RESUMEN

Toxic puffers accumulate tetrodotoxin (TTX), a well-known neurotoxin, by feeding on TTX-bearing organisms and using it to defend themselves from predators. Our previous studies have demonstrated that toxic puffers are attracted to 5,6,11-trideoxytetrodotoxin (TDT), a nontoxic TTX analog that is simultaneously accumulated with TTX in toxic puffers and their prey. In addition, activity labeling using immunohistochemistry targeting neuronal activity marker suggests that TDT activates crypt olfactory sensory neurons (OSN) of the green spotted puffer. However, it remains to be determined whether individual crypt OSNs can physiologically respond to TDT. By employing electroporation to express GCaMP6s in OSNs, we successfully identified a distinct group of oval OSNs that exhibited a specific calcium response when exposed to TDT in green spotted puffers. These oval OSNs showed no response to amino acids (AAs), which serve as food odor cues for teleosts. Furthermore, oval morphology and surface positioning of TDT-sensitive OSNs in the olfactory epithelium closely resemble that of crypt OSNs. These findings further substantiate that TDT is specifically detected by crypt OSNs in green spotted puffer. The TDT odor may act as a chemoattractant for finding conspecific toxic puffers and for feeding TTX-bearing organisms for effective toxification.

Asunto(s)

Odorantes , Neuronas Receptoras Olfatorias , Tetraodontiformes , Tetrodotoxina , Animales , Tetrodotoxina/farmacología , Neuronas Receptoras Olfatorias/efectos de los fármacos , Neuronas Receptoras Olfatorias/metabolismo , Odorantes/análisis , Calcio/metabolismo

RESUMEN

The object of this study was to trace TwHf-derived toxins in raw honey and clarify their acute toxic effect related to the addition of honey or sugars. TwHf flowers, raw honey from TwHf planting base and from beekeepers in high-risk area were detected using LC-MS/MS. The results revealed five target toxins were detected in TwHf flowers; only celastrol was detected in one raw honey sample, as a food safety risk factor, celastrol had been traced back to TwHf flowers from raw honey. In a series of acute toxic tests on zebrafish, toxification effects were observed when honey, mimic honey or sugar was mixed with toxins. The degree of toxicity varied among various sugar-based solutions. At the same mass concentration, they follow this order: raw honey/mimic honey > glucose > fructose. The main toxic target organs of triptolide and celastrol with honey were the heart and liver.

Asunto(s)

Diterpenos , Miel , Triterpenos Pentacíclicos , Fenantrenos , Tripterygium , Animales , Miel/análisis , Cromatografía Liquida , Pez Cebra , Espectrometría de Masas en Tándem , Azúcares , Compuestos Epoxi

RESUMEN

Tetrodotoxin (TTX), or pufferfish toxin, has been frequently detected in edible bivalves around the world during the last decade and is problematic in food hygiene and safety. It was reported recently that highly concentrated TTX was detected in the midgut gland of the akazara scallop Chlamys (Azumapecten) farreri subsp. akazara collected in coastal areas of the northern Japanese archipelago. The toxification of the bivalve was likely to involve the larvae of the flatworm, Planocera multitentaculata. However, the overall status of bivalve TTX toxification has not been elucidated. In this study, 14 species/subspecies of bivalves from various Japanese waters were subjected to LC-MS/MS analysis to reveal TTX toxification state, demonstrating that the Pectinidae, including C. farreri akazara, Chlamys farreri nipponensis, Chlamys (Mimachlamys) nobilis, and Mizuhopecten yessoensis, accumulated TTX in their midgut gland. Many individuals of C. farreri akazara and C. farreri nipponensis were found with high concentrations of TTX, while C. nobilis and M. yessoensis exhibited low concentrations. The extent of TTX accumulation in C. farreri akazara and C. farreri nipponensis varied widely by region and season. Curiously, no other bivalve species investigated in this study showed evidence of TTX. These results suggest that monitoring for TTX, like other shellfish toxins, is necessary to ensure that pectinid bivalves are a safe food resource.

Asunto(s)

Pectinidae , Platelmintos , Tetrodotoxina , Animales , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Tetrodotoxina/análisis

RESUMEN

Toxic puffers accumulate their defense substance (tetrodotoxin; TTX) through the food chain. Although the previous study suggests that 5,6,11-trideoxyTTX, a nontoxic TTX analog detected simultaneously with TTX in toxic puffers or their prey, acts as an olfactory chemoattractant for grass puffers, it is unclear whether toxic puffers are commonly attracted to 5,6,11-trideoxyTTX, and which types of olfactory sensory neurons (OSNs) detect 5,6,11-trideoxyTTX. Here, we demonstrated that green spotted puffer, a phylogenetically distant species from the grass puffer, is attracted to 5,6,11-trideoxyTTX. 5,6,11-TrideoxyTTX administration made green spotted puffers stay longer at the administered site, whereas a food odor (l-Arg) made them actively swim throughout the aquarium. Attractive responses were not observed when TTX or its vehicle was administered, nor when 5,6,11-trideoxyTTX was administered to anosmic fish. Furthermore, double immunohistochemistry with activity marker and crypt OSN marker antibodies labeled oval cells with apical invagination on the olfactory epithelium surface treated with 5,6,11-trideoxyTTX. These results suggest that 5,6,11-trideoxyTTX acts as an olfactory chemoattractant detected by crypt OSNs, and attraction to 5,6,11-trideoxyTTX odor appears to be a trait shared by toxic puffers for social communication or effective toxification.

Asunto(s)

Neuronas Receptoras Olfatorias , Tetraodontiformes , Animales , Factores Quimiotácticos , Odorantes , Mucosa Olfatoria , Tetrodotoxina/química , Tetrodotoxina/farmacología

RESUMEN

Tetrodotoxin (TTX)-bearing fish ingest TTX from their preys through the food chain and accumulate TTX in their bodies. Although a wide variety of TTX-bearing organisms have been reported, the missing link in the TTX supply chain has not been elucidated completely. Here, we investigated the composition of TTX and 5,6,11-trideoxyTTX in juveniles of the pufferfish, Chelonodon patoca, and toxic goby, Yongeichthys criniger, using LC-MS/MS, to resolve the missing link in the TTX supply chain. The TTX concentration varied among samples from different localities, sampling periods and fish species. In the samples from the same locality, the TTX concentration was significantly higher in the toxic goby juveniles than in the pufferfish juveniles. The concentration of TTX in all the pufferfish juveniles was significantly higher than that of 5,6,11-trideoxyTTX, whereas the compositional ratio of TTX and 5,6,11-trideoxyTTX in the goby was different among sampling localities. However, the TTX/5,6,11-trideoxyTTX ratio in the goby was not different among samples collected from the same locality at different periods. Based on a species-specific PCR, the detection rate of the toxic flatworm (Planocera multitentaculata)-specific sequence (cytochrome c oxidase subunit I) also varied between the intestinal contents of the pufferfish and toxic goby collected at different localities and periods. These results suggest that although the larvae of the toxic flatworm are likely to be responsible for the toxification of the pufferfish and toxic goby juveniles by TTX, these fish juveniles are also likely to feed on other TTX-bearing organisms depending on their habitat, and they also possess different accumulation mechanisms of TTX and 5,6,11-trideoxyTTX.

Asunto(s)

Venenos de los Peces/análisis , Venenos de los Peces/química , Venenos de los Peces/toxicidad , Peces , Tetraodontiformes , Tetrodotoxina/análisis , Tetrodotoxina/toxicidad , Animales , Cromatografía Liquida , Japón , Espectrometría de Masas en Tándem

RESUMEN

Given that traditional anticancer therapies fail to significantly improve the prognoses of triple negative breast cancer (TNBC), new modalities with high efficiency are urgently needed. Herein, by mixing the metal-phenolic network formed by tannic acid (TA), bleomycin (BLM), and Fe3+ with glutathione peroxidase 4 (GPX4) inhibitor (ML210) loaded hollow mesoporous Prussian blue (HMPB) nanocubes, the HMPB/ML210@TA-BLM-Fe3+ (HMTBF) nanocomplex is prepared to favor the ferroptosis/apoptosis synergism in TNBC. During the intracellular degradation, Fe3+ /Fe2+ conversion mediated by TA can initiate the Fenton reaction to drastically upregulate the reactive oxygen species level in cells, subsequently induce the accumulation of lipid peroxidation, and thereby cause ferroptotic cell death; meanwhile, the released ML210 efficiently represses the activity of GPX4 to activate ferroptosis pathway. Besides, the chelation of Fe2+ with BLM leads to in situ BLM toxification at tumor site, then triggers an effective apoptosis to synergize with ferroptosis for tumor therapy. As a result, the superior in vivo antitumor efficacy of HMTBF is corroborated in a 4T1 tumor-bearing mice model regarding tumor growth suppression, indicating that the nanoformulations can serve as efficient ferroptosis and apoptosis inducers for use in combinatorial TNBC therapy.

Asunto(s)

Ferroptosis , Nanopartículas , Neoplasias de la Mama Triple Negativas , Animales , Apoptosis , Bleomicina , Línea Celular Tumoral , Ferrocianuros , Humanos , Ratones , Polifenoles , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico

RESUMEN

Tetrodotoxin (TTX), also known as pufferfish toxin, has been detected in marine edible bivalves worldwide. In this study, several bivalve species, Azumapecten farreri subsp. akazara, Patinopecten yessoensis and Mytilus galloprovincialis, collected from the Pacific side of the northern Japanese Islands, were studied for the accumulation of TTX in the presence of toxic planocerid larvae. LC-MS/MS analysis demonstrated that TTX was detected only in the midgut gland of A. farreri subsp. akazara. Toxic flatworm-specific PCR and direct sequencing of the amplicons showed that the DNA fragments of the Planocera multitentaculata COI gene were detected in the gut contents of the toxified bivalves. The planocerid larvae were also detected in the environmental seawaters. Toxification experiments in the aquarium demonstrated that the mussel M. galloprovincialis was also toxified by feeding on the toxic flatworm larvae. These results suggest that the source of TTX accumulation in edible bivalves is toxic flatworm larvae.

Asunto(s)

Mytilus , Platelmintos , Contaminantes Químicos del Agua , Animales , Cromatografía Liquida , Larva , Espectrometría de Masas en Tándem , Tetrodotoxina/toxicidad , Contaminantes Químicos del Agua/toxicidad

RESUMEN

Prodrugs that allow in situ chemical conversion of less toxic precursors into active drugs in response to certain stimuli are promising anticancer candidates. Herein, we present a novel design of nanoprodrugs with a "degradation-mediated self-toxification" strategy, which realizes intracellular synthesis of anticancer agents using the nanoparticles' own degradation fragments as the precursors. To fulfill this concept, a metal complexing dicyclohexylphosphine (DCP) organosilane is carefully screened out from various ligands to conjugate onto Pd(OH)2 nanodots confined hollow silica nanospheres (PD-HSN). This constructed nanoprodrug shows acid-triggered degradation in lysosomes and neutralizes protons to induce lysosomes rupturing, generating predesigned less toxic fragments (Pd2+ and DCP-silicates) that complex into DCP/Pd complex in situ for inducing DNA damage, leading to enhanced anticancer activity against various cancer cell lines as well as in a xenograft tumour model.

Asunto(s)

Antineoplásicos/farmacología , Diseño de Fármacos , Nanopartículas/química , Compuestos de Organosilicio/farmacología , Profármacos/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Concentración de Iones de Hidrógeno , Ligandos , Lisosomas/química , Ratones , Estructura Molecular , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Compuestos de Organosilicio/síntesis química , Compuestos de Organosilicio/química , Profármacos/síntesis química , Profármacos/química

RESUMEN

In this work, we present the design and synthesis of novel fully synthetic analogues of the bisbenzylisoquinoline tetrandrine, a molecule with numerous pharmacological properties and the potential to treat life-threatening diseases, such as viral infections and cancer. Its toxicity to liver and lungs and the underlying mechanisms, however, are controversially discussed. Along this line, novel tetrandrine analogues were synthesized and biologically evaluated for their hepatotoxicity, as well as their antiproliferative and chemoresistance reversing activity on cancer cells. Previous studies suggesting CYP-mediated toxification of tetrandrine prompted us to amend/replace the suspected metabolically instable 12-methoxy group. Of note, employing several in vitro models showed that the proposed CYP3A4-driven metabolism of tetrandrine and analogues is not the major cause of hepatotoxicity. Biological characterization revealed that some of the novel tetrandrine analogues sensitized drug-resistant leukemia cells by inhibition of the P-glycoprotein. Interestingly, direct anticancer effects improved in comparison to tetrandrine, as several compounds displayed a markedly enhanced ability to reduce proliferation of drug-resistant leukemia cells and to induce cell death of liver cancer cells. Those enhanced anticancer properties were linked to influences on activation of the kinase Akt and mitochondrial events. In sum, our study clarifies the role of CYP3A4-mediated toxicity of the bisbenzylisoquinoline alkaloid tetrandrine and provides the basis for the exploitation of novel synthetic analogues for their antitumoral potential.

Asunto(s)

Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Quinolinas/síntesis química , Quinolinas/farmacología , Antineoplásicos/química , Antineoplásicos/toxicidad , Línea Celular Tumoral , Técnicas de Química Sintética , Citocromo P-450 CYP3A/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Quinolinas/química , Quinolinas/toxicidad

RESUMEN

In situ toxification of less toxic substance for the generation of effective anticarcinogens at the specific tumor tissue has been a novel paradigm for combating cancer. Significant efforts have been recently dedicated to turning clinical-approved drugs into anticancer agents in specific tumor microenvironment by chemical reactions. Herein, a hollow mesoporous Prussian blue (HMPB)-based therapeutic nanoplatform, denoted as DSF@PVP/Cu-HMPB, is constructed by encapsulating alcohol-abuse drug disulfiram (DSF) into the copper-enriched and polyvinylpyrrolidone (PVP)-decorated HMPB nanoparticles to achieve in situ chemical reaction-activated and hyperthermia-amplified chemotherapy of DSF. Upon tumor accumulation of DSF@PVP/Cu-HMPB, the endogenous mild acidity in tumor condition triggers the biodegradation of the HMPB nanoparticle and the concurrent co-releases of DSF and Cu2+ , thus forming cytotoxic bis(N,N-diethyl dithiocarbamato)copper(II) complexes (CuL2 ) via DSF-Cu2+ chelating reaction. Moreover, by the intrinsic photothermal-conversion effect of PVP/Cu-HMPBs, the anticancer effect of DSF is augmented by the hyperthermia generated upon near-infrared irradiation, thus inducing remarkable cell apoptosis in vitro and tumor elimination in vivo on both subcutaneous and orthotopic tumor-bearing models. This strategy of in situ drug transition by chemical chelation reaction and photothermal-augmentation provides a promising paradigm for designing novel cancer-therapeutic nanoplatforms.

Asunto(s)

Antineoplásicos/química , Cobre/química , Disulfiram/química , Ferrocianuros/química , Nanomedicina , Nanopartículas/química , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis , Línea Celular Tumoral , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Complejos de Coordinación/uso terapéutico , Cobre/metabolismo , Disulfiram/metabolismo , Humanos , Rayos Infrarrojos , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/mortalidad , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Terapia Fototérmica , Porosidad , Povidona/química , Tasa de Supervivencia , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Tetrodotoxin (TTX), a potent neurotoxin, is found in various phylogenetically diverse taxa. In marine environments, the pufferfish is at the top of the food chain among TTX-bearing organisms. The accumulation of TTX in the body of pufferfish appears to be of the food web that begins with bacteria. It is known that toxic pufferfishes possess TTX from the larval/juvenile stage. However, the source of the TTX is unknown because the maternally sourced TTX is extremely small in quantity. Therefore, the TTX has to be obtained from other organisms or directly from the environment. Here, we report evidence that the source of TTX for toxic fish juveniles including the pufferfish (Chelonodon patoca) and the goby (Yongeichthys criniger) is in the food organisms, as seen in their gut contents. Next generation sequencing analysis for the mitochondrial COI gene showed that the majority of the sequence recovered from intestinal contents of these toxic fishes belonged to the flatworm Planocera multitentaculata, a polyclad flatworm containing highly concentrated TTX from the larval stage. PCR specific to P. multitentaculata also showed that DNA encoding the planocerid COI gene was strongly detected in the intestinal contents of the goby and pufferfish juveniles. Additionally, the planocerid specific COI sequence was detected in the environmental seawater collected from the water around the sampling locations for TTX-bearing fish. These results suggest that planocerid larvae are the major TTX supplier for juveniles of TTX-bearing fish species.

Asunto(s)

Platelmintos/metabolismo , Tetraodontiformes/metabolismo , Tetrodotoxina/metabolismo , Animales , Cadena Alimentaria , Larva , Perciformes , Filogenia

RESUMEN

In my 2010 review, I addressed conventional water analysis and biosensing of organic pollutants in Japan between 1960s and 2000s. It is now timely to reexamine current analytical and biomonitoring approaches in view of the new challenges in assessing pollution, particularly in closed water bodies, as pollutants tend to accumulate in these endorheic basins. In the present review series, I presented current water environment and its microbial biosensors. In this part, I presented current data of the water quality of these water bodies in Japan and established the need to further develop microbial biosensor technologies to address and monitor water quality here. Graphical Abstract Current water pollution indirectly occurring by anthropogenic eutrophication (Part I).

Asunto(s)

Técnicas Biosensibles/tendencias , Contaminación del Agua , Calidad del Agua , Técnicas Biosensibles/métodos , Monitoreo del Ambiente/métodos , Japón

RESUMEN

The ubiquitous occurrence of polycyclic aromatic hydrocarbons (PAHs) leads to constant human exposure at low levels. Toxicologically relevant are especially the high-molecular weight substances due to their (pro-)carcinogenic potential. Following ingestion or uptake, the eukaryotic phase I metabolism often activates these substances to become potent DNA binders, and unsurprisingly metabolism and DNA-adduct formation of model substances such as benzo[a]pyrene (B[a]P) are well studied. However, apart from being subjected to eukaryotic transformations PAHs are also carbon and energy sources for the myriads of commensal microbes inhabiting man's every surface. Yet, we know little about the microbiome's PAH-metabolism capacity and its potentially adverse impact on the human host. This study now shows that readily isolable skin commensals transform B[a]P into a range of highly cyto- and genotoxic metabolites that are excreted in toxicologically relevant concentrations during growth. The respective bacterial supernatants contain a mixture of established eukaryotic as well as hitherto unknown prokaryotic metabolites, the combination of which leads to an increased toxicity. Altogether we show that PAH metabolism of the microbiome has to be considered a potential hazard.

Asunto(s)

Bacillus licheniformis/metabolismo , Daño del ADN , Queratinocitos/efectos de los fármacos , Micrococcus luteus/metabolismo , Hidrocarburos Policíclicos Aromáticos/toxicidad , Piel/efectos de los fármacos , Bacillus licheniformis/genética , Línea Celular , Supervivencia Celular/efectos de los fármacos , Ensayo Cometa , Cromatografía de Gases y Espectrometría de Masas , Humanos , Queratinocitos/metabolismo , Queratinocitos/microbiología , Fase I de la Desintoxicación Metabólica , Microbiota , Micrococcus luteus/genética , Piel/metabolismo , Piel/microbiología

RESUMEN

Marine pufferfish of the family Tetraodontidae accumulate a considerable amount of tetrodotoxin (TTX), mainly in the liver and ovary. The detailed distribution of TTX in pufferfish body tissues, however, remains poorly understood. Here we investigated the tissue distribution and biliary excretion of TTX in cultured pufferfish Takifugu rubripes juveniles (6-month-old, 81.5 ± 2.0 g body weight) for 24 h after intramuscular administration of 0.25 µg TTX/g body weight into the caudal muscle. The blood TTX concentration was 0.53 ± 0.15 µg/mL at 1 h, and gradually decreased to 0.05 ± 0.01 µg/mL at 24 h after administration (p < 0.05). The TTX concentration in the liver declined from 1.59 ± 0.10 µg/g at 1 h to 0.48 ± 0.21 µg/g at 24 h (p < 0.05). In contrast, the TTX concentration in the skin increased from 0.27 ± 0.04 µg/g at 1 h to 0.48 ± 0.08 µg/g at 24 h (p < 0.05). The concentration of TTX in the bile remarkably increased from 0.08 ± 0.03 µg/mL at 1 h to 0.39 ± 0.05 µg/mL at 8 h (p < 0.05) and remained at almost the same level at 24 h. These findings indicate that TTX was excreted from the liver into the gallbladder bile in the pufferfish T. rubripes juveniles.

Asunto(s)

Eliminación Hepatobiliar/fisiología , Takifugu/metabolismo , Tetrodotoxina/farmacocinética , Animales , Disponibilidad Biológica , Cromatografía Liquida , Inyecciones Intramusculares , Espectrometría de Masas en Tándem , Tetrodotoxina/administración & dosificación , Distribución Tisular/fisiología

RESUMEN

Pufferfish accumulate tetrodotoxin (TTX) mainly in the liver and ovary. This study aims at investigating the effect of TTX accumulation in the liver of cultured specimens of torafugu Takifugu rubripes on the hepatic gene expression by microarray analysis on Day 5 after the intramuscular administration of 0.25 mg TTX/kg body weight into the caudal muscle. TTX was detected in the liver, skin and ovary in the TTX-administered individuals. The total amount of TTX accumulated in the body was 67 ± 8% of the administered dose on Day 5. Compared with the buffer-administered control group, a total of 59 genes were significantly upregulated more than two-fold in the TTX-administered group, including those encoding chymotrypsin-like elastase family member 2A, transmembrane protein 168 and Rho GTP-activating protein 29. In contrast, a total of 427 genes were downregulated by TTX administration, including those encoding elongation factor G2, R-spondin-3, nuclear receptor activator 2 and fatty acyl-CoA hydrolase precursor. In conclusion, our results demonstrate that the intramuscular administration of TTX changes the expression of hepatic genes involved in various signaling pathways.