Cytoprotective and anti-apoptotic action of HSP70 stress protein in Oreochromis niloticus exposed to residual dilutions of insecticides with fipronil and ethiprole

Modulating Nitric Oxide: Implications for Cytotoxicity and Cytoprotection

Despite the significant progress in the fields of biology, physiology, molecular medicine, and pharmacology; the designation of the properties of nitrogen monoxide in the regulation of life-supporting functions of the organism; and numerous works devoted to this molecule, there are still many open questions in this field. It is widely accepted that nitric oxide (•NO) is a unique molecule that, despite its extremely simple structure, has a wide range of functions in the body, including the cardiovascular system, the central nervous system (CNS), reproduction, the endocrine system, respiration, digestion, etc. Here, we systematize the properties of •NO, contributing in conditions of physiological norms, as well as in various pathological processes, to the mechanisms of cytoprotection and cytodestruction. Current experimental and clinical studies are contradictory in describing the role of •NO in the pathogenesis of many diseases of the cardiovascular system and CNS. We describe the mechanisms of cytoprotective action of •NO associated with the regulation of the expression of antiapoptotic and chaperone proteins and the regulation of mitochondrial function. The most prominent mechanisms of cytodestruction-the initiation of nitrosative and oxidative stresses, the production of reactive oxygen and nitrogen species, and participation in apoptosis and mitosis. The role of •NO in the formation of endothelial and mitochondrial dysfunction is also considered. Moreover, we focus on the various ways of pharmacological modulation in the nitroxidergic system that allow for a decrease in the cytodestructive mechanisms of •NO and increase cytoprotective ones.

Acute sublethal exposure to ethiprole impairs physiological and oxidative status in the Neotropical fish Astyanax altiparanae

Ethiprole, a phenylpyrazole insecticide, has been increasingly used in the Neotropical region to control stink bug pests in soybean and maize fields. However, such abrupt increases in use may have unintended effects on non-target organisms, including those inhabiting freshwater ecosystems. Here, we evaluated the effects of acute (96 h) sublethal exposure to ethiprole (up to 180 μg/L, which is equivalent to 0.013% of the recommended field dose) on biomarkers of stress in the gills, liver, and muscle of the Neotropical fish Astyanax altiparanae. We further recorded potential ethiprole-induced effects on the structural histology of A. altiparanae gills and liver. Our results showed that ethiprole exposure increased glucose and cortisol levels in a concentration-dependent manner. Ethiprole-exposed fish also exhibited higher levels of malondialdehyde and greater activity of antioxidant enzymes, such as glutathione-S-transferase and catalase, in both gills and liver. Furthermore, ethiprole exposure led to increased catalase activity and carbonylated protein levels in muscle. Morphometric and pathological analyses of the gills revealed that increasing ethiprole concentration resulted in hyperemia and loss of integrity of the secondary lamellae. Similarly, histopathological analysis of the liver demonstrated higher prevalence of necrosis and inflammatory infiltrates with increasing ethiprole concentration. Altogether, our findings demonstrated that sublethal exposure to ethiprole can trigger a stress response in non-target fish species, which may lead to potential ecological and economic imbalances in Neotropical freshwater systems.

β-1,3-glucan improved the health and immunity of juvenile African catfish (Clarias gariepinus) and neutralized the histological changes caused by lead and fipronil pollutants

BACKGROUND

Water pollutants cause adverse effects in aquatic ecosystems. The immunomodulatory and mitigating effects of dietary 1,3-glucan on fipronil and lead-induced intoxication in African catfish (Clarias gariepinus) were investigated. Two hundred forty catfish were randomly divided into four equal groups: those in the first group were fed basic diet and served as controls; those in the second group were supplemented with β-1,3-glucan (0.1%); those in the third group were exposed to combination of lead nitrate at 0.041 mg/L (1/10 96 h LC50) and fipronil at 2.8 mg/l (1/10 96 h LC50); and those in the fourth group were exposed to combination of fipronil, lead, and β-1,3-glucan. The health status, haematological, immunological, and histological changes were all evaluated.

RESULT

Swelling on the dorsolateral side, spinal column deviation, sluggish movement, skin bleaching, excessive mucus secretion, significant variations in blood indices-related measures, and a 45% death rate were observed in the third group. There was a significant reduction in interleukin-1 (IL-1) and interleukin-6 (IL-6) and immunoglobulin M (IgM) concentrations, as well as decrease in their corresponding gene expression, indicating that fipronil and lead had immunosuppressive activity. Severe catarrhal enteritis and mucinous degeneration of the lining epithelium, and notable depletion of white pulp, congested red pulp and hemosiderosis were common pathological findings in the spleen. β-1,3-glucan alone or in combination with fipronil and lead provoked physical activity, blood indices, with elevations in IL-1β, IL-2, IL-6, and IgM concentrations, as well as up-regulation in their genes' expression in splenic tissues, when compared to the third group. The spleen and intestine had normal histological architecture with 5% mortalities. There were no fish deaths in the β-1,3-glucan-alone or control groups.

CONCLUSION

The use of β-1,3-glucan (0.1%) as dietary supplement could be implemented to protect against the toxic effects of fipronil and lead toxicity by improving the health and immunological parameters of intoxicated catfish.

Integrated biomarker approach strongly explaining in vivo sub-lethal acute toxicity of butachlor on Labeo rohita

Butachlor herbicide belongs to the family of chloroacetanilide group, widely used for control of grass and broadleaf weeds in paddy fields however, its repeated application may result in aquatic pollution. Butachlor residue has been detected in aquatic environments, which may produce toxic effects on non-target organisms including fish. Keeping this in mind, the present study was designed to estimate the LC₅₀ of butachlor (Shaktiman®), and to evaluate the sub-lethal toxicity at two concentrations (12.42 μg L^-1 and 62.10 μg L^-1) in Labeo rohita for a period of 24, 48, and 72 h. Fish exposed to butachlor reduced the counts of red blood cells (RBC), haemoglobin (HGB), hematocrit (HCT), and white blood cells (WBC). A significant (p < 0.05) increase in the antioxidant enzyme (superoxide dismutase-SOD, glutathione-s-transferase-GST), and hepatic enzyme (glutamate-oxaloacetate transaminase-GOT, glutamate-pyruvate transaminase-GPT) were noticed in butachlor exposed fish. Heat shock protein 70 (HSP70) and HSP90 in gill; cortisol, protein, albumin, globulin, and triglyceride in serum were increased upon exposure of butachlor. On the contrary, complement 3 (C3) and immunoglobulin (IgM) in serum was found to be decreased compared to control fish. The findings thus suggest that the fish upon exposure to butachlor disrupts the biomarkers which ultimately leads to growth retardation in fish.

Ameliorative effect of Spirulina and Saccharomyces cerevisiae against fipronil toxicity in Oreochromis niloticus

The ameliorative effects of Spirulina and Saccharomyces cerevisiae (S. cerevisiae) against fipronil toxicity in Nile tilapia fish were investigated. Fipronil is a kind of pesticide that is widely used in agriculture, thus this trial was conducted to evaluate the effect of fipronil on growth related parameters (final body weight, feed intake, weight gain, feed conversion ratio, specific growth rate, and protein efficiency ratio), hematology related parameters (RBCs, WBCs, hemoglobin, packed cell volume, and deferential leukocytic count), biochemistry related parameters (alanine aminotransferase, aspartate aminotransferase, total protein, albumin, urea, and creatinine), histopathology of liver, intestine, gills, and spleen, and gene expression of antioxidants, stress, inflammatory, apoptotic, and related to junction proteins genes as SOD and GPx, COX II, TNF-α, Casp-3, and Claudin-3, respectively, in Nile tilapia (Oreochromis niloticus). Four hundred and five Nile tilapia fish were distributed in a glass aquarium into nine groups according to the Spirulina and S. cerevisiae supplemented diets, with or without fipronil contaminated water. The classified groups are control, Sc: S. cerevisiae (4 g/Kg diet), Sp: Spirulina (1 g/100 g diet), Fb1: 0.0021 mg fipronil/L, ScFb1: S. cerevisiae (4 g/Kg diet) with 0.0021 mg fipronil/L, SpFb1: Spirulina (1 g/100 g diet) with 0.0021 mg fipronil/L, Fb2: 0.0042 mg fipronil/L, ScFb2: S. cerevisiae (4 g/Kg diet) with 0.0042 mg fipronil/L, and SpFb2: Spirulina (1 g/100 g diet) with 0.0042 mg fipronil/L. The results of the present investigation indicated the negative effect of fipronil on the growth performance parameters of Nile tilapia, which was confirmed by the results of hematology, biochemistry, and histopathology. In addition, the results of gene expression of antioxidants, stress, inflammatory, and apoptotic genes indicate the genotoxicity of fipronil. However, these negative effects were ameliorated by Spirulina and Saccharomyces dietary supplementation.

Assessment of the effect of sub-lethal acute toxicity of Emamectin benzoate in Labeo rohita using multiple biomarker approach

Emamectin benzoate (EMB) is a potent neurotoxin agent, widely used for ectoparasites control in aquaculture, but their detailed toxicological implications in Labeo rohita are unknown. Thus, this study was conceptualized to determine the LC₅₀ and to investigate the effects of two sub-lethal concentrations 1/50th of 96 h LC₅₀ (1.82 μgL^-1) and 1/10thof 96 h LC₅₀ (9.1 μgL^-1) on hemato-immunological and biochemical responses in L. rohita (mean weight 25.54 ± 2.3 g and length 10.35 ± 2.4 cm) for a period of 24 h, 48 h, and 72 h. LC₅₀ of EMB were 163 μgL^-1, 112 μgL^-1, 99 μgL^-1 and 91 μgL^-1 at 24 h, 48 h, 72 h, and 96 h respectively. The safe limit at 96 h LC₅₀ of EMB was 2.30 μgL^-1. In EMB treated fish, red blood cells, white blood cells, hemoglobin, and hematocrit counts were reduced (p < 0.05) significantly. Superoxide dismutase (SOD) activity in the liver and kidney declined (p < 0.05) at 72 h while in gill and muscle the activity increased significantly. Glutathione-s-transferase (GST) activity in the liver, gill, and kidney increased (p < 0.05) while muscle decreased significantly. Catalase (CAT) activity in liver, gill, and muscle decreased while in kidney increases. Glutamic-oxaloacetic acid transaminase (GOT) activity and Glutamate pyruvate transaminase (GPT) activity were increased in liver, kidney, and muscle tissue. The change in serum triglycerides, serum protein level was noticed. The level of cortisol, heat shock protein 70 (HSP70), and HSP90 increased (p < 0.05) while the immunological responses like immunoglobulin M (IgM) and complement 3(C3) activity decreased (p < 0.05) in EMB exposed fish. Thus, EMB exposure at two sub-lethal concentrations in L. rohita induces several hemato-immuno, and biochemical alterations in blood, serum, and different organs. The overall result of the present study indicated that EMB is toxic to fish even for a short-term exposure and low doses, and therefore utmost caution should be taken to prevent their drainage into water bodies.