Genotoxicity assessment of acute exposure of chlorpyrifos to freshwater fish Channa punctatus (Bloch) using micronucleus assay and alkaline single-cell gel electrophoresis

Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridylphosphorothioate) is one of the organophosphate pesticides widely used in agricultural practices throughout world and irreversible inhibitor of cholinesterase in all animal species. Limited efforts have been made to study acute genotoxic effects of chlorpyrifos (CPF) in different tissues of fish using genotoxic biomarkers. Therefore, the present investigation was aimed to study the induction of DNA damage by CPF in freshwater teleost fish Channapunctatus using micronucleus assay (MN assay) and alkaline single-cell gel electrophoresis (comet assay). The value of LC(50) - 96 h of CPF was determined as 811.98 microgl(-1) for C. punctatus, in a semi-static system and on the basis of LC(50) value three acute concentrations viz., 203, 406 and 609 microgl(-1) were determined. The fishes were exposed to the different concentrations of CPF for 96 h and samplings were done at regular intervals for assessment of the MN frequencies and DNA damage. In general, significant effects (P<0.01) from both concentrations and time of exposure were observed in exposed fishes. It was found that the micronucleus induction was highest on 96 h at all concentrations in the peripheral blood. Similar trend was observed for the DNA damage measured in terms of the percentage of tail DNA in the lymphocyte and gill cells. This study explored the combined use of micronucleus assay and comet assay for in vivo laboratory studies using fresh water fish for screening the genotoxic potential of xenobiotics.     

Nickel oxide nanoparticles exert cytotoxicity via oxidative stress and induce apoptotic response in human liver cells (HepG2)

Increasing use of nickel oxide nanoparticles (NiO NPs) necessitates an improved understanding of their potential impact on human health. Previously, toxic effects of NiO NPs have been investigated, mainly on airway cells. However, information on effect of NiO NPs on human liver cells is largely lacking. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and induction of apoptotic response in human liver cells (HepG2) due to NiO NPs exposure. Prepared NiO NPs were crystalline and spherical shaped with an average diameter of 44 nm. NiO NPs induced cytotoxicity (cell death) and ROS generation in HepG2 cells in dose-dependent manner. Further, ROS scavenger vitamin C reduced cell death drastically caused by NiO NPs exposure indicating that oxidative stress plays an important role in NiO NPs toxicity. Micronuclei induction, chromatin condensation and DNA damage in HepG2 cells treated with NiO NPs suggest that NiO NPs induced cell death via apoptotic pathway. Quantitative real-time PCR analysis showed that following the exposure of HepG2 cells to NiO NPs, the expression level of mRNA of apoptotic genes (bax and caspase-3) were up-regulated whereas the expression level of anti-apoptotic gene bcl-2 was down-regulated. Moreover, activity of caspase-3 enzyme was also higher in NiO NPs treated cells. To the best of our knowledge this is the first report demonstrating that NiO NPs caused cytotoxicity via ROS and induced apoptosis in HepG2 cells, which is likely to be mediated through bax/bcl-2 pathway. This work warrants careful assessment of Ni NPs before their commercial and industrial applications.     

Susceptibility of the freshwater pulmonate snail Lymnea luteola L. to copper oxide nanoparticle

Copper oxide nanoparticles (CuONP) are among the most widely used engineered nanoparticles and thus likely to permate the environment predominantly in sediments. The present study was designed to examine the adverse effects of CuONP in freshwater snail Lymnea luteola L. (L. luteola) exposed for 5 days. Induction of oxidative stress in digestive gland was evidenced by a decrease in reduced glutathione (GSH) levels, and activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) whereas lipid peroxidation levels were increased at CuONP 7 or 21 µg/L. Superoxide dismutase activity was numerically higher at lower concentration of CuONP at 1 day but significantly decreased at 5 days. Catalase activity was reduced at 2 days but elevated at lower concentration of CuONP at 5 days. DNA impairment was noted in L. luteola based upon comet assay findings and expressed in terms of % tail DNA and olive tail moment. Results indicate that interaction of CuONP with snail produces toxicity, which is mediated by oxidative stress.     

Role of ROS generation in acute genotoxicity of azoxystrobin fungicide on freshwater snail Lymnaea luteola L

Environmental Science and Pollution Research - Azoxystrobin (AZ) is an aryloxy pyrimidine fungicide extensively applied in the agriculture field all over the world. There is a little information...     

The ameliorative effects of ceftriaxone and vitamin E against cisplatin-induced nephrotoxicity

Environmental Science and Pollution Research - Nephrotoxicity is a common adverse effect of treatment with cisplatin (CDDP). This study was performed to evaluate the antioxidant and...     

Potential histopathological and molecular changes in rat vas deferens inhaled by Boswellia papyrifera and Boswellia carterii

Boswellia papyrifera and Boswellia carterii released from smoke contaminate indoor environment and consequently adversely affect humans as evidenced by respiratory disturbances. The aim of this study was to determine the effects of these plants on pathological and biochemical changes in vas deferens of albino rats. Animals were administered 4 g/kg body weight B. papyrifera and B. carterii daily for 120 days along with controls. Significant changes were observed in epithelial cell types and some cells showed signs of degeneration. The ultrastructural studies revealed marked changes in cytoplasmic organelles. Microvilli were missing and lysosomes were found in the cytoplasm. In addition, all treated groups plasma fructose and other biochemical parameters were decreased indicating reduced energy necessary for motility and contractility of spermatozoa. Many spermatozoa were disorganized and agglomerated. Data suggest that smoke from these plants adversely affects vas deferens.     

Detection of oxidative stress and DNA damage in freshwater snail <Emphasis Type="Italic">Lymnea leuteola</Emphasis> exposed to profenofos

Extensive production and use of organophosphate pesticide in agriculture, has risen concerned about its ecotoxicity and risk assessment of insecticides, which are more important. Therefore, the present investigation was aimed to study the induction of oxidative stress and DNA damage by organophosphate insecticide profenofos (PFF) in freshwater snail Lymnea luteola (L. luteola). The median lethal value (96 h LC₅₀) of PFF was estimated as 1.26 mg/L for L. luteola in a semi-static system and on the basis of LC₅₀ value three concentrations viz., 0.126 (1/10 of LC₅₀, Sublethal I), 0.63 (1/2 of LC₅₀, Sublethal II) and 0.84 mg/L (2/3 of LC₅₀, Sublethal III) were determined. Snails were exposed to above-mentioned concentrations of PFF along with solvent control (acetone) and negative control for 96 h. The haemolymph was collected at 24 and 96 h of after treatment. In heamolymph of PFF exposed snail, lipid peroxide, glutathione reduced glutathione S transferase and superoxide dismutase activities at the tested concentrations significantly differ from those in the control. The genotoxicity induced in hemocytes of treated snails was measured by alkaline single cell gel electrophoresis assay. The data of this experiment demonstrated significantly enhancement of oxidative stress and DNA damage in the treated snails as compared to controls. Also, we observed statistically significant correlations of ROS with DNA damage (% tail DNA) (R² = 0.9708) for 24 h and DNA damage (R2 = 0.9665) for 96 h.

Results of the current experiment can be useful in risk evaluation of PFF among aquatic organisms. The study confirmed the use of comet assay for in vivo laboratory experiments using freshwater snail for selecting the toxic potential of industrial chemicals and environmental contaminants.

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An Original Halo-Alkaline Protease from <Emphasis Type="Italic">Bacillus halodurans</Emphasis> Strain US193: Biochemical Characterization and Potential Use as Bio-Additive in Detergents

Over a hundred of halophilic/halotolerant microorganisms were screened for alkaline protease production. The bacterium showing the highest enzyme production was characterized and identified as Bacillus halodurans US193 on the basis of 16S rRNA gene analysis. It was alkalophilic, thermophilic and halotolerant since it grew optimally at pH 9.7 and 50?°C with tolerance of up to 125 g NaCl l^?1. The alkaline protease was purified 4.9 times with about 40186.1 U/mg as specific activity. It exhibited optimal activity at pH 10, 70?°C and 0.25 M NaCl with perfect stability at wide ranges of pH (6–12), temperatures (30–60?°C) and NaCl concentrations (0–2 M). The serine alkaline protease maintained high stability in the presence of Cu²⁺, Mg²⁺, Ba²⁺ and Ca²⁺ ions, various organic solvents [50% (v/v)] and ionic and non ionic detergent additives. In addition, it was more compatible with various commercialized detergents than other reported detergent proteases, and was very efficient in blood stain removal. These findings let B. halodurans US193 alkaline protease be an ideal candidate for many industrial processes at harsh conditions, especially as a bio-additive in detergent industry.     

Enhanced solid waste management by understanding the effects of gender, income, marital status, and religious convictions on attitudes and practices related to street littering in Nablus - Palestinian territory

Litter is recognized as a form of street pollution and a key issue for solid waste managers. Nablus district (West Bank, Palestinian Territory), which has an established network of urban and rural roads, suffers from a wide-spread litter problem that is associated with these roads and is growing steadily with a well-felt negative impact on public health and the environment. The purpose of this research was to study the effects of four socio-economic characteristics (gender, income, marital status, and religious convictions) of district residents on their attitudes, practices, and behavior regarding street litter generation and to suggest possible remedial actions. All four characteristics were found to have strong correlations, not only with littering behavior and practices, but also with potential litter prevention strategies. In particular, the impact of religious convictions of the respondents on their littering habits and attitudes was very clear and interesting to observe.     

Fluoride induces DNA damage and cytotoxicity in human hepatocellular carcinoma cells

Humans are primarily exposed to fluoride (Fl), a widespread environmental pollutant, via contaminated drinking water and foodstuffs. The aim of this study was to examine whether sodium fluoride (NaF) exerted cytotoxic effects in human hepatocarcinoma (HepG2) cells. HepG2 cells were incubated with different concentrations of NaF and reactive oxygen species (ROS) levels, cell cycle, apoptosis, and DNA damage determined. Concentration-dependent studies showed that exposure to HepG2 cells with different concentrations of NaF for 24 hr significantly decreased cell viability and intracellular antioxidant capacity. Furthermore, NaF exposure increased lipid peroxidation levels and accumulation of intracellular ROS; and lowered antioxidant glutathione concentrations. In addition to oxidative impairments, NaF treatment enhanced HepG2 cell death via apoptotic pathway as evidenced by DNA fragmentation and cell cycle arrest. Sodium fluoride treatment unregulated p53 level, and Bax and Bcl2 expression. Diminished cell viability and changes in cell cycle accompanied a rise in p53 expression.