Exposure to Nickel Oxide Nanoparticles Induces Alterations in Antioxidant System, Metabolic Enzymes and Nutritional Composition in Muscles of Heteropneustes fossilis.

The current study was performed to explore potential toxic effect of nickel oxide nanoparticles (NiO NPs) on muscle tissue of catfish, Heteropneustes fossilis. Fishes were exposed to different concentrations of NiO NPs (12 mg/L, 24 mg/L, 36 mg/L and 48 mg/L) for a period of 14 days. Results revealed that NiO NPs caused significant increase in Ni accumulation, metallothionein content, lipid peroxidation and activity of different antioxidant enzymes (catalase, glutathione s transferase and glutathione reductase) while decrease in activity of superoxide dismutase (p < 0.05). Data also reported induction of Na+/K+ ATPase activity initially and then its decrease in concentration dependent manner. Fourier transform infrared spectroscopy revealed shift and changes in spectra of muscle of NiO NPs treated fishes. Fluctuations in activity of aspartate amino transferase, alanine amino transferase and alkaline phosphatase were also noticed. Nutritional contents like protein, lipid, and moisture significantly reduced while glucose and ash percent increased.

Assessment of hazardous impact of nickel oxide nanoparticles on biochemical and histological parameters of gills and liver tissues of Heteropneustes fossilis.

BACKGROUND: The aim of the present study was to assess the hazardous impact of nickel oxide nanoparticles (NiO NPs) on gills and liver of Heteropneustes fossilis. METHODS: Fishes were treated with four concentrations of NiO NPs for a period of 14 days. Nickel accumulation, lipid peroxidation, antioxidant enzymes activities (superoxide dismutase, catalase, glutathione s transferase & glutathione reductase), liver enzymes activities (aspartate amino transferase, alanine transaminase, & alkaline phosphatase), Na+/K+ ATPase activity, FTIR, metallothionein content, ethoxyresorufin-o-deethylase activity, immunohistochemistry, histology and scanning electron microscopy were analyzed in both gills and liver tissues. RESULTS: Results revealed increased accumulation of nickel in both the tissues of exposed fishes. Lipid peroxidation and activities of different antioxidant enzymes increased (except superoxide dismutase) in both the tissues after exposure. Fluctuations in liver enzymes activities and variation in the activity of Na+/K+ ATPase were also observed. FTIR data revealed shift in peaks position in both the tissues. Level of metallothionein and its expression as well as activity of ethoxyresorufin-o-deethylase and expression of CYP1A also increased in both the target tissues of treated fishes. Furthermore, histological investigation and scanning electron microscopy showed structural damages in gills as well as liver tissues of exposed fishes. CONCLUSION: Our results suggest that NiO NPs cause deteriorating effects on the gill and liver tissues of fish, therefore effluents containing these nanoparticles should be treated before their release into water bodies.

Assessment of the potential threat of nickel(II) oxide nanoparticles to fish Heteropneustes fossilis associated with the changes in haematological, biochemical and enzymological parameters.

The present study has been conducted to evaluate the potential threat of NiO nanoparticles (NiO NPs) on an edible fish Heteropneustes fossilis. Fishes selected for the study were exposed to four concentrations of NiO NPs (12, 24, 36 and 48 mg/l) for the period of 14 days, and various haematological, biochemical and enzymological changes in the exposed fishes were examined. Results revealed that maximum fluctuations were seen in 48-mg/l-exposed fishes when compared with the control in terms of the haematological parameters (RBC count, WBC count, Hb content, Ht% and O2 carrying capacity of blood), enzymatic activities (AST, ALP, ALT and LDH) and biochemical parameters (level of cholesterol, triglycerides, glucose, total protein, albumin, globulin, bilirubin and creatinine). However, 12 mg/l treatment to the fishes showed its least impact on aforesaid parameters. Furthermore, Ni accumulation and changes in cortisol level in the blood were also noticed in all the treated fishes. Structural changes, such as membrane and nuclear disintegration, micronucleus, deformed and vacuolated cells, and enucleation were also observed in RBCs of NiO NP-treated fishes. Conclusively, our study provides useful information and insight for the possible ecotoxicity of NiO NPs on aquatic organisms and emphasizes upon the importance of treatment of effluents containing nanoparticles before their release into the aquatic system.

Heavy metal pollution due to coal washery effluent and its decontamination using a macrofungus, Pleurotus ostreatus.

Release of the effluent generated during washing of coal became a major problem for coal industries due to presence of many toxic metals and other pollutants. These effluents are the main source of pollution in rivers and other water bodies. Therefore in this study, we tried to analyse the toxicity of coal washery effluent (CWE) collected from one of the washery plant situated in Dhanbad, India. CWE was found to be very toxic containing large amount of suspended particles and many heavy metals above than their permissible limits. Mycoremediation of CWE was also performed to decontaminate heavy metals from the CWE using a macrofungi Pleurotus ostreatus. Efficiency of Pleurotus for remediation of heavy metals was found to be highest in the 50% diluted effluent (57.2% Mn, 82.6% Zn, 98.0% Ni, 99.9% Cu, 99.3% Co, 99.1% Cr, 89.2% Fe and 35.6% Pb) followed by 25% diluted effluent (33.0% Mn, 55.1% Zn, 97.8% Ni, 99.7% Cu, 97% Co, 84.4% Cr, 87.1% Fe and 73.4% Pb) and raw effluent (23.3% Mn, 73.1% Zn, 78.7% Ni, 87.5% Cu, 59.3% Co, 64.6% Cr, 34.6% Fe and 11.3% Pb) respectively. Increased activity of antioxidant enzymes, lipid peroxidation, concentration of metallothionein proteins and changes in peaks of FTIR spectra were also observed in fungal mycelia grown on the CWE containing media due to accumulation of different metals. Overall this study suggests that Pleurotus can be used as promising option for removal of heavy metals from the effluent released from washery plants and dilution of effluent could increase the efficiency of remediation.

Evaluation of pollution of Ganga River water using fish as bioindicator.

Ganga River, life line of millions of people got heavily polluted due to uncontrolled anthropogenic activities. To monitor the effect of pollution of the river on its aquatic life, a field study was conducted by analyzing the different biomarker enzymes and biochemical parameters in the various tissues (muscles, liver, gills, kidney, brain, and skin) of the Indian major carp Labeo rohita collected from the River Ganga from different study sites of Varanasi district. Activities of antioxidant enzymes, e.g., superoxide dismutase, catalase, and level of lipid peroxidation were found to be higher in the fish collected from the river showing pollutant-induced oxidative stress in the fish. Disturbed health status of the river fish was also manifested by increased activities of aspartate amino transferase, alanine amino transferase, and alkaline phosphatase. Concentration of nutritionally important biomolecules (proteins, lipids, and moisture) and energy value were also found to be significantly lower in the tissues of the River fish indicating its decreased nutritional value due to oxidative stress caused by different pollutants.

Contamination of metals in different tissues of rohu (Labeo rohita, Cyprinidae) collected from the Indian River Ganga.

In the present paper, accumulation of zinc (Zn), iron (Fe), copper (Cu), chromium (Cr), nickel (Ni), manganese (Mn) and lead (Pb) was determined in different tissues (skin, muscles, liver, gills, kidney and brain) of rohu (Labeo rohita) collected from the River Ganga in Varanasi, India. Concentrations of Cu (except gills), Fe and Cr (except brain for Cr) in most of the tissues were above the permissible safe limits for human consumption suggested by the Food and Agricultural Organization (FAO 1983). Concentrations of all metals were higher in River Ganga fish than those from the University fish farm. With the exception of Zn in skin, muscle and brain tissue, the studied metals were bioaccumulated in all tissues. The total metal accumulation or metal pollution index was highest in liver (20.8 ± 0.50) followed by kidney (16.8 ± 0.44), gills (15.2 ± 0.15), muscles (12.1 ± 0.08), skin (10.5 ± 0.53) and brain (7.0 ± 0.02).

Contamination of the River Ganga and its toxic implication in the blood parameters of the major carp Labeo rohita (Ham).

A field study was conducted to examine different physicochemical properties of water and various haematological and biochemical parametres of the fish Labeo rohita collected from the Ganga River (National river of India) at Varanasi district, India. The water was found to be greatly contaminated with a number of dissolved metals (Fe, Cr, Zn, Cu, Mn, Ni and Pb) whose concentrations were above the safe limits suggested by Bureau of Indian Standard (BIS 1991) for drinking water (Fe, 1,353.33 %; Cr, 456 %; Mn, 553.33 %; Ni, 4,490 % and Pb, 1,410 %). The metal accumulation in the fish blood was very high (Fe, 2,408 %; Cr, 956.57 %; Zn, 464.90 %; Cu, 310.57 %; Mn, 1,115.48 %) in comparison to the control fish maintained under strict quality control. Lower values of the various haematological parameters (total erythrocytes count, haemoglobin, haematocrit, mean corpuscular volume and O2-carrying capacity) in the river fish in comparison to the control indicate toxic manifestation exerted by the contaminated river water on the fish. The higher level of total leucocytes count further illustrates stressed condition of the river fish. The toxic impact of the Ganga water is also expressed in the fish by the presence of higher levels of cholesterol, glucose, elevated activities of the enzymes aspartate amino transferase and alanine amino transferase, and lowered protein concentration.

Phytoremediation of the toxic effluent generated during recovery of precious metals from polymetallic sea nodules.

Recovery of metals from the polymetallic sea nodules at the pilot plant at National Metallurgical Laboratory, Jamshedpur, India has generated a highly toxic effluent. This effluent contains several metals like Mn, Cu, Zn, Fe, Pb, Cr, and Cd that pollute the neighboring water bodies when discharged. Hence detoxification of this effluent was practiced using two plants: Lemna minor and Azolla pinnata for 7 days. During investigation A. pinnata removed 96% of Mn, 97% of Cu, 98% of Zn, 70% of Fe, 96% of Pb, 93% of Cr, 78% of Cd, and was comparatively more effective than L. minor which removed 94% of Mn, 86% of Cu, 62% of Zn, 74% of Fe, 84% of Pb, 63% of Cr, 78% of Cd. During the 7 days of experiment chlorophyll content decreased by 51% and 59% in A. pinnata and L. minor respectively. Based on our findings we can suggest that these two plants have wide range of metal retention potentialities hence can be of routine use for purification of toxic effluents.