Biological effects of the antihypertensive losartan under different ocean acidification scenarios

Ocean acidification enhances the embryotoxicity of CuO nanoparticles to Oryzias melastigma

Concerns are raised towards individual effects of ocean acidification (OA) and engineered nanoparticles (NPs) on marine organisms. However, there are scarce studies regarding nanotoxicity under OA conditions. We investigated the combined effects of OA (pHs, 7.70 and 7.40) and CuO NPs on the embryotoxicity of marine medaka Oryzias melastigma and the bioavailability of CuO NPs in embryos. The results showed that OA alleviated the aggregation of CuO NPs and promoted the dissolution of CuO NPs in seawater (increased by 0.010 and 0.029 mg/L under pHs 7.70 and 7.40, respectively). Synergistic effects of OA with CuO NPs on medaka embryos were observed as indicated by much higher mortality and oxidative damage. Importantly, the enhanced toxicity of CuO NPs to medaka embryos under OA conditions mainly originated from the higher bioavailability of particulate CuO (e.g., 30.28 mg/kg at pH 7.40) rather than their released Cu²⁺ ions (e.g. 3.04 mg/kg at pH 7.40). The weaker aggregation of NPs under OA conditions resulted in higher penetration of individual particles (or small aggregates) into embryos through the micropyle and chorionic pores, causing enhanced bioavailability of NPs. The obtained results provided underlying insights into understanding the risk of NPs to marine ecosystem under OA conditions.

Antagonism toxicity of CuO nanoparticles and mild ocean acidification to marine algae

The toxicity of CuO nanoparticles (NPs) to marine microalgae (Emiliania huxleyi) under ocean acidification (OA) conditions (pHs 8.10, 7.90, 7.50) was investigated. CuO NPs (5.0 mg/L) caused significant toxicity (e.g., 48-h growth inhibition, 20%) under normal pH (8.10), and severe OA (pH 7.50) increased the toxicity of CuO NPs (e.g., 48-h growth inhibition, 68%). However, toxicity antagonism was observed with a growth inhibition (48 h) decreased to 37% after co-exposure to CuO NPs and mild OA (pH 7.90), which was attributed to the released Cu²⁺ ions from CuO NPs. Based on biological responses as obtained from RNA-sequencing, the dissolved Cu²⁺ ions (0.078 mg/L) under mild OA were found to increase algae division (by 17%) and photosynthesis (by 28%) through accelerating photosynthetic electron transport and promoting ATP synthesis. In addition, mild OA enhanced EPS secretion by 41% and further increased bioavailable Cu²⁺ ions, thus mitigating OA-induced toxicity. In addition, excess Cu²⁺ ions could be transformed into less toxic Cu₂S and Cu₂O based on X-ray absorption near-edge spectroscopy (XANES) and high-resolution transmission electron microscopy (HR-TEM), which could additionally regulate the antagonism effect of CuO NPs and mild OA. The information advances our knowledge in nanotoxicity to marine organisms under global climate change.

Occurrence, ecological risk assessment and prioritization of pharmaceuticals and abuse drugs in estuarine waters along the São Paulo coast, Brazil

The pollution of the surface waters by pharmaceuticals and personal care products (PPCPs) has attracted worldwide attention, but data regarding their occurrence and potential risks for the aquatic biota on tropical coastal rivers of South America are still scarce. In this context, the occurrence and the preliminary ecological risk assessment of eleven pharmaceuticals of various therapeutic classes (including cocaine and its primary metabolite, benzoylecgonine) were investigated, for the first time, in five rivers of São Paulo, southeast Brazil, covering a coastline of about 140 km, namely Perequê River, Itinga River, Mongaguá River, Itanhaém River and Guaraú River. Although these five rivers are born in well-preserved areas of the Atlantic rainforest biome, on its way to sea and when they cross the urban perimeter, they receive untreated sewage discharges containing a complex mixture of contaminants. In addition, a "persistence, bioaccumulation and toxicity" (PBT) approach allowed to pre-select the priority PPCPs to be monitored in this coastline. Identification of several PPCPs in the samples was done using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Ten PPCPs were successfully quantified in all five rivers, namely caffeine (9.00-560.00 ng/L), acetaminophen (<LOQ-22.24 ng/L), benzoylecgonine (0.30-14.93 ng/L), atenolol (0.12-13.22 ng/L), losartan (0.10-8.42 ng/L), diclofenac (0.76-3.93 ng/L), cocaine (0.05-3.22 ng/L), furosemide (<LOQ-3.16), carbamazepine (0.04-0.50 ng/L) and orphenadrine (<LOQ-0.14 ng/L). From an ecological risk perspective, caffeine, acetaminophen and losartan can be considered as priority PPCPs because they showed low to moderate risks to algae, crustacean and fishes. However, using the PBT approach, carbamazepine and orphenadrine were also classified as priority compounds, followed by furosemide, acetaminophen, cocaine and losartan (all in second position) and caffeine, atenolol, diclofenac and benzoylecgonine (all in third position). This study provides valuable information to reinforce the importance of continuous monitoring of the coastal rivers of South America (containing PPCPs and illicit drugs) whose diffuse loads flow continuously into the marine ecosystems. Furthermore, ecotoxicological studies (especially with tropical marine organisms) to assess the long-term toxicity of these bioactive compounds are urgent.

Health effects and risks associated with the occurrence of pharmaceuticals and their metabolites in marine organisms and seafood

Pharmaceuticals and their metabolites are continuously invading the marine environment due to their input from the land such as their disposal into the drains and sewers which is mostly followed by their transfer into wastewater treatment plants (WWTPs). Their incomplete removal in WWTPs introduces pharmaceuticals into oceans and surface water. To date, various pharmaceuticals and their metabolites have been detected in marine environment. Their occurrence in marine organisms raises concerns regarding toxic effects and development of drug resistant genes. Therefore, it is crucial to review the health effects and risks associated with the presence of pharmaceuticals and their metabolites in marine organisms and seafood. This is an important study area which is related to the availability of seafood and its quality. Hence, this study provides a critical review of the information available in literature which relates to the occurrence and toxic effects of pharmaceuticals in marine organisms and seafood. This was initiated through conducting a literature search focussing on articles investigating the occurrence and effects of pharmaceuticals and their metabolites in marine organisms and seafood. In general, most studies on the monitoring of pharmaceuticals and their metabolites in marine environment are conducted in well developed countries such as Europe while research in developing countries is still limited. Pharmaceuticals present in freshwater are mostly found in seawater and marine organisms. Furthermore, the toxicity caused by different pharmaceutical mixtures was observed to be more severe than that of individual compounds.

Solution blow spinning polysulfone-Aliquat 336 nanofibers: synthesis, characterization, and application for the extraction and preconcentration of losartan from aqueous solutions

Nanofibers are materials used in a wide range of applications due to their unique physicochemical properties. As an alternative to the most common method of its manufacturing (electrospinning) blow spinning has been used since it has greater production efficiency and simplicity. A wide variety of polymers is used for its preparation and can be modified to improve the interaction and selectivity toward specific analytes. Thereby nanofibers have been used for the extraction or removal of organic compounds such as drugs but there are still few reports of drug extractions like losartan. In this work polysulfone-Aliquat 336 nanofibers were prepared using the blow spinning method to extract and preconcentrate losartan. The studies showed that Aliquat 336 incorporation significantly improve the extraction of losartan with polysulfone fibers. Adsorption process was thermodynamically favorable with an adsorption capacity of 15.45 mg·g−1. Thus, it was possible to extract more than 92% of initial losartan using 10 mg of polysulfone-Aliquat 336 fibers (9 and 3.5% (w/v)), at pH 6 from deionized water and synthetic wastewater. Finally, losartan preconcentration was evaluated to facilitate its quantification using ultraviolet–visible spectrometry (UV-Vis), which allowed the determination of this drug at concentrations below the detection limit.