Effects of the food colorant carmoisine on zebrafish embryos at a wide range of concentrations.

Since the middle of the twentieth century, the use of dyes has become more common in every food group as well as in the pharmaceutical, textile and cosmetic industries. Azo dyes, including carmoisine, are the most important of the dye classes with the widest color range. In this study, the effects of carmoisine exposure on the embryonic development of zebrafish at a wide dose scale, including recommended and overexposure doses (from 4 to 2000 ppm), were investigated in detail. For this purpose, many morphological and physiological parameters were examined in zebrafish exposed to carmoisine at determined doses for 96 h, and the mechanisms of action of the changes in these parameters were tried to be clarified with the metabolite levels determined. The no observed effect concentration (NOEC) and median lethal concentration (LC50) were recorded at 5 ppm and 1230.53 ppm dose at 96 hpf, respectively. As a result, it was determined that the applied carmoisine caused serious malformations, reduction in height and eye diameter, increase in the number of free oxygen radicals, in apoptotic cells and in lipid accumulation, decrease in locomotor activity depending on the dose and at the highest dose, decrease in blood flow rate. In the metabolome analysis performed to elucidate the metabolism underlying all these changes, 45 annotated metabolites were detected.

Co-exposure effect of different colour of LED lights and increasing temperature on zebrafish larvae (Danio rerio): Immunohistochemical, metabolomics, molecular and behaviour approaches.

Although there are studies in the literature on the effects of different coloured light-emitting diodes (LEDs) on different organisms, there is limited information on how these effects change with temperature increase. In this study, the effects of blue, green, red and white LED lights on the early development process of zebrafish (Danio rerio (Hamilton, 1822)) were comprehensively investigated. In addition, to simulate global warming, it was examined how a one-degree temperature increase affects this process. For this purpose, zebrafish embryos, which were placed at 4 hpf (hours post fertilization) in an incubator whose interior was divided into four areas, were kept at three different temperatures (28, 29 and 30 °C) for 120 h. The group kept in a dark environment was chosen as the control. The temperature of the control group was also increased at the same rate as the other groups. The results showed that at the end of the exposure period, temperature and light colour caused an increase in body malformations. Histopathological damage and immunopositive signals of HSP 70 and 8-OHdG biomarkers in larval brains, increase in free oxygen radicals, apoptotic cells and lipid accumulation throughout the body, increase in locomotor activity, decrease in heart rate and blood flow, and significant changes in more than thirty metabolite levels were detected. In addition, it has been determined that many metabolic pathways are affected, especially glutathione, vitamin B6 and pyrimidine metabolism. Moreover, it has been observed that a one-degree temperature increase worsens this negative effect. It was concluded that blue light was the closest light to the control group and was less harmful than other light colours. The study revealed that blue light produced results that were most similar to those seen in the control group.

Antioxidant/protective effects of carob pod (Ceratonia siliqua L.) water extract against deltamethrin-induced oxidative stress/toxicity in zebrafish larvae.

In our study, the antioxidant capacity of carob pods water extract (CPWE) against deltamethrin (DM)-induced oxidative stress, a widely used pesticide around the world, was investigated in vitro and in vivo in a zebrafish model. The in vitro antioxidant capacity of the obtained extract was evaluated with different methods using trolox, BHA and BHT standard antioxidants. For in vivo experiments, 4hpf zebrafish embryos were exposed to 10 ppb and 25 ppb DM for 120 h and the larvae were treated with 1-10 and 100 ppm CPWE for 4 h at 72th hours. According to the results obtained, it has been determined that the exposure of zebrafish to DM during the developmental period causes important body malformations, decrease in survival rate, reduction in eye size, shortening in body length and decrease in locomotor activity in the dark period. In addition, according to the results of whole-mount staining, it was determined that DM caused a significant increase in the amount of free oxygen radicals and apoptotic cells. It was also confirmed by metabolome analysis that CPWE application for 4 h reduced DM-induced toxicity and oxidative stress. As a result, it can be said that CPWE has an important antioxidant capacity in eliminating DM-induced oxidative stress.

Global warming and glyphosate toxicity (II): Offspring zebrafish modelling with behavioral, morphological and immunohistochemical approaches.

The increase in temperature due to global warming greatly affects the toxicity produced by pesticides in the aquatic ecosystem. Studies investigating the effects of such environmental stress factors on next generations are important in terms of the sustainability of ecosystems. In this study, the effects of parental synergistic exposure to glyphosate and temperature increase on the next generation were investigated in a zebrafish model. For this purpose, adult zebrafish were exposed to 1 ppm and 5 ppm glyphosate for 96 h at four different temperatures (28.5, 29.0, 29.5, 30.0 °C). At the end of this period, some of the fish were subjected to the recovery process for 10 days. At the end of both treatments, a new generation was taken from the fish and morphological, physiological, molecular and behavioral analysis were performed on the offspring. According to the results, in parallel with the 0.5-degree temperature increase applied to the parents with glyphosate exposure, lower survival rate, delay in hatching, increased body malformations and lower blood flow and heart rate were detected in the offspring. In addition, according to the results of whole mouth larva staining, increased apoptosis, free oxygen radical formation and lipid accumulation were detected in the offspring. Moreover, it has been observed that the temperature increases to which the parents are exposed affects the light signal transmission and serotonin pathways in the offspring, resulting in more dark/light locomotor activity and increased thigmotaxis.

The anxiolytic and circadian regulatory effect of agarwood water extract and its effects on the next generation; zebrafish modelling.

Anxiety is one of the most common psychiatric symptoms worldwide. Studies show that there is an increase of >25 % in the prevalence of anxiety with the onset of the COVID-19 pandemic process. Due to the various side effects of drugs used in the treatment of anxiety, interest in natural therapeutic alternatives has increased. Agarwood is a plant used as a natural therapeutic due to its sedative effect as well as many effects such as antioxidant and antibacterial. Although there are many studies with agarwood, comprehensive behavioral studies, including the next generation, are limited. In present study, zebrafish fed with diets containing 10-100 ppm water extract of Agarwood (AWE) for 3 and 8 weeks were exposed to predator stress using Oscar fish in order to test the potential anxiolytic effect of AWE. At the end of the period, zebrafish exposed to predator stress were subjected to anxiety and circadian tests. Histopathological evaluation and immunofluorescent analyzes of BDNF and 5HT4-R proteins were performed in the brains of zebrafish. The effects on the next generation were examined by taking offspring from zebrafish. According to the results, it was observed that AWE had a healing effect on anxiety-like behaviors and on the disrupted circadian rhythm triggered by the predatory stress it applied, especially in the 8 weeks 100 ppm group. Interestingly, it was also found to be effective in offspring of zebrafish fed diets with AWE.

Fluoride exposure causes behavioral, molecular and physiological changes in adult zebrafish (Danio rerio) and their offspring.

Fluoride exposure through drinking water, foods, cosmetics, and drugs causes genotoxic effects, oxidative damage, and impaired cognitive abilities. In our study, the effects of fluoride on anxiety caused by the circadian clock and circadian clock changes in a zebrafish model were investigated at the molecular level on parents and the next generations. For this purpose, adult zebrafish were exposed to 1.5 ppm, 5 ppm, and 100 ppm fluoride for 6 weeks. At the end of exposure, anxiety-like behaviors and sleep/wake behaviors of the parent fish were evaluated with the circadian rhythm test and the novel tank test. In addition, antioxidant enzyme activities and melatonin levels in brain tissues were measured. In addition, morphological, physiological, molecular and behavioral analyzes of offspring taken from zebrafish exposed to fluoride were performed. In addition, histopathological analyzes were made in the brain tissues of both adult zebrafish and offspring, and the damage caused by fluoride was determined. The levels of BMAL1, CLOCK, PER2, GNAT2, BDNF and CRH proteins were measured by immunohistochemical analysis and significant changes in their levels were determined in the F- treated groups. The data obtained as a result of behavioral and molecular analyzes showed that parental fluoride exposure disrupts the circadian rhythm, causes anxiety-like behaviors, and decreases the levels of brain antioxidant enzymes and melatonin in parents. In addition, delay in hatching, increase in death and body malformations, and decrease in blood flow velocity, and locomotor activity was observed in parallel with dose increase in offspring. On the other hand, an increase in offspring apoptosis rate, ROS level, and lipid accumulation was detected. As a result, negative effects of fluoride exposure on both parents and next generations have been identified.

Global warming and glyphosate toxicity (I): Adult zebrafish modelling with behavioural, immunohistochemical and metabolomic approaches.

Global warming further increases the toxic threat of environmental pollutants on organisms. In order to reveal the dimensions of this threat more clearly, it is of great importance that the studies be carried out with temperature differences as close as possible to the temperature values that will represent the global climate projection. In our study, how the toxicity of glyphosate, which is widely used around the world, on zebrafish changes with temperature increases of 0.5° was investigated on behavioral and molecular basis. For this purpose, adult zebrafish were exposed to glyphosate at concentrations of 1 ppm and 5 ppm for 96 h in four environments with a temperature difference of 0.5° (28.5; 29.0; 29.5; 30.0 °C). At the end of the exposure, half of the zebrafish were sampled and remaining half were left for a 10-day recovery process. At the end of the trials, zebrafish were subjected to circadian rhythm and anxiety tests. In addition, histopathological, immunohistochemical and metabolome analyses were performed on brain tissues. As a result, it has been detected that anxiety and circadian rhythm were disrupted in parallel with the increased temperature and glyphosate concentration, and increased histopathological findings and 5-HT4R and GNAT2 immunopositivity in the brain. As a result of metabolome analysis, more than thirty annotated metabolites have been determined due to the synergistic effect of temperature increase and glyphosate exposure. As a conclusion, it was concluded that even a temperature increase of 0.5° caused an increasing effect of glyphosate toxicity in the zebrafish model.

Nano-sized polystyrene plastic particles affect many cancer-related biological processes even in the next generations; zebrafish modeling.

With the ever-increasing plastic pollution, the nano-sized plastic particles that are constantly released from the main materials have a greater potential threat. Studies continue on how to eliminate plastic waste, which has become a global problem, from nature. We are aware that complete elimination is not easy at all, but it is not known clearly that even if it is successful, its effects on organisms will also disappear completely. In this study, zebrafish injected with 20 nm-sized polystyrene particles (PS) only during the embryonic period were grown in an environment without plastic exposure. The effects of PS on their offspring embryo/larvae were examined at morphological, molecular and metabolomic levels. Results showed that parental PNP exposure caused significant malformations, decreased survival rate, increased heart rate and blood flow rate, as well as decreased eye size, height and locomotor activity, which were attributed to growth retardation in the offspring. According to the results of whole-mount immunofluorescence larval staining, cell death and reactive oxygen species were significantly increased, while lipid accumulation was decreased in new generation larvae from zebrafish injected with PNP. In order to elucidate the mechanisms underlying these morphological, physiological and molecular damages, the metabolome analyses were performed by evaluating the Q-TOF MS/MS spectra with chemometric analyses in the offspring larvae. According to the metabolomics results, 28 annotated metabolomes suggested by the OPLS-DA analysis that may vary significantly through a variable in projection scores were detected. In addition, it was detected that the significantly increased histopathological findings and immunopositivity of JNK, H2A.X, PI3 and NOP10 in new generation larvae. In conclusion, it has been shown that exposure to PS, even only during the embryonic period, may affect many cancer-related biological processes in the next generation.

Is sodium carboxymethyl cellulose (CMC) really completely innocent? It may be triggering obesity.

The toxicity of sodium carboxymethyl cellulose (CMC), which has GRAS status and has been determined as "ADI non specified", was re-evaluated with a new modelling and molecular-based data. For this purpose, CMC, a food additive, was injected to the yolk sac (food) of the zebrafish embryo by the microinjection method at the 4th hour of fertilization at different concentrations. As a result, it was found that CMC showed no toxic effects within the framework of the parameters studied. But, we determined increasing lipid accumulation in zebrafish embryos exposed to CMC in a dose-dependent manner. To elucidate the mechanism underlying this lipid accumulation, the expression levels of genes related to obesity-linked lipid metabolism were examined. Our findings show that while CMC does not cause a toxic effect in zebrafish embryos, it can lead important effects on lipid metabolism by causing changes in the expression of some genes associated with obesity.