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The marine toxins of the Okadaic acid (OA) group are natural compounds produced by dinoflagellates that enters the food chain by accumulating in seafood. They are responsible for Diarrhetic Shellfish Poisoning (DSP) events in humans over the world and therefore are also jointly named as Diarrhetic Shellfish Toxins (DSTs). The main objective of this study was to evaluate symptoms, toxicity, absorption, distribution, and elimination of OA, Dinophysistoxin-1 (DTX1), and Dinophysistoxin-2 (DTX2) at the sublethal dose of 90 μg toxin/kg bw administered through voluntary feeding to mice. The toxin comparison highlighted that OA and DTX1 induced more severe and specific symptoms such as diarrhea. After oral ingestion toxins were distributed through the entire organism being detected in liver, kidney, stomach, small and large intestine. Predominant excretion of the toxins was observed in feces, with OA exhibiting fast elimination, while DTX2 was showing prolonged excretion. The passage and accumulation of toxins in gastrointestinal organs instigated macroscopic damage in the stomach, small and large intestine that could persist up to 120 h. These findings highlight the importance of pharmacokinetic of sublethal doses of DSTs administered by voluntary feeding in their toxicity and their implication for public health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Omarigliptin (OMG) is an antidiabetic drug indicated for the treatment of type 2 diabetes mellitus. Forced degradation studies are practical experiments to evaluate the stability of drugs and to establish degradation profiles. Herein, we present the investigation of the degradation products (DPs) of OMG formed under various stress conditions. OMG was subjected to hydrolytic (alkaline and acidic), oxidative, thermal, and photolytic forced degradation. A stability-indicating ultra-fast liquid chromatography method was applied to separate and quantify OMG and its DPs. Five DPs were adequately separated and detected in less than 6 min, while other published methods detected four DPs. MS was applied to identify and obtain information on the structural elucidation of the DPs. Three m/z DPs confirmed previously published research, and two novel DPs were described in this paper. The toxicity of OMG and its DPs were investigated for the first time using in vitro cytotoxicity assays, and the sample under oxidative conditions presented significant cytotoxicity. Based on the results from forced degradation studies, OMG was found to be labile to hydrolysis, oxidation, photolytic, and thermal stress conditions. The results of this study contribute to the quality control and stability profile of OMG., (© 2024 John Wiley & Sons Ltd.)

Multistress effects lead to unpredicted consequences in aquatic ecotoxicology and are extremely concerning. The goal of this study was to trace how specific effects of the antibiotic salinomycin (Sal) and microplastics (MP) on the bivalve molluscs are manifested in the combined environmentally relevant exposures. Unio tumidus specimens were treated with Sal (0.6 μg L -1 ), MP (1 mg L -1 , 2 μm size), and both at 18 °C (Mix) and 25 °C (MixT) for 14 days. The redox stress and apoptotic enzyme responses and the balance of Zn/Cu in the digestive gland were analyzed. The shared signs of stress included a decrease in NAD + /NADH and Zn/Cu ratios and lysosomal integrity and an increase in Zn-metallothioneins and cholinesterase levels. MP caused a decrease in the glutathione (GSH) concentration and redox state, total antioxidant capacity, and Zn levels. MP and Mix induced coordinated apoptotic/autophagy activities, increasing caspase-3 and cathepsin D (CtD) total and extralysosomal levels. Sal activated caspase-3 only and increased by five times Cu level in the tissue. Due to the discriminant analysis, the cumulative effect was evident in the combined exposure at 18 °C. However, under heating, the levels of NAD + , NADH, GSH, GSH/GSSG and metallothionein-related thiols were decreased, and coordination of the cytosolic and lysosomal death stimuli was distorted, confirming that heating and pollution could exert unexpected synergistic effects on aquatic life., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Okadaic acid (OA) and its analogues cause diarrhetic shellfish poisoning (DSP) in humans, and risk assessments of these toxins require toxicity equivalency factors (TEFs), which represent the relative toxicities of analogues. However, no human death by DSP toxin has been reported, and its current TEF value is based on acute lethality. To properly reflect the symptoms of DSP, such as diarrhea without death, the chronic toxicity of DSP toxins at sublethal doses should be considered. In this study, we obtained acute oral LD 50 values for OA and dinophysistoxin-1 (DTX-1) (1069 and 897 μg/kg, respectively) to set sublethal doses. Mice were treated with sublethal doses of OA and DTX-1 for 7 days. The mice lost body weight, and the disease activity index and intestinal crypt depths increased. Furthermore, these changes were more severe in OA-treated mice than in the DTX-1-treated mice. Strikingly, ascites was observed, and its severity was greater in mice treated with OA. Our findings suggest that OA is at least as toxic as DTX-1 after repeated oral administration at a low dose. This is the first study to compare repeated oral dosing of DSP toxins. Further sub-chronic and chronic studies are warranted to determine appropriate TEF values for DSP toxins.

Okadaic acid (OA) is a marine biotoxin associated with diarrhetic shellfish poisoning (DSP), posing some threat to human beings. The oral toxicity of OA is complex, and the mechanism of toxicity is not clear. The interaction between OA and gut microbiota may provide a reasonable explanation for the complex toxicity of OA. Due to the complex environment in vivo, an in vitro study may be better for the interactions between OA and gut microbiome. Here, we conducted an in vitro fermentation experiment of gut bacteria in the presence of 0-1000 nM OA. The remolding ability of OA on bacterial composition was investigated by 16S rDNA sequencing, and differential metabolites in fermentation system with different concentration of OA was detected by LC-MS/MS. We found that OA inhibited some specific bacterial genera but promoted others. In addition, eight possible metabolites of OA, including dinophysistoxin-2 (DTX-2), were detected in the fermentation system. The abundance of Faecalitalea was strongly correlated with the possible metabolites of OA, suggesting that Faecalitalea may be involved in the metabolism of OA in vitro. Our findings confirmed the direct interaction between OA and gut bacteria, which helps to reveal the metabolic process of OA and provide valuable evidence for elucidating the complex toxicity of OA.

The existing information supports the use of this material as described in this safety assessment. Tetrahydro-6-(3-pentenyl)-2H-pyran-2-one was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that tetrahydro-6-(3-pentenyl)-2H-pyran-2-one is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class II material, and the exposure to tetrahydro-6-(3-pentenyl)-2H-pyran-2-one is below the TTC (0.009 mg/kg/day, 0.009 mg/kg/day, and 0.47 mg/day, respectively). Data and read-across to 5-hydroxy-7-decenoic acid δ-lactone (CAS # 25,524-95-2) show that there are no safety concerns for tetrahydro-6-(3-pentenyl)-2H-pyran-2-one for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on data and ultraviolet/visible (UV/Vis) spectra; tetrahydro-6-(3-pentenyl)-2H-pyran-2-one is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; tetrahydro-6-(3-pentenyl)-2H-pyran-2-one was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Enlightened by the available structural biology information, a novel series of dihydrothiopyrano[4,3- d ]pyrimidine derivatives were rationally designed via scaffold hopping and molecular hybridization strategies. Notably, compound 20a yielded exceptionally potent antiviral activities (EC 50 = 4.44-54.5 nM) against various HIV-1 strains and improved resistance profiles (RF = 0.5-5.6) compared to etravirine and rilpivirine. Meanwhile, 20a exhibited reduced cytotoxicity (CC 50 = 284 μM) and higher SI values (SI = 5210-63992). Molecular dynamics simulations were performed to rationalize the distinct resistance profiles. Besides, 20a displayed better solubility (sol. = 12.8 μg/mL) and no significant inhibition of the main CYP enzymes. Furthermore, 20a was characterized for prominent metabolic stability and in vivo safety properties. Most importantly, the hERG inhibition profile of 20a (IC 50 = 19.84 μM) was a remarkable improvement. Overall, 20a possesses huge potential to serve as a promising drug candidate due to its excellent potency, low toxicity, and favorable drug-like properties.

2,5-Bis-[8-(4,8-dimethyl-nona-3,7-dienyl)-5,7-dihydroxy-8-methyl-3-keto-1,2,7,8-teraahydro-6 H -pyran[ a ]isoindol-2-yl]-pentanoic acid (FGFC1) is a marine pyran-isoindolone derivative isolated from a rare marine microorganism Stachybotrys longispora FG216, which showed moderate antithrombotic(fibrinolytic) activity. To further enhance its antithrombotic effect, a series of new FGFC1 derivatives ( F1 - F7 ) were synthesized via chemical modification at C-2 and C-2' phenol groups moieties and C-1″ carboxyl group. Their fibrinolytic activities in vitro were evaluated. Among the derivatives, F1 - F4 and F6 showed significant fibrinolytic activities with EC 50 of 59.7, 87.1, 66.6, 82.8, and 42.3 μM, respectively, via enhancement of urokinase activity. Notably, derivative F6 presented the most remarkable fibrinolytic activity (2.72-fold than that of FGFC1). Furthermore, the cytotoxicity of derivative F6 was tested as well as expression of Fas/Apo-1 and IL-1 on HeLa cells. The results showed that, compared to FGFC1, derivative F6 possessed moderate cytotoxicity and apoptotic effect on HeLa cells (statistical significance p > 0.1), making F6 a potential antithrombotic agent towards clinical application.

Plants are a natural source of bioactive compounds such as secondary metabolites. These molecules, also called phytochemicals, are fundamental for plant survival and often show therapeutic properties used for the treatment of human diseases. Asperuloside is a secondary metabolite which belongs to iridoid glycosides and is commonly present in the plant family Rubiaceae. In this review we aim to summarize the scientific knowledge on asperuloside, with a special emphasis on its pharmacological properties as anti-viral, anti-malarial, anti-protozoal, anti-tumorigenic, anti-hypertensive, anti-obesity, immunomodulatory, anti-inflammatory and antioxidant agent. Preclinical studies in animal models suggest that asperuloside has therapeutic potential that could be evaluated in humans. However, despite its tangible phytochemical characteristics, no clinical trial has been performed so far. Thus, we hope that this review will facilitate scientific dissemination of asperuloside pharmacological properties and encourage researchers to evaluate both pharmacokinetic and toxicity of asperuloside in animal models. This will be the first step towards clinical studies in humans., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome. RIFM staff are employees of the Research Institute for Fragrance Materials, Inc. (RIFM). The Expert Panel receives a small honorarium for time spent reviewing the subject work.

The phycotoxins, okadaic acid (OA) and dinophysistoxins 1 and 2 (DTX-1 and -2), are protein phosphatase PP2A and PP1 inhibitors involved in diarrhetic shellfish poisoning (DSP) in humans. Data on the in vivo acute toxicity of the OA-group toxins show some differences and the European Food Safety Authority (EFSA) has determined toxicity equivalent factors (TEFs) of one for the reference toxin, OA, as well as for DTX-1 and 0.6 for DTX-2. However, recent in vitro studies indicated that DTX-1 seems to be more toxic than OA. As OA was described as apoptotic and aneugenic compound, we analyzed the DNA damage responses induced by the 3 toxins through γH2AX and pH3 biomarkers on proliferative HepaRG cells using High Content Analysis. We quantitatively examined the responses for γH2AX and pH3 by benchmark dose analyzing (BMD) using PROAST software. We found that the three toxins increased both γH2AX- and pH3-positive cells populations in a concentration-dependent manner. The 3 toxins induced mitotic arrest, characteristic of aneugenic compounds, as well as DNA strand-breaks concomitantly to cytotoxicity. BMD analysis showed that DTX-1 is the most potent inducer of DNA damage, followed by OA and DTX-2. The quantitative genotoxic data provided in this study are additional findings for reconsidering the estimated TEFs of this group of phycotoxins., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A scallop midgut gland certified reference material, NMIJ CRM 7520-a, was developed for validation and quality assurance during the inspection of shellfish for diarrhetic shellfish toxins. The candidate material was prepared by using naturally-toxic and nontoxic boiled midgut glands spiked with okadaic acid (OA). The homogeneity and stability of the material were found to be appropriate. For the characterization of OA and dinophysistoxin-1 (DTX1), nine participants were involved in a co-laboratory study based on the Japanese Official Testing Method, where the compounds were assayed by liquid chromatography-tandem mass spectrometry following alkaline hydrolysis. The analytical values were obtained by the standard addition method with a standard spiking solution calibrated using the standard-solution certified reference materials OA and DTX1. The certified concentrations with expanded uncertainties (coverage factor k = 2, approximate 95% confidence interval) were determined to be (0.205 ± 0.061) mg/kg for OA and (0.45 ± 0.11) mg/kg for DTX1., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

2-Isobutyl-4-methyltetrahydro-2H-pyran-4-ol) was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol is not genotoxic, does not have skin sensitization potential, and provided an MOE >100 for the repeated dose, developmental, and reproductive toxicity endpoints. The local respiratory toxicity endpoint was completed using the TTC (Threshold of Toxicological Concern) for a Cramer Class III material (0.47 mg/day). The phototoxicity/photoallergenicity endpoint was completed based on UV spectra and data on 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol. The environmental endpoints were evaluated; 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol was found not to be PBT as per the IFRA Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Azaspiracids (AZAs) are marine toxins that are produced by Azadinium and Amphidoma dinoflagellates that can contaminate edible shellfish inducing a foodborne poisoning in humans, which is characterized by gastrointestinal symptoms. Among these, AZA1, -2, and -3 are regulated in the European Union, being the most important in terms of occurrence and toxicity. In vivo studies in mice showed that, in addition to gastrointestinal effects, AZA1 induces liver alterations that are visible as a swollen organ, with the presence of hepatocellular fat droplets and vacuoles. Hence, an in vitro study was carried out to investigate the effects of AZA1, -2, and -3 on liver cells, using human non-tumor IHH hepatocytes., Results: The exposure of IHH cells to AZA1, -2, or -3 (5 × 10 -12 -1 × 10 -7 M) for 24 h did not affect the cell viability and proliferation (Sulforhodamine B assay and 3 H-Thymidine incorporation assay), but they induced a significant concentration-dependent increase of mitochondrial dehydrogenases activity (MTT reduction assay). This effect depends on the activity of mitochondrial electron transport chain complex I and II, being counteracted by rotenone and tenoyl trifluoroacetone, respectively. Furthermore, AZAs-increased mitochondrial dehydrogenase activity was almost totally suppressed in the K + -, Cl - -, and Na + -free media and sensitive to the specific inhibitors of K ATP and hERG potassium channels, Na + /K + , ATPase, and cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels., Conclusions: These results suggest that AZA mitochondrial effects in hepatocytes derive from an imbalance of intracellular levels of K + and, in particular, Cl - ions, as demonstrated by the selective reduction of toxin effects by CFTR chloride channel inhibition.

Salinomycin is a polyether ionophore antibiotic having anti-tumorigenic property in various types of cancer. Elevated thymidine phosphorylase (TP) levels, a key enzyme in the pyrimidine nucleoside salvage pathway, are associated with an aggressive disease phenotype and poor prognoses. Heat shock protein 90 (Hsp90) is a ubiquitous molecular chaperone that is responsible for the stabilization and maturation of many oncogenic proteins. In this study, we report whether Hsp90 inhibitor 17-AAG could enhance salinomycin-induced cytotoxicity in NSCLC cells through modulating TP expression in two non-small-cell lung cancer (NSCLC) cell lines, A549 and H1975. We found that salinomycin increased TP expression in a MKK3/6-p38 MAPK activation manner. Knockdown of TP using siRNA or inactivation of p38 MAPK by pharmacological inhibitor SB203580 enhanced the cytotoxic and growth inhibition effects of salinomycin. In contrast, enforced expression of MKK6E (a constitutively active form of MKK6) reduced the cytotoxicity and cell growth inhibition of salinomycin. Moreover, Hsp90 inhibitor 17-AAG enhanced cytotoxicity and cell growth inhibition of salinomycin in NSCLC cells, which were associated with down-regulation of TP expression and inactivation of p38 MAPK. Together, the Hsp90 inhibition induced TP down-regulation involved in enhancing the salinomycin-induced cytotoxicity in A549 and H1975 cells., (Copyright © 2019. Published by Elsevier B.V.)

Peniciketal A (Pe-A), a spiroketal compound, is isolated from the saline soil-derived fungus Penicillium raistrickii. However, the underlying molecular mechanistic basis for the effects of Pe-A on leukemia is poorly understood. Here, we investigated that Pe-A reduced cell proliferation in three leukemia cell lines (THP-1, K562 and HL60). Importantly, Pe-A showed little cytotoxicity in primary mouse embryonic fibroblast (MEF) cells in a long-duration treatment. For the mechanistic research, we identified 3449 differentially expressed Pe-A-induced proteins through liquid chromatography-tandem mass spectrometry (LC-MS/MS) with TMT label in THP-1 cells. Results showed that many identified proteins were involved in apoptosis and/or autophagy. Then, we confirmed that Pe-A induced not only apoptosis via the mitochondrial pathway but also cytoprotective autophagy by activating the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway indeed. In addition, Pe-A also arrested the cell cycle at the G0-G1 phase by regulating the expressions of checkpoint protein. Collectively, these results provide new insights into the mechanisms that Pe-A may target autophagy-related or apoptosis-related pathways to suppress the development of human leukemia., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Cancer is a significant health threat in cats. Chemoresistance is prevalent in solid tumors. The ionophore salinomycin has anti-cancer properties and may work synergistically with chemotherapeutics. The purpose of our study was to determine if salinomycin could decrease cancer cell viability when combined with doxorubicin in feline sarcoma and carcinoma cells., Results: We established two new feline injection-site sarcoma cell lines, B4 and C10, and confirmed their tumorigenic potential in athymic nude mice. B4 was more resistant to doxorubicin than C10. Dose-dependent effects were not observed until 92 μM in B4 cells (p = 0.0006) vs. 9.2 μM (p = 0.0004) in C10 cells. Dose-dependent effects of salinomycin were observed at 15 μM in B4 cells (p = 0.025) and at 10 μM in C10 cells (p = 0.020). Doxorubicin plus 5 μM salinomycin decreased viability of B4 cells compared to either agent alone, but only at supra-pharmacological doxorubicin concentrations. However, doxorubicin plus 5 μM salinomycin decreased viability of C10 cells compared to either agent alone at doxorubicin concentrations that can be achieved in vivo (1.84 and 4.6 μM, p < 0.004). In SCCF1 cells, dose-dependent effects of doxorubicin and salinomycin were observed at 9.2 (p = 0.036) and 2.5 (p = 0.0049) μM, respectively. When doxorubicin was combined with either 1, 2.5, or 5 μM of salinomycin in SCCF1 cells, dose-dependent effects of doxorubicin were observed at 9.2 (p = 0.0021), 4.6 (p = 0.0042), and 1.84 (p = 0.0021) μM, respectively. Combination index calculations for doxorubicin plus 2.5 and 5 μM salinomycin in SCCF1 cells were 0.4 and 0.6, respectively., Conclusions: We have developed two new feline sarcoma cell lines that can be used to study chemoresistance. We observed that salinomycin may potentiate (C10 cells) or work synergistically (SCCF1 cells) with doxorubicin in certain feline cancer cells. Further research is indicated to understand the mechanism of action of salinomycin in feline cancer cells as well as potential tolerability and toxicity in normal feline tissues.

Background: Pyrano[3,2-c]quinoline derivatives 6a-n were synthesized via simple two-step reactions and evaluated for their in vitro α-glucosidase inhibitory activity., Methods: Pyrano[3,2-c]quinoline derivatives 6a-n derivatives were prepared from a two-step reaction: cycloaddition reaction between 1-naphthyl amine 1 and malonic acid 2 to obtain benzo[h]quinoline-2(1H)-one 3 and reaction of 3 with aryl aldehydes 4 and Meldrum's acid 5. The anti- α-glucosidase activity and kinetic study of the synthesized compounds were evaluated using α-glucosidase from Saccharomyces cerevisiae and p-nitrophenyl-a-D-glucopyranoside as substrate. The α-glucosidase inhibitory activity of acarbose was evaluated as positive control., Results: All of the synthesized compounds, except compounds 6i and 6n, showed more inhibitory activity than the standard drug acarbose and were also found to be non-cytotoxic. Among the synthesized compounds, 1-(2-bromophenyl)-1H-benzo[h]pyrano[3,2-c]quinoline-3,12(2H,11H)-dione 6e displayed the highest α-glucosidase inhibitory activity (IC50 = 63.7 ± 0.5 µM). Kinetic study of enzyme inhibition indicated that the most potent compound, 6e, is a non-competitive inhibitor of α-glucosidase with a Ki value of 72 µM. Additionally, based on the Lipinski rule of 5, the synthesized compounds were found to be potential orally active drugs., Conclusion: Our results suggest that the synthesized compounds are promising candidates for treating type 2 diabetes., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The present study aims to evaluate the potential for the pollution of the environment by two herbicides (quizalofop-p-ethyl and cycloxydim), using the Allium test. The species in question is Allium cepa (onion, 2 n = 16), one of the most common plant indicators of environmental pollution. The working method consisted of obtaining the meristematic roots of Allium cepa and their treatment with herbicides at three different concentrations (0.5%, 1%, and 1.5%) for each herbicide for 24 h, for comparison with an untreated control. The results obtained from the cytological study indicated a strong cytotoxic and genotoxic effect for both herbicides, but especially for quizalofop-p-ethyl, where the mitotic index decreased from 30.2% (control) to 9.6% for the variant treated with 1.5% herbicide. In this case, a strong mitodepressive effect was shown by a highly significant percentage (35.4%) of chromosomal aberrations and nuclear alterations: stickiness, fragments, C-mitosis, lobulated nucleus, micronuclei, and nuclear erosion. The mitodepressive effect as well as the percentage of chromosomal aberrations increased with a higher herbicide concentration. The obtained results suggest the strong potential for pollution of the two herbicides, particularly at concentrations higher than 0.5%; therefore, we recommend caution in their use to avoid undesirable effects on the environment.

The protective effect of taurine against inflammation, apoptosis and oxidative stress in traumatic brain injury was investigated in the present study. Taurine is a non‑proteogenic and essential amino acid in animals. It plays a critical nutritional role in brain cell growth, differentiation, and development. Taurine is involved in regeneration and neuroprotection in the injured nervous system, and is an effective antioxidant against lead‑, cadmium‑, and exercise‑induced oxidative stress. Astrocytes and neuron cells were co‑cultured and cells were treated with different concentrations of taurine (100, 200 and 300 mg/l) for 72 h, and the levels of reactive oxygen species, malondialdehyde, reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase, acetylcholinesterase, tumor necrosis factor‑α, interleukin‑6, caspase‑3, p53, B‑cell lymphoma 2 and Bcl‑2‑associated X protein were determined. These inflammatory, apoptotic, and oxidative stress markers were substantially increased in injured cells, and returned to normal levels following taurine supplementation. Thus, taurine supplementation may be effective against oxidative stress, apoptosis, and inflammation in injured brain cells.

Salinomycin (SAL) is a polyether antibiotic, which is commonly used as a coccidiostat and has recently shown to exhibit anticancer activity. The toxic action of the drug may be connected with the extent and routes of its biotransformation. The cytotoxic potential of SAL and its combination with tiamulin and prednisolone was investigated using three cell models from rat: primary hepatocytes, hepatoma cells (FaO) and myoblasts (L6). The four biochemical endpoints were assessed: mitochondrial and lysosomal activity, total cell protein content and membrane integrity. The metabolites of SAL in the medium from cell cultures were determined using LC-MS/MS. The cytotoxicity of SAL was time-, concentration- and cells dependent. The most sensitive endpoint was the inhibition of lysosomal activity. Tiamulin increased SAL cytotoxicity, whereas the opposite results were observed for prednisolone. Primary hepatocytes were the most efficient in SAL biotransformation both in terms of its intensity and number of produced metabolites. The range of the cytotoxicity and mode of salinomycin interaction with tiamulin and prednisolone cannot be explained by the biotransformation alone., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

An interlaboratory comparison (ILC) was organized as a measure of the analytical competency in the liquid chromatography-tandem mass spectrometry quantification of okadaic acid (OA) and dinophysistoxin-1 (DTX1) in scallop midgut gland samples. The test sample was prepared using boiled midgut glands of naturally contaminated scallops with DTX1 and its esters by spiking with OA, and homogeneity and stability of this test sample was assessed to be appropriate. Twenty laboratories participated in the ILC based on the Japanese official testing method; they submitted two sets of analytical concentrations of target analytes along with the details of their analytical protocols. For assessing these data, assigned values were established from another ILC where ten participants quantified the target analytes by the standard addition method. The mean analytical results of the former ILC showed good agreement with the assigned values, and the corresponding relative reproducibility standard deviations met the criterion of CODEX STAN 292. Meanwhile, the results of more than half of the participants were out of the uncertainty range of the assigned values; these participants were encouraged to investigate their protocols to improve their analytical capability., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The mouse bioassay for diarrhetic shellfish poisoning toxins has been used worldwide. In this study, dinophysistoxin-1 (DTX-1) and okadaic acid (OA) were compared for toxicity. The lethality rate increased and the median survival time decreased in a dose-dependent manner in both DTX-1 and OA. The median lethal dose value was 150.4 µg/kg (95% confidence interval=130.1-171.2 µg/kg) for DTX-1 and 185.6 µg/kg (95% confidence interval=161.2-209.6 µg/kg) for OA. The toxicity equivalent factor 1:1 has been used for OA and DTX-1 in the EU and Japan. Thus, it may be considered that toxicity potential of DTX-1 has remained underestimated as compared to that of OA and DTX-1 might be more toxic than OA.

Background: Harpagoside (HAR) is an active component of Scrophularia ningpoensis (SN), which has anti-inflammatory and anti-immune effects. SN is used widely in China to treat various diseases. Recently, SN has been used as a traditional Chinese medicine injection and used clinically. However, allergic responses to these injections are frequently reported., Aim: We examined whether the main component of SN, HAR, is associated with the allergic reaction to SN., Methods: This study assessed the effects of HAR in mice and mast cell activation to characterize its anaphylactic effects and underlying mechanisms. Mice hindpaw swelling, serum allergy factor detection, enzyme-linked immunosorbent assays, and degranulation assays were performed to measure allergic mediators both in vivo and in vitro., Results: The present study indicated that HAR induced paw swelling, interleukin-6, inositol triphosphate, tumor necrosis factor-α, and histamine increases in mice. Our in vitro data also showed that HAR induced β-hexosaminidase, inositol triphosphate, and interleukin-6 release, leading to mast cell degranulation. In contrast, neither C48/80 nor HAR induced local anaphylaxis in STOCK Kit W-sh /HNihrJaeBsmJNju mice., Conclusions: HAR is a potential sensitization compound in SN, and these results provide information for the safe clinical use of SN.

To improve the druggability of salinomycin, a 20-epi-amino-20-deoxysalinomycin derivatives library was synthesized with high efficacy from which a few salinomycin derivatives with high potency and selectivity were identified through comprehensive cytotoxicity assay, including a fluorine-19 magnetic resonance sensitive tool molecule. Using a K-ras cellular model, salinomycin and its derivatives showed different molecular mode of action from literature reports. These results would be valuable for developing salinomycin-based cancer therapy., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

A study with DNA microarrays was performed to investigate the effects of two diarrhetic and one azaspiracid shellfish poison, okadaic acid (OA), dinophysistoxin-1 (DTX-1) and azaspiracid-1 (AZA-1) respectively, on the whole-genome mRNA expression of undifferentiated intestinal Caco-2 cells. Previously, the most responding genes were used to develop a dedicated array tube test to screen shellfish samples on the presence of these toxins. In the present study the whole genome mRNA expression was analyzed in order to reveal modes of action and obtain hints on potential biomarkers suitable to be used in alternative bioassays. Effects on key genes in the most affected pathways and processes were confirmed by qPCR. OA and DTX-1 induced almost identical effects on mRNA expression, which strongly indicates that OA and DTX-1induce similar toxic effects. Biological interpretation of the microarray data indicates that both compounds induce hypoxia related pathways/processes, the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress. The gene expression profile of AZA-1 is different and shows increased mRNA expression of genes involved in cholesterol synthesis and glycolysis, suggesting a different mode of action for this toxin. Future studies should reveal whether identified pathways provide suitable biomarkers for rapid detection of DSPs in shellfish., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Azaspiracids (AZAs) are marine algal toxins that can be accumulated by edible shellfish to cause a foodborne gastrointestinal poisoning in humans. In the European Union, only AZA1, -2 and -3 are currently regulated and their concentration in shellfish is determined through their toxic equivalency factors (TEFs) derived from the intraperitoneal lethal potency in mice. Nevertheless, considering the potential human exposure by oral route, AZAs TEFs should be calculated by comparative oral toxicity data. Thus, the acute oral toxicity of AZA1, -2 and -3 was investigated in female CD-1 mice treated with different doses (AZA1: 135-1100μg/kg; AZA2 and AZA3: 300-1100μg/kg) and sacrificed after 24h or 14days. TEFs derived from the median lethal doses (LD 50 ) were 1.0, 0.7 and 0.5, respectively for AZA1, -2 and -3. In fact, after 24h from gavage administration, LD 50s were 443μg/kg (AZA1; 95% CL: 350-561μg/kg), 626μg/kg (AZA2; 95% CL: 430-911μg/kg) and 875μg/kg (AZA3; 95% CL: 757-1010μg/kg). Mice dead more than 5h after the treatment or those sacrificed after 24h (doses: ≥175μg AZA1/kg, ≥500μg AZA2/kg and ≥600μg AZA3/kg) showed enlarged pale liver, while increased serum markers of liver alteration were recorded even at the lowest doses. Blood chemistry revealed significantly increased serum levels of K + ions (≥500mg/kg), whereas light microscopy showed tissue changes in the gastrointestinal tract, liver and spleen. No lethality, macroscopic, tissue or haematological changes were recorded two weeks post exposure, indicating reversible toxic effects. LC-MS/MS analysis of the main organs showed a dose-dependency in gastrointestinal absorption of these toxins: at 24h, the highest levels were detected in the stomach and, in descending order, in the intestinal content, liver, small intestine, kidneys, lungs, large intestine, heart as well as detectable traces in the brain. After 14days, AZA1 and AZA2 were still detectable in almost all the organs and intestinal content., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Palytoxin, isolated from a zoanthid of the genus Palythoa, is the most potent marine toxin known. Intoxication by palytoxin leads to vasoconstriction, hemorrhage, ataxia, muscle weakness, ventricular fibrillation, pulmonary hypertension, ischemia and death. Palytoxin and its numerous derivatives (congeners) may enter the food chain and accumulate mainly in fishes and crabs, causing severe human intoxication and death following ingestion of contaminated products. Furthermore, toxic effects in individuals exposed via inhalation or skin contact to marine aerosol in coincidence with Ostreopsis blooms, have been reported. Blooms of the benthic dinoflagellate Ostreopsis cf. ovata are a concern in the Mediterranean Sea, since this species produces a wide range of palytoxin-like compounds listed among the most potent marine toxins. Thus, the formerly unsuspected broad distribution of the benthic dinoflagellate Ostreopsis spp. has recently posed a problem of risk assessment for human health. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide. This review summarized and discussed the pharmacology and toxicology data of palytoxin and its congeners, including their cytotoxicity, human and animal toxicities. Moreover, the risk assessment and their control strategies including prevention and treatment assays were evaluated.

Background/aims: Okadaic acid (OA) and the structurally related compounds dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2) are marine phycotoxins that cause diarrheic shellfish poisoning (DSP) in humans due to ingestion of contaminated shellfish. In order to guarantee consumer protection, the regulatory authorities have defined the maximum level of DSP toxins as 160 µg OA equivalent kg-1 shellfish meat. For risk assessment and overall toxicity determination, knowledge of the relative toxicities of each analogue is required. In absence of enough information from human intoxications, oral toxicity in mice is the most reliable data for establishing Toxicity Equivalence Factors (TEFs)., Methods: Toxins were administered to mice by gavage, after that the symptomatology and mice mortality was registered over a period of 24 h. Organ damage data were collected at necropsy and transmission electron microscopy (TEM) was used for ultrastructural studies. Toxins in urine, feces and blood were analyzed by HPLC-MS/MS. The evaluation of in vitro potencies of OA, DTX1 and DTX2 was performed by the protein phosphatase 2A (PP2A) inhibition assay., Results: Mice that received DSP toxins by gavage showed diarrhea as the main symptom. Those toxins caused similar gastrointestinal alterations as well as intestine ultrastructural changes. However, DSP toxins did not modify tight junctions to trigger diarrhea. They had different toxicokinetics and toxic potency. The lethal dose 50 (LD50) was 487 µg kg-1 bw for DTX1, 760 µg kg-1 bw for OA and 2262 µg kg-1 bw for DTX2. Therefore, the oral TEF values are: OA = 1, DTX1 = 1.5 and DTX2 = 0.3., Conclusion: This is the first comparative study of DSP toxins performed with accurate well-characterized standards and based on acute toxicity data. Results confirmed that DTX1 is more toxic than OA by oral route while DTX2 is less toxic. Hence, the current TEFs based on intraperitoneal toxicity should be modified. Also, the generally accepted toxic mode of action of this group of toxins needs to be reevaluated., (© 2018 The Author(s). Published by S. Karger AG, Basel.)

A ring-closing alkene metathesis (RCM)/ oxyselenation-selenoxide elimination sequence was established to the sodium salts E- and Z-25 of the originally proposed structure for the recently isolated cytotoxin aruncin B (1), as well as to the sodium salt Z-34 of a related ethyl ether regioisomer; however, none of their corresponding free acids could be obtained. Their acid sensitivity, together with detailed analysis of the spectroscopic data indicated that profound structural revision was necessary. This led to reassignment of aruncin B as a Z-γ-alkylidenebutenolide Z-36. Although a related RCM/ oxyselenation-selenoxide elimination sequence was used to confirm the γ-alkylidenebutenolide motif, a β-iodo Morita-Baylis-Hillman reaction/ Sonogashira cross-coupling-5-exo-dig lactonisation sequence was subsequently developed, due to its brevity and flexibility for diversification. Aruncin B (36), together with 14 γ-alkylidenebutenolide analogues, were generated for biological evaluation., (© 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

In the context of global climate change where harmful algal blooms (HABs) might become more frequent and more severe, several studies have been conducted on the perturbation of embryonic development of marine animals by microalgal toxins. Okadaic acid (OA) and analogs (DSP toxins) produced by dinoflagellates of the genera Dynophysis and Prorocentrum are known to disturb embryogenesis. This study investigated the impact of dissolved DSP toxin (OA and Dinophysistoxin 1, DTX-1) exposure on embryo development of Longfin yellowtail Seriola rivoliana. Eggs were exposed to different concentrations of dissolved DSP toxins (low treatment: at 120μgl -1 OA eq; high treatment 175μgl -1 OA eq.). The first objective was to study the global toxic effect of DSP toxins with hatching percentages. Secondly, the effect of these toxins was investigated at molecular and functional level by measuring expression of responsible genes for bone morphogenetic protein (BMP) and proliferating cell nuclear antigen (PCNA) measuring phosphatase enzyme (serine/threonine and alkaline phosphatases) activities. Our results showed drastic mortalities induced by DSP toxins in both low and high concentration treatments. Activities of both protein and alkaline phosphatases were significantly inhibited by DSP toxin treatments, whose effects on gene expression were less evident, but levels of BMP expression in eggs treated with the lowest toxin concentration were significantly different from that in the control treatment. This work revealed an embryotoxic effect of DSP toxins resulting in high mortality of eggs. Phosphatase inhibition could have participated in part in these global effects by perturbing the regulation of pathways related to embryogenesis and resulting in a perturbation of gene expression., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Triple-negative breast cancer (TNBC) is one of the most aggressive cancers in women. Additionally, presence of residual cancer stem cells (CSC) in TNBC has challenged the efficacy of chemotherapy. Thus, the development of new molecules with potential action against CSC is fundamental. In this study, six synthetic analogues of theonelladin C, a 3-alkylpyridine marine alkaloid, were tested for cytotoxic activity against human TNBC cell line (BT-549) and tumorspheres derived from BT-549. Cytotoxicity assay was performed by sulforhodamine B (SRB). BT-549 and tumorspheres were examined for CD44 +/high /CD24 -/low markers, indicative of CSC profile, by flow cytometry. Clonogenic assay was performed to verify inhibiting growth of tumorspheres by the synthetic analogues. Cell death by apoptosis was investigated employing annexin V assay. SRB assay on BT-549 cells revealed that compounds 1c and 2c were the most active of the series, with IC 50 values of 18.66 and 9.8 μm, respectively. Compounds 1c and 2c were able to reduce both CSC-like population (CD44 +/high /CD24 -/low ) and non-CSC population (CD44 +/high /CD24 +/high ) in tumorsphere model. Clonogenic and annexin V assays confirmed the ability of 1c and 2c to induce growth inhibition and apoptosis in BT-549 cells and tumorspheres. These preliminary data indicate that these compounds are a promising class for development of anticancer agents., (© 2016 John Wiley & Sons A/S.)

Paederus dermatitis is an irritant dermatitis caused by pederin, a toxin produced by the rove beetle (Paederus). The disease occurs worldwide, but it is often not recognized as a history of contact with the insect is frequently absent. It is commonly seen in the rainy season. Crushing the insect releases pederin, resulting in the characteristic linear lesions with a burning sensation that heal with hyperpigmentation. Treatment comprises immediate washing of the area to eliminate the toxin and topical application of a topical steroid-antibiotic combination. Preventive measures may include reducing the insect population in the surroundings, avoiding contact of insects with the skin, minimizing the lesions after contact. Awareness of the etiology and clinical manifestations makes it easier to suspect this condition even in the absence of a history of exposure to the insect. We present a comprehensive review of the etiopathogenesis, pathology, clinical features, treatment and prevention of Paederus dermatitis and also review the biology of the insect and its behavior.

Ingestion of shellfish with dinophysistoxin-2 (DTX2) can lead to diarrheic shellfish poisoning (DSP). The official control method of DSP toxins in seafood is the liquid chromatography-mass spectrometry analysis (LC-MS). However in order to calculate the total toxicity of shellfish, the concentration of each compound must be multiplied by individual Toxicity Equivalency Factor (TEF). Considering that TEFs caused some controversy and the scarce information about DTX2 toxicity, the aim of this study was to characterize the oral toxicity of DTX2 in mice. A 4-Level Up and Down Procedure allowed the characterization of DTX2 effects and the estimation of DTX2 oral TEF based on determination of the lethal dose 50 (LD50). DTX2 passed the gastrointestinal barrier and was detected in urine and feces. Acute toxicity symptoms include diarrhea and motionless, however anatomopathology study and ultrastructural images restricted the toxin effects to the gastrointestinal tract. Nevertheless enterocytes microvilli and tight junctions were not altered, disconnecting DTX2 diarrheic effects from paracellular epithelial permeability. This is the first report of DTX2 oral LD 50 (2262 μg/kg BW) indicating that its TEF is about 0.4. This result suggests reevaluation of the present TEFs for the DSP toxins to better determine the actual risk to seafood consumers., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Harpagophytum procumbens (Hp) has been used as antiinflammatory and analgesic agent for the treatment of rheumatic diseases. The principal active component of Hp is harpagoside (HA). We tested the toxicity of this new therapeutic agent in a hepatic cell line (HepG2/C3A). Hp was found to be cytotoxic, and HA was found to decrease the number of cells in S phase, increase the number of cells in G2/M phase and induce apoptosis. Neither Hp nor HA was genotoxic. The expression of CDK6 and CTP3A4 was reduced by Hp, and both HA and Hp caused a significant reduction of CYP1A2 and CYP3A4 expression. It is possible that the cytotoxicity caused by HA and Hp does not involve transcriptional regulation of the cyclins and CDKs tested but is instead related to the inhibition of metabolism. This is evidenced by the results of an MTT assay and changes in the expression of genes related to drug metabolism, leading to cell death. Indeed, the cells exhibited decreased proliferation upon exposure to Hp and HA. The data show that treatment with either Hp or HA can be cytotoxic, and this should be taken into consideration when balancing the risks and benefits of treatments for rheumatic diseases. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

One of the proposed mechanisms to explain why Diarrhetic Shellfish Poison (DSP) toxins are tumor promoters is founded on the capacity of these toxins to increase TNF-α secretion. Although macrophages are the principal cells in the activation of the inflammatory response, the immune profile that Okadaic acid (OA) and Dinophysistoxin-1 (DTX-1) trigger in these cells has not been fully explored. We have therefore investigated the effect of various concentrations of both toxins on the activity of several inflammatory factors. Our results demonstrate that OA and DTX-1, at sublethal doses, stimulate secretion of inflammatory factors. Nevertheless DTX-1 was more potent than OA in increasing TNF-α and IL-6 as well as their dependent chemokines KC, MCP-1, LIX, MIP-1 α, MIP-1 β and MIP-2. On the other hand, secretion of IFN-γ and the anti-inflammatory cytokines, IL-4 and IL-10, was unaffected. In addition, DTX-1 also raises matrix metalloproteinase-9 (MMP-9) activity. In this study, for the first time the effect of OA and DTX-1 over the secretion of pro-inflammatory and carcinogenic signals in macrophages are compared, showing that DTX-1 is ten times more potent that OA. The inflammatory profile produced by DTX-1 is shown for the first time. The safe limit regulation should be changed to DSP toxins zero tolerance in the shellfish to be consumed by humans., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Environmental contamination is suggested to contribute to amphibian population declines. However, the effects of a contaminant on a particular amphibian species can differ among populations. The authors investigated the toxic effects of 2 herbicide formulations on different populations and on representative developmental stages of the European common frog (Rana temporaria). Larvae from forest populations were more sensitive to a commonly used glyphosate-based herbicide compared with individuals from agrarian land. Median lethal concentrations correlated with measured glyphosate levels in the breeding ponds, which may be a sign of evolved tolerances. The reverse result was observed for a less commonly used cycloxydim-based herbicide. Effects of the glyphosate-based herbicide were stronger for earlier larval stages compared with later larval stages. Hence, applications in early spring (when early larvae are present in breeding ponds) pose greater risk concerning acute toxic effects on R. temporaria. With regard to late larval stages, short exposure (96 h) of prometamorphic larvae prolonged time to metamorphosis, but only at the highest test concentration that did not significantly induce mortality. This could be due to impairment of the thyroid axis. Notably, nearly all test concentrations of the 2 herbicides provoked growth retardation. Further research on how evolved or induced tolerances are acquired, actual contamination levels of amphibian habitats, and potential endocrine effects of glyphosate-based herbicides is necessary. Environ Toxicol Chem 2017;36:190-200. © 2016 SETAC., (© 2016 SETAC.)

Background: Pharmacophore hybridization by bioconjugation, in which two bioactive moieties are covalently linked, is one of the current strategies in drug discovery for the development of new compounds with improved affinity and efficacy relative to those of the parent molecules. Prompted by the idea that cancer cells may be effectively killed by 3'-azido-3'-deoxythymidine (AZT) and salinomycin (SAL) individually, we synthesized hybrids of these compounds. The development of this type of derivatives, which can easily penetrate the lipid-rich cell membranes and then undergo hydrolysis inside the cancer cells, is an important research area., Methods: Efficient methods for the synthesis of two new conjugates are presented. The first method is based on the 'click' chemistry and involves the copper(I) catalysed 1,3-dipolar Huisgen cycloaddition reaction. In the second method AZT as well as SAL are connected by the ester bond under mild reaction conditions. The in vitro anti-proliferative activity of both conjugates against several drugsensitive and drug-resistant cancer cell lines as well as toxicity against normal murine embryonic fibroblasts are also determined., Results: Our studies clearly showed that the hybrid obtained via esterification reaction (SAL-OAZT) seems to be attractive in the fight against neoplastic diseases because it helps to overcome a strong drug-resistance of the cancer cell lines examined at low micromolar concentrations. The anticancer activity of this hybrid is also connected with high selectivity indexes (low toxicity) against normal cells.On the other hand, the 'click' conjugate (SAL-AZT) is practically inactive against the drug-resistant cancer cell lines tested and weakly active against the drug-sensitive ones. Also no synergistic effect has been found between SAL and AZT against eight cancer cell lines studied., Conclusion: All of our findings support a strategy to decrease the doxorubicin concentration in combination with SAL-O-AZT hybrid in order to reduce the toxicity of this drug, as recently demonstrated for SAL. The advantages of the SAL-O-AZT conjugate over SAL are better RI and SI parameters at similar IC50values., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Okadaic acid (OA) and the closely related dinophysistoxins (DTXs) are algal toxins that accumulate in shellfish and are known serine/threonine protein phosphatase (ser/thr PP) inhibitors. Phosphatases are important modulators of enzyme activity and cell signaling pathways. However, the interactions between the OA/DTX toxins and phosphatases are not fully understood. This study sought to identify phosphatase targets and characterize their structure-activity relationships (SAR) with these algal toxins using a combination of phosphatase activity and cytotoxicity assays. Preliminary screening of 21 human and yeast phosphatases indicated that only three ser/thr PPs (PP2a, PP1, PP5) were inhibited by physiologically saturating concentrations of DTX2 (200 nM). SAR studies employed naturally-isolated OA, DTX1, and DTX2, which vary in degree and/or position of methylation, in addition to synthetic 2- epi -DTX2. OA/DTX analogs induced cytotoxicity and inhibited PP activity with a relatively conserved order of potency: OA = DTX1 ≥ DTX2 >> 2- epi -DTX. The PPs were also differentially inhibited with sensitivities of PP2a > PP5 > PP1. These findings demonstrate that small variations in OA/DTX toxin structures, particularly at the head region (i.e., C1/C2), result in significant changes in toxicological potency, whereas changes in methylation at C31 and C35 (tail region) only mildly affect potency. In addition to this being the first study to extensively test OA/DTX analogs' activities towards PP5, these data will be helpful for accurately determining toxic equivalence factors (TEFs), facilitating molecular modeling efforts, and developing highly selective phosphatase inhibitors., Competing Interests: Authors declare no conflicts of interest. This publication does not constitute an endorsement of any commercial product or intend to be an opinion beyond scientific or other results obtained by the National Oceanic and Atmospheric Administration (NOAA). No reference shall be made to NOAA, or this publication furnished by NOAA, to any advertising or sales promotion which would indicate or imply that NOAA recommends or endorses any proprietary product mentioned herein, or which has as its purpose an interest to cause the advertised product to be used or purchased because of this publication.

Azaspiracids (AZAs) are the most recently discovered group of biotoxins and are the cause of azaspiracid shellfish poisoning (AZP) in humans. To date over thirty analogues have been identified. However, toxicological studies of AZAs are limited due to the lack of availability of toxins and toxin standards. Most data available are on acute toxicity and there are no data available on genotoxicity of AZAs. This study presents an integrated approach investigating the genotoxic potential of AZA1-3 in cell culture systems using the Comet assay combined with assays to provide information on possible apoptotic processes, cytotoxicity and changes in cell number. Results demonstrate a time and dose dependent increase in DNA fragmentation in most cell lines, indicating a genotoxic effect of AZA1-3. However, a significant reduction in cell number and a clear shift from early to late apoptosis was observed for all analogues in Jurkat T cells and HepG-2 cells; CaCo-2 cells did not show a clear apoptotic profile. Late apoptotic/necrotic cells correlate well with the percentage of tail DNA for all analogues in all three cell lines. All data taken together indicate that AZA1-3 is not genotoxic per se and demonstrate apoptotic/necrotic processes to be involved to some extent in AZAs toxicity. The sensitivities of cell lines and the different potencies of AZA1-3 are in agreement with the literature available. The order of sensitivity for all three AZAs tested in the present study is, in increasing order, CaCo-2 cells < HepG-2 cells < Jurkat T cells. The order of potency of AZA1-3 varies among the cell lines., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Rising worldwide cancer incidence and resistance to current anti-cancer drugs necessitate the need for new pharmaceutical compounds and drug delivery system. Two novel series of biscoumarin (1-4) and dihydropyran (5-16) derivatives were synthesized via a one-pot multicomponent condensation reaction and evaluated for their antitumor activity in vitro. The X-ray crystal structure analysis of four representative compounds 2, 7, 10 and 13 confirmed the structures of these compounds. Compounds 1-4 showed the most potent antitumor activity among the total 16 derivatives. More interestingly, preliminary mechanism studies revealed that the most potent compound 4 induced apoptosis and arrested the cell cycle at the S phase in HUTU80 cells. Additionally, the increased accumulation of HUTU80 cells in the sub G1 peak further pointed to the occurence of the cell apoptosis. The selectivity index analysis demonstrated that all the biscoumarin compounds (SI=3.1-7.5) possess higher selectivity towards intestinal epithelial adenocarcinoma cell line (HuTu80) than positive control drug carboplatin (SI=1.6-1.8). The biscoumarin compounds also showed no obvious acute toxicity on mice., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Potent anti-cancer compounds FR901464 and its methyl-ketal derivative spliceostatin A (SSA) inhibit cell cycle progression at G1 and G2/M phases. These compounds bind to the spliceosome and inhibit the splicing reaction. However, the molecular mechanism underlying G1 arrest after SSA treatment remains unknown. In this study, we found that ~90% of SSA-treated cells arrested at G1 phase after cell cycle synchronization. SSA treatment caused upregulation of the p27 cyclin-dependent kinase inhibitor both at mRNA and protein levels. In addition to p27, we observed expression of p27*, a C-terminal truncated form of p27 that is translated from CDKN1B (p27) pre-mRNA accumulated after splicing inhibition. Overexpression of p27 or p27* inhibited the exit from G1 phase after a double thymidine block. Conversely, knocking down of p27 by siRNA partially suppressed the G1 phase arrest caused by SSA treatment. There results suggest that G1 arrest in SSA-treated cells is caused, at least in part, by upregulation of p27 and p27*.

The aim of this study was to investigate (i) the cytotoxic effects of lipophilic phycotoxins, including okadaic acid (OA) and dinophysistoxin-1 and -2 (DTX-1 and DTX-2), pectenotoxin-2 (PTX-2), yessotoxin (YTX), spirolide (SPX), and azaspiracids-1, -2 and -3 (AZA-1, AZA-2 and AZA-3), in human HepaRG cells using a multiparametric high content analysis approach, (ii) the ability of nine lipophilic phycotoxins to act as PXR agonists in a HepG2-PXR cell line, (iii) their potential to induce CYP450 activity, and (iv) the role of CYP3A4 in cytotoxicity induced by lipophilic phycotoxins. Our results indicate that while OA, DTX-1 and DTX-2 activated PXR-dependent transcriptional activity in HepG2 cells, no increase of CYP450 (1A2, 3A4, 2C9, 2C19) activities were observed in HepaRG cell following a 72h treatment with these toxins. Multiparametric analysis showed that OA, DTX-1, DTX-2, and PTX-2 were highly cytotoxic in HepaRG cells; inducing cell loss, activation of caspase-3 and γ-H2AX formation. However, no toxicity was observed for YTX, SPX, and AZAs. Moreover, we found that inhibition of CYP3A4 activity by ketoconazole enhances the toxic effects of OA, DTX-1, DTX-2, and PTX-2 in HepaRG cells. Taken together, these results suggest that CYP3A4-mediated metabolism of some lipophilic phycotoxins decreases their in vitro toxicity., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The effect of canning in pickled sauce and autoclaving on weight, toxin content, toxin concentration and toxicity of steamed mussels was studied. Weight decreased by 25.5%. Okadaic acid (OA) and DTX2 content of mussel meat decreased by 24.1 and 42.5%, respectively. The estimated toxicity of the mussel remained nearly unchanged (increased by 2.9%). A part of the toxins lost by the mussels was leached to the sauce but the remaining part should have been thermally degraded. DTX2 underwent more degradation than OA and, in both toxins, free forms more than conjugated ones. This process, therefore, cannot be responsible for the large increments of toxicity of processed mussels -relative to the raw ones-sometimes detected by food processing companies. The final product could be monitored in several ways, but analysing the whole can content or the mussel meat once rehydrated seems to be the most equivalents to the raw mussel controls., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

After publication of karlotoxin 2 (KmTx2; 1), the harmful algal bloom dinoflagellate Karlodinium sp. was collected and scrutinized to identify additional biologically active complex polyketides. The structure of 1 was validated and revised at C49 using computational NMR tools including J-based configurational analysis and chemical-shift calculations. The characterization of two new compounds [KmTx8 (2) and KmTx9 (3)] was achieved through overlaid 2D HSQC NMR techniques, while the relative configurations were determined by comparison to 1 and computational chemical-shift calculations. The detailed evaluation of 2 using the NCI-60 cell lines, NMR binding studies, and an assessment of the literature supports a mode of action (MoA) for targeting cancer-cell membranes, especially of cytostatic tumors. This MoA is uniquely different from that of current agents employed in the control of cancers for which 2 shows sensitivity., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This irritant blister dermatitis is caused by the genus Paederus whose geographical distribution is worldwide, with a higher incidence in tropical areas. It is induced by direct skin contact with pederin, a blistering and caustic substance found in the abdomen (coelome) of Paederus insects (insect order Coleoptera: family Staphylinidae). The diagnosis is based on the presence of typical clinical features combined with compatible epidemiological features. Our goal is to describe the epidemiological and clinical features of this irritant contact dermatitis in Cameroon through a retrospective study conducted at the end of the rainy season at the Oku Hospital in Northwest Cameroon and to also include cases reported at the medical center of the French Embassy in Yaounde during this same timeframe. In addition, we conducted a literature review of paederus dermatitis. Nineteen patients were included in this study. More than half of the patients presented with more than two lesions predominantly localized to the face or the neck; less than half had complications manifesting as either localized or respiratory reactions and three patients presented periorbital involvement. This study confirms the presence of paederus dermatitis in Cameroon. It is mainly localized in the unusual geoclimatic region of the western high mountains within the country, as well as the usual warm, moist areas of Yaounde. The clinical evolution of this dermatitis is usually one of spontaneous and uneventful resolution with complications being rare. Curative treatment is one of localized topical therapies while oral antibiotic therapy should be reserved for more complicated cases.