatory drug shifts innate immune cells to a less active state. Such a mechanism of action would be ideal for reducing inflammation in the lung, especially with patients suffering from chronic respiratory diseases, where inflammation can be lethal.
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Affiliation(s)
- Devon M Keeler
- UNCW Center for Marine Science, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA.
| | - Meghan K Grandal
- UNCW Center for Marine Science, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA.
| | - Jennifer R McCall
- UNCW Center for Marine Science, 5600 Marvin K Moss Lane, Wilmington, NC 28409, USA.
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22
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J Kramer B, J Bourdelais A, Kitchen SA, Taylor AR. Uptake and localization of fluorescently-labeled Karenia brevis metabolites in non-toxic marine microbial taxa. JOURNAL OF PHYCOLOGY 2019; 55:47-59. [PMID: 30239000 DOI: 10.1111/jpy.12787] [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: 02/25/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
Brevetoxin (PbTx) is a neurotoxic secondary metabolite of the dinoflagellate Karenia brevis. We used a novel, fluorescent BODIPY-labeled conjugate of brevetoxin congener PbTx-2 (B-PbTx) to track absorption of the metabolite into a variety of marine microbes. The labeled toxin was taken up and brightly fluoresced in lipid-rich regions of several marine microbes including diatoms and coccolithophores. The microzooplankton (20-200 μm) tintinnid ciliate Favella sp. and the rotifer Brachionus rotundiformis also took up B-PbTx. Uptake and intracellular fluorescence of B-PbTx was weak or undetectable in phytoplankton species representative of dinoflagellates, cryptophytes, and cyanobacteria over the same (4 h) time course. The cellular fate of two additional BODIPY-conjugated K. brevis associated secondary metabolites, brevenal (B-Bn) and brevisin (B-Bs), were examined in all the species tested. All taxa exhibited minimal or undetectable fluorescence when exposed to the former conjugate, while most brightly fluoresced when treated with the latter. This is the first study to observe the uptake of fluorescently-tagged brevetoxin conjugates in non-toxic phytoplankton and zooplankton taxa, demonstrating their potential in investigating whether marine microbes can serve as a significant biological sink for algal toxins. The highly variable uptake of B-PbTx observed among taxa suggests some may play a more significant role than others in vectoring lipophilic toxins in the marine environment.
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Affiliation(s)
- Benjamin J Kramer
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Andrea J Bourdelais
- MARBIONC, CREST Research Park, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Sheila A Kitchen
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
| | - Alison R Taylor
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, USA
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23
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Setterholm NA, McDonald FE. Sequential exo-mode oxacyclizations for the synthesis of the CD substructure of brevenal. J Antibiot (Tokyo) 2019; 72:364-374. [PMID: 30607013 DOI: 10.1038/s41429-018-0124-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/19/2018] [Accepted: 10/27/2018] [Indexed: 11/09/2022]
Abstract
We describe a novel strategy for synthesizing the CD bicyclic ether substructure of the fused polycyclic ether natural product brevenal. This product arises from a three-step sequence beginning with (1) regio- and diastereoselective iodoetherification of an acyclic diene-diol, followed by (2) alkene metathesis with an epoxyalkene synthon, concluding with (3) palladium-catalyzed cycloisomerization. Despite the modest yield and long reaction period for the cycloisomerization step, these studies provide valuable insights into the nature of byproducts generated and the mechanisms by which they form. This work demonstrates a portion of a larger synthetic strategy for constructing the pentacyclic core of brevenal from an acyclic precursor.
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Affiliation(s)
| | - Frank E McDonald
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA.
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24
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Kelley EH, Jamison TF. Synthesis of the ABC framework of tamulamides A and B. Bioorg Med Chem 2018; 26:5327-5335. [PMID: 29729986 DOI: 10.1016/j.bmc.2018.04.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 11/29/2022]
Abstract
Synthesis of the fused tetrahydrofuran motif comprising the ABC rings of the marine ladder polyethers tamulamides A and B has been achieved via two different polyepoxide cascade strategies. Investigations into a triepoxide cascade under aqueous conditions revealed the importance of the electronic nature of the cascade end-group with this initial approach. Ultimately, a diepoxide cascade under basic conditions proved most successful, providing the ABC tetrahydropyran triad in 41% yield.
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Affiliation(s)
- Elizabeth H Kelley
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, United States
| | - Timothy F Jamison
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, United States.
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25
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Immune effects of the neurotoxins ciguatoxins and brevetoxins. Toxicon 2018; 149:6-19. [PMID: 29360534 DOI: 10.1016/j.toxicon.2018.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/27/2017] [Accepted: 01/04/2018] [Indexed: 11/21/2022]
Abstract
Ciguatoxins (CTXs) and brevetoxins (PbTxs) are phycotoxins that can accumulate along the marine food chain and thus cause seafood poisoning in humans, namely "ciguatera fish poisoning" (CFP) and "neurotoxic shellfish poisoning" (NSP), respectively. CFP is characterized by early gastrointestinal symptoms and typical sensory disorders (paraesthesia, pain, pruritus and cold dysaesthesia), which can persist several weeks and, in some cases, several months or years. NSP is considered a mild form of CFP with similar but less severe symptoms. After inhaled exposure, PbTxs can also cause respiratory tract irritation in healthy subjects and asthma exacerbations in predisposed subjects, whose respiratory functions may be disrupted for several days following PbTx inhalation. Mechanistically, it is well established that CTX- or PbTx-induced disturbances are primarily mainly due to voltage-gated sodium channel activation in sensory and motor peripheral nervous system. However, little is known about the pathophysiology or a potential individual susceptibility to long lasting effects of CFP/NSP. In addition to their action on the nervous system, PbTxs and CTXs were also shown to exert effects on the immune system. However, their role in the pathophysiology of syndromes induced by CTX or PbTx exposure is poorly documented. The aim of this review is to inventory the literature thus far on the inflammatory and immune effects of PbTxs and CTXs.
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26
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Assunção J, Guedes AC, Malcata FX. Biotechnological and Pharmacological Applications of Biotoxins and Other Bioactive Molecules from Dinoflagellates. Mar Drugs 2017; 15:E393. [PMID: 29261163 PMCID: PMC5742853 DOI: 10.3390/md15120393] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 12/26/2022] Open
Abstract
The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale-with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth-even though shearing-related issues remain a major challenge.
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Affiliation(s)
- Joana Assunção
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
| | - A Catarina Guedes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, P-4450-208 Matosinhos, Portugal.
| | - F Xavier Malcata
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
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27
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Hurtak JA, McDonald FE. Synthesis of the ABC Substructure of Brevenal by Sequential exo-Mode Oxacyclizations of Acyclic Polyene Precursors. Org Lett 2017; 19:6036-6039. [DOI: 10.1021/acs.orglett.7b02538] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jessica A. Hurtak
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Frank E. McDonald
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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Gonzalez-Romero R, Suarez-Ulloa V, Rodriguez-Casariego J, Garcia-Souto D, Diaz G, Smith A, Pasantes JJ, Rand G, Eirin-Lopez JM. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 186:196-204. [PMID: 28315825 DOI: 10.1016/j.aquatox.2017.03.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 06/06/2023]
Abstract
Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs.
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Affiliation(s)
- Rodrigo Gonzalez-Romero
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Victoria Suarez-Ulloa
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Javier Rodriguez-Casariego
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA; Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Daniel Garcia-Souto
- Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo, Spain
| | - Gabriel Diaz
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Abraham Smith
- Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Juan Jose Pasantes
- Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo, Spain
| | - Gary Rand
- Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA.
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Botana LM, Hess P, Munday R, Nathalie A, DeGrasse SL, Feeley M, Suzuki T, van den Berg M, Fattori V, Garrido Gamarro E, Tritscher A, Nakagawa R, Karunasagar I. Derivation of toxicity equivalency factors for marine biotoxins associated with Bivalve Molluscs. Trends Food Sci Technol 2017. [DOI: 10.1016/j.tifs.2016.09.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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McCall JR, Goodman AJ, Jacocks HM, Thompson A, Baden DG, Bourdelais AJ. Development of a fluorescence assay for the characterization of brevenal binding to rat brain synaptosomes. JOURNAL OF NATURAL PRODUCTS 2014; 77:2014-20. [PMID: 25226846 PMCID: PMC4176390 DOI: 10.1021/np500118p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Indexed: 06/03/2023]
Abstract
The marine dinoflagellate Karenia brevis produces a family of neurotoxins known as brevetoxins. Brevetoxins elicit their effects by binding to and activating voltage-sensitive sodium channels (VSSCs) in cell membranes. K. brevis also produces brevenal, a brevetoxin antagonist, which is able to inhibit and/or negate many of the detrimental effects of brevetoxins. Brevenal binding to VSSCs has yet to be fully characterized, in part due to the difficulty and expense of current techniques. In this study, we have developed a novel fluorescence binding assay for the brevenal binding site. Several fluorescent compounds were conjugated to brevenal to assess their effects on brevenal binding. The assay was validated against the radioligand assay for the brevenal binding site and yielded comparable equilibrium inhibition constants. The fluorescence-based assay was shown to be quicker and far less expensive and did not generate radioactive waste or need facilities for handling radioactive materials. In-depth studies using the brevenal conjugates showed that, while brevenal conjugates do bind to a binding site in the VSSC protein complex, they are not displaced by known VSSC site specific ligands. As such, brevenal elicits its action through a novel mechanism and/or currently unknown receptor site on VSSCs.
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Affiliation(s)
- Jennifer R. McCall
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
| | - Allan J. Goodman
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
| | - Henry M. Jacocks
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
| | - Alysha
M. Thompson
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
| | - Daniel G. Baden
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
| | - Andrea J. Bourdelais
- Center
for Marine Science, University of North
Carolina at Wilmington, Wilmington, North Carolina 28409, United States
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Structure activity relationship of brevenal hydrazide derivatives. Mar Drugs 2014; 12:1839-58. [PMID: 24686558 PMCID: PMC4012454 DOI: 10.3390/md12041839] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 11/17/2022] Open
Abstract
Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model.
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Abstract
This review covers the isolation, chemical structure, biological activity, structure activity relationships including synthesis of chemical probes, and pharmacological characterization of neuroactive marine natural products; 302 references are cited.
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Affiliation(s)
- Ryuichi Sakai
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan.
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A nebulized complex traditional Chinese medicine inhibits Histamine and IL-4 production by ovalbumin in guinea pigs and can stabilize mast cells in vitro. Altern Ther Health Med 2013; 13:174. [PMID: 23849630 PMCID: PMC3716888 DOI: 10.1186/1472-6882-13-174] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 07/01/2013] [Indexed: 11/24/2022]
Abstract
Background Traditional Chinese medicines have been used for anti-asthma treatment for several centuries in many Asian countries, and have been shown to effectively relieve symptoms. Our previous study demonstrated that a complex traditional Chinese medicine (CTCM) administered in nebulized form through the intratracheal route is effective against early-phase air-flow obstruction and can inhibit IL-5 production in ovalbumin (OVA)-sensitized guinea pigs. However, the antiasthmatic mechanisms of CTCMs are still unclear. Methods In this study, we examined the underlying mechanism of a CTCM that we used in our previous study in order to ascertain its function in the early-phase response to OVA challenge. In each group, 10–12 unsensitized or OVA-sensitized guinea pigs were treated with nebulized CTCM before OVA challenge, and the airway responses of the animals to OVA were recorded. Bronchoalveolar lavage fluid (BALF) samples were collected 5 min after OVA challenge, and the histamine and IL-4 contents in the BALF were measured. P815 cells (a mouse mast cell line) were untreated or pretreated with CTCM or cromolyn sodium (a mast cell stabilizer), and incubated with Compound 48/80 (mast cell activator) for 9 hr. The levels of histamine and IL-4 released from the cells were quantified. Results We found that the inhibition of bronchoconstriction by the CTCM was attenuated by pretreatment with propranolol, suggesting that the CTCM has a bronchodilator effect that is associated with beta-adrenergic receptor. Our results also showed that the CTCM inhibited histamine and IL-4 secretion in the OVA-induced airway hypersensitivity in guinea pigs at 5 min post-OVA challenge, and in vitro study revealed that the CTCM is able to stabilize mast cells. Conclusion In conclusion, our results suggested that the CTCM is a kind of bronchodilator and also a mast cell stabilizer. Our findings provide useful information regarding the possible mechanism of the CTCM, and show its potential for application in the treatment of allergenic airway disease.
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Gold EP, Jacocks HM, Bourdelais AJ, Baden DG. Brevenal, a brevetoxin antagonist from Karenia brevis, binds to a previously unreported site on mammalian sodium channels. HARMFUL ALGAE 2013; 26:12-19. [PMID: 23789024 PMCID: PMC3684244 DOI: 10.1016/j.hal.2013.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Brevetoxins are a family of ladder-frame polyether toxins produced by the marine dinoflagellate Karenia brevis. During blooms of K. brevis, inhalation of brevetoxins aerosolized by wind and wave action can lead to asthma-like symptoms in persons at the beach. Consumption of either shellfish or finfish contaminated by K. brevis blooms can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are due to binding at a defined site on, and subsequent activation of, voltage-sensitive sodium channels (VSSCs) in cell membranes (site 5). In addition to brevetoxins, K. brevis produces several other ladder-frame compounds. One of these compounds, brevenal, has been shown to antagonize the effects of brevetoxin. In an effort to further characterize to effects of brevenal, a radioactive analog ([3H]-brevenol) was produced by reducing the side-chain terminal aldehyde moiety of brevenal to an alcohol using tritiated sodium borohydride. A KD of 67 nM and Bmax of 7.1 pmol/mg protein were obtained for [3H]-brevenol in rat brain synaptosomes, suggesting a 1:1 matching with VSSCs. Brevenal and brevenol competed for [3H]-brevenol binding with Ki values of 75 nM and 56 nM, respectively. However, although both brevenal and brevenol can inhibit brevetoxin binding, brevetoxin was completely ineffective at competition for [3H]-brevenol binding. After examining other site-specific compounds, it was determined that [3H]-brevenol binds to a site that is distinct from the other known sites including the brevetoxin site (site 5) although some interaction with site 5 is apparent.
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Affiliation(s)
- Elena P. Gold
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Henry M. Jacocks
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Andrea J. Bourdelais
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Daniel G. Baden
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
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Kumar-Roiné S, Taiana Darius H, Matsui M, Fabre N, Haddad M, Chinain M, Pauillac S, Laurent D. A review of traditional remedies of ciguatera fish poisoning in the Pacific. Phytother Res 2012; 25:947-58. [PMID: 21287650 DOI: 10.1002/ptr.3396] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ciguatera fish poisoning (CFP) is an illness caused by eating tropical coral fish contaminated with ciguatoxins (CTXs). The clinical management of patients with CFP is generally supportive and symptomatic in nature as no antidote exists. Of the many drugs prescribed, several have been claimed to be efficient in small, uncontrolled studies, but the outcomes of treatments with these medicines are often contradictory. In New Caledonia, traditional remedies are commonly employed in the treatment of CFP and of the 90 plant species catalogued as useful in CFP, the most popular herbal remedy by far is a decoction prepared from the leaves of Heliotropium foertherianum Diane & Hilger (Boraginaceae). Other important plants used in the treatment of CFP include Euphorbia hirta L. (Euphorbiaceae) and Vitex L. sp. (Lamiaceae). This review focuses on the evidence for efficacy of these species and pharmacological studies which support their use. Other plants used in CFP and the conventional treatment of CFP are also discussed briefly.
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Affiliation(s)
- Shilpa Kumar-Roiné
- UMR 152-Laboratoire de Pharmacochimie des Substances Naturelles et Pharmacophores Redox, Université de Toulouse, UPS, 118 Rte de Narbonne, F-31062 Toulouse Cedex 9, France
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McCall JR, Jacocks HM, Baden DG, Bourdelais AJ. Development of a competitive fluorescence-based synaptosome binding assay for brevetoxins. HARMFUL ALGAE 2012; 19:85-91. [PMID: 22984362 PMCID: PMC3440185 DOI: 10.1016/j.hal.2012.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Brevetoxins are a family of ladder-frame polyether toxins produced during blooms of the marine dinoflagellate Karenia brevis. Inhalation of brevetoxins aerosolized by wind and wave action can lead to asthma-like symptoms in beach goers. Consumption of either shellfish or finfish exposed to K. brevis blooms can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are due to activation of voltage-sensitive sodium channels (VSSCs) in cell membranes. Binding of brevetoxin analogs and competitors to site 5 on these channels has historically been measured using a radioligand competition assay that is fraught with difficulty, including slow analysis time, production of radioactive waste, and cumbersome and expensive methods associated with the generation of radioactive labeled ligands. In this study, we describe the development of a novel fluorescent synaptosome binding assay for the brevetoxin receptor. BODIPY(®)-conjugated to PbTx-2 was used as the labeled ligand. The BODIPY(®)-PbTx-2 conjugate was found to displace [(3)H]-PbTx-3 from its binding site on VSSCs on rat brain synaptosomes with an equilibrium inhibition constant of 0.11 nM. We have shown that brevetoxin A and B analogs are all able to compete for binding with the fluorescent ligand. Most importantly, this assay was validated against the current site 5 receptor binding assay standard, the radioligand receptor assay for the brevetoxin receptor using [(3)H]-PbTx-3 as the labeled ligand. The fluorescence based assay yielded equilibrium inhibition constants comparable to the radioligand assay for all brevetoxin analogs. The fluorescence based assay was quicker, far less expensive, and did not generate radioactive waste or need radioactive facilities. As such, this fluorescence-based assay can be used to replace the current radioligand assay for site 5 on voltage-sensitive sodium channels and will be a vital tool for future experiments examining the binding affinity of various ligands for site 5 on sodium channels.
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Affiliation(s)
- Jennifer R. McCall
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
- Corresponding Author, Tel: 910-962-2081, FAX: 910-962-2410,
| | - Henry M. Jacocks
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Daniel G. Baden
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Andrea J. Bourdelais
- Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
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Helyes Z, Hajna Z. Endotoxin-Induced Airway Inflammation and Asthma Models. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2012. [DOI: 10.1007/978-1-62703-077-9_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Ebine M, Fuwa H, Sasaki M. Total synthesis of (-)-brevenal: a streamlined strategy for practical synthesis of polycyclic ethers. Chemistry 2011; 17:13754-61. [PMID: 22052481 DOI: 10.1002/chem.201101437] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/08/2011] [Indexed: 11/09/2022]
Abstract
We describe a streamlined strategy for the practical synthesis of trans-fused polycyclic ethers and its application to a concise total synthesis of (-)-brevenal, a new pentacyclic polyether natural product with intriguing biological activities. The B-, D-, and E-rings were constructed by TEMPO/PhI(OAc)(2)-mediated oxidative lactonization of the corresponding 1,6-diols, with minimal need for manipulation of oxygen functionalities. The B- and E-ring lactones were appropriately functionalized by Suzuki-Miyaura coupling of lactone-derived enol phosphates and subsequent stereoselective hydroboration. The A-ring was formed by our mixed thioacetalization methodology. The AB- and DE-ring fragments were assembled through Suzuki-Miyaura coupling, and the C-ring was forged in the same manner as that for the A-ring. More than two grams of the pentacyclic polyether core of (-)-brevenal have been synthesized by the synthetic route developed in this study.
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Affiliation(s)
- Makoto Ebine
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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Inhibitory effects of inhaled complex traditional Chinese medicine on early and late asthmatic responses induced by ovalbumin in sensitized guinea pigs. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 11:80. [PMID: 21943157 PMCID: PMC3188474 DOI: 10.1186/1472-6882-11-80] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 09/24/2011] [Indexed: 11/27/2022]
Abstract
Background Many formulae of traditional Chinese medicines (TCMs) have been used for antiasthma treatment dating back many centuries. There is evidence to suggest that TCMs are effective as a cure for this allergenic disease administered via gastric tubes in animal studies; however, their efficacy, safety and side effects as an asthmatic therapy are still unclear. Methods In this study, guinea pigs sensitized with ovalbumin (OVA) were used as an animal model for asthma challenge, and the sensitization of animals by bronchial reactivity to methacholine (Mch) and the IgE concentration in the serum after OVA challenge were estimated. Complex traditional Chinese herbs (CTCM) were administered to the animals by nebulization, and the leukocytes were evaluated from bronchoalveolar lavage fluid (BALF). Results The results showed that inhalation of CTCM could abolish the increased lung resistance (13-fold increase) induced by challenge with OVA in the early asthmatic response (EAR), reducing to as low as baseline (1-fold). Moreover, our results indicated higher IgE levels (range, 78-83 ng/ml) in the serum of sensitized guinea pigs than in the unsensitized controls (0.9 ± 0.256 ng/ml). In addition, increased total leukocytes and higher levels of eosinophils and neutrophils were seen 6 hours after challenge, and the increased inflammatory cells were reduced by treatment with CTCM inhalation. The interleukin-5 (IL-5) level in BALF was also reduced by CTCM. Conclusion Our findings indicate a novel method of administering traditional Chinese medicines for asthma treatment in an animal model that may be more effective than traditional methods.
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Bean JA, Fleming LE, Kirkpatrick B, Backer LC, Nierenberg K, Reich A, Cheng YS, Wanner A, Benson J, Naar J, Pierce R, Abraham WM, Kirkpatrick G, Hollenbeck J, Zaias J, Mendes E, Baden DG. Florida Red Tide Toxins (Brevetoxins) and Longitudinal Respiratory Effects in Asthmatics. HARMFUL ALGAE 2011; 10:744-748. [PMID: 22053149 PMCID: PMC3204579 DOI: 10.1016/j.hal.2011.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Having demonstrated significant and persistent adverse changes in pulmonary function for asthmatics after 1 hour exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols, we assessed the possible longer term health effects in asthmatics from intermittent environmental exposure to brevetoxins over 7 years. 125 asthmatic subjects were assessed for their pulmonary function and reported symptoms before and after 1 hour of environmental exposure to Florida red tide aerosols for upto 11 studies over seven years. As a group, the asthmatics came to the studies with normal standardized percent predicted pulmonary function values. The 38 asthmatics who participated in only one exposure study were more reactive compared to the 36 asthmatics who participated in ≥4 exposure studies. The 36 asthmatics participating in ≥4 exposure studies demonstrated no significant change in their standardized percent predicted pre-exposure pulmonary function over the 7 years of the study. These results indicate that stable asthmatics living in areas with intermittent Florida red tides do not exhibit chronic respiratory effects from intermittent environmental exposure to aerosolized brevetoxins over a 7 year period.
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Affiliation(s)
- Judy A Bean
- Children's Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, 45229
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Osmotic stress triggers toxin production by the dinoflagellate Karenia brevis. Proc Natl Acad Sci U S A 2011; 108:10597-601. [PMID: 21670286 DOI: 10.1073/pnas.1104247108] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
With the increase in frequency of harmful algal blooms (HABs) worldwide, a better understanding of the mechanisms that influence toxin production is needed. Karenia brevis, the major HAB dinoflagellate in the Gulf of Mexico, produces potent neurotoxins, known as brevetoxins. Human health is directly impacted by blooms of K. brevis through consumption of shellfish contaminated by accumulated brevetoxins (neurotoxic shellfish poisoning) or from aerosolized brevetoxins in sea spray (reduced respiratory function); however, the reason for brevetoxin production has remained a mystery. Here we show that brevetoxin production increased dramatically in response to osmotic stress in three of the four K. brevis clones examined. By rapidly changing salinity to simulate a shift from oceanic conditions to a decreased salinity typical of coastal conditions, brevetoxin production was triggered. As a result, brevetoxin cell quota increased by >14-fold, while growth rate remained unchanged. Live images of K. brevis cells were also examined to assess changes in cell volume. In the K. brevis Wilson clone, cells responded quickly to hypoosmotic stress by increasing their brevetoxin cell quota from ∼10 to 160 pg of brevetoxin per cell, while cell volume remained stable. In contrast, the K. brevis SP1 clone, which has a consistently low brevetoxin cell quota (<1 pg per cell), was unable to balance the hypoosmotic stress, and although brevetoxin production remained low, average cell volume increased. Our findings close a critical gap in knowledge regarding mechanisms for toxin production in K. brevis by providing an explanation for toxin production in this harmful dinoflagellate.
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Abstract
This Article describes the total synthesis of the marine ladder toxin brevenal utilizing a convergent synthetic strategy. Critical to the success of this work was the use of olefinic-ester cyclization reactions and the utilization of glycal epoxides as precursors to C-C and C-H bonds.
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Affiliation(s)
- Yuan Zhang
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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Zaias J, Fleming LE, Baden DG, Abraham WM. Repeated exposure to aerosolized brevetoxin-3 induces prolonged airway hyperresponsiveness and lung inflammation in sheep. Inhal Toxicol 2011; 23:205-11. [PMID: 21456953 DOI: 10.3109/08958378.2011.558936] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CONTEXT During a Florida red tide, brevetoxins (PbTxs) produced by Karenia brevis become aerosolized and can cause both immediate and prolonged airway symptoms in humans, especially in those with preexisting airway disease (e.g., asthma). Although environmental monitoring indicates that toxins remain airborne for up to 4 consecutive days, there is little information on airway responses after multiple-day exposures. OBJECTIVES To delineate putative mechanisms leading to pulmonary dysfunction after PbTx exposure, we studied airway responses before and after multiple exposures to aerosol PbTx-3, the most potent PbTx produced, in nonallergic (healthy) and in allergic sheep, which serve as a surrogate for patients with compromised airways. METHODS Both groups were exposed to 20 breaths of increasing concentrations of PbTx-3 (30-300 pg/mL) for 4 consecutive days. Airway responsiveness to carbachol (1 and 8 days after) and airway inflammation as assessed by bronchoalveolar lavage (0 and 7 days after) were measured. RESULTS Both groups developed airway hyperresponsiveness (AHR) 1 day after challenge; the severity was concentration dependent and more severe in the allergic group. AHR remained after 8 days, but the difference in the severity between the groups was lost. Both groups developed an inflammatory response after exposure to 300 pg/mL PbTx-3. Immediately after exposure, lung neutrophilia was prominent. This neutrophilia persisted for 7 days in addition to increases in total cells and macrophages. CONCLUSION Repeated exposures to PbTx-3 result in prolonged AHR and lung inflammation. These pathophysiologic responses could be underlying contributors to the prolonged respiratory symptoms in humans after red tides.
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Affiliation(s)
- Julia Zaias
- University of Miami, Miller School of Medicine, Division of Comparative Pathology, Miami, Florida, 33140 USA
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45
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Kirkpatrick B, Fleming LE, Bean JA, Nierenberg K, Backer LC, Cheng YS, Pierce R, Reich A, Naar J, Wanner A, Abraham WM, Zhou Y, Hollenbeck J, Baden DG. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure. HARMFUL ALGAE 2011; 10:138-143. [PMID: 21499552 PMCID: PMC3076944 DOI: 10.1016/j.hal.2010.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.
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Affiliation(s)
| | - Lora E Fleming
- NSF AND NIEHS Oceans and Human Health Center, University of Miami Rosenstiel School of Marine and Atmospheric Sciences, Miami, Florida, 33149
- University of Miami School of Medicine, Miami, Florida, 33136
| | - Judy A Bean
- Children's Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio, 04524
| | | | - Lorraine C Backer
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, 30341
| | - Yung Sung Cheng
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico, 87108
| | | | - Andrew Reich
- Florida Department of Health, Tallahassee, Florida, 32399
| | - Jerome Naar
- Center for Marine Science, University of North Carolina at Wilmington, Wilmington, NC, 28409
| | - Adam Wanner
- University of Miami School of Medicine, Miami, Florida, 33136
| | | | - Yue Zhou
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico, 87108
| | - Julie Hollenbeck
- NSF AND NIEHS Oceans and Human Health Center, University of Miami Rosenstiel School of Marine and Atmospheric Sciences, Miami, Florida, 33149
| | - Daniel G Baden
- Center for Marine Science, University of North Carolina at Wilmington, Wilmington, NC, 28409
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Fleming LE, Kirkpatrick B, Backer LC, Walsh CJ, Nierenberg K, Clark J, Reich A, Hollenbeck J, Benson J, Cheng YS, Naar J, Pierce R, Bourdelais AJ, Abraham WM, Kirkpatrick G, Zaias J, Wanner A, Mendes E, Shalat S, Hoagland P, Stephan W, Bean J, Watkins S, Clarke T, Byrne M, Baden DG. Review of Florida Red Tide and Human Health Effects. HARMFUL ALGAE 2011; 10:224-233. [PMID: 21218152 PMCID: PMC3014608 DOI: 10.1016/j.hal.2010.08.006] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.
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Affiliation(s)
- Lora E Fleming
- NSF NIEHS Oceans and Human Health Center, University of Miami, 4600 Rickenbacker Causeway, Miami, FL, 33149
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Fuwa H, Ebine M, Sasaki M. Recent Applications of the Suzuki-Miyaura Cross-coupling to Complex Polycyclic Ether Synthesis. J SYN ORG CHEM JPN 2011. [DOI: 10.5059/yukigoseikyokaishi.69.1251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Fuwa H. Total Synthesis of Structurally Complex Marine Oxacyclic Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2010. [DOI: 10.1246/bcsj.20100209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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49
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Brevetoxin-2 induces an inflammatory response in an alveolar macrophage cell line. Int J Hyg Environ Health 2010; 213:352-8. [DOI: 10.1016/j.ijheh.2010.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 06/16/2010] [Accepted: 06/24/2010] [Indexed: 01/05/2023]
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50
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Crimmins MT, Shamszad M, Mattson AE. A highly convergent approach toward (-)-brevenal. Org Lett 2010; 12:2614-7. [PMID: 20446718 DOI: 10.1021/ol1008203] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Progress toward a highly convergent, asymmetric synthesis of brevenal is reported. Construction of the AB-ring and E-ring cyclic ether fragments was achieved through asymmetric alkylation/ring-closing metathesis strategies. A Horner-Wadsworth-Emmons olefination was used in a key bond-forming step to couple the advanced cyclic fragments and enable rapid access to the AB-E ring system.
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Affiliation(s)
- Michael T Crimmins
- Kenan and Caudill Laboratories of Chemistry, University of North Carolina at Chapel Hill, North Carolina 27599, USA.
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