Oxidative stress and DNA damage in relation to transition metals overload in Abu-Qir Bay, Egypt

Studies on bioaccumulation patterns, biochemical and genotoxic effects of copper on freshwater fish, Catla catla: an in vivo analysis

Abstract During present study, the copper (Cu) mediated oxidative stress was measured that induced DNA damage by concentrating in the tissues of fish, Catla catla (14.45±1.24g; 84.68±1.45mm) (Hamilton,1822). Fish fingerlings were retained in 5 groups for 14, 28, 42, 56, 70 and 84 days of the exposure period. They were treated with 2/3, 1/3, 1/4 and 1/5 (T1-T4) of 96h lethal concentration of copper. Controls were run along with all the treatments for the same durations. A significant (p < 0.05) dose and time dependent concentration of Cu was observed in the gills, liver, kidney, muscles, and brain of C. catla. Among organs, the liver showed a significantly higher concentration of Cu followed by gills, kidney, brain, and muscles. Copper accumulation in these organs caused a significant variation in the activities of enzymes viz. superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). The SOD activity varied significantly in response to the exposure time of Cu as 56 > 70 > 42 > 84 > 28 > 14 days while CAT activity exhibited an inverse relationship with the increase in Cu concentration. POD activity showed a significant rise with an increase in Cu exposure duration. Comet assay exhibited significant DNA damage in the peripheral erythrocytes of Cu exposed C. catla. Among four exposure concentrations, 2/3rd of LC50 (T1) caused significantly higher damage to the nuclei compared to control. Increased POD and SOD activity, as well as a decrease in CAT activity in response to Cu, demonstrates the involvement of a protective mechanism against reactive oxygen species (ROS), whereas increased ROS resulted in higher DNA damage. These above-mentioned molecular markers can be efficiently used for the biomonitoring of aquatic environments and conservation of edible fish fauna.

Use of Zebrafish as a Model Organism to Study Oxidative Stress: A Review

Dioxygen is an integral part of every living organism, but its concentration varies from organ to organ. Production of metabolites from dioxygen may result in oxidative stress. Since oxidative stress has the potential to damage various biomolecules in the cell, therefore, it has presently become an active field of research. Oxidative stress has been studied in a wide range of model organisms from vertebrates to invertebrates, from rodents to piscine organisms, and from in vivo to in vitro models. But zebrafish (adults, larvae, or embryonic stage) emerged out to be the most promising vertebrate model organism to study oxidative stress because of its vast advantages (transparent embryo, cost-effectiveness, similarity to human genome, easy developmental processes, numerous offspring per spawning, and many more). This is evidenced by voluminous number of researches on oxidative stress in zebrafish exposed to chemicals, radiations, nanoparticles, pesticides, heavy metals, etc. On these backgrounds, this review attempts to highlight the potentiality of zebrafish as model of oxidative stress compared with other companion models. Several areas, from biomedical to environmental research, have been covered to explain it as a more convenient and reliable animal model for experimental research on oxidative mechanisms.

Differential Bioaccumulation of Trace Elements and Rare Earth Elements in the Muscle, Kidneys, and Liver of the Invasive Indo-Pacific Lionfish (Pterois spp.) from Cuba

The Indo-Pacific lionfish is a saltwater fish that inhabits the Red Sea waters and the Indian and Pacific oceans; it is an invasive species in the western Atlantic and was recently introduced into the local diet in the USA, Central and South America, and the Caribbean with the aim of controlling the invasion of this species. Due to its predatory nature, it tends to bioaccumulate metals and other contaminants via the marine food web and could thus constitute a suitable species for monitoring aquatic ecosystems. The presence and distribution of 23 trace elements and 16 rare earth elements (REEs) were investigated by inductively coupled plasma-mass spectrometry (ICP-MS) in the muscle, liver, and kidneys of lionfish from Cuba. Significant differences in metal concentrations were found in the different fish organs. The liver and kidneys registered the highest concentrations for most trace elements and for ΣREE, thus demonstrating that they are effective bioindicators of possible pollution on the environment in which fish live, and assuming great importance in the choice of early biomonitoring. Trace element concentrations in the muscle are instead of crucial interest for consumer safety. The limits set by EU regulations and Cuban guidelines for Cd and Pb in fish muscle were never exceeded, suggesting that lionfish from Cuba could therefore represent a good source of minerals and proteins for the local population. Graphical abstract.

Iron mediated hematological, oxidative and histological alterations in freshwater fish Labeo rohita

Iron is an essential element for many physiological functions of several organisms but in excess it causes toxicity. High iron content in water bodies of mountainous states is considered as one of the major factor, responsible for low productivity in aquaculture systems. But, till date comprehensive reports on the adverse effect of iron overload in aquatic organisms, especially cultured fishes are scanty. Therefore, the present study was undertaken to investigate the adverse effects of iron overload in economically important aquaculture fish species Labeo rohita. Three sub-lethal test concentration of iron (ferrous) viz., 1/16th, 1/8th and 1/4th of LC₅₀ (post 96 h) i.e. 8.25, 16.51 and 33.01 mg L^-1, respectively, were used for in vivo exposure. Blood cells and tissue samples of the control & exposed specimens were sampled at intervals of 24, 48, 72 and 96 h to assess alterations in hematological, oxidative stress and histological parameters. Significant changes in erythrocyte and leukocyte counts, hemoglobin, lipid peroxidation, antioxidant enzyme activity (super oxide dismutase and catalase) and tissue iron accumulation were observed in the exposed fish. Significant increase in lipid peroxidation, coupled with significant reduction in free radicals scavengers like super oxide dismutase and catalase revealed a compromised anti-oxidative defense mechanism in the fishes exposed to iron overload. Histological examination of gills and liver showed severe tissue injury and histological alternations. Severity was found to increase in time and concentration dependent manner. Perl's staining revealed accumulation of excess iron in liver of the exposed fish. The observed patho-physiological changes in the present study provide the most comprehensive insight of iron overload stress in L. rohita.

Hemp (Marijuana) reverted Copper-induced toxic effects on the essential fatty acid profile of Labeo rohita and Cirrhinus mrigala

Heavy metals pollution affects the nutritive value of fish. This study examined if the inclusion of dietary hempseed (HS) and hempseed oil (HO) in the diet of the fish could revert the copper-induced toxic effects on muscle fatty acid profile of rohu (Labeo rohita) and mrigal (Cirrhinus mrigala). Fingerlings of both species were exposed to a sub-lethal concentration of copper i.e., 20% of LC₅₀ (1.34 ppm for rohu and 1.52 ppm for mrigal) for 96 h for 30 days. Following exposure, fish were maintained on graded levels of HO (1, 2 and 3%) or on HS (5, 10 and 15%) for 50 days. Copper exposure showed a significant effect on the fatty acid composition of both species; increased their saturated (SFA) to unsaturated (USFA) and altered their omega-3/omega-6 (ω-3/ω-6) ratios. However, feeding graded levels of hempseed products reverted the toxic effects of copper on the fatty acid profile of both the species, significantly increased muscle total fatty acid contents, improved ω-3/ω-6 ratios, and decreased SFA / USFA ratio in % inclusion dependent manner. Furthermore, hempseed product showed a species-specific effect on USFA. The ω-3/ω-6 ratios decreased in the muscle of C. mrigala whereas an increasing trend with an increase in hempseed product % inclusion was observed in L. rohita. Moreover, HS showed a higher impact on both species as compared to HO. With the findings of this study, hempseed product could be recommended as a feed ingredient for enhancing the essential fatty acid contents of fish which in turn can have a good impact on consumer health.

DNA damage in a liver tissue of metal exposed Clethrionomys glareolus

It is widely known that some toxic agents may act on DNA strand resulting in its damages. One of the possible impairments is formation of abasic sites in DNA. The aim of this study was to indicate a presence of these DNA sites in the liver tissue of bank voles inhabiting the vicinity of zinc/lead smelters. Samples that were used originated from animals collected from unpolluted (Niepołomice, Teleśnica Oszwarowa, Mikołajki) and polluted (Miasteczko Śląskie, Katowice, Olkusz) populations. They significantly differed in terms of tissue lead concentrations in the kidney and liver. The means of detected AP sites per 10⁵ bp ranged between 3.39 (Teleśnica Oszwarowa) to 5.13 (Miasteczko Śląskie). Statistical analysis (ANOVA) showed no difference in terms of number of the AP sites between single populations. However, t-test showed significant difference between the unpolluted and polluted populations. Factorial ANOVA indicated that sex is not a factor influencing the number of AP sites. The analyses revealed statistically significant relationships between the number of AP sites and Cu concentrations in the liver, and also Pb and Cd concentrations in the kidney.

A Comparative Assessment of Biological Effects and Chemical Profile of Italian Asphodeline lutea Extracts

The present study aims to highlight the therapeutic potential of Asphodeline lutea (AL), a wild edible plant of the Mediterranean diet. Roots, aerial parts, and flowers of AL at two different phenological stages were collected from three locations in Italy. The inhibitory activities of extracts on strategic enzymes linked to human diseases were assessed. The antioxidant properties were evaluated in vitro, using six standard bioassays. The phenolic and anthraquinone profiles were also established using HPLC-PDA. Zinc, cadmium, lead, and copper contents were also determined. All the samples inhibited acetylcholinesterase (from 1.51 to 2.20 mg GALAEs/g extract), tyrosinase (from 7.50 to 25.3 mg KAEs/g extract), and α-amylase (from 0.37 to 0.51 mmol ACAEs/g extract). Aloe-emodin and physcion were present in all parts, while rhein was not detected. The phenolic profile and the heavy metals composition of specimens gathered from three different regions of Italy were different. It can be argued that samples collected near the street can contain higher concentrations of heavy metals. The experimental data confirm that the A. lutea species could be considered as a potential source of bioactive metabolites, and its consumption could play a positive and safe role in human health maintenance.

Biochemical, Histopathological and Molecular Responses in Gills of Leuciscus cephalus Exposed to Metals

Gills are major targets for acute metal toxicity in fish, due to their permanent contact with aquatic pollutants. To assess the effects of metals on gills of the Leuciscus cephalus (chub), fish individuals were collected from two sites in the Tur River, Romania, in upstream (site 1) and downstream (site 2) of a metal pollution source. Quantitative and hyperspectral analyses showed that Zn, Sr, and Fe concentrations were significantly higher in gills from site 2 compared with site 1. Malondialdehyde and advanced oxidation protein products levels increased 17 and 28%, respectively, whereas reduced glutathione level diminished significantly in the gills of fish collected from site 2 compared to site 1. The activities of superoxide dismutase, catalase, and glutathione-S-transferase increased significantly at 41, 21, and 28%, respectively. Proliferating cell nuclear antigen (PCNA) protein levels, as well as the amount of DNA damage, were significantly increased for site 2 compared with site 1. The induced oxidative stress generated hyperplasia, hypertrophy, and inflammation in the epithelial cells and apoptosis. Hence, this could suggest that gill cells have tried to counteract the oxidative stress-induced DNA fragmentation by PCNA up-regulation, but the PCNA expression decreased on longer time due to the low level of GSH, resulting in apoptosis.