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22 pages, 5946 KiB

Open AccessArticle

Effects of Various Marine Toxins on the Mouse Intestine Organoid Model

by Nengzhuang Wang, Minghua Liu, Fengrui Bi, Long Ma, Lina Qin, Yao Wang, Kai Gu, Xuemei Ge and Hongli Yan

Toxins 2022, 14(12), 829; https://doi.org/10.3390/toxins14120829 - 24 Nov 2022

Cited by 3 | Viewed by 1795

Abstract

Because of their trace existence, exquisite structure and unique role, highly toxic marine biotoxins have always led to the development of natural product identification, structure and function research, chemistry and biosynthesis, and there are still many deficiencies in the injury and protection of [...] Read more.

Because of their trace existence, exquisite structure and unique role, highly toxic marine biotoxins have always led to the development of natural product identification, structure and function research, chemistry and biosynthesis, and there are still many deficiencies in the injury and protection of highly toxic organisms, toxin biosynthesis, rapid detection, poisoning and diagnosis and treatment. In this study, a mouse intestine organoid (MIO) model was constructed to explore the effects of the marine toxins okadaic acid (OA) and conotoxin (CgTx) on MIO. The results showed that the cell mortality caused by the two toxins at middle and high concentrations was significantly higher than the cell mortality of the control group, the ATPase activity in each group exposed to OA was significantly lower than the ATPase activity of the control group, all the CgTx groups were significantly higher than that of the control group, and the number of apoptotic cells was not significantly higher than the number of apoptotic cells of the control group. Through RNA-Seq differential genes, Gene Ontology (GO) and pathway analysis, and Gene Set Enrichment Analysis (GSEA) experimental results, it was demonstrated that OA reduced cell metabolism and energy production by affecting cell transcription in MIO. Ultimately, cell death resulted. In contrast, CgTx upregulated the intracellular hormone metabolism pathway by affecting the nuclear receptor pathway of MIO, which resulted in cell death and the generation of energy in large amounts. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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14 pages, 2644 KiB

Open AccessArticle

Toxic Responses of Different Shellfish Species after Exposure to Prorocentrum lima, a DSP Toxins Producing Dinoflagellate

by Mei-Hua Ye, Da-Wei Li, Qiu-Die Cai, Yu-Hu Jiao, Yang Liu, Hong-Ye Li and Wei-Dong Yang

Toxins 2022, 14(7), 461; https://doi.org/10.3390/toxins14070461 - 5 Jul 2022

Cited by 8 | Viewed by 2391

Abstract

Prorocentrum lima is a global benthic dinoflagellate that produces diarrhetic shellfish poisoning (DSP) toxins, which can be ingested by filter-feeding bivalves, and eventually pose a great threat to human health through food chain. After being exposed to P. lima, different bivalves may [...] Read more.

Prorocentrum lima is a global benthic dinoflagellate that produces diarrhetic shellfish poisoning (DSP) toxins, which can be ingested by filter-feeding bivalves, and eventually pose a great threat to human health through food chain. After being exposed to P. lima, different bivalves may accumulate various levels of DSP toxins and display different toxic responses. However, the underlying mechanism remains unclear. Here, we found that the content of okadaic acid-equivalents (OA-eq) varied in the digestive glands of the three bivalves including Crassostrea gigas, Mytilus coruscus and Tegillarca granosa after P. lima exposure. The degree of esterification of OA-eq in the three bivalves were opposite to the accumulation of OA-eq. The digestive gland tissues of the three bivalve species were damaged to different degrees. The transcriptional induction of Nrf2 targeted genes such as ABCB1 and GPx indicates the functionality of Nrf2 pathway against DSP toxins in bivalves. The oyster could protect against DSP toxins mainly through ABC transporters and esterification, while the mussel and clam reduce the damage induced by DSP toxins mainly by regulating the expression of antioxidant genes. Our findings may provide some explanations for the difference in toxic response to DSP toxins in different shellfish. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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13 pages, 1495 KiB

Open AccessArticle

Matrix Effect of Diverse Biological Samples Extracted with Different Extraction Ratios on the Detection of β-N-Methylamino-L-Alanine by Two Common LC-MS/MS Analysis Methods

by Peng Zhao, Jiangbing Qiu, Aifeng Li, Guowang Yan, Min Li and Ying Ji

Toxins 2022, 14(6), 387; https://doi.org/10.3390/toxins14060387 - 2 Jun 2022

Cited by 3 | Viewed by 2365

Abstract

Neurotoxin β-N-methylamino-L-alanine (BMAA) is hypothesized as an important pathogenic factor for neurodegenerative diseases such as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS-PDC). Comparative study on the accuracy of BMAA analyzed by the regular LC-MS/MS methods is still limited for different biological matrices. In [...] Read more.

Neurotoxin β-N-methylamino-L-alanine (BMAA) is hypothesized as an important pathogenic factor for neurodegenerative diseases such as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS-PDC). Comparative study on the accuracy of BMAA analyzed by the regular LC-MS/MS methods is still limited for different biological matrices. In this study, a free-BMAA sample of cyanobacterium and BMAA-containing positive samples of diatom, mussel, scallop, and oyster were extracted with varied extraction ratios (ER) ranging from 1:20 to 1:2000. These extracts were then purified by MCX cartridges. After SPE purification, these different biological samples were analyzed by two common LC-MS/MS analysis methods, a direct analysis without derivatization by a hydrophilic interaction liquid chromatography (HILIC)-MS/MS and pre-column 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatization combined with a C18 column. The results suggested that the recoveries of BMAA spiked in the cyanobacterial sample were close to 100% in the total soluble form extracts with the ER of 1:100 (g/mL) and the precipitated bound form extracts with the ER of 1:500. The recommended ER for the precipitated bound form of BMAA in diatoms and the total soluble form of BMAA in mollusks are 1:500 and 1:50, respectively. The quantitative results determined by the AQC derivatization method were lower than those determined by the direct analysis of the HILIC method in diatom and mollusk samples. The results of the HILIC method without the derivatization process were closer to the true value of BMAA in cyanobacteria. This work contributes to the performance of the solid-phase extraction (SPE) purification protocol and the accuracy of BMAA analysis by LC-MS/MS in diverse biological samples. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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12 pages, 2657 KiB

Open AccessArticle

Proteomic Studies of the Mechanism of Cytotoxicity, Induced by Palytoxin on HaCaT Cells

by Dingyuan Cheng, Bowen Deng, Qiling Tong, Siyi Gao, Boyi Xiao, Mengxuan Zhu, Ziyu Ren, Lianghua Wang and Mingjuan Sun

Toxins 2022, 14(4), 269; https://doi.org/10.3390/toxins14040269 - 10 Apr 2022

Cited by 2 | Viewed by 3452

Abstract

Palytoxin (PLTX) is a polyether marine toxin isolated from sea anemones. It is one of the most toxic nonprotein substances, causing many people to be poisoned every year and to die in severe cases. Despite its known impact on Na⁺,K⁺ [...] Read more.

Palytoxin (PLTX) is a polyether marine toxin isolated from sea anemones. It is one of the most toxic nonprotein substances, causing many people to be poisoned every year and to die in severe cases. Despite its known impact on Na⁺,K⁺-ATPase, much still remains unclear about PLTX’s mechanism of action. Here, we tested different concentrations of PLTX on HaCaT cells and studied its distributions in cells, its impact on gene expression, and the associated pathways via proteomics combined with bioinformatics tools. We found that PLTX could cause ferroptosis in HaCaT cells, a new type of programmed cell death, by up-regulating the expression of VDAC3, ACSL4 and NCOA4, which lead to the occurrence of ferroptosis. PLTX also acts on the MAPK pathway, which is related to cell apoptosis, proliferation, division and differentiation. Different from its effect on ferroptosis, PLTX down-regulates the expression of ERK, and, as a result, the expressions of MAPK1, MAP2K1 and MAP2K2 are also lower, affecting cell proliferation. The genes from these two mechanisms showed interactions, but we did not find overlap genes between the two. Both ferroptosis and MAPK pathways can be used as anticancer targets, so PLTX may become an anticancer drug with appropriate modification. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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16 pages, 5330 KiB

Open AccessArticle

Preparation and Evaluation of a Horse Antiserum against the Venom of Sea Snake Hydrophis curtus from Hainan, China

by Bo Wang, Guoyan Liu, Min Luo, Xin Zhang, Qianqian Wang, Shuaijun Zou, Fuhai Zhang, Xia Jin and Liming Zhang

Toxins 2022, 14(4), 253; https://doi.org/10.3390/toxins14040253 - 1 Apr 2022

Viewed by 2462

Abstract

Sea snake venom is extremely toxic, and it can induce severe respiratory failure and cause high mortality. The most effective first aid treatment for sea snake bites is to inject antivenom as soon as possible. However, in China, there are only four types [...] Read more.

Sea snake venom is extremely toxic, and it can induce severe respiratory failure and cause high mortality. The most effective first aid treatment for sea snake bites is to inject antivenom as soon as possible. However, in China, there are only four types of terrestrial snake antivenoms, none of which are effective in the treatment of sea snake bites. In order to develop an antivenom for the dominant species of sea snakes in Chinese seas, Hydrophis curtus venom (HcuV) was chosen as the antigen to immunize horses. From immune plasma, a high-titer Hydrophis curtus antivenom (HcuAV) was prepared. In vitro assessment showed that HcuAV had a cross-neutralizing capacity against HcuV and Hydrophis cyanocinctus venom (HcyV). In vivo assessment indicated that HcuAV injection could significantly improve the survival rates of the HcuV and HcyV envenomated mice (0% to 100% and 87.5%, respectively) when it was injected at a sufficient amount within the shortest possible time. In addition, HcuAV could also effectively alleviate multiple organ injuries caused by HcuV. These results provide experimental support for the future clinical application of HcuAV. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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19 pages, 3302 KiB

Open AccessArticle

A Novel SELEX Based on Immobilizing Libraries Enables Screening of Saxitoxin Aptamers for BLI Aptasensor Applications

by Rong Zhou, Yun Gao, Chengfang Yang, Xiaojuan Zhang, Bo Hu, Luming Zhao, Han Guo, Mingjuan Sun, Lianghua Wang and Binghua Jiao

Toxins 2022, 14(3), 228; https://doi.org/10.3390/toxins14030228 - 21 Mar 2022

Cited by 11 | Viewed by 3612

Abstract

Saxitoxin (STX) is one of the potent marine biotoxins that has high rate of lethality. However, there are no effective treatments at present, and the existing detection methods need to be further explored because of ethical problems or technical limitations. In this work, [...] Read more.

Saxitoxin (STX) is one of the potent marine biotoxins that has high rate of lethality. However, there are no effective treatments at present, and the existing detection methods need to be further explored because of ethical problems or technical limitations. In this work, oligonucleotide aptamers toward STX were screened based on immobilizing libraries on Immobilized Metal-Chelate (IMC), such as Ni-NTA Sepharose, and the IMC-SELEX was conducted by the G-quadruplex library and the random library, respectively. Aptamer 45e (from the G-quadruplex library) and aptamer 75a were obtained after optimization, and aptamer 45e turned out to have a higher affinity toward STX. Furthermore, it was found that the hydrogen bonding and the van der Waals forces (VDW) played major roles in the high efficiency and specificity between STX and 45e by means of molecular docking and dynamics simulation. Based on this, aptamer 45e-1 with the K_d value of 19 nM was obtained by further optimization, which was then used to construct a simple, label-free and real-time optical BLI aptasensor for the detection of STX. This aptasensor showed good reproducibility and stability. In summary, with the advantages of screening aptamers of high efficiency and specificity toward the targets, the proposed IMC-SELEX provides a promising screening strategy for discovering aptamers, which could be used as the potential molecular recognition elements in the fields of biomedicine, food safety and environmental monitoring. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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20 pages, 2229 KiB

Open AccessArticle

Selection, Characterization, and Optimization of DNA Aptamers against Challenging Marine Biotoxin Gymnodimine-A for Biosensing Application

by Xiaojuan Zhang, Yun Gao, Bowen Deng, Bo Hu, Luming Zhao, Han Guo, Chengfang Yang, Zhenxia Ma, Mingjuan Sun, Binghua Jiao and Lianghua Wang

Toxins 2022, 14(3), 195; https://doi.org/10.3390/toxins14030195 - 5 Mar 2022

Cited by 9 | Viewed by 2973

Abstract

Gymnodimines (GYMs), belonging to cyclic imines (CIs), are characterized as fast-acting toxins, and may pose potential risks to human health and the aquaculture industry through the contamination of sea food. The existing detection methods of GYMs have certain defects in practice, such as [...] Read more.

Gymnodimines (GYMs), belonging to cyclic imines (CIs), are characterized as fast-acting toxins, and may pose potential risks to human health and the aquaculture industry through the contamination of sea food. The existing detection methods of GYMs have certain defects in practice, such as ethical problems or the requirement of complicated equipment. As novel molecular recognition elements, aptamers have been applied in many areas, including the detection of marine biotoxins. However, GYMs are liposoluble molecules with low molecular weight and limited numbers of chemical groups, which are considered as “challenging” targets for aptamers selection. In this study, Capture-SELEX was used as the main strategy in screening aptamers targeting gymnodimine-A (GYM-A), and an aptamer named G48nop, with the highest K_D value of 95.30 nM, was successfully obtained by screening and optimization. G48nop showed high specificity towards GYM-A. Based on this, a novel aptasensor based on biolayer interferometry (BLI) technology was established in detecting GYM-A. This aptasensor showed a detection range from 55 to 1400 nM (linear range from 55 to 875 nM) and a limit of detection (LOD) of 6.21 nM. Spiking experiments in real samples indicated the recovery rate of this aptasensor, ranging from 96.65% to 109.67%. This is the first study to report an aptamer with high affinity and specificity for the challenging marine biotoxin GYM-A, and the new established aptasensor may be used as a reliable and efficient tool for the detection and monitoring of GYMs in the future. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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12 pages, 3076 KiB

Open AccessArticle

Development of Immunochromatographic Strip for Detection of αB-VxXXIVA-Conotoxin Based on 5E4 Monoclonal Antibody

by Hengkun Tang, Haimei Liu, Rui Chen, Yehong Gao, Mingke Dong, Sumei Ling, Rongzhi Wang and Shihua Wang

Toxins 2022, 14(3), 191; https://doi.org/10.3390/toxins14030191 - 4 Mar 2022

Cited by 6 | Viewed by 2853

Abstract

Given the application of αB-VxXXIVA-conotoxin (αB-CTX) in analgesics and cancer chemotherapeutics, and its threat to humans, it is urgent to develop a rapid, effective and accurate method for the analysis and detection of αB-CTX in real shellfish and medicine drug samples. In the [...] Read more.

Given the application of αB-VxXXIVA-conotoxin (αB-CTX) in analgesics and cancer chemotherapeutics, and its threat to humans, it is urgent to develop a rapid, effective and accurate method for the analysis and detection of αB-CTX in real shellfish and medicine drug samples. In the present study, two different immunochromatographic strips were established for αB-CTX detection, based on the monoclonal antibody 5E4 against αB-CTX, and the visual limits of detection (vLOD) for the colloidal gold nanoparticles-based strip (AuNPs-based strip) and nanoflowers-based strip (AuNFs-based strip) were 4 μg/mL and 1.5 μg/mL, respectively. The developed AuNPs-/AuNFs-based strips have good specificity and accuracy, and the detection results were analyzed in less than 10 min, without using an instrument. In view of the excellent repeatability and usability, the established methods could be applied to detect and analyze the content of αB-CTX in real samples. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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13 pages, 1342 KiB

Open AccessCommunication

Concentrations of Tetrodotoxin (TTX) and Its Analogue 4,9-Anhydro TTX in Different Tissues of the Silver-Cheeked Pufferfish (Lagocephalus sceleratus, Gmelin, 1789) Caught in the South-Eastern Mediterranean Sea, Lebanon

by Abed El Rahman Hassoun, Ivana Ujević, Sharif Jemaa, Romana Roje-Busatto, Céline Mahfouz, Milad Fakhri and Nikša Nazlić

Toxins 2022, 14(2), 123; https://doi.org/10.3390/toxins14020123 - 8 Feb 2022

Cited by 10 | Viewed by 3099

Abstract

Pufferfishes are among the best-known marine organisms that accumulate marine biotoxins such as Tetrodotoxin (TTX). In the Mediterranean Sea, the silver-cheeked toadfish Lagocephalus sceleratus is the most reported TTX-bearer, causing many fatal and non-fatal cases. In Lebanon, no previous studies have measured TTX [...] Read more.

Pufferfishes are among the best-known marine organisms that accumulate marine biotoxins such as Tetrodotoxin (TTX). In the Mediterranean Sea, the silver-cheeked toadfish Lagocephalus sceleratus is the most reported TTX-bearer, causing many fatal and non-fatal cases. In Lebanon, no previous studies have measured TTX levels although the possibility of TTX-poisoning is high since L. sceleratus is caught in different sizes and can be mistaken with other small fishes. Hence, this study reports TTX and its analogue 4,9-anhydro TTX in L. sceleratus collected from Lebanese waters in the Eastern Mediterranean Sea. The results show that TTX concentrations in fish tissues varied between 0.10 and 252.97 µg/g, while those of 4,9-anhydro TTX oscillated between 0.01 and 43.01 µg/g. Internal organs of L. sceleratus were the most toxic parts of its body, with the highest TTX levels found in gonads (mainly ovaries) and liver, followed by the muscles and skin with concentrations always exceeding the safety level. Toxicity fluctuations of L. sceleratus, its expansion, ecological and economic effects were also elucidated. Based on the present findings, it has been confirmed that L. sceleratus constitutes a health, ecological and economic risks, and therefore its trade in seafood markets should be banned to avoid any potential intoxication. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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13 pages, 1203 KiB

Open AccessArticle

The Caspase Homologues in Scallop Chlamys farreri and Their Expression Responses to Toxic Dinoflagellates Exposure

by Zhongcheng Wei, Wei Ding, Moli Li, Jiaoxia Shi, Huizhen Wang, Yangrui Wang, Yubo Li, Yiqiang Xu, Jingjie Hu, Zhenmin Bao and Xiaoli Hu

Toxins 2022, 14(2), 108; https://doi.org/10.3390/toxins14020108 - 31 Jan 2022

Cited by 6 | Viewed by 2665

Abstract

The cysteine aspartic acid-specific protease (caspase) family is distributed across vertebrates and invertebrates, and its members are involved in apoptosis and response to cellular stress. The Zhikong scallop (Chlamys farreri) is a bivalve mollusc that is well adapted to complex marine [...] Read more.

The cysteine aspartic acid-specific protease (caspase) family is distributed across vertebrates and invertebrates, and its members are involved in apoptosis and response to cellular stress. The Zhikong scallop (Chlamys farreri) is a bivalve mollusc that is well adapted to complex marine environments, yet the diversity of caspase homologues and their expression patterns in the Zhikong scallop remain largely unknown. Here, we identified 30 caspase homologues in the genome of the Zhikong scallop and analysed their expression dynamics during all developmental stages and following exposure to paralytic shellfish toxins (PSTs). The 30 caspase homologues were classified as initiators (caspases-2/9 and caspases-8/10) or executioners (caspases-3/6/7 and caspases-3/6/7-like) and displayed increased copy numbers compared to those in vertebrates. Almost all of the caspase-2/9 genes were highly expressed throughout all developmental stages from zygote to juvenile, and their expression in the digestive gland and kidney was slightly influenced by PSTs. The caspase-8/10 genes were highly expressed in the digestive gland and kidney, while PSTs inhibited their expression in these two organs. After exposure to different Alexandrium PST-producing algae (AM-1 and ACDH), the number of significantly up-regulated caspase homologues in the digestive gland increased with the toxicity level of PST derivatives, which might be due to the higher toxicity of GTXs produced by AM-1 compared to the N-sulphocarbamoyl analogues produced by ACDH. However, the effect of these two PST-producing algae strains on caspase expression in the kidney seemed to be stronger, possibly because the PST derivatives were transformed into highly toxic compounds in scallop kidney, and suggested an organ-dependent response to PSTs. These results indicate the dedicated control of caspase gene expression and highlight their contribution to PSTs in C. farreri. This work provides a further understanding of the role of caspase homologues in the Zhikong scallop and can guide future studies focussing on the role of caspases and their interactions with PSTs. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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12 pages, 3916 KiB

Open AccessArticle

Optimization of Surface-Enhanced Raman Spectroscopy Detection Conditions for Interaction between Gonyautoxin and Its Aptamer

by Yan Liu, Lijuan He, Yunli Zhao, Yongbing Cao, Zhiguo Yu and Feng Lu

Toxins 2022, 14(1), 49; https://doi.org/10.3390/toxins14010049 - 11 Jan 2022

Cited by 1 | Viewed by 2201

Abstract

This study aimed to optimize the detection conditions for surface-enhanced Raman spectroscopy (SERS) of single-stranded DNA (ssDNA) in four different buffers and explore the interaction between gonyautoxin (GTX1/4) and its aptamer, GO18. The influence of the silver colloid solution and MgSO₄ concentration [...] Read more.

This study aimed to optimize the detection conditions for surface-enhanced Raman spectroscopy (SERS) of single-stranded DNA (ssDNA) in four different buffers and explore the interaction between gonyautoxin (GTX1/4) and its aptamer, GO18. The influence of the silver colloid solution and MgSO₄ concentration (0.01 M) added under four different buffered conditions on DNA SERS detection was studied to determine the optimum detection conditions. We explored the interaction between GTX1/4 and GO18 under the same conditions as those in the systematic evolution of ligands by exponential enrichment technique, using Tris-HCl as the buffer. The characteristic peaks of GO18 and its G-quadruplex were detected in four different buffer solutions. The change in peak intensity at 1656 cm⁻¹ confirmed that the binding site between GTX1/4 and GO18 was in the G-quadruplex plane. The relative intensity of the peak at 1656 cm⁻¹ was selected for the GTX1/4–GO18 complex (I₁₆₅₆/I₁₀₉₉) to plot the ratio of GTX1/4 in the Tris-HCl buffer condition (including 30 μL of silver colloid solution and 2 μL of MgSO₄), and a linear relationship was obtained as follows: Y = 0.1867X + 1.2205 (R² = 0.9239). This study provides a basis for subsequent application of SERS in the detection of ssDNA, as well as the binding of small toxins and aptamers. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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14 pages, 1383 KiB

Open AccessArticle

Development of an Efficient Extraction Method for Harvesting Gymnodimine-A from Large-Scale Cultures of Karenia selliformis

by Zhixuan Tang, Jiangbing Qiu, Guixiang Wang, Ying Ji, Philipp Hess and Aifeng Li

Toxins 2021, 13(11), 793; https://doi.org/10.3390/toxins13110793 - 10 Nov 2021

Cited by 8 | Viewed by 2824

Abstract

Gymnodimine-A (GYM-A) is a fast-acting microalgal toxin and its production of certified materials requires an efficient harvesting technology from the large-scale cultures of toxigenic microalgae. In this study the recoveries of GYM-A were compared between several liquid-liquid extraction (LLE) treatments including solvents, ratios [...] Read more.

Gymnodimine-A (GYM-A) is a fast-acting microalgal toxin and its production of certified materials requires an efficient harvesting technology from the large-scale cultures of toxigenic microalgae. In this study the recoveries of GYM-A were compared between several liquid-liquid extraction (LLE) treatments including solvents, ratios and stirring times to optimize the LLE technique for harvesting GYM-A from Karenia selliformis cultures, of which the dichloromethane was selected as the extractant and added to microalgal cultures at the ratio 55 mL L⁻¹ (5.5%, v/v). The recovery of GYM-A obtained by the LLE technique was also compared with filtration and centrifugation methods. The stability of GYM-A in culture media were also tested under different pH conditions. Results showed that both the conventional filter filtration and centrifugation methods led to fragmentation of microalgal cells and loss of GYM-A in the harvesting processes. A total of 5.1 µg of GYM-A were obtained from 2 L of K. selliformis cultures with a satisfactory recovery of 88%. Interestingly, GYM-A obviously degraded in the culture media with the initial pH 8.2 and the adjusted pH of 7.0 after 7 days, but there was no obvious degradation in the acidic medium at pH 5.0. Therefore, the LLE method developed here permits the collection of large-volume cultures of K. selliformis and the high-efficiency extraction of GYM-A. This work provides a simple and valuable technique for harvesting toxins from large-scale cultures of GYM-producing microalgae. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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Review

Jump to: Research

18 pages, 4548 KiB

Open AccessReview

Gambierdiscus and Its Associated Toxins: A Minireview

by Da-Zhi Wang, Ye-Hong Xin and Ming-Hua Wang

Toxins 2022, 14(7), 485; https://doi.org/10.3390/toxins14070485 - 14 Jul 2022

Cited by 9 | Viewed by 5303

Abstract

Gambierdiscus is a dinoflagellate genus widely distributed throughout tropical and subtropical regions. Some members of this genus can produce a group of potent polycyclic polyether neurotoxins responsible for ciguatera fish poisoning (CFP), one of the most significant food-borne illnesses associated with fish consumption. [...] Read more.

Gambierdiscus is a dinoflagellate genus widely distributed throughout tropical and subtropical regions. Some members of this genus can produce a group of potent polycyclic polyether neurotoxins responsible for ciguatera fish poisoning (CFP), one of the most significant food-borne illnesses associated with fish consumption. Ciguatoxins and maitotoxins, the two major toxins produced by Gambierdiscus, act on voltage-gated channels and TRPA1 receptors, consequently leading to poisoning and even death in both humans and animals. Over the past few decades, the occurrence and geographic distribution of CFP have undergone a significant expansion due to intensive anthropogenic activities and global climate change, which results in more human illness, a greater public health impact, and larger economic losses. The global spread of CFP has led to Gambierdiscus and its toxins being considered an environmental and human health concern worldwide. In this review, we seek to provide an overview of recent advances in the field of Gambierdiscus and its associated toxins based on the existing literature combined with re-analyses of current data. The taxonomy, phylogenetics, geographic distribution, environmental regulation, toxin detection method, toxin biosynthesis, and pharmacology and toxicology of Gambierdiscus are summarized and discussed. We also highlight future perspectives on Gambierdiscus and its associated toxins. Full article

(This article belongs to the Special Issue Marine Biotoxins: Predicting and Cumulative Risk Assessment)

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