Oxidative stress biomarkers, biochemical responses and Na+ -K+ -ATPase activities in Nile tilapia, Oreochromis niloticus exposed to diclofenac

Multi-biomarker approach to assess the toxicity of carbamazepine, a neuropharmaceutical, in the female fish Astyanax lacustris (Teleostei: Characidae)

Carbamazepine (CBZ) is a pharmaceutical commonly used in the treatment of epilepsy and bipolar disorder and has been detected in different aquatic ecosystems worldwide. Considering its possible role in altering nervous system and reproduction, this study aimed to evaluate the effects of CBZ on molecular and cellular biomarkers of the teleost Astyanax lacustris. Results demonstrated that CBZ, in environmentally relevant concentrations (500 ng L-1) increases fshβ gene expression levels, decreases muscle protein content and hepatic LPO (500 ng L-1 and 1250 ng L-1 of CBZ). Nonetheless, no effects were observed towards enzymatic activities, steroid plasma levels and/or lipid content. Considering that A. lacustris inhabits clean and polluted environments, it is possible to suggest that animals possess a level of tolerance to stressors, allowing them to maintain reproductive functions regardless of environmental challenges.

Histopathological fingerprints and biochemical changes as multi-stress biomarkers in fish confronting concurrent pollution and parasitization

The current investigation examined histopathological and serum biochemical profiles to assess the interactive effects of river Saraswati's impaired physicochemical regime and parasite infection by ectoparasites (Trichodina sp., Gyrodactylus sp.) and endoparasites (Eustrongylides sp.) on health of fish (Channa punctatus). This study aimed at assessing the synergistic effects of the degraded water quality and parasitization on fish health looking through the lens of histopathology and serum biochemistry. Low dissolved O2, high free CO2, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) indicate deteriorating water quality due to organic loading. The histopathological investigations revealed distinctive histopathological changes in gill, liver, and kidney of the fish as "signature" impairments inflicted by chronic (co)exposure to pollution and/or parasitization. Stress enzymes and altered serum biochemistry furnish excellent indicators of fish health because of their correlation with pollution and parasitization. Destined in a vicious cycle, fish health becomes adversely affected by degrading water qualities and parasitic infection in solo or combo.

The research progress on the impact of antibiotics on the male reproductive system

Antibiotics are extensively utilized in the livestock and poultry industry and can accumulate in animals and the environment, leading to potential health risks for humans via food and water consumption. Research on antibiotic toxicity, particularly their impact as endocrine disruptors on the male reproductive system, is still in its nascent stages. This review highlights the toxic effect of antibiotics on the male reproductive system, detailing the common routes of exposure and the detrimental impact and mechanisms of various antibiotic classes. Additionally, it discusses the protective role of food-derived active substances against the reproductive toxicity induced by antibiotics. This review aims to raise awareness about the reproductive toxicity of antibiotics in males and to outline the challenges that must be addressed in future research.

Chronic exposure to tris (2-chloroethyl) phosphate (TCEP) induces brain structural and functional changes in zebrafish (Danio rerio): A comparative study on the environmental and LC50 concentrations of TCEP

Tris (2-chloroethyl) phosphate (TCEP) is a crucial organophosphorus flame retardant widely used in many industrial and commercial products. Available reports reported that TCEP could cause various toxicological effects on organisms, including humans. Unfortunately, toxicity data for TCEP (particularly on neurotoxicity) on aquatic organisms are lacking. In the present study, Danio rerio were exposed to different concentrations of TCEP for 42 days (chronic exposure), and oxidative stress, neurotoxicity, sodium, potassium-adenosine triphosphatase (Na+, K+-ATPase) activity, and histopathological changes were evaluated in the brain. The results showed that TCEP (100 and 1500 µg L-1) induced oxidative stress and significantly decreased the activities of antioxidant enzymes (SOD, CAT and GR) in the brain tissue of zebrafish. In contrast, the lipid peroxidation (LPO) level was increased compared to the control group. Exposure to TCEP inhibited the acetylcholinesterase (AChE) and Na+,K+-ATPase activities in the brain tissue. Brain histopathology after 42 days of exposure to TCEP showed cytoplasmic vacuolation, inflammatory cell infiltration, degenerated neurons, degenerated purkinje cells and binucleate. Furthermore, TCEP exposure leads to significant changes in dopamine and 5-HT levels in the brain of zebrafish. The data in the present study suggest that high concentrations of TCEP might affect the fish by altering oxidative balance and inducing marked pathological changes in the brain of zebrafish. These findings indicate that chronic exposure to TCEP may cause a neurotoxic effect in zebrafish.

The Antioxidant and Hepatoprotective Potential of Berberine and Silymarin on Acetaminophen Induced Toxicity in Cyprinus carpio L

Berberine (BBR) and silymarin (SM) are natural compounds extracted from plants known for their antioxidant and chemoprotective effects on the liver. The present study aimed to investigate the beneficial properties of BBR and SM and the association of BBR with SM on liver function using fish as "in vivo" models. Moreover, the study investigated their hepatoprotective role after acetaminophen (APAP) exposure. For this purpose, the fish (N = 360; 118.4 ± 11.09 g) were fed with control or experimental diets for 9 weeks. In the experimental diets, the feed was supplemented with either SM (1 g/kg feed), BBR (100 and 200 mg/kg feed), or a combination of BBR with SM (SM 1 g/kg feed + BBR 100 mg/kg feed and, respectively, SM 1 g/kg feed + BBR 200 mg/kg feed). After the feeding trial, seven fish from each tank were randomly selected and exposed to a single APAP dose. The selected serum biochemical markers, oxidative stress markers, and lysozyme activity were used to evaluate the efficiency of the supplements on carp's health profile, particularly regarding the hepatopancreas function. Our results showed that the inclusion of SM and BBR (either as a single or in combination) reduced the serum contents of total cholesterol, triglyceride, and alanine transaminase. An increase in the high-density cholesterol was observed after the administration of BBR or BBR in association with SM. Both supplements showed hepatoprotective activity against APAP-induced hepatotoxicity, especially BBR. The ameliorative effects of SM (1 g) in association with BBR (100 mg) were highlighted by the modulation of the nonspecific immune system and oxidative stress alleviation after APAP exposure.

Spirulina (Arthrospira maxima) mitigates the toxicity induced by a mixture of metal and NSAID in Xenopus laevis

Cadmium (Cd) is often detected in the environment due to its wide use in industry; also, NSAIDs are one of the most consumed pharmaceuticals, particularly diclofenac (DCF). Several studies have reported the presence of both contaminants in water bodies at concentrations ranging from ng L-1 to μg L-1; in addition, they have shown that they can induce oxidative stress in aquatic species and disturb signal transduction, cell proliferation, and intercellular communication, which could lead to teratogenesis. Spirulina has been consumed as a dietary supplement; its antioxidant, anti-inflammatory, neuroprotective, and nutritional properties are well documented. This work aimed to evaluate if Spirulina reduces the damage induced by Cd and DCF mixture in Xenopus laevis at early life stages. FETAX assay was carried out: 20 fertilized oocytes were exposed to seven different treatments on triplicate, control, Cd (24.5 μg L-1), DCF (149 μg L-1), Cd + DCF, Cd+DCF+Spirulina (2 mg L-1), Cd+DCF+Spirulina (4 mg L-1), Cd+DCF+Spirulina (10 mg L-1), malformations, mortality, and growth were evaluated after 96 h, also lipid peroxidation, superoxide dismutase and catalase activity were determined after 192 h. Cd increased DCF mortality, Cd and DCF mixture increased the incidence of malformations as well as oxidative damage; on the other hand, the results obtained show that Spirulina can be used to reduce the damage caused by the mixture of Cd and DCF since it promotes growth, reduce mortality, malformations, and oxidative stress in X. laevis.

A study to assess the health effects of an anticancer drug (cyclophosphamide) in zebrafish (Danio rerio): eco-toxicity of emerging contaminants

Cyclophosphamide (CP) is widely used for treating various kinds of cancer. Because of its high intake, metabolism and excretion, these anticancer medications have been detected in the aquatic environment. There is very limited data on the toxicity and effects of CP on aquatic organisms. The present study aims to assess the toxic effect of CP on certain oxidative stress biomarkers (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione-GSH, glutathione S-transferases-GST and lipid peroxidation-LPO), protein, glucose, metabolising enzymes (aspartate aminotransferase-AST, alanine aminotransferase-ALT), and ion-regulatory markers (sodium ions-Na⁺, potassium ions-K⁺, and chloride ions-Cl^-), and histology in the gills and liver of Danio rerio at environmentally relevant concentrations (10, 100 and 1000 ng L^-1). Exposure to CP for 42 days led to a significant decrease in SOD, CAT, GST, GPx and GSH levels in the gills and liver tissues of zebrafish. The level of lipid peroxidation in the gills and liver tissues of zebrafish was significantly increased compared to the control group. Chronic exposure significantly changes protein, glucose, AST, ALT, Na⁺, K⁺ and Cl^- biomarkers. Fish exposed to different levels of CP showed necrosis, inflammation, degeneration and hemorrhage in the gills and hepatic tissues. The observed changes in the studied tissue biomarkers were proportional to both dose and time. In conclusion, CP at environmentally relevant concentrations causes oxidative stress, energy demand, homeostasis disturbances, and enzyme and histological alterations in the vital tissues of zebrafish. These alterations were similar to the toxic effects reported in mammalian models.

The potential effect of Moringa oleifera ethanolic leaf extract against oxidative stress, immune response disruption induced by abamectin exposure in Oreochromis niloticus

Abamectin (ABM), a naturally fermented product of Streptomyces avermitilis, is applied to pest control in livestock and agriculture fields. The aim of the current study is to evaluate the protective effects of Moringa oleifera leaf ethanolic extract (MOE) on biochemical changes including oxidative stress indices, immune response marker, lipid profiles as well as mRNA expression of immune related genes, and abamectin (ABM, 5% EC) residue levels in Nile tilapia (Oreochromis niloticus) exposed to a sub-lethal concentration (0.5 µg/l) for 28 days. Disturbance in liver and kidney biomarkers was markedly increased in ABM-exposed fish compared to the control group. Malondialdehyde levels in the liver and brain tissues, as well as the activities of glutathione-s-transferase, superoxide dismutase, and glutathione peroxides, all increased significantly in ABM group. Additionally, ABM exposure increased the levels of interleukin 10 beta and growth factor gene expression. On the other hand, fish exposed to ABM had significantly lower serum alkaline phosphatase, creatinine, high-density lipoprotein, glutathione peroxides in brain, glutathione in liver and brain tissues, lysozyme activity, nitric oxide, immunoglobulin M, tumor necrosis factor, and interleukin 1 beta as compared to the control group. The recorded detrimental effects of ABM on tilapia have been overcome by the addition of MOE to the diet (1%) and ameliorating hepato-renal damage and enhancing antioxidant activity, innate immune responses, and upregulating the anti-inflammatory gene expression. Therefore, it could be concluded that MOE dietary supplementation at 1% could be used to counteract the oxidative stress, immune response disruption induced by abamectin exposure in Oreochromis niloticus, and reduce its accumulation in fish tissues.

Neurotoxic, biotransformation, oxidative stress and genotoxic effects in Astyanax altiparanae (Teleostei, Characiformes) males exposed to environmentally relevant concentrations of diclofenac and/or caffeine

The present study evaluated neurotoxic, biotransformation, genotoxic and antioxidant responses to relevant environmental concentrations of diclofenac (0.4 μg L^-1) and caffeine (27.5 μg L^-1), separate and combined, in adult males of the freshwater fish Astyanax altiparanae after a subchronic exposure (14 days). Fish exposed to diclofenac and caffeine, both separate and combined, revealed a neurotoxic effect through the inhibition of acetylcholinesterase activity in the muscle, while diclofenac alone and in combination caused cyclooxygenase inhibition. Caffeine alone produces genotoxicity on this species but, when combined with diclofenac, it potentiates hepatic lipoperoxidation and the inhibition of oxidative stress enzymes, while diclofenac alone or in combination produces a general inhibition of important enzymes. This study suggests that aquatic contamination produced by these pharmaceuticals has the potential to affect homeostasis and locomotion in A. altiparanae and compromise their immune system and general health.

Effects of short-term exposure to tralopyril on physiological indexes and endocrine function in turbot (Scophthalmus maximus)

Tralopyril is an emerging marine antifouling agent with potential toxic effects on non-target aquatic organisms. To evaluate the toxicity of tralopyril, to turbot (Scophthalmus maximus), we assessed biomarkers, including oxidative stress, neurotoxicity, and osmotic homeostasis regulation enzymes, after a 7-day exposure to tralopyril (5 μg/L, 15 μg/L, 30 μg/L). Superoxide dismutase activity was significantly decreased at 30 μg/L, and Ca²⁺-Mg²⁺-ATPase activity in the gills was significantly increased at 15 μg/L and 30 μg/L. No statistically significant differences in the responses of acetylcholinesterase and nitric oxide were detected. In addition, 15 μg/L and 30 μg/L tralopyril induced hyperthyroidism, reflected by significantly increased of T3 levels. The expression levels of hypothalamus-pituitary-thyroid axis-related genes were also upregulated. The molecular docking results showed that the thyroid system disruption was not caused by competitive binding to the receptor. In addition, the integrated biomarker response index showed that 15 μg/L tralopyril had the greatest effect on turbot. In general, tralopyril caused oxidative damage, affected energy metabolism, and interfered with the endocrine system. These findings could provide reference data for assessing the ecological risk of tralopyril in marine environments.