Effects of atrazine, diuron and glyphosate mixtures on zebrafish embryos: acute toxicity and oxidative stress responses.

Synthetic pesticides are known for their toxic effects on non-target aquatic organisms. However, little is known about their effects when present in mixtures, which are closer to realistic exposure scenarios. Therefore, this study evaluates the toxicity of pesticides such as diuron, atrazine and glyphosate, individually and in combination, in zebrafish embryos, investigating their mechanisms of oxidative stress.

The genus Artemia, the nanoplastics, the microplastics, and their toxic effects: a review.

Plastic pollution is a threat to the marine environment, the destination of mismanaged plastic. Due to reduced size, microplastics and nanoplastics (MNPs) can interact with a wide range of organisms. Non-selective filter feeder zooplanktonic microcrustaceans are potential targets for MNP accumulation.

Effects of the toxic dinoflagellates Prorocentrum lima and Ostreopsis cf. ovata on immune responses of cultured oysters Crassostrea gasar.

Oyster production in Brazil has been highlighted as an important economic activity and is directly impacted by the quality of the environment, which is largely the result of human interference and climate change. Harmful algal blooms occur in aquatic ecosystems worldwide, including coastal marine environments which have been increasing over the last decades as a result of global change and anthropogenic activities. In this study, the native oysters Crassostrea gasar from Northeast of Brazil were exposed to two toxic benthic dinoflagellate species, Prorocentrum lima and Ostreopsis cf.

Single and combined toxicity of amino-functionalized polystyrene nanoparticles with potassium dichromate and copper sulfate on brine shrimp Artemia franciscana larvae.

The increasing use and disposal of plastics has become a persistent problem in the marine environment, calling for studies that refer to realistic scenarios to understand their effects on biota. Particularly, the understanding about the effects of co-exposure with nanoplastic particles and metals on aquatic organisms is still limited. The present work aimed to investigate the acute toxicity of amino-functionalized polystyrene nanoparticles (PS-NH; 50 nm) as proxy for nanoplastics on brine shrimp Artemia franciscana larvae under different culture conditions and at different stages of development, as well as the combined effect with two reference toxicants - potassium dichromate (KCrO) and copper sulfate (CuSO).

Mitochondrial permeability transition pore in sea urchin female gametes.

Mitochondrial permeability transition pore (MPTP) has been associated to calcium homeostasis and reactive oxygen species (ROS) generation in several cell types. While extensively investigated in somatic cells, there are few data regarding MPTP phenomenon in gametes. The aim of the present work was to investigate MPTP occurrence in sea urchin female gametes.

Mitochondrial permeability transition pore (MPTP) desensitization increases sea urchin spermatozoa fertilization rate.

Mitochondrial permeability transition pore (MPTP) is a protein complex whose opening promotes an abrupt increase in mitochondrial inner membrane permeability. Calcium signaling pathways are described in gametes and are involved in the fertilization process. Although mitochondria may act as Ca(2+) store and have a fast calcium-releasing mechanism through MPTP, its contribution to fertilization remains unclear.

Effects of salinity and temperature on in vitro cell cycle and proliferation of Perkinsus marinus from Brazil.

Field and in vitro studies have shown that high salinities and temperatures promote the proliferation and dissemination of Perkinsus marinus in several environments. In Brazil, the parasite infects native oysters Crassostrea gasar and Crassostrea rhizophorae in the Northeast (NE), where the temperature is high throughout the year. Despite the high prevalence of Perkinsus spp.

Antimitotic activity of the pyrimidinone derivative py-09 on sea urchin embryonic development.

Chemotherapy is the main cancer treatment and consists of drug administration that interferes with several metabolic pathways, leading to tumor cell death. Antimitotic drugs have a relevant role in chemotherapy. This study aimed to investigate the effect of a pyrimidinone derivative (6-(p-Anisyl)-2-(p-chlorophenyl)-4-oxo-3,4-dihydropyrimidine-5-carbonitrile, Py-09) on sea urchin embryonic development model.

Photoprotective effect of coumarin and 3-hydroxycoumarin in sea urchin gametes and embryonic cells.

Ultraviolet radiation B (UVB) represents 5% of all solar UV radiation and chronic exposure can induce harmful biological responses, including skin cancer. Prospection of new drugs with photoprotective properties and less toxic effects is constant and natural products have been the main options in this field. Coumarins are a group of natural phenolic compounds that shows several pharmacological activities.

ATP-binding cassette transporters protect sea urchin gametes and embryonic cells against the harmful effects of ultraviolet light.

Embryos of marine organisms whose development occurs externally are particularly sensitive to ultraviolet (UV) light (bands A and B, respectively, UVA and UVB). ATP-binding cassette (ABC) transporters are the first line of cellular defense against chemical or physical stress. The present work investigated the involvement of ABC transporters on UVA or UVB effects on eggs, spermatozoa, and embryonic cells of the sea urchin Echinometra lucunter.

Immunological responses of the mangrove oysters Crassostrea gasar naturally infected by Perkinsus sp. in the Mamanguape Estuary, Paraíba state (Northeastern, Brazil).

Perkinsus genus includes protozoan parasites of marine mollusks, especially bivalves. In the last four years, this parasite has been detected in mangrove oysters Crassostrea rhizophorae and Crassostrea gasar from the Northeastern region of Brazil. Hemocytes are the key cells of the oyster immune system, being responsible for a variety of cellular and humoral reactions, such as phagocytosis, encapsulation and the release of several effector molecules that control the invasion and proliferation of microorganisms.

Involvement of ABCB1 and ABCC1 transporters in sea urchin Echinometra lucunter fertilization.

Fertilization is an ordered sequence of cellular interactions that promotes gamete fusion to form a new individual. Since the pioneering work of Oskar Hertwig conducted on sea urchins, echinoderms have contributed to the understanding of cellular and molecular aspects of the fertilization processes. Studies on sea urchin spermatozoa reported the involvement of a plasma membrane protein that belongs to the ABC proteins superfamily in the acrosome reaction.

Antimitotic activity on sea urchin embryonic cells of seven antiparasitic Morita-Baylis-Hillman adducts: a potential new class of anticancer drugs.

In the present work we described improvements in the 1-7 antiparasitic Morita-Baylis-Hillman Adducts synthesis and their antimitotic activity on sea urchin embryonic cells. The 2-[Hydroxy(2-nitrophenyl)methyl]acrylonitrile (1) and 2-[Hydroxy(4-bromophenyl) methyl]acrylonitrile (4) were the most effective compounds to block the progression to embryonic morula stage (EC(50) = 75.8 μM and 72.

Extracellular Ca2+ influx is crucial for the early embryonic development of the sea urchin Echinometra lucunter.

The involvement of Ca(2+) in the activation of eggs and in the first steps of the embryonic development of several species is a well-known phenomenon. An association between Ca(2+) sources with the fate of the blastopore during embryonic development has been investigated by several authors. Ca(2+) influx mediated by voltage-gated channels and Ca(2+) mobilization from intracellular stores are the major sources of Ca(2+) to egg activation and succeeding cell divisions.

Influence of fetal bovine serum on cytotoxic and genotoxic effects of lectins in MCF-7 cells.

Canavalia ensiformis (ConA), Canavalia brasiliensis (Conbr), and Cratylia floribunda (CFL) lectins have exhibited glucose-mannose binding specificity. We investigated the effect of fetal bovine serum (FBS) concentrations (1, 5, 10, and 20%) on the cytotoxic effect of these lectins against breast tumor cell line MCF-7. Cell viability was examined using the MTT reduction assay.

Characterization of functional activity of ABCB1 and ABCC1 proteins in eggs and embryonic cells of the sea urchin Echinometra lucunter.

ABC transporter (ATP-binding-cassette transporter) proteins have been strongly associated with the phenomenon of multidrug resistance in cancer cells. Furthermore, their physiological expression has been studied in many organisms, including bacteria, fungi, plants and vertebrate or invertebrate animals. Their widespread expression through the evolution demonstrates their relevance to the survival of living things.

Cyclosporin A does not protect the disruption of the inner mitochondrial membrane potential induced by potassium ionophores in intact K562 cells.

Mitochondrial dysfunction has been widely associated with programmed cell death. Studies of intact cells are important for the understanding of the process of cell death and its relation to mitochondrial physiology. Using cytofluorometric approaches we studied the mitochondrial behavior in an erythroleukemic cell line.

Ouabain exacerbates activation-induced cell death in human peripheral blood lymphocytes.

Lymphocytes activated by mitogenic lectins display changes in transmembrane potential, an elevation in the cytoplasmic Ca2+ concentrations, proliferation and/or activation induced cell death. Low concentrations of ouabain (an inhibitor of Na+,K+-ATPase) suppress mitogen-induced proliferation and increases cell death. To understand the mechanisms involved, a number of parameters were analyzed using fluorescent probes and flow cytometry.

Mitotracker green is a P-glycoprotein substrate.

P-glycoprotein has a widespread expression on normal tissues. The protein has also been strongly associated with the multidrug resistance phenotype (MDR) on tumor cells. The employment of flow cytometry and confocal microscopy has contributed to the discovery and application of new particular fluorescent dyes.

CPT-11-induced cell death in leukemic cells is not affected by the MDR phenotype.

CPT-11 is a topoisomerase I (Topo I) inhibitor which was initially described as active in multi-drug resistance (MDR) tumors. The MDR phenomenon is characterized by the overexpression of efflux pumps which are able to extrude a range of drugs non-related chemical or functionally. In this work, we treated leukemic cells with CPT-11 300 microM at 24h and compared its cytotoxicity with the activity of efflux pumps and with cell cycle phase.