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.

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-β, TGF-α and IL1-β) 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)

Simple Summary

The aim of this analysis was to reveal the effects of Citrus aurantium essential oil on growth performance, histopathological effect on digestive system organs, expression levels of some growth-related genes in the muscle tissue and some immune-related genes in the head kidney of common carp Cyprinus carpio. To determine the effect of essential oil on carp, experimental diets containing different concentrations of essential oil were prepared, and the fish were fed these diets for 60 days. At the end of the feeding experiment, it was observed that low-dose essential oil supplementation increased immune related gene expression levels and growth-related gene expression levels in head kidney and muscle tissue, respectively. Pathological findings were observed in the liver and intestines of fish fed with high doses of essential oil supplemented diets.

Abstract

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 NO_0.25, NO_{0. 05}, NO₁ and NO_1.5, 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 NO_0.25 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 NO_0.25 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 N_1.5 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.

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.

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 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.

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 butylated hydroxytoluene (BHT) on the cryopreservation of common carp (Cyprinus carpio) spermatozoa

The aim of the present study was to test the effects of butylated hydroxytoluene (BHT) on the cryopreservation of common carp spermatozoa. BHT is widely used in the cryopreservation of the spermatozoa of different animal species and successfully sustains the characteristics of spermatozoa during freezing and thawing, but it has not previously been used with fish. After sampling, common carp spermatozoa were diluted with an extender composed of modified Kurokura's extender, 10% DMSO, and 10% egg yolk containing 0.0001, 0.001, 0.01, 0.1, 1, 2.5, 5, or 10mM BHT and subsequently frozen in liquid nitrogen. The post-thaw spermatozoa characteristics (i.e., progressive motility percentage (%), duration of progressive motility (s), fertilization rate (%), and eyed-eggs rate (%)) were evaluated and compared with those of the control group. There were significant increases in the percentage of progressive motility and the duration of progressive motility at the concentrations of 0.1 and 0.001mM BHT (P<0.05). The duration of post-thawed spermatozoa progressive motility at 0.001mM BHT was significantly greater than that of the other groups (39.6±0.4s, P<0.05), and the fertilization rates and eyed-eggs rates were also higher following the 0.1 and 1mM BHT treatments. BHT at concentrations of more than 1mM caused sperm immobility during the preparatory stages of the sperm freezing. We concluded that 0.001-0.1mM BHT can be beneficial for the cryopreservation of common spermatozoa.