Ecotoxicological effects of polystyrene nanoplastics on common carp: Insights into blood parameters, DNA damage, and gene expression.

Plastics are ubiquitous in modern society due to their cost-effectiveness, lightweight nature, and versatility. However, their extensive use and inadequate recycling have led to a significant environmental challenge, with plastic waste accumulating rapidly and causing ecological and health problems, especially in aquatic environments. Nanoplastics, particles ranging from 1 to 100 nm, have emerged as a particularly concerning subset due to their ability to easily penetrate biological barriers and accumulate in tissues. In this study, we investigated the toxicity of carboxylate-modified polystyrene nanoplastics (PS-NPs) on common carp (Cyprinus carpio), a species often used in ecotoxicology research due to its ability to accumulate pollutants. The PS-NPs were characterized, and their effects on DNA damage gene expression related to oxidative stress and immunity were examined. PS-NPs with a diameter of 20-30 nm were found to possess a spherical shape and negatively charged surfaces. Exposure to PS-NPs led to significant DNA damage in the blood and brain cells of common carp, with higher concentrations resulting in more severe damage. Additionally, PS-NP exposure influenced the expression of genes related to antioxidative defense and stress response in the liver. Specifically, genes encoding superoxide dismutase (SOD), catalase (CAT), and heat shock protein 70 (Hsp70) showed upregulation, while glutathione peroxidase (GPx) and glutathione S-transferase (GST) exhibited downregulation at higher PS-NP concentrations. Furthermore, the immune-related genes interleukin-1ß (IL-1ß), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) displayed dose-dependent downregulation in the liver tissue. These findings suggest that exposure to PS-NPs induces oxidative stress, disrupts immune responses, and causes DNA damage in common carp. The results highlight the need for further research on the environmental impacts of PS-NPs and underscore the importance of proper waste management and recycling practices to mitigate plastic pollution.

Effects of glutamine on growth performance, nutrient content, fatty acid profile, and blood parameters of rainbow trout (Oncorhynchus mykiss).

In this study, different amounts of glutamine were added to the diet of rainbow trout, and they were then fed for a period of 90 days. The current research investigated the effects of glutamine on various aspects of rainbow trout, including growth performance, condition factor, viscerosomatic index, hepatosomatic index, carcass composition, fatty acid profile, hematological parameters, and biochemical parameters. The study's findings revealed that adding glutamine to the diet of rainbow trout had a beneficial impact on their growth features. The rainbow trout group that was fed a 2% concentration of glutamine experienced the most notable increase in growth rate. A statistically significant difference in growth was observed among all groups (p < 0.05). Adding glutamine to the diet increased the amount of protein and decreased the fat content in the flesh of the fish. Glutamine exerted an influence on the blood and biochemistry parameters of fish, as well as their fatty acid composition. In conclusion, the inclusion of glutamine in the diet of fish could potentially enhance their immune system, improve the quality of their muscles, and enhance their growth performance.

Effect of alpha-lipoic acid on oxidative stress, viability and motility in the common carp (Cyprinus carpio) spermatozoa after short-term storage and cryopreservation.

As known for different metabolic functions, α-lipoic acid (ALA) has been tested for spermatozoa preservation of animals as well as of human, but not for fish spermatozoa. The present study determined the effects of ALA on short and long-term (cryopreservation) preservation of common carp (Cyprinus carpio) spermatozoa, for the first time. For that, spermatozoa were diluted in extenders containing 0 (control), 0.025, 0.05, 0.1, 0.5, 1, 2, 5, and 10 mM of ALA concentrations in both short-term preservation and cryopreservation. Spermatozoa motility parameters by computer-assisted semen analysis, viability, lipid peroxidation and catalase activity in spermatozoa were conducted in both 2nd and 120th hours of short-term storage and post-thaw samples. Higher percentages of total spermatozoa motility (80 ± 3) and viability (87 ± 3) were observed in 0.5 mM ALA group after 120 h of incubation. In post-thaw samples, higher percentages of these parameters were in 1 mM ALA group (74 ± 3 and 83 ± 2, respectively). Moreover, the results have shown that the addition of ALA until concentrations of 2 mM improved especially spermatozoa curvilinear velocity, maintained viability, and suppressed excessive lipid peroxidation during the preservations. In conclusion, the additions of 0.5 mM ALA for short-term preservation and 1 mM ALA for cryopreservation were the optimal concentrations, and shown the protective effects on common carp spermatozoa, when considering all measured parameters together.

The in vitro effect of cypermethrin on quality and oxidative stress indices of rainbow trout Oncorhynchus mykiss spermatozoa.

There is limited information on the scientific literature about the effect of in vitro exposure of fish sperm to pesticides. In vitro effect of cypermethrin on sperm quality and oxidative stress has not yet been fully investigated. Therefore, the effects of cypermethrin, a type II pyrethroid insecticide, on quality and oxidative stress of spermatozoa were examined in vitro. To explore the potential in vitro toxicity of cypermethrin, fish spermatozoa were incubated with different concentrations of cypermethrin (1.025, 2.05 and 4.1 µg/l) for 2 h. The motility rate and duration of sperm were determined after exposure to cypermethrin. Reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) in spermatozoa were analyzed for determination of oxidant and antioxidant balance. Our results indicated that spermatozoa motility and duration significantly decreased with exposure to cypermethrin. Additionally, activity of GSH-Px (P<0.05) and MDA and GSH levels increased in a concentration-dependent manner while CAT activity decreased (P<0.05). Consequently, the oxidant and antioxidant status and sperm quality were affected by quantitative changes and different concentrations of cypermethrin.

CRYOPRESERVATION OF GOLDFISH (Carassius auratus) SPERMATOZOA: EFFECTS OF EXTENDER SUPPLEMENTED WITH TAURINE ON SPERM MOTILITY AND DNA DAMAGE.

BACKGROUND: Amino acids, present in seminal plasma at high concentration, protect spermatozoa against cell damage during cryopreservation. OBJECTIVE: Experiments were designed to analyze the effect of semen extender supplemented with taurine on post-thawed sperm motility and duration, as well as DNA damage. MATERIALS AND METHODS: Extenders were supplemented with 1, 2 or 4 mM taurine. Semen samples were diluted at the ratio of 1:9 with the extenders. Diluted samples were aspirated into 0.25 ml French straws and 0.1 ml pellets. DNA damage was assessed with the comet assay after cryopreservation. RESULTS: The percentage and duration of sperm motility were significantly increased by taurine. Additionally, sperm motility and the motility period in pellets were higher than in straws. The best concentration of taurine was 4 mM, and the highest post-thaw motility rate (72.50 ± 3.54 %) and duration (17.50 ± 0.71 s) were obtained from the extender with 4 mM in pellets. DNA damage was decreased after taurine supplementation. CONCLUSION: Pellets could be used for goldfish sperm cryopreservation. The addition of 4 mM taurine increases the post-thaw motility and decreases DNA damage on goldfish semen.

Effects of dietary garlic (Allium sativum) oil on growth performance, haemato-biochemical and histopathology of cypermethrin-intoxicated Nile tilapia (Oreochromis niloticus).

BACKGROUND: When pesticides are introduced into wetlands by agriculture, fish quickly absorb them through their gills. Pesticides reduce hatchability, impede growth, and antioxidant response, killing fish. Therefore, it's crucial to find effective pesticide mitigation methods for fish. OBJECTIVE: In this study, the effects of garlic (Allium sativum) oil on the growth, haematology, biochemistry and histopathology parameters of Nile tilapia (Oreochromis niloticus) exposed to cypermethrin toxicity were investigated. METHODS: In the research, cypermethrin was added to the water of the experimental groups at a rate of 1:20 of the LC50 value, and 1.00% garlic oil was added to the fish feed. Fish with an initial weight of 30.26 ± 0.26 g were fed for 45 days. RESULTS: At the end of feeding, the final weights were determined as 69.39 ± 0.41 (G1), 61.81 ± 0.65 (G2), 82.25 ± 0.36 (G3), and 75.04 ± 0.68 (G4) grams, respectively. Histopathological examinations revealed serious lesions in the gill, liver, brain, and muscle tissues in the cypermethrin group, whereas these lesions were minimal or absent in the garlic oil group. CONCLUSIONS: Garlic oil supplementation had positive effects on growth, haematology, blood biochemistry, hepatosomatic index and histopathological parameters. These findings suggest that garlic oil is a potential protective agent against cypermethrin toxicity.

Evaluation of metabolic stress status in common carp (Cyprinus carpio) exposed to the fungicide folpet.

Among pesticides, fungicides are the most extensively used ones in agriculture and their effects on fish health and indirectly human health are needed to evaluate. Folpet has been used for over 50 years as a fungicide across the world. The mechanism of action of folpet on non-target aquatic organisms is so poorly understood and there is no available information about potential acute toxicity of folpet and its mechanism of action in non-target aquatic organisms. With this motivation, two successive experiments were set up: first, 96 h-LC50 value of folpet for common carp (Cyprinus carpio) was determined; and second, effects of different sublethal concentrations (0, 0.025, 0.50, 0.1 and 0.15 mg/L) of folpet on hematological serum biochemical blood parameters, DNA damages, expression levels of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and cortisol receptor (HSP70) genes were evaluated in this study. It was calculated that 0.199 mg/L of folpet was the 96 h-LC50 value. After the folpet exposure for 14 days, significant decreases in red blood cells, hemoglobin, hematocrit, serum total protein, and GST gene expression levels were observed while serum glucose, liver enzymes activities, and expression levels of CAT, SOD, GPx, HSP70 genes increased. Also, folpet induced a significant genotoxic effect on the blood cells regarding to DNA damages. Consequently, the results have shown the toxic effects of folpet even at the lowest concentration on common carp.

Alterations in blood parameters, DNA damage, oxidative stress and antioxidant enzymes and immune-related genes expression in Nile tilapia (Oreochromis niloticus) exposed to glyphosate-based herbicide.

In this study, effects of different concentrations (0, 5, 10, 20, 30, and 40 mg/L) of glyphosate-based herbicide (GBH) on Nile tilapia (Oreochromis niloticus) were investigated after a 14-day of exposure. After determination of LC50 value, effects of GBH on hematological and serum biochemical parameters in blood samples, DNA damage, lipid peroxidation and catalase activity in liver tissues, expression levels of antioxidant enzyme-related genes (SOD, CAT, GPx, and GST) and immune-related genes (TGF-ß, TGF-α and IL1-ß) were evaluated. The LC50 value has been found as 44.4 mg/L for GBH. GBH exposure at all concentrations caused alterations in blood parameters. GBH induced oxidative stress in liver and DNA damage in blood. Antioxidant enzyme-related genes were significantly up-regulated to suppress oxidative stress. On the other hand, the expression levels of immune-related genes decreased in fish exposure to particularly ≥20 mg/L GBH.

Effects of Essential Oil Derived from the Bitter Orange (Citrus aurantium) on Growth Performance, Histology and Gene Expression Levels in Common Carp Juveniles (Cyprinus carpio).

The aim of this study was to detect effects of bitter orange (Citrus aurantium) essential oil, commonly called neroli oil (NO) (0, 0.25, 0.50, 1, and 1.5% referred to as NO0 NO0.25, NO0. 05, NO1 and NO1.5, respectively) on growth performance output and expression levels of some growth-related genes in the muscle tissue and some immune-related genes in the head kidney and pathological differences in digestive system organs of common carp Cyprinus carpio. The NO0.25 group had a large improvement in growth efficiency at the end of the 60-day feeding cycle. Real-time PCR (Bio RAD, USA) system was used to detect variations in gene expression levels. Furthermore, NO supplementation of up to 0.25% in muscle tissue controlled the release of growth hormone (GH) and insulin-like growth factor I (IGF-I). Furthermore, in the NO0.25 treatment category, immune response gene levels TNF-α, IL-8 and IL-1ß increased in head kidney tissue. In the histological examination of the liver and intestine, there were significant differences between fish fed with N1 and N1.5 diets. This study confirms that dietary supplementation of NO up to 0.25% can improve common carp growth efficiency and increase the expression of genes (GH and IGF-I) related to muscle growth, TNF-α, IL-8 and IL-1ß genes related to immune status, and liver and intestine histological status of common carp.

Seasonal and age-related changes in semen characteristics and composition of seminal plasma in sex-reverse female rainbow trout (Oncorhynchus mykiss) in comparison with normal males.

All-male or all-female progeny is preferable in reproduction of fish species. In rainbow trout, all-female progeny is desirable, and the most common and healthful approach is to use sex reversed (SR) females as broodstock by including androgen hormones through the diet at the larval stage. The purpose of this study was to determine the differences and changes of seminal plasma ions (Na+, K+, Ca2+, Mg2+ and Cl-) and pH in 2 to 3 and 3 to 4 year-old SR females, compared with 2 to 3 year-old normal (N) males at the beginning, middle, and end of the spawning season (SS). Additionally, osmolality, spermatozoa concentration, and sperm motility characteristics were determined. Percentages of sperm motility of SR females were negatively correlated with seminal plasma pH and sperm concentrations (r = -0.479 and r = -0.534, respectively, P < 0.05). Seminal plasma pH (7.14 ± 0.05 to 7.40 ± 0.10) in SR females was less than for N males (7.66 ± 0.10 to 8.04 ± 0.10) at all periods of the SS (P < 0.05). The Ca2+ concentrations in the mid-SS were 0.74 ± 0.23 mM in N males, 1.09 ± 0.29 mM in 2 to 3 year-old SR females, and 0.83 ± 0.29 in 2 to 3 year-old SR females, without significant differences (P > 0.05). Furthermore, using of 2 to 3 year-old rather than 3 to 4 year-old SR females for reproduction could provide an advantage in terms of sperm motility characteristics. These findings could be useful for not only understanding of SR of semen from sexually reversed females but also for design of a maturation medium both for further studies and aquaculture production.

Acute exposure to boron in Nile tilapia (Oreochromis niloticus): Median-lethal concentration (LC50), blood parameters, DNA fragmentation of blood and sperm cells.

Recently, Boron (B) contamination of aquatic ecosystem has received considerable critical attention due to its toxic effects at high concentrations on plants as well as animals. Previous studies on toxic effects of B have not dealt with DNA damages in blood and sperm cells of Nile tilapia (Oreochromis niloticus), together with blood parameters. This study consisted of two successive experiments purposes to determine these findings, including the median-lethal concentration (LC50) of B for Nile tilapia. In the first one, at 96 h, LC50 of B for Nile tilapia was 141.42 mg L-1 B. In the second one, Nile tilapia were treated with five elevated B concentrations (1, 5, 25, 50 and 100 mg L-1 B) and hematological, serum biochemical parameters, and DNA damages of Nile tilapia in these treatments were determined comparing with the control after 14 days of exposure. Hematological parameters (red blood cell count, hematocrit, and hemoglobin) were similar to each other in all groups while serum biochemical parameters (glucose, total protein, cholesterol, alkaline phosphatase, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase) in B treatments, especially in 50 and 100 mg L-1 B groups, were found significantly higher (P < 0.05). DNA fragmentation was detected in all blood cells in ≥25 mg L-1 B treatments, while all sperm cells in 100 mg L-1 B treatments. These results demonstrated the harmful effects of B at high concentration (50 and 100 mg L-1 B) on the DNA integrity of blood and sperm cells, and also the serum biochemical parameters.

The in vitro effect of Lambda-cyhalothrin on quality and antioxidant responses of rainbow trout Oncorhynchus mykiss spermatozoa.

There is little information in the scientific literature about effect of in vitro exposure of fish spermatozoa to pesticides. In vitro effect of Lambda-cyhalothrin (LCT) on sperm quality and oxidative stress has not been fully explored yet. The effects of LCT, which is a synthetic pyrethroid insecticide, on quality and oxidative stress of spermatozoa were investigated in vitro due to extensively use to control a wide range of insect pests in agriculture, public health, and homes and gardens. To explore the potential in vitro toxicity of LCT, fish spermatozoa were incubated with different concentrations of LCT (0.6, 1.2 and 2.4 µg/L) for 2h. Reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) in spermatozoa were analyzed for determination of oxidant and antioxidant balance. Our results indicated that the percentage and duration of sperm motility significantly decreased with exposure to LCT. Activity of GSH-Px and MDA (P<0.05) and GSH levels (P<0.05) increased in a concentration-dependent manner while CAT activity decreased (P<0.05). In conclusion, the oxidant and antioxidant status and sperm quality were affected by increasing concentrations of LCT.

Effect of semen extender supplementation with cysteine on postthaw sperm quality, DNA damage, and fertilizing ability in the common carp (Cyprinus carpio).

Amino acids have an important biological role for prevention of cell damage during cryopreservation. The objective of this study is to determine the effects of cysteine on postthaw sperm motility, duration of sperm motility, DNA damage, and fertility in the common carp (Cyprinus carpio). Sperm collected from 10 individuals was cryopreserved in extenders containing different cysteine concentrations (2.5, 5, 10, and 20 mM). Semen samples diluted at the ratio of 1:9 by the extenders were subjected to cryopreservation. After dilution, the semen was aspirated into 0.25-mL straws; the straws were placed on the tray, frozen in nitrogen vapor, and plunged into liquid nitrogen. DNA damage was evaluated by comet assay after cryopreservation. Our results indicated that an increase in the concentration of cysteine caused a significant increase in the motility rate and duration of sperm in the common carp (C carpio; P < 0.05). Comparing all concentrations of cysteine, the best concentration of cysteine was 20 mM. Higher postthaw motility (76.00 ± 1.00%) and fertilization (97.00 ± 1.73%) rates were obtained with the extender at the concentration of 20 mM. Supplementation of the extender with cysteine was increased the fertilization and hatching rate and decreased DNA damage. Consequently, cysteine affected the motility, fertilization, and DNA damage positively, and extenders could be supplemented with cysteine.