Biochemical and hematological studies on perch, Perca fluviatilis, from the cadmium-contaminated river Emån

Toxicity, Antibacterial, and Phytochemical Analyses of Antrocaryon klaineanum Pierre Extracts

Medicinal plants are traditionally used in Gabon to treat several types of illnesses. The study's purpose was to determine the toxic, antibacterial, and anti-inflammatory effects of Antrocaryon klaineanum Pierre extracts and to characterize their phytochemical compounds. Toxicity was evaluated on frog tadpoles (Phrynobatrachus africanus Hallowell). The microorganism susceptibility test was performed by the diffusion method, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated using the microdilution technique. Anti-inflammatory activity was tested through protein denaturation and membrane stabilization methods. Chromatography and molecular network techniques were used to characterize chemical compounds. The lethality test showed that the lethal concentration (LC₅₀) increased from 110.03 ± 1.25 to 15.86 ± 2.21 μg/mL after 24 and 96 hours of exposure. In tadpoles exposed to 7.81 μg/mL extract, the first mortalities (12.5%) were observed on the fifth day of exposure. A relative decrease in mature erythrocytes exposed to plant extracts was observed. The antibacterial activity shows that the Ak F₂, Ak F₃, and Ak F₄ fractions (from the water-ethanol crude extract) gave the greatest antibacterial activities compared to the other extracts. The water, water-acetone, and water-ethanol extracts showed good inhibition of denaturation. The haemolysis test shows that the extracts exhibited good anti-inflammatory activities. Phytochemical characterisation revealed four major compounds, including monogallate epicatechin and hydroxy-ergostadian. The molecular network revealed five main clusters. Our study shows that A. klaineanum Pierre could be a promising natural product for the isolation of molecules with potential biological activities.

Assessment of copper, chromium, and lead toxicity in fish (Ctenopharyngodon idella Valenciennes, 1844) through hematological biomarkers

Hematological variances were seen in Ctenopharyngodon idella when exposed to (LC50 and LC85) copper, chromium, and lead concentration groups. The metal-exposed blood samples after collection were analyzed for comparative analysis of hematological alterations in the reference and treated groups at the different exposure hours. A significant reduction (p < 0.05) in hemoglobin, RBC, hematocrit, total leucocyte, and lymphocyte counts was observed with the increase in metal concentrations, whereas a significant incline (p < 0.05) in granulocyte and monocyte counts was observed with the administered doses of selected toxic metals as compared with the values obtained from the reference group. More pronounced changes in hematological indices both for the red and white blood cells were noticed at the highest dose of LC85-administered metal groups. The induced hematological changes were independent of the exposed duration pattern. The present investigation has significantly contributed in knowledge assessment of metal toxicity based on inclusive evaluation of dose-response relationships.

Protective role of Spirulina platensis against UVA-induced haemato-biochemical and cellular alterations in Clarias gariepinus

Recently, it has become widely recognized that ultraviolet A (UVA) exposure is harmful for both aquatic and terrestrial organisms. Many studies have reported the effects of UVA on aquatic animals, especially fish, but little is known about the antioxidant role of microalgae in ameliorating the negative effects of UVA exposure. Recently, there has been great interest in using Spirulina platensis (SP) as a dietary antioxidant agent. Therefore, this study aimed to investigate the protective role of SP against UVA-induced effects by analysing haemato-biochemical alterations and erythrocyte cytotoxic and genotoxic biomarkers in African catfish (Clarias gariepinus). Fish were exposed to UVA, UVA + 100 mg/L SP extract, UVA + 200 mg/L SP extract for 3 days (UVA exposure: 1 h/day), and were not subjected to treatment (control group). The results showed the presence of some morphological malformations in red blood cells (RBCs) after UVA exposure. Additionally, nuclear abnormalities, including micronuclei, were observed. UVA induced alterations in most of the haemato-biochemical indices. Adding SP to the fish aquaria restored the haemato-biochemical parameters to their control values. In addition, SP repaired cellular damage in a dose-dependent manner. We conclude that SP plays a modulatory role in preventing and/or repairing the haemotoxic effects induced by UVA.

Use of hematological parameters to assess the efficiency of quince (Cydonia oblonga Miller) leaf extract in alleviation of the effect of ultraviolet--A radiation on African catfish Clarias gariepinus (Burchell, 1822)

The present study aimed to elucidate the negative impacts of UVA on some biochemical and hematological variables of the economically important African catfish, Clarias gariepinus and investigates the putative role of quince (Cydonia oblonga Miller) leaf extract in protection and/or alleviation of such negative impacts. Changes in the hematological and blood biochemical values often reflect alteration of physiological state. Blood parameters can be useful for the measurement of physiological disturbances in stressed fish and thus provide information about the level of damage in the fish. We found a significant (P<0.05) decrease in the red blood cell counts, hemoglobin and hematocrit in the groups exposed to UVA compared to the control groups. Exposure to UVA induced marked red cell shrinkage (increased mean cell hemoglobin concentration) and showed an elevation in mean cell volume and mean cell hemoglobin in the blood of the exposed fish compared to the control. A significant (P<0.05) reduction in the total white blood cells was recorded in the exposed fish compared to the control. The biochemical parameters (blood glucose, total plasma protein, blood cholesterol, plasma creatinine, aspartic amino transferase and alanine amino transferase) exhibited a significant increase in the blood of fish exposed to UVA. Methanolic extract of quince leaf before ripening of the fruits was analyzed by GC/MS. To investigate the biological impact of this extract and its biologically active components, this extract was tested for its putative role in alleviation of UVA effect on catfish. Quince leaf extract had the ability to prevent hematotoxic stress induced by UVA and resulted in enhancement of the immune system of catfish represented by significant (P<0.05) increase in the number of white blood cells and lymphocytes of the catfish. Quince extract also protected the red blood cells from UVA damage. To our knowledge this is the first report of the effect of quince leaf extract on an aquatic organism.

[Anemia induced by cadmium intoxication]

Anemia is commonly induced by chronic cadmium (Cd) intoxication. Three main factors are involved in the development of Cd-induced anemia: hemolytic, iron-deficiency, and renal. Intravascular hemolysis can occur at the early stage of Cd exposure owing to the direct damaging effect on erythrocytes. In addition, Cd that accumulates in erythrocytes affects membrane cytoskeletons and decreases cell deformability, and these cells are then trapped and destroyed in the spleen. Iron deficiency can be detected in animals after an oral exposure to Cd, which competes with iron for absorption in the intestines, leading to anemia. However, an increase in body iron content along with anemia is often observed in cases of parenteral exposure or itai-itai disease. Therefore, it is estimated that Cd disrupts the efficient usage of iron in hemoglobin synthesis in the body. Renal anemia is observed during the very last phase of chronic, severe Cd intoxication, such as itai-itai disease, showing a decrease in the production of erythropoietin from renal tubular cells. Because the renal anemia is based on the same pathophysiology as Cd-induced osteomalacia, which is derived from the disturbance of mineral metabolism due to renal tubular dysfunction, it is reasonable to include renal anemia in the criteria for the diagnosis of itai-itai disease. Hemodilution could also contribute to the development of Cd-induced anemia. Bone marrow hypoplasia or the inhibition of heme synthesis might only be involved in Cd-induced anemia in severe cases of Cd intoxication.

Long-term monitoring of the health status of female perch (Perca fluviatilis) in the Baltic Sea shows decreased gonad weight and increased hepatic EROD activity

Annual investigations of the health status of female perch (Perca fluviatilis) were performed during 8-13 years in order to detect long-term, large-scale changes in the Baltic Sea. These background data are also meant to be used as baselines in recipient investigations at various point sources in the Baltic Sea. Fish were sampled at three coastal sites in Sweden: two in the Baltic Proper (since 1988) and one in the Bothnian Bay (since 1993). In all, 19 biochemical, physiological and histopathological variables were measured. By reflecting central functions of life, such as red blood cell functions, immune defence, liver function, biotransformation processes, intermediary metabolism, ion balance, and reproduction, the selected variables give a good picture of the health status of the fish. The most important observations were strong trends towards decreased gonadosomatic index (relative gonad size) and increased hepatic EROD activity in female perch in the Baltic Proper. Most of the other variables varied little between the years. The reduced gonad size and the EROD induction indicate that factors in the environment, e.g. the occurrence of pollutants, affect important physiological functions, such as reproduction and biotransformation processes, in fish even in a reference area in the Baltic Proper. It is urgent to make further studies in order to identify which pollutant(s) or other possible cause(s) are responsible for the observed biological effects.

Seasonal variation in carbohydrate and lipid metabolism of yellow perch (Perca flavescens) chronically exposed to metals in the field

The effects of heavy metals on growth, intermediary metabolism and enzyme activities were investigated in yellow perch (Perca flavescens), sampled in summer and fall from lakes situated along a contamination gradient of Cd, Zn and Cu in the mining region of Rouyn-Noranda, Québec. An exposure-dependent decrease in condition factor was observed in both seasons. Liver glycogen and triglyceride reserves were higher in summer than in fall in fish from the reference lake, while the seasonal pattern was different in fish from the contaminated lakes. Plasma free fatty acids (FFA) levels were also influenced by season and contamination. Activities of malic enzyme (ME) and glucose 6-phosphate dehydrogenase (G6PDH) in the liver were higher in the summer than in the fall in reference lakes whereas no seasonal variations were detected in fish from contaminated lakes. Activities of pyruvate kinase (PyK), aspartate transaminase (AST), phosphoenolpyruvate carboxykinase (PEPCK) and malate dehydrogenase (MDH), were higher in fish from contaminated lakes in fall but not in summer. Chronic exposure of yellow perch to sublethal levels of heavy metals impairs growth and alters the seasonal cycling of liver glycogen and triglycerides as well as the activities of metabolic enzymes.

Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 1. Hematological and population level assessment

Sunfish were collected from coal ash effluent-receiving streams and Ohio River watershed reference sites to assess the effects of exposure to low-level selenium concentrations. Selenium, copper, and arsenic concentrations were statistically higher in tissue samples from exposed fish than in reference fish. Leukopenia, lymphocytosis, and neutropenia were evident in exposed fish and were indicative of metal exposure and effect. White blood cell counts and percent lymphocyte values were significantly correlated with liver selenium concentrations. Plasma protein levels were significantly lower in exposed fish than in fish from the Ohio River, indicating that exposed fish may have been nutritionally stressed. Condition factors for fish from the ash pond-receiving streams were the same as, or lower than, those of fish from the reference sites. There was no evidence that the growth rate of fish in the receiving streams differed from that of fish in the reference streams. Despite liver selenium concentrations which exceeded reported toxicity thresholds and evidence of significant hematological changes, there were no significant differences in fish condition factors, liver-somatic indices, or length-weight regressions related to selenium.

Kinetics of cadmium accumulation and elimination in carp Cyprinus carpio tissues

Carp (Cyprinus carpio) were tested for cadmium accumulation and elimination during and after a simulated pollution exposure. Fish were distributed in two 1000-l indoor concrete aquaria supplied with a continuous flow (8 l min(-1)) of well water. The cadmium concentration was maintained at 53 microg l(-1) in one aquarium and 443 microg l(-1) in the other aquarium for 127 days. The exposure phase was followed by a 43-day depuration period. The cadmium accumulation in liver, kidney and muscle was measured by means of ICP-MS. The data showed that cadmium exposure produces significant cadmium uptake in tissues. Cadmium concentrations increased sharply in kidney and liver, whereas the pollutant level in muscle was only significant after 106 days. After 127 days of Cd exposure (53 microg l(-1)), the cadmium concentration in kidney was 4-fold higher than in liver and 50-fold higher than in muscle for a toxic level of 53 microg l(-1). At a Cd of 443 microg l(-1), kidney cadmium content was 2-fold higher than in liver and 100-fold higher than in muscle. In kidney and liver, the toxic concentration increased as the concentration of pollutant in water increased. During the 43 depuration days, the loss of accumulated cadmium was rapid and immediate in muscle. Conversely, no loss of cadmium was observed in kidney and liver.

Immunotoxicity of low level cadmium exposure in fish: an alternative animal model for immunotoxicological studies

Cadmium represents a major aquatic pollutant in many parts of the world. Yet, despite the fact that cadmium accumulates in high concentrations in fish tissues, is found in polluted aquatic environments, and is carcinogenic and immunotoxic in a variety of mammalian species, the effects of cadmium on the immune responses of directly exposed aquatic species have not been clearly defined. This study was designed to assess the effects of in vivo cadmium exposure, at a concentration found in contaminated aquatic environments, on the immune defense mechanisms of fish. In this study, no effects were observed upon body weight, lysozyme activity, of cell viability, despite the high concentration of accumulated cadmium in the gills and liver. Furthermore, in the absence of any clinical manifestations or overt toxicity, exposure of rainbow trout to waterborne cadmium at 2 ppb altered macrophage-mediated immune functions, including phagocytosis and free radical production, in a time-dependent manner. Similar immunotoxic effects of cadmium have also been observed in mammals. Although interspecies comparisons between mammalian and fish immune responses are extremely complicated and need to be approached with caution, results from this study suggest the applicability of fish as an additional/alternative animal model for immunotoxicological studies.

Accumulation of cadmium by channel catfish (Ictalurus punctatus): influx from environmental solutions

1. The accumulation of cadmium (Cd) from external environmental solutions was measured in channel catfish (Ictalurus punctatus) with the aid of 109Cd and by direct analysis of tissues. 2. Acute uptake (with 109Cd) was concentration dependent and was increased by changing the external pH from 7.3 to 5.0 and decreased by raising the Ca concentration from 0.1 mM to 3.0 mM. 3. The presence of external Zn did not change the uptake of the Cd. 4. In chronic 7-day experiments, fasted catfish were found to accumulate the toxic metal in their liver and kidneys from external media with Cd concentrations as low as 10(-9) M (about 0.1 microgram/l). 5. Concentrations were greater in the kidneys than the liver. 6. Detectable amounts of Cd (less than 0.03 microgram/g net wt) were not found in muscle in this time at external concentrations of Cd less than 10(-5) M (less than 1.0 mg/l).

Few intra-lake variations of physiological parameters in perch, Perca fluviatilis

Intra-lake variations in physiological parameters, representing haematology, plasma ion composition and carbohydrate metabolism, were investigated in perch (Perca fluviatilis), inhabiting a comparatively unpolluted lake. Provided the perch were subjected to a standardized procedure for capture, handling, recovery after capture, and sampling, only few and minor differences were observed in 21 parameters investigated when 3 groups were compared to a control group of perch. It is concluded that the experimental design used is suitable for the examination of the physiological status of perch in the field.