RAPD-PCR analysis for molecular characterization and genotoxic studies of a new marine fish cell line derived from Dicentrarchus labrax

Genetic relatedness and diversity of Capillaria species infecting bayad (Bagrus bajad) in upper Egypt

BACKGROUND

This study investigates the genetic characteristics of Capillaria isolates from the infected fish, Bagrus bajad, and their relation to human Capillaria philippinensis using Random Amplified Polymorphic DNA (RAPD-PCR) analysis. Fifteen fish Capillaria were isolated and compared to identified human C. philippinensis using six primers: M-are, M-1, G-7, G-11, G-15, and G-18.

RESULTS

All six primers successfully amplified DNA, highlighting their efficacy in distinguishing between human and fish Capillaria isolates. The analysis revealed distinctive banding patterns between fish and human isolates, with variations in size and number of DNA fragments. Additionally, genetic similarity analysis showed intriguing patterns of relatedness, with certain pairs exhibiting high similarity percentages. Comparative assessment of RAPD polymorphism demonstrated consistent findings of 100% polymorphism across all primers. The Unweighted Pair Group Method with Arithmetic Mean Algorithm (UPGMA) evaluated the closest relationship between human and fish isolates. These results underscore the utility of RAPD analysis in delineating the genetic diversity among Capillaria isolates from different hosts.

CONCLUSION

Overall, this study contributes to our understanding of the genetic variability and relatedness among Capillaria isolates, shedding light on their evolutionary dynamics and zoonotic potential.

Potential probiotic lactobacilli strains isolated from artisanal Mexican Cocido cheese: evidence-based biosafety and probiotic action-related traits on in vitro tests

The biosafety of four potentially probiotic lactobacilli strains, isolated from artisanal Mexican Cocido cheese, was assessed through in vitro tests aimed to determine (1) the antibiotic susceptibility profile by broth microdilution, (2) the transferability of antibiotic resistance determinants by filter-mating, and (3) the phenotypic and genotypic stability during serial batch sub-culture (100-day period) by evaluating physiological and probiotic features and RAPD-PCR fingerprinting. Lactobacilli strains exhibited multidrug-resistance; however, resistance determinants were not transferred in the filter-mating assay. Significant (p < 0.05) differences were observed in bacterial morphology and some functional and technological properties when strains were serially sub-cultured over 50 generations (G50), compared to the initial cultures (G0). Conversely, the strains did not show mucinolytic and hemolytic activities either at G0 or after 100 generations (G100). Genetic polymorphism and genomic template instability on selected strains were detected, which suggest possible evolutionary arrangements that may occur when these bacteria are largely cultured. Our findings suggest that the assessed strains did not raise in vitro biosafety concerns; however, complementary studies are still needed to establish the safe potential applications in humans and animals.

Evaluation of Apical and Molecular Effects of Algae Pseudokirchneriella subcapitata to Cerium Oxide Nanoparticles

Cerium oxide engineered nanoparticles (nCeO₂) are widely used in various applications and are, also, increasingly being detected in different environmental matrixes. However, their impacts on the aquatic environment remain poorly quantified. Hence, there is a need to investigate their effects on non-target aquatic organisms. Here, we evaluated the cytotoxic and genotoxic effects of <25 nm uncoated-nCeO₂ on algae Pseudokirchneriella subcapitata. Apical (growth and chlorophyll a (Chl a) content) and genotoxic effects were investigated at 62.5-1000 µg/L after 72 and 168 h. Results demonstrated that nCeO₂ induced significant growth inhibition after 72 h and promotion post 96-168 h. Conversely, nCeO₂ induced enhanced Chl a content post 72 h, but no significant changes were observed between nCeO₂-exposed and control samples after 168 h. Hence, the results indicate P. subcapitata photosynthetic system recovery ability to nCeO₂ effects under chronic-exposure conditions. RAPD-PCR profiles showed the appearance and/or disappearance of normal bands relative to controls; indicative of DNA damage and/or DNA mutation. Unlike cell recovery observed post 96 h, DNA damage persisted over 168 h. Thus, sub-lethal nCeO₂-induced toxicological effects may pose a more serious threat to algae than at present anticipated.

TiO2-NPs and cadmium co-exposure: in vitro assessment of genetic and genomic DNA damage on Dicentrarchus labrax embryonic cells

The increased titanium dioxide nanoparticles (TiO₂-NPs) spread and their interaction with organic and inorganic pollutants arouses concern for the potential hazards for organisms and environment. This study tested in vitro the genotoxic effects of TiO₂-NPs (1 μg/mL) and cadmium (Cd) (0.1 μg/mL) co-exposure using Dicentrarchus labrax embryonic cells (DLEC) as experimental model. The genotoxicity tests (Comet assay, Diffusion Assay and Random Amplification of Polymorphic DNA (RAPD-PCR) were conducted after 3, 24 and 48 hours of exposure to TiO₂-NPs and Cd alone and in combination. The results showed that the percentage of DNA damage and apoptotic cells increases following 48 hours TiO₂-NPs exposure, while DNA instability was detected for all the times tested. Cd induced genotoxic effects starting from 3 hour-exposure and for all the treatment times. Cd + TiO₂-NPs co-exposure did not cause any genomic damage or apoptosis for all the exposure times. The possibility that Cd and TiO₂-NPs form aggregates no longer able of penetrating the nucleus and damaging the genetic material is discussed.

Genotoxicity Evaluation of Metformin in Freshwater Planarian Dugesia japonica by the Comet Assay and RAPD Analysis

Objective

To investigate the genotoxicity of metformin on planarian with different concentrations and exposure times.

Methods

The planarians were treated, respectively, with 10 mmol/L and 50 mmol/L metformin for 1, 3, and 5 days, and then, the comet assay and random amplified polymorphic DNA (RAPD) analysis were performed. 13 random primers were used for PCR amplification with the genomic DNAs as templates. Planarians cultured in clear water were used as the control. Genomic template stability (GTS) was calculated by comparing and analyzing the RAPD patterns of the control group and the treatment groups.

Results

In the comet assay, DNA damage of planarians treated with 10 mmol/L metformin for 1, 3, and 5 days was 10.2%, 25.4%, and 36.8%, respectively, and that of planarians treated with 50 mmol/L metformin was 40.6%, 62.8%, and 65.4%, respectively. GTS values of planarians exposed to 10 mmol/L metformin for 1, 3, and 5 days were 64.1%, 62.8%, and 52.6%, respectively, and those of planarians exposed to 50 mmol/L metformin for 1, 3, and 5 days were 52.6%, 51.3%, and 50%, respectively. DNA damage increased and GTS values decreased with the increasing metformin exposure concentration and exposure time.

Conclusion

Metformin has certain genotoxicity on planarian in a dose- and time-related manner. The comet assay and RAPD analysis are highly sensitive methods for detecting genotoxicity with drugs.

Improving plant-based genotoxicity bioassay through AFLP technique for trace metal-contaminated water: insights from Myriophyllum aquaticum (Vell.) Verdc. and Cd

In this work, we evaluated whether the species Myriophyllum aquaticum (Vell.) Verdc. can be a promising material for devising reliable eco-toxicological tests for Cd-contaminated waters. Plants of M. aquaticum were exposed to Cd, using different concentrations (1 mg L^-1, 2.5 mg L^-1, 5 mg L^-1, and 10 mg L^-1; experiment 1) and exposure times (2.5 mg L^-1 for 3 days, 7 days, 14 days, and 21 days; experiment 2). Plant growth and Cd accumulation were monitored during the treatment period, and Cd genotoxicity was assessed by analyzing Cd-induced changes in the AFLP fingerprinting profiles using famEcoRI_(TAC)/MseI_(ATG) and hexEcoRI_(ACG)/MseI_(ATG) pairs of primers. Root and shoot growth was reduced already at the lowest Cd concentration used (about 20% reduction for roots and 60% for shoots at 1 mg L^-1; experiment 1) and after 7 days (about 50% reduction for roots and 70% for shoots; experiment 2). The primer combinations produced 154 and 191 polymorphic loci for experiments 1 and 2, respectively. Mean genetic diversity (He) reduction among the treatment groups was observed starting from 2.5 mg L^-1 (He 0.211 treated vs 0.236 control; experiment 1) and after 3 days (He 0.169 treated vs 0.261 control; experiment 2), indicating that results obtained from AFLP profiles did not match with plant growth measurements. Therefore, our results showed that M. aquaticum proved to be a suitable model system for the investigation of Cd genotoxicity through AFLP fingerprinting profile, whereas the more classic eco-toxicological tests based only on biometric parameters could not correctly estimate the risk associated with undetected Cd genotoxicity.

Acaricidal and pathogenic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick, Argas persicus (Argasidae)

This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick, Argas persicus. The acaricidal effect of B. bassiana (at 10⁶-10¹⁰ conidia/mL) was concentration- and time-dependent. At 10⁶ conidia/mL, the accumulated mortality of treated females ranged from 3.33 ± 3.3 to 13.33 ± 3.3% over 21 days. However, the mortality was remarkably increased after the application of 10¹⁰ conidia/mL, ranging from 6.67 ± 3.3 to 80 ± 5.8%. Females treated with various conidial concentrations exhibited complete inhibition of oviposition. Light and electron microscopic examination of the ovary of engorged female ticks at 3, 6 and 9 days after treatment with 10⁷ conidia/mL revealed that the oocytes exhibited drastic changes that affected their growth and development. The overall damage observed in the ovary included loss of grape-like appearance, distortion of oocytes, cytoplasmic vacuolation, degeneration of organelles and myelin figure formation. Previtellogenic oocyte progression was completely inhibited as the vitellogenic phase was not observed. Random amplified polymorphic DNA (RAPD-PCR) and inter simple sequence repeat (ISSR) methods were used to assess the genotoxic effects of B. bassiana at 10⁷ conidia/mL on engorged female A. persicus over 3 weeks. The lowest percentage of genomic template stability was recorded in paralyzed ticks after 3 weeks. The study demonstrated the efficacy of B. bassiana as a biocontrol agent against A. persicus as it interfered with its reproduction, movement and viability and disrupted its normal tissue and DNA integrity.

Biotransformation of Reactive Red 141 by Paenibacillus terrigena KKW2-005 and Examination of Product Toxicity

A total of 37 bacterial isolates were obtained from dye-contaminated soil samples at a textile processing factory in Nakhon Ratchasima Province, Thailand, and the potential of the isolates to decolorize and biotransform azo dye Reactive Red 141 (RR141) was investigated. The most potent bacterium was identified as Paenibacillus terrigena KKW2-005, which showed the ability to decolorize 96.45% of RR141 (50 mg/l) within 20 h under static conditions at pH 8.0 and a broad temperature range of 30-40°C. The biotransformation products were analyzed by using UV-Vis spectrophotometry and Fourier-transform infrared spectroscopy. Gas chromatography-mass spectroscopy analysis revealed four metabolites generated from the reductive biodegradation, namely sodium 3-diazenylnaphthalene-1,5-disulfonate (I), sodium naphthalene-2-sufonate (II), 4-chloro-1,3,5-triazin-2-amine (III) and N¹-(1,3,5-triazin-2-yl) benzene-1,4-diamine (IV). Decolorization intermediates reduced phytotoxicity as compared with the untreated dye. However, they had phytotoxicity when compared with control, probably due to naphthalene and triazine derivatives. Moreover, genotoxicity testing by high annealing temperature-random amplified polymorphic DNA technique exhibited different DNA polymorphism bands in seedlings exposed to the metabolites. They compared to the bands found in seedlings subjected to the untreated dye or distilled water. The data from this study provide evidence that the biodegradation of Reactive Red 141 by P. terrigena KKW2-005 was genotoxic to the DNA seedlings.

Antibiotic-Resistant Enterobacteriaceae in Wastewater of Abattoirs

Antibiotic-resistant Enterobacteriaceae are regularly detected in livestock. As pathogens, they cause difficult-to-treat infections and, as commensals, they may serve as a source of resistance genes for other bacteria. Slaughterhouses produce significant amounts of wastewater containing antimicrobial-resistant bacteria (AMRB), which are released into the environment. We analyzed the wastewater from seven slaughterhouses (pig and poultry) for extended-spectrum β-lactamase (ESBL)-carrying and colistin-resistant Enterobacteriaceae. AMRB were regularly detected in pig and poultry slaughterhouse wastewaters monitored here. All 25 ESBL-producing bacterial strains (19 E. coli and six K. pneumoniae) isolated from poultry slaughterhouses were multidrug-resistant. In pig slaughterhouses 64% (12 of 21 E. coli [57%] and all four detected K. pneumoniae [100%]) were multidrug-resistant. Regarding colistin, resistant Enterobacteriaceae were detected in 54% of poultry and 21% of pig water samples. Carbapenem resistance was not detected. Resistant bacteria were found directly during discharge of wastewaters from abattoirs into water bodies highlighting the role of slaughterhouses for environmental surface water contamination.

Genetic Variation between Triploid and Diploid Clarias gariepinus (Burchell, 1822) Using RAPD Markers

This study was designed to examine the use of RAPD markers in discriminating triploid and diploid African catfish Clarias gariepinus (Burchell, 1822). Following a routine technique, triploidy was induced by cold shock and confirm by erythrocyte measurement in C. gariepinus. Thereafter, 80 RAPD markers were screened; out of which, three showed the highest percentage of polymorphism (i.e., OPB 16 = 71.43%; OPC 14 = 61.9%; OPD 12 = 75%). The results obtained showed genotype differences between triploid and diploid without overlapping. However, the development of a Sequence Characterized Amplified Region (SCAR) marker was not achievable because progenies of triploid and diploid C. gariepinus could not be differentiated based on a specific fragment. Consequently, the genetic distance showed high similarities for both treatments and the UPGMA-generated dendrogram could not separate the treatments into two distinct clusters. It was concluded that RAPD makers cannot be used to separate the ploidy status of fishes.

Adsorption of Cd to TiO2-NPs Forms Low Genotoxic AGGREGATES in Zebrafish Cells

The aquatic environment is involved in the pollutants spreading mechanisms, including nanomaterials and heavy metals. The aims of this study were to assess the in vivo genotoxicity of Cd (1 mg/L) and to investigate the genomic effects generated by its co-exposure with TiO₂-NPs (10 µg/L). The study was performed using zebrafish as a model for 5, 7, 14, 21, and 28 days of exposure. The genotoxic potential was assessed by three experimental approaches: DNA integrity, degree of apoptosis, and molecular alterations at the genomic level by genomic template stability (% GTS) calculation. Results showed an increased in DNA damage after Cd exposure with a decrease in % GTS. The co-exposure (TiO₂-NPs + Cd) induced a no statistically significant loss of DNA integrity, a reduction of the apoptotic cell percentage and the recovery of genome stability for prolonged exposure days. Characterization and analytical determinations data showed Cd adsorption to TiO₂-NPs, which reduced free TiO₂-NPs levels. The results of our study suggest that TiO₂-NPs could be used for the development of controlled heavy metal bioremediation systems.

Effect of Fe3O4 and CuO Nanoparticles on Morphology, Genotoxicity, and miRNA Expression on Different Barley (Hordeum vulgare L.) Genotypes

Metal nanoparticles (NPs) have an influence on plant growth and development. They can alter plant shoot and root length, fresh biomass production, and even influence the genome. Nanoparticles are also able to affect expression levels of plant microRNAs. MicroRNAs are able to protect plants from biotic stress, including pathogens which cause powdery mildew. In this study, Hordeum vulgare L. varieties "Marthe" and "KWS Olof" were grown in hydroponics with magnetic iron oxide (Fe3O4) and copper oxide (CuO) NPs added at 17, 35, and 70 mg/L. Plant morphology, genotoxicity, and expression of miR156a were investigated. The Fe3O4 and CuO NPs demonstrated different effects on the barley varieties, namely, Fe3O4 nanoparticles increased plant shoot and root lengths and fresh biomass, while CuO nanoparticles decreased them. CuO NPs presence caused larger changes on barley genome compared to Fe3O4 NPs. Thus, Fe3O4 NPs reduced genome stability to 72% in the "Marthe" variety and to 76.34% in the "KWS Olof" variety, while CuO NPs reduced genome stability to 53.33% in "Marthe" variety and in the "KWS Olof" variety to 68.81%. The miR156a expression levels after Fe3O4 NPs treatment did not change in the "Marthe" variety, but increased in the "KWS Olof" variety, while CuO NPs treatment increased miRNA expression levels in the "Marthe" variety but decrease them in the "KWS Olof" variety. As NPs are able to influence miRNA expression and miRNAs can affect the plant resistance, obtained results suggest that tested NPs may alter plant resistance response to pathogens.

In vitro ameliorative effects of ellagic acid on vitality, motility and DNA quality in human spermatozoa

Oxidative stress (OS) plays a significant role in the etiology of male infertility, resulting in the impairment of male reproduction. This condition, characterized by an imbalance in the levels of oxidizing and antioxidant species in the seminal fluid, has a harmful impact on sperm functions and DNA integrity. The present study aimed to evaluate the anti-genotoxic action of ellagic acid, a polyphenolic molecule of natural origin having a powerful antigenotoxic, anti-inflammatory and antiproliferative role. An OS condition was induced in vitro by incubating normozoospermic human semen samples in benzene for 45, 60 and 90 min. DNA integrity was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay, RAPD-PCR was performed to calculate the genome template stability, while the percentage of intracellular reactive oxygen species (ROS) was assessed by the 2', 7'-dichlorofluorescein assay. Our results showed that ellagic acid has a consistent protective effect on DNA integrity, as well as on sperm vitality and motility, by counteracting generation of intracellular ROS. The results of this study suggest ellagic acid as a suitable molecule to protect sperm DNA from oxidative stress, with a potentially significant translational impact on the management of the male infertility.

Establishment and characterization of a gill cell line from pearl gentian grouper (Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀) and its application in cadmium toxicology

A novel gill cell line from pearl gentian grouper (Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀, PGGG cell line) was established, its application in cadmium (Cd) toxicology was demonstrated in this study. Primary cultures and PGGG subcultures were carried out at 25 °C in Dulbecco's Modified Eagle medium/F12 medium (1:1; pH 7.2) supplemented with 15% fetal bovine serum (FBS). Primary PGGG cells were spindle-shaped, proliferated into a confluent monolayer within two weeks and were continuously subcultured over passage 60. The growth of cells at passages 20, 40, and 60 was examined. Chromosome analysis revealed that the chromosomal number of normal PGGG cells was 48, but the number of cells with the normal chromosomes number decreased during the passaging process. Cadmium is one of the most toxic metals in aquatic systems and has been associated with multiple animal and human health problems. To interpret the cytotoxicity and related mechanisms of cadmium, PGGG cells were used as an in vitro model. After treatment with cadmium at concentrations ranging from 1 µM to 500 µM, PGGG cells demonstrated dose- and time-dependent cytotoxicity, manifested as morphological abnormalities and a viability decline. Further, it was found that the reactive oxygen species (ROS) and malondialdehyde (MDA) levels were elevated following cadmium exposure, and related genes involved in the antioxidant system, including those encoding catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and Kelch-like- ECH-associated protein 1 (Keap1), were regulated differently. In addition, PGGG cells treated with cadmium had the typical features associated with apoptosis, including phosphatidylserine (PS) externalization; upregulated expression of caspase-3, -8, and -9; and apoptotic body formation. In general, the PGGG cell line may serve as a useful tool for studying the toxic mechanisms of cadmium or other toxicants or for toxicity testing and environment monitoring.

Protective activity of ellagic acid in counteract oxidative stress damage in zebrafish embryonic development

During its development, embryo is easily susceptible to reactive oxygen species (ROS). Evidence demonstrate protective role of the antioxidants, improving both cellular growth and embryonic development. Among these, ellagic acid (EA) is a natural antioxidant with anti-inflammatory and anti-carcinogen properties. The aim of this work was to assess in vitro the protective and anti-genotoxic role of EA during Danio rerio (zebrafish) embryonic development. For the study, zebrafish embryos were treated with H₂O₂ (15 μM, 30 μM and 45 μM) to simulate an oxidative damage, and with EA (2.5 mM, 5 mM and 10 mM) for 8, 20, 24, 48, 96 hpf (hours post fertilization). Vitality rate, alterations in the morphology and behavior of the larvae and the genomic stability were analyzed. The exposure to H₂O₂ caused genotoxicity for all exposure times. The incubation in 45 μM H₂O₂ and 30 μM H₂O₂ resulted in increased mortality rate of the larvae, as well as 10 mM EA. The co-exposure was performed using to 15 μM H₂O₂ and 2.5 mM and 5 mM EA and it demonstrated the EA capacity to protect the embryo DNA and development from the oxidative insult. Particularly, the co-exposure to 15 mM H₂O₂ and 5 mM EA showed an increase in the embryo survival rate and absence of alterations in morphology and behavior at 96 hpf. Interestingly, we observed a higher genomic stability at 8h and 20h co-exposure (15 mM H₂O₂ and 5 mM EA) time. The decline observed in ROS concentration for both exposure times confirmed the observation. In conclusion, EA protects the zebrafish embryonic development from DNA oxidative damage increasing the embryo survival rate and improving morphological parameters of the larvae.

In Vitro Effects of Titanium Dioxide Nanoparticles (TiO2NPs) on Cadmium Chloride (CdCl2) Genotoxicity in Human Sperm Cells

The environmental release of titanium dioxide nanoparticles (TiO₂NPs) associated with their intensive use has been reported to have a genotoxic effect on male fertility. TiO₂NP is able to bind and transport environmental pollutants, such as cadmium (Cd), modifying their availability and/or toxicity. The aim of this work is to assess the in vitro effect of TiO₂NPs and cadmium interaction in human sperm cells. Semen parameters, apoptotic cells, sperm DNA fragmentation, genomic stability and oxidative stress were investigated after sperm incubation in cadmium alone and in combination with TiO₂NPs at different times (15, 30, 45 and 90 min). Our results showed that cadmium reduced sperm DNA integrity, and increased sperm DNA fragmentation and oxidative stress. The genotoxicity induced by TiO₂NPs-cadmium co-exposure was lower compared to single cadmium exposure, suggesting an interaction of the substances to modulate their reactivity. The Quantitative Structure-Activity Relationship (QSAR) computational method showed that the interaction between TiO₂NPs and cadmium leads to the formation of a sandwich-like structure, with cadmium in the middle, which results in the inhibition of its genotoxicity by TiO₂NPs in human sperm cells.

NPs-TiO2 and Lincomycin Coexposure Induces DNA Damage in Cultured Human Amniotic Cells

Titanium dioxide nanoparticles (NPs-TiO2 or TiO2-NPs) have been employed in many commercial products such as medicines, foods and cosmetics. TiO2-NPs are able to carry antibiotics to target cells enhancing the antimicrobial efficiency; so that these nanoparticles are generally used in antibiotic capsules, like lincomycin, added as a dye. Lincomycin is usually used to treat pregnancy bacterial vaginosis and its combination with TiO2-NPs arises questions on the potential effects on fetus health. This study investigated the potential impact of TiO2-NPs and lincomycin co-exposure on human amniocytes in vitro. Cytotoxicity was evaluated with trypan blue vitality test, while genotoxic damage was performed by Comet Test, Diffusion Assay and RAPD-PCR for 48 and 72 exposure hours. Lincomycin exposure produced no genotoxic effects on amniotic cells, instead, the TiO2-NPs exposure induced genotoxicity. TiO2-NPs and lincomycin co-exposure caused significant increase of DNA fragmentation, apoptosis and DNA damage in amniocytes starting from 48 exposure hours. These results contribute to monitor the use of TiO2-NPs combined with drugs in medical application. The potential impact of antibiotics with TiO2-NPs during pregnancy could be associated with adverse effects on embryo DNA. The use of nanomaterials in drugs formulation should be strictly controlled in order to minimize risks.

In vitro genotoxic effects of titanium dioxide nanoparticles (n-TiO2 ) in human sperm cells

Titanium dioxide nanoparticles (TiO₂ -NPs) are one of the most widely engineered nanoparticles used. The study has been focused on TiO ₂ -NPs genotoxic effects on human spermatozoa in vitro. TiO ₂ -NPs are able to cross the blood-testis barrier induced inflammation, cytotoxicity, and gene expression changes that lead to impairment of the male reproductive system. This study presents new data about DNA damage in human sperms exposed in vitro to two n-TiO ₂ concentrations (1 µg/L and 10 µg/L) for different times and the putative role of reactive oxygen species (ROS) as mediators of n-TiO ₂ genotoxicity. Primary n-TiO ₂ characterization was performed by transmission electron microscopy. The dispersed state of the n-TiO ₂ in media was spectrophotometrically determined at 0, 24, 48, and 72 hr from the initial exposure. The genotoxicity has been highlighted by different experimental approaches (comet assay, terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL] test, DCF assay, random amplification of polymorphic DNA polymerase chain reaction [RAPD-PCR]). The comet assay showed a statistically significant loss of sperm DNA integrity after 30 min of exposure. Increased threshold of sperm DNA fragmentation was highlighted after 30 min of exposure by the TUNEL Test. Also, the RAPD-PCR analysis showed a variation in the polymorphic profiles of the sperm DNA exposed to n-TiO ₂ . The evidence from the DCF assay showed a statistically significant increase in intracellular ROS linked to n-TiO ₂ exposure. This research provides the evaluation of n-TiO ₂ potential genotoxicity on human sperm that probably occurs through the production of intracellular ROS.

Growth performance, biochemical, cytological and molecular aspects of rabbits exposed to lead toxicity

Heavy metals have enormous variety of deleterious effects on many organs in the body. This study demonstrated the toxic influences of lead on the growth, biochemical, cellular and molecular aspects of developing rabbits. Seventy-five rabbits (New Zealand NZW) were divided into five equal groups as follows; control (C) and four treatment groups (T1-4) orally administered lead acetate solution as follow T1: 20, T2: 30, T3: 50 and T4: 70 mg/kg body weight. Lead resulted in a significant decrease in live body weight, daily body weight gain and feed intake in T3 and T4 compared to those in other groups. Blood haematology measurements such as red blood cells, haematocrit (HCT), mean corpuscular volume, platelet, white blood cells and lymphocytes were significantly influenced by the high level of lead. Oral administration of lead significantly reduced total proteins in the serum. It was observed that the high lead level led to significantly (p < 0.05) increased levels of aspartate aminotransferase, alanine aminotransferase enzymes, urea and creatinine. Four random amplified polymorphic DNA primers polymorphism were detected among the treatment groups. Total number of induced bands (loss or appearance) compared with control group were 4, 10, 10 and 14 bands using primers P1, P2, P3 and P4 respectively. Number of micronuclei showed a dose-response increase and the difference was highly significant especially between control compared with T3 and T4 groups. From our results, we can conclude that exposure of rabbits to lead acetate resulted in negative effects on the growth performance and altered the haematological and biochemical parameters, in addition to its adverse impact on cytological and molecular characterization of animals.

Melatonin attenuates caspase-dependent apoptosis in the thoracic aorta by regulating element balance and oxidative stress in pinealectomised rats

The aim of this study was to explain the possible mechanisms by which melatonin deficiency results in cardiovascular injury and to investigate the effects of melatonin administration on important signalling pathways and element equilibrium in the thoracic aorta (TA). For this purpose, we analysed the cellular and molecular effects of melatonin deficiency or administration on oxidative stress, DNA damage, molecular chaperone response, and apoptosis induction in TA tissues of pinealectomised rats using ELISA, RAPD, qRT-PCR, and Western blot assays. The results showed that melatonin deficiency led to an imbalance in essential element levels, unfolded or misfolded proteins, increased lipid peroxidation, and selectively induced caspase-dependent apoptosis in TA tissues without significantly affecting the Bcl-2/BAX ratio (2.28 in pinealectomised rats, 2.73 in pinealectomised rats treated with melatonin). In pinealectomised rats, the genomic template stability (80.22%) was disrupted by the significantly increased oxidative stress, and heat shock protein 70 (20.96-fold), TNF-α (1.73-fold), caspase-8 (2.03-fold), and caspase-3 (2.87-fold) were markedly overexpressed compared with the sham group. Melatonin treatment was protective against apoptosis and inhibited oxidative damage. In addition, melatonin increased the survivin level and improved the regulation of element equilibrium in TA tissues. The results of the study indicate that melatonin deficiency induces TNF-α-related extrinsic apoptosis signals and that the administration of pharmacological doses of melatonin attenuates cardiovascular toxicity by regulating the increase in the rate of apoptosis caused by melatonin deficiency in TA tissue of Sprague–Dawley rats.

In vitro evaluation of cytotoxic and genotoxic effects of Di(2-ethylhexyl)-phthalate (DEHP) on European sea bass (Dicentrarchus labrax) embryonic cell line

Marine litter is extensively distributed in the marine environment, and plastic debris, of which litter is mostly composed, can be a major source of pollutants. Among them, Di(2-ethylhexyl)-phthalate (DEHP) is the most abundantly used plastic additive, and it has been reported to affect biochemical processes both in humans and wildlife; however, studies on its toxicological effects on marine organisms are still scarce. In this survey, we studied the cytotoxic, genotoxic, and mutagenic effects of DEHP in European sea bass embryonic cell line (DLEC) by applying specific in vitro tests. Results showed a significant decrease in cell viability starting at 0.01 mM of DEHP after 24 h together with a significant increase in apoptosis and necrosis, morphological changes and cell detachment. Consistently, we detected a moderate increase in DNA strand breaks from 0.02 mM, and a dose-dependent increase in of micronucleus frequency from 0.01 mM, accompanied by a significant inhibition of cell proliferation, which suggested a possible aneugenic effect of this phthalate. Our results demonstrate that in vitro exposure to DEHP had a dose-dependent cytotoxic and genotoxic effects in DLEC cell line, encouraging further investigation into its effects in in vivo and/or ex vivo cell systems of marine organisms.

Phytobeds with Fimbristylis dichotoma and Ammannia baccifera for treatment of real textile effluent: An in situ treatment, anatomical studies and toxicity evaluation

Fimbristylis dichotoma, Ammannia baccifera and their co-plantation consortium FA independently degraded Methyl Orange, simulated dye mixture and real textile effluent. Wild plants of F. dichotoma and A. baccifera with equal biomass showed 91% and 89% decolorization of Methyl Orange within 60h at a concentration of 50ppm, while 95% dye removal was achieved by consortium FA within 48h. Floating phyto-beds with co-plantation (F. dichotoma and A. baccifera) for the treatment of real textile effluent in a constructed wetland was observed to be more efficient and achieved 79%, 72%, 77%, 66% and 56% reductions in ADMI color value, COD, BOD, TDS and TSS of textile effluent, respectively. HPTLC, GC-MS, FTIR, UV-vis spectroscopy and activated oxido-reductive enzyme activities confirmed the phytotrasformation of parent dye in to new metabolites. T-RFLP analysis of rhizospheric bacteria of F. dichotoma, A. baccifera and consortium FA revealed the presence of 88, 98 and 223 genera which could have been involved in dye removal. Toxicity evaluation of products formed after phytotransformation of Methyl Orange by consortium FA on bivalves Lamellidens marginalis revealed less damage of the gills architecture when analyzed histologically. Toxicity measurement by Random Amplification of Polymorphic DNA (RAPD) technique revealed bivalve DNA banding pattern in treated Methyl Orange sample suggesting less toxic nature of phytotransformed dye products.

Genotoxicity evaluation of zinc oxide nanoparticles in Swiss mice after oral administration using chromosomal aberration, micronuclei, semen analysis, and RAPD profile

The expanded uses of zinc oxide nanoparticles (ZnO NPs) have grown rapidly in the field of nanotechnology. Thus, rising production of nanoparticles (NPs) increases the possible risks to the environment and occupationally exposed humans. Hence, it is indispensable to appraise the safety toxicity including genotoxicity for these NPs. In the present study, we have evaluated the genotoxic effect of ZnO NPs after oral administration to Swiss mice at dose levels of 300 and 2000 mg/kg body weight. These doses were administered for 2 days at 24 h apart. Chromosomal aberration (CA) and micronucleus tests were conducted following Organization for Economic Co-operation and Development guidelines. DNA damage was evaluated at 0, 24, 48, and 72 h posttreatment using a randomly amplified polymorphic DNA (RAPD) assay; additionally, semen analyses were also performed at 34.5 days post oral exposure. The reactive oxygen species (ROS), 8-oxo-2'-deoxyguanosine and CAs were increased ( p < 0.05) at the highest dosage (2000 mg/kg) of ZnO NPs compared to controls. Aberrant sperm morphology with reduced sperm count and motility were also present ( p < 0.05) in the high-dose group. Based on the RAPD assay, the genomic template stability within the high-dose group (<90%) was less than the controls (100%). The results suggested that ZnO NPs are mildly genotoxic in a dose-related manner and this toxicity were induced by generation of ROS.

Genotoxicity Evaluation of an Urban River on Freshwater Planarian by RAPD Assay

The aim of this study was to evaluate the genotoxic potential of an urban river - the Wei River in Xinxiang, China using randomly amplified polymorphic DNA (RAPD) assay in planarians. The results showed that the total number of polymorphic bands and varied bands in RAPD patterns of treated planarians decreased with the water sample site far away from the sewage outlet of a factory. In addition, the genome template stability of treated groups decreased and the degree of the decline was negatively related to the distance between the sample site and the sewage outlet, suggesting that the Wei River water had genotoxicity effects on planarians and strengthening the management of the Wei River was necessary. Furthermore, this work also indicated that RAPD assay in planarians was a very promising test for environmental monitoring studies.

Genotoxicity evaluation of ionic liquid 1-octyl-3-methylimidazolium bromide in freshwater planarian Dugesia japonica using RAPD assay

The randomly amplified polymorphic DNA (RAPD) assay has been used to detect DNA alternation and mutation recently. However, the effectiveness of this method in detecting DNA damage in planarians, a model organism for assessing the toxicity of environmental pollutants is unknown. In the present study, RAPD assay was used to detect the DNA damage in planarians treated by the ionic liquid 1-octyl-3-methylimidazolium bromide ([C₈mim]Br) for the first time. Among the 20 test RAPD primers, 13 primers with 60-70% GC content produced unique polymorphic band profiles. A total of 60 bands were observed in the untreated control planarians. In comparison with the control group, the [C₈mim]Br-treated groups displayed differences in RAPD patterns in the band intensity, disappearance of normal bands and appearance of new bands. The variation of RAPD profiles showed both concentration- and time-effect relationships. Meanwhile, the genomic template stability (GTS) of treated planarians decreased and exhibited negative correlation to the exposure concentration and time of [C₈mim]Br. Our results suggested that [C₈mim]Br had genotoxic effects on planarians, and this DNA damage analysis would lay the foundation for further elucidating the toxicity mechanisms of ionic liquids on planarians. Furthermore, RAPD analysis was proved to be a highly sensitive method for the detection of DNA damage induced by environmental pollutants like toxic chemicals on planarians.

Establishment of a new teleost brain cell line (DLB-1) from the European sea bass and its use to study metal toxicology

In teleost fish, there are no commercial cell lines for the European sea bass (Dicentrarchus labrax). Thus, we have established the sea bass brain (DLB-1) cell line, using a fish retrovirus for immortalization, which resemble epithelial cells and express glial cells markers. Exposure to metals [Cd, methylmercury (MeHg), Pb or As] produces cytotoxicity and induction of reactive oxygen species (ROS) production. Interestingly, cell cycle analysis of DLB-1 cells shows that exposure to metals alters it significantly. Moreover, all the metals induce apoptosis as indicated by sub-Go/G1 population and annexin V binding. Finally, exposure of DLB-1 cells to metals also produces significant alterations at gene expression level, which confirm the above functional results. This is the first study in which metal cytotoxicity has been evaluated in a fish brain cell line and results seem to support that DLB-1 cells are suitable for toxicological studies.

Anti-genotoxic ability of α-tocopherol and Anthocyanin to counteract fish DNA damage induced by musk xylene

Many compounds released into the environment are able to interact with genetic material. The main purpose of genetic toxicology is to investigate the adverse effects of genotoxic molecules such as reduced fitness, changes in gene frequencies and their impact on genetic diversity in populations following genotoxic exposure. However, the ecological effects of many genotoxic compounds remain poorly understood. The aim of this research was to evaluate the genotoxic activity of an artificial musk (musk xylene, MX) and the potential anti-genotoxicity against this chemical compound of two antioxidant substances (α-tocopherol and an anthocyanins enriched extract). The studies were performed both in vivo and in vitro, using the teleost Danio rerio and the DLEC (Dicentrarchus labrax embryonic cells) cell line. We carried out the exposure to these substances at different times. DNA and cell damage and their possible repair were detected by various experimental approaches: DNA strand breaks (Comet Assay), degree of apoptosis (Diffusion Assay) and molecular alterations at the genomic level (RAPD-PCR technique). Data were collected and analyzed for statistical significance using the Student's t test. The results of this study showed that MX exhibited a genotoxic activity even after short exposure times. The anti-genotoxicity experiments evidenced that both α-tocopherol and Anthocyanin were able to contrast the genotoxic effects induced by MX, both in vivo and in vitro.

n-TiO2 and CdCl2 co-exposure to titanium dioxide nanoparticles and cadmium: Genomic, DNA and chromosomal damage evaluation in the marine fish European sea bass (Dicentrarchus labrax)

Due to the large production and growing use of titanium dioxide nanoparticles (n-TiO2), their release in the marine environment and their potential interaction with existing toxic contaminants represent a growing concern for biota. Different end-points of genotoxicity were investigated in the European sea bass Dicentrarchus labrax exposed to n-TiO2 (1mgL(-1)) either alone and combined with CdCl2 (0.1mgL(-1)) for 7 days. DNA primary damage (comet assay), apoptotic cells (diffusion assay), occurrence of micronuclei and nuclear abnormalities (cytome assay) were assessed in peripheral erythrocytes and genomic stability (random amplified polymorphism DNA-PCR, RAPD assay) in muscle tissue. Results showed that genome template stability was reduced after CdCl2 and n-TiO2 exposure. Exposure to n-TiO2 alone was responsible for chromosomal alteration but ineffective in terms of DNA damage; while the opposite was observed in CdCl2 exposed specimens. Co-exposure apparently prevents the chromosomal damage and leads to a partial recovery of the genome template stability.

Inhibition of cadmium- induced genotoxicity and histopathological changes in Nile tilapia fish by Egyptian and Tunisian montmorillonite clay

Cadmium (Cd) is an important inorganic toxicant widely distributed in the environment because of its various industrial uses. The aims of the current study were to investigate the efficacy of purified Egyptian and Tunisian montmorillonite clays (EMC and TMC) to inhibit genotoxicity and histological alterations induced by cadmium chloride (CdCl2) utilizing the Nile tilapia fish as an in vivo model. Chromosomal aberrations (CAs), micronucleus (MN) frequencies and DNA fingerprinting profile were genotoxic end points and histopathological changes that were used in this investigation. Six groups of fish were treated for 2 weeks and included control group, CdCl2-treated group and groups treated with EMC or TMC alone or in combination with CdCl2. The present results revealed that, treatment of fish with CdCl2 exhibited significant increased in the number of micronucleated erythrocytes (MnRBCs), frequency of CAs and instability of genomic DNA. Treatment of EMC and TMC in combination with CdCl2 significantly reduced the frequency of MnRBCs by the percentage of 53.28% and 60.77% and the frequency of CAs by 43.91% and 52.17% respectively. As well as, normalized DNA fingerprinting profile and significantly improved histopathological picture induced by Cadmium treatment. It is worth mention that both clays have the ability to tightly bind CdCl2 and decreased its cytotoxicity and genotoxicity; however, Tunisian clay was more efficient in binding with the CdCl2 than Egyptian clay.

Genotoxicity assessment of TiO2 nanoparticles in the teleost Danio rerio

Titanium dioxide nanoparticles (TiO2 NPs), widely used in paints, pharmaceutical preparations and in many consumer products, have been shown to induce cytotoxicity, genotoxicity and carcinogenic responses both in vitro and in vivo. Numerous studies have shown the potential impact of nanoparticles on a series of aquatic organisms and their toxicity has been linked to their dissolution, surface properties and size. In vitro studies have raised concerns about the toxicity of TiO2 NPs, but there are very limited data on ecotoxicity to aquatic life. This in vivo study aimed to describe the genotoxicity of TiO2 NPs in the zebrafish Danio rerio. After 2 weeks of adaptation, groups of zebrafish were exposed to TiO2 NPs (1 and 10μg/L) for 5, 7, 14, 21 and 28 days. The genotoxic potential of TiO2 NPs was assessed by the Comet assay, the Diffusion assay and RAPD-PCR technique. The use of multi-biomarkers has become an important aspect of ecotoxicology to evaluate environmental quality through a wide panel of biological responses triggered by contaminants. The highest genotoxic effect was observed at the maximum concentrations of nanoparticles (10μg/L) with all three tests at 14 and 21 days of exposure. The results suggests the presence of mechanisms that can reduce the n-TiO2 genotoxicity. Future studies are necessary to analyze the DNA repairing capacity in zebrafish cells and so verify the role of the antioxidant defence system in modulating the response to exposure to n-TiO2 in fish.

Influence of titanium dioxide nanoparticles on 2,3,7,8-tetrachlorodibenzo-p-dioxin bioconcentration and toxicity in the marine fish European sea bass (Dicentrarchus labrax)

The present study investigated the influence of nano-TiO(2) (1 mg L(-1)) on 2,3,7,8-tetrachlorodibenzo-p-dioxin(2,3,7,8-TCDD) (46 pg L(-1)) bioconcentration and toxicity in the European sea bass (Dicentrarchus labrax) during 7 days in vivo exposure. A multimarkers approach was applied in different organs: detoxification in liver; innate immunity and pro-inflammatory response and adaptive immunity in gills and spleen; genotoxicity in peripheral erythrocytes and muscle. Bioconcentration of 2,3,7,8-TCDD in presence of nano-TiO2 was investigated in liver, skin and muscle as well as interaction between nano-TiO2 and organic pollutants in artificial sea water (ASW). Nano-TiO2 negatively influenced immune response induced by 2,3,7,8-TCDD in spleen but not in gills and reduced the DNA damage induced by 2,3,7,8-TCDD in erythrocytes. nano-TiO2 did not interfere with 2,3,7,8-TCDD detoxification and bioconcentration according to the observed no interaction of the nano-TiO2 with organic pollutants in ASW.

Assessment of arsenic-induced DNA damage in goldfish by a polymerase chain reaction-based technique using random amplified polymorphic DNA markers

Arsenic is a groundwater contaminant of global concern. It is a potent human carcinogen, and its marked genotoxic effects have been reported in several human and animal studies. The present work investigates the applicability of the random amplified polymorphic DNA (RAPD) assay to study the DNA-damaging effects of arsenic at low-level exposure in goldfish Carassius auratus. Four experimental groups of fish, A, B, C and D, were exposed to 0, 10, 50, and 1,000 µg L(-1) of arsenic, respectively, in aquaria water for 15 consecutive days. Genomic DNA extraction was followed by RAPD-polymerase chain reaction amplification for each fish separately. One arbitrary decamer primer (PUZ-19) of 33 primers used appeared as the most informative and was capable of exhibiting marked alterations in RAPD profiles between arsenic-exposed and unexposed (control) samples. Different sets of 11 loci were amplified in various experimental groups with four clear polymorphic bands by the primer PUZ-19. The X and XIII amplification loci, which were prominent in the unexposed group, failed to appear in the arsenic-exposed groups. In contrast, the I and XI RAPD bands appeared as new amplification loci in all of the exposed groups. Such alterations in genomic DNA, however, did not exhibit a clear dose-dependent tendency. The RAPD assay, because of its efficacy to unmask alterations in genomic DNA induced by arsenic at low exposure level of 10 µg L(-1), appears to be a sensitive and potential tool for detecting arsenic genotoxicity.