Biotoxicity and tissue-specific oxidative stress induced by Gemini surfactant as a protocol on fingerlings of Cirrhinus mrigala (Ham.): An integrated experimental and theoretical methodology

Environmental toxicity assessment of engineered nanoparticles manifest histo-hemato alterations to fresh water fish

The present study rigorously examined the toxicological effects of nanoparticles (NPs), specifically nickel (Ni) and chromium oxide (Cr3O4) NPs, synthesized under controlled conditions and characterized. To evaluate their potential environmental impact exposed the freshwater fish Labeo rohita (L. rohita) to environmentally relevant concentrations of both NPs within a controlled laboratory conditions. Vital organs, including gills and liver were subjected to histopathological analysis, revealing profound alterations in tissue architecture that were distinctly correlated with pathological damage. The lesions exhibited moderate to severe changes that are further correlated with the semi-quantitative mean alteration value (MAV). Furthermore, conducted a quantitative assessment of tissue-specific morphological changes. Notably, there was a significant reduction in critical hematological changes, including red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin concentrations and other parameters. All of which exhibited significant fluctuations in relation to increasing NPs concentrations. These findings underscore the critical necessity for continued investigation into the ecological risks associated with these nanoparticles.

Effects of sodium dodecylbenzene sulfonate (SDBS) on zebrafish (Danio rerio) gills and blood

Sodium dodecylbenzene sulfonate (SDBS) is an important surfactant used as a cleaning agent and industrial additive to remove unwanted chemicals which have been detected in the aquatic environment. The aim of this study was to examine the toxicological potential of SDBS on the gills of adult male zebrafish (Danio rerio) exposed to this chemical. For the 96 hr acute exposure, fish were divided into three groups: control, 0.25 mg/L, and 0.5 mg/L of SDBS. After the experiment, morphophysiological analyses (gill histopathology and histochemistry), oxidative stress (determination of gill activities of superoxide dismutase (SOD) and catalase (CAT)), and hematological analyses (leukocyte differentiation) were conducted. Data demonstrated that SDBS at both tested concentrations altered the histopathological index and initiated circulatory disturbances, as well as adverse, progressive, and immunological changes in the gills. In the 0.5 mg/L group, SOD activity decreased significantly, but CAT activity was not altered. Prominent blood changes observed in this group were neutrophilia and lymphocytosis. The number of mucous and chloride cells increased significantly in both groups. Taken together, our findings demonstrated that exposure of D. rerio to SDBS, even for 96 hr, produced adverse morphological and hematological effects associated with a reduction in SOD activity. Our findings indicate that exposure of aquatic species to the anionic surfactant SDBS may lead to adverse consequences associated with oxidative stress. Therefore, this study highlights the risks that this substance may pose to aquatic ecosystems and emphasizes the need for further investigations and strict regulations on its disposal.

Oxidative Stress and Histopathological Changes in Gills and Kidneys of Cyprinus carpio following Exposure to Benzethonium Chloride, a Cationic Surfactant

One cationic surfactant with a wide spectrum of microbiocidal activity is benzethonium chloride (BEC). Despite being widely used, the toxicity data on vertebrate organisms are limited. Therefore, we aimed to evaluate within this study the acute toxicity of BEC on the gills and kidneys of Cyprinus carpio (European carp). An alteration of the antioxidant enzymes activities (glutathione reductase, glutathione peroxidase and glutathione S-transferase) was noticed after 96 h of exposure, along with an elevation of lipid peroxidation and decreased concentration of reduced glutathione, which confirmed that BEC was able to induce toxicity to these tissues. These metabolic effects were correlated with unspecific structural changes observed in gills and kidneys, having moderate degree of severity (such as an increase of melanomacrophages aggregation incidence and cytoplasm vacuolation of goblet cells in collecting tubules) and generally being compatible with life for the exposure time studied. The most severe structural effects were observed in gills after 96 h, noticing a lamellar aneurysm, hemorrhages and lamellar epithelium disruption due to the blood vessels and pillar cells damages and increased blood flow inside the lamellae. By our research we can confirm the utility of biochemical and histological analyses in the fish organs as tools for monitoring the water quality and ecotoxicological potential of chemicals.

Profound implication of histological alterations, haematological responses and biocidal assessment of cationic amphiphiles unified with their molecular architecture

The interfacial properties depicting the micellization behaviour of the cationic amphiphiles (surfactants) belonging to the class of quaternary ammonium salts varying in degree of hydrophobicity were evaluated using tensiometry, conductivity and fluorescence spectrophotometric methods at 303.15 K. The impact of the amphiphilic nature of these amphiphiles as a function of their concentration is accounted against the selective microbial strains using the well-diffusion approach. Also, its influence on the histological (shrinkage/curling of lamellae, necrosis, haemorrhage, hyperplasia of villi in gills and intestine) alterations and haematological (blood parameters) changes in fingerling of Cirrhinus mrigala (C. mrigala) offers an insight into the stern damages reported as aquatic toxicity. The lesions exhibited moderate to severe alterations that are further correlated with the semi-quantitative mean alteration value (MAV). The in vitro and in vivo findings are explained significantly in terms of amphiphilic hydrophobicity which followed the order: C₁₆TAB > C₁₂TAB. All the observed outcomes are rationalized by the structural assessment of the selected amphiphiles as specified by the computational simulation approach using density functional theory (DFT) with B3LYP method and 3-21G basis source set. This work also portrays the biodegradability of these cationic amphiphiles and their fate on the environment. Graphical abstract Molecular architecture of cationic amphiphiles integrated with their in vitro and in vivo rejoinders.

Recent advances in the application of magnetic Fe3O4 nanomaterials for the removal of emerging contaminants

Emerging contaminants (ECs) are widely distributed and potentially hazardous to human health and the ecological system. However, traditional wastewater treatment techniques are not sufficient to remove ECs. Magnetic nanomaterials are made of ferromagnetic or superparamagnetic magnetic elements such as iron and nickel, which can be easily separated from the aqueous solution, making them ideal adsorbents for contaminants in water. This review focused on the synthesis approaches of magnetic Fe₃O₄ nanoparticles (MFNs), as well as surface modification in order to improve their stability and functional diversity. Also, a detailed summary on the state-of-art application of magnetic nanomaterials on the removal of ECs was addressed. Additionally, challenges and future prospective of applying magnetic nanomaterials into real-world cases were discussed, in which the green and simple synthesis and evaluation of the toxic effects of MFNs are still of great challenge. This work summarizes the recent progress of using magnetic nanomaterials as promising and powerful tools in the treatment of ECs-contaminated water, benefiting researchers interested in nanomaterials and environmental studies.

Evaluation of Sub-Lethal Toxicity of Benzethonium Chloride in Cyprinus carpio Liver

Benzenthonium chloride (BEC, Hyamine 1622) is a quaternary ammonium surfactant with cationic properties widely used in cleaning, sanitation, and medical products that can become harmful to humans and also to the environment. This study aimed to evaluate its acute effects on Cyprinus carpio fish in terms of oxidative stress and morphological changes on hepatic tissue in order to show the sub-lethal toxicity of BEC. Fish were exposed to 1 mg/L BEC for 24, 48, and 96 h, and the liver samples were collected. The most significant changes were noticed after 96 h of exposure when the entire antioxidant enzyme system was affected. The activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase decreased by 44%, 31%, 30%, and 45%, respectively, compared to control. Glucose-6-phosphate dehydrogenase activity decreased by 29% after 96 h of control, inducing a reduction of NADPH formation which decreased by half the level of reduced glutathione, the main non-enzymatic antioxidant. These effects correlated with the raised value of lipid peroxidation after 96 h and the morphology changes on hepatic tissue, such as cytoplasmic vacuolization and nuclear hypertrophy that could affect the normal function of the liver. All of these results showed acute toxicity of BEC on C. carpio after 96 h of exposure, causing oxidative stress response at the hepatic level.