Embrioni riba kao alternativni model u toksikologiji: revijalni pregled

Povećan broj ksenobiotika ugrožava životnu sredinu. Ova bioaktivna jedinjenja dospevaju u vodenu sredinu na različite načine i imaju značajan uticaj na akvatični živi svet. Za procenu opasnosti i rizika industrijskih hemikalija, proizvoda zaštite bilja, biocida, dodataka u hrani i lekova koriste se testovi na životinjama. Akutni test toksičnosti za ribe je obavezni korak u procesu ispitivanja toksičnosti hemikalija. Međutim njihova ekotoksikološka relevantnost je pod znakom pitanja. Povrh toga ribe se u ovim testovima podvrgavaju značajnom bolu i patnji. U skladu sa filozofijom 3r (redukcija/smanjenje, refinement/prečišćavanje, replacement/zamena) embrioni riba se smatraju metodom zamene ili prečišćavanja budući da ovi razvojni stadijumi nisu zakonski zaštićeni (Direktiva 2010/63/EU) i izgleda da osećaju manju bol i patnju. Cilj ovog pregleda bio je da se sumiraju dostupni podaci o testovima toksičnosti na embrionima riba i ukaže na moguće perspektive korišćenja ovog modela u savremenoj toksikologiji. Princip testa toksičnosti sa embrionima riba zasniva se na izloženosti vijabilnih embriona ksenobioticima, od oplođenja do kraja embriogeneze. Test toksičnosti sa embrionima riba validiran je u OECD studiji i prihvaćen kao OECD TG 236 96-h test za procenu toksičnosti za embrione riba. Određuje se letalnost koja je označena koagulacijom embriona, nedostatkom somita, ispravljanja repa ili otkucaja srca. Povrh smrtnosti, složeniji pokazatelji kao što je razvoj očiju, prisustvo krvotoka ili razvojne malformacije mogu se uočiti na stadijumima izvaljenih eleutero embriona. Mogućnost praćenja različitih pokazatelja čini embrione riba odličnim modelom za ispitivanje i razumevanje mehanizama toksičnosti i indikatorom mogućih nepovoljnih i dugotrajnih efekata. Na osnovu izvedenih istraživanja, test toksičnosti sa embrionima riba je razumna alternativa akutnom testu toksičnosti na ribama. Raspon mogućih aplikacija je značajan i ima mnogo perspektiva u budućnosti: kao što je dalja identifikacija molekularnih markera – indikatora načina delovanja ili uspostavljanje veze među efektima u kratkotrajnim testovima sa embrionima i dugotrajnih efekata na individue. Test toksičnosti sa embrionima riba takođe može da doprinese smanjenju broja eksperimenata na životinjama što je jedan od osnovnih principa EU legislative u oblasti dobrobiti

Effect of the surface functionalization of a waste-derived activated carbon on pharmaceuticals' adsorption from water

The functionalization of a paper mill sludge-based activated carbon (AC) was addressed in this work for the first time. Four different procedures have been accomplished in order to introduce amine functional groups (AC-NH2 and AC-APTES), thiol functional groups (AC-MPTMS), and a covalent organic polymer (AC-COP) onto the AC surface. The materials were characterized showing that the functionalization was succeeded, with a reduction of the specific surface area (SBET), except for AC-MPTMS. The produced ACs were tested for the removal of six pharmaceuticals - carbamazepine (CBZ), lorazepam (LOR), sulfamethoxazole (SMX), piroxicam (PIR), paroxetine (PAR), and venlafaxine (VEN) - from different matrices (ultrapure water, ultrapure water with pH adjusted to 7.6, and effluent from a municipal wastewater treatment plant (WWTP)). The results indicated textural parameters, SBET, micropore area and micropore volume, as the main factors influencing the adsorption, except for AC-NH2 which showed a great specificity for PAR and VEN. Also, AC-MPTMS presented a high removal percentage of the antibiotic SMX in wastewater. Overall, AC-MPTMS and AC-APTES provided, respectively, the best and the poorest adsorptive performance. Although the functionalization did not result in the enhancement of pharmaceuticals’ adsorption as compared with the parent AC, the selectivity for some pharmaceuticals was highly improved.publishe

Naproxen affects multiple organs in fish but is still an environmentally better alternative to diclofenac

The presence of diclofenac in the aquatic environment and the risks for aquatic wildlife, especially fish, have been raised in several studies. One way to manage risks without enforcing improved wastewater treatment would be to substitute diclofenac (when suitable from a clinical perspective) with another non-steroidal anti-inflammatory drug (NSAID) associated with less environmental risk. While there are many ecotoxicity-studies of different NSAIDs, they vary extensively in set-up, species studied, endpoints and reporting format, making direct comparisons difficult. We previously published a comprehensive study on the effects of diclofenac in the three-spined stickleback (Gasterosteus aculeatus). Our present aim was to generate relevant effect data for another NSAID (naproxen) using a very similar setup, which also allowed direct comparisons with diclofenac regarding hazards and risks. Sticklebacks were therefore exposed to naproxen in flow-through systems for 27 days. Triplicate aquaria with 20 fish per aquarium were used for each concentration (0, 18, 70, 299 or 1232 mu g/L). We investigated bioconcentration, hepatic gene expression, jaw lesions, kidney and liver histology. On day 21, mortalities in the highest exposure concentration group unexpectedly reached >= 25 % in all three replicate aquaria, leading us to terminate and sample that group the same day. On the last day (day 27), the mortality was also significantly increased in the second highest exposure concentration group. Increased renal hematopoietic hyperplasia was observed in fish exposed to 299 and 1232 mu g/L. This represents considerably higher concentrations than those expected in surface waters as a result of naproxen use. Such effects were observed already at 4.6 mu g/L in the experiment with diclofenac (lowest tested concentration). Similar to the responses to diclofenac, a concentration-dependent increase in both relative hepatic gene expression of c7 (complement component 7) and jaw lesions were observed, again at concentrations considerably higher than expected in surface waters. Naproxen bioconcentrated less than diclofenac, in line with the observed effect data. An analysis of recent sales data and reported concentrations in treated sewage effluent in Sweden suggest that despite higher dosages used for naproxen, a complete substitution would only be expected to double naproxen emissions. In summary, naproxen and diclofenac produce highly similar effects in fish but the environmental hazards and risks are clearly lower for naproxen. Hence, if there are concerns for environmental risks to fish with diclofenac, a substitution would be advisable when naproxen presents an adequate alternative from a clinical point-of-view

Effects of antidepressants with different modes of action on early life stages of fish and amphibians

Drugs are excreted from the human body as both original substances and as metabolites and enter aquatic environment through waste water. The aim of this study was to widen the current knowledge considering the effects of waterborne antidepressants with different modes of action-amitriptyline, venlafaxine, sertraline-on embryos of non-target aquatic biota-fish (represented by Danio rerio) and amphibians (represented by Xenopus tropicalis). The tested concentrations were 0.3; 3; 30; 300 and 3000 mu g/L. in case of amitriptyline and venlafaxine and 0.1; 1; 10; 100 and 1000 mu g/L for sertraline. Test on zebrafish embryos was carried out until 144 h post fertilization, while test on Xenopus embryos was terminated after 48 h. Lethal and sublethal effects as well as swimming alterations were observed at higher tested concentrations that are not present in the environment. In contrast, mRNA expression of genes related to heart, eye, brain and bone development (nkx2.5, otx 2, bmp4 and pax 6) seems to be impacted also at environmentally relevant concentrations. In a wider context, this study reveals several indications on the ability of antidepressants to affect non target animals occupying environments which may be contaminated by such compounds. (C) 2019 Elsevier Ltd. All rights reserved

Do the total mercury concentrations detected in fish from Czech ponds represent a risk for consumers?

AbstractMercury is one of the important pollutants of the environment. Therefore, it’s necessary to monitor quantity of mercury especially in aquatic ecosystems. The main goal of the presented study was to compare the content of total mercury in tissues of fish coming from the Czech Republic, an important carp exporter, with focus on comparison of mercury content between 3 different ponds, its comparison between different fish species and between different tissues of the same species, and estimation whether the mercury content in tissues meets the limit given in the Commission Regulation (EC) No. 1881/2006 or not. Total mercury concentration was measured in 90 fish specimen sampled from three ponds (Velky Kocelovicky, Mysliv and Zehunsky) in autumn 2018. The values of total mercury in fish tissues was measured by atomic absorption spectrometry. The content of total mercury in the tissues decreased as follows: muscle &gt; liver &gt; gonads &gt; scales. The highest average content of total mercury in muscle was 0.1517 ± 0.0176 mg/kg coming from pike caught in Velky Kocelovicky pond. In contrast, the lowest average content of total mercury in muscle 0.0036 ± 0.0003 mg/kg was found in carp tissue coming from the locality of Zehunsky pond. We confirmed that the predatory fish are more exposed to mercury than non-predatory fish. None of the monitored localities exceeded the set regulatory limit. Thus, our study shows that fish coming from these ponds are safe in terms of total mercury content.</jats:p

Evaluation of Tramadol Hydrochloride Toxicity to Juvenile Zebrafish—Morphological, Antioxidant and Histological Responses

The presence of pharmaceuticals in water bodies is associated with the increasing consumption of these substances and limited elimination from wastewater. Pharmaceutical residues and their metabolites may have an unfavorable impact on fish and other aquatic biota. As the purification of wastewater from tramadol is very limited and the knowledge on its effects on non-target organisms is low, we decided to assess the subchronic impact of tramadol hydrochloride on fish—on the mortality, growth and histopathology, together with the impact on selected indices of oxidative stress. The juvenile growth toxicity test was carried out on zebrafish (Danio rerio), in accordance with the Organisation for European Economic Cooperation Guidelines 215 (Fish, Juvenile Growth Test). The fish were exposed to a range of tramadol hydrochloride concentrations (0.2, 2, 20, 200 and 600 µg/L) for 28 days. The outcome of this study suggests that chosen concentrations of tramadol hydrochloride did not affect either mortality or growth (regarding weight, length and specific growth rate). However, the results of this study indicate that 28-day exposure can negatively influence selected indices of oxidative stress, which is a harmful imbalance between free radicals and antioxidants in an organism. A significant increase was observed in glutathione S-transferase activity in the experimental group exposed to 2 µg/L tramadol hydrochloride, compared to the control. Moreover, lipid peroxidation was observed in groups exposed to 20 and 200 µg/L, in comparison to the control.</jats:p

High Resolution Mass Spectrometry Analysis of the Sertraline Residues Contained in the Tissues of Rainbow Trout Reared in Model Experimental Conditions

The growing consumption of pharmaceuticals in the human population and the insufficient efficiency of their elimination in waste water has a long-term negative impact on the environment of aquatic ecosystems, including the organisms that inhabit them. A significant contributor is the consumption of anti-depressants from the SSRI group, which corresponds to their increasing concentration in the environment. The aim of this work was to determine if antidepressant sertraline is able to be stored in fish organisms and to evaluate the content of residues in various body tissues. Rainbow trout (Oncorhynchuss mykkis) was selected as the test organism and was artificially exposed to the antidepressant for 1 month (concentrations 0; 4.2; 44 and 400 ng.g-1 sertraline in the feed). Liver, kidney, brain and muscle tissue biopsies samples were taken for analysis. Detection was performed using an Accela 1250 LC pump and an Accela autosampler coupled with a high-performance mass analyzer with a heated electrospray ionization source Q-Exactive Orbitrap, operating in positive ionization mode and in PRM mode (m/z 306.08108→275.03888 and 309.009991→275.03888 for sertraline and internal standard, respectively). The limit of quantification of the method was 0.1 ng.g-1 of sertraline and the calibration curve showed a good linearity up to 20 ng.g-1. From the collected data, amount of residues was found in the liver, kidney and brain. In contrast, the incidence of residues in muscle tissue was not detected in all groups, which is favorable from the point of view of fish meat consumption, by humans.</jats:p