Biochemistry biomarkers and metal levels as indicators of environmental pollution in Danio rerio exposed to the Sorocaba River (S.P.), Brazil.

Metal contamination of the environment poses a significant threat to human health and can cause significant damage to aquatic ecosystems. Danio rerio was exposed to Sorocaba River water for 96 h from two different sites in summer (S) and winter (W). Concentrations of Al, Cd, Cu, Mn and Zn were determined in the exposure water and in sediment. At the end of the exposure, the concentrations of Al, Cu and Mn at the Ibiúna point (P1) and Mn at the Itupararanga point (P2) decreased compared to the initial concentrations in the water. In summer and winter, the highest concentrations of Cu and Mn were found in the sediment. Exposure to the Sorocaba River water caused various responses both in summer and winter. For example, GPx decreased in winter, Glutathione S-Transferase (GST) increased in summer, and Nitric Oxide Synthase (NOS) decreased in both seasons in the viscera. In winter, SOD Superoxide Dismutase (SOD) increased, while GPx and GST (winter) decreased in muscle; regarding viscera carbonyl proteins, there was an increase in the summer at P2. Acetylcholinesterase activity decreased in the brain in winter at P2 and NOS decreased in the summer-exposed groups and increased in the winter P2-exposed group. Lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) decreased in viscera (S, P1) and increased in muscle (S, P1 and P2). The glucose and triglycerides increased in muscle, both in summer and winter. Correlation analysis revealed associations between biomarkers from different organs. These alterations suggest that the fish experienced oxidative stress in response to exposure to the Sorocaba River, contaminated with metals, highlighting their vulnerability to environmental pollutants.

Changes in blood parameters and metabolism in bullfrog tadpoles, Lithobates catesbeianus, (Shaw, 1802) after exposure to the Sorocaba River (São Paulo, Brazil) water.

This study evaluated the genetic damage, oxidative stress, neurotoxicity, and energy metabolism in bullfrog tadpoles (Lithobates catesbeianus) exposed to water from two sites of the Sorocaba River, Ibiúna (PI), and Itupararanga reservoir (PIR), in summer and winter. After 96-h exposure, the erythrocyte number decreased in PI and increase in PIR in summer. Bullfrogs show oxidative unbalance (liver, kidney, and muscle), with alterations in the nitric oxide synthase and glucose 6-phosphate dehydrogenase. Cholinesterase increased in the brain in PI and PIR in the summer and decreased in PI in the winter. It also increased in the muscle in both PI and PIR in the winter. Tadpoles show alterations in the activity of the metabolic enzymes (liver, kidney, and muscle), such as phosphofructokinase, pyruvatokinase, malate dehydrogenase, and lactate dehydrogenase; and in the amount of glucose and triglycerides metabolites. Exposure to the Sorocaba River reflected a stressful situation for L. catesbeianus as the changes caused to their metabolism associated with oxidative stress and neurotoxicity may have effects on the development of tadpoles.

Response of hepatic biomarkers in Physalaemus nattereri (Anura) to different benzo(α)pyrene exposure routes.

For over 40 years, anurans have been used as a study model to assess the adverse effects of benzo(α)pyrene (BαP), which include genotoxic, hepatotoxic, and immunotoxic effects. In these studies, BαP is administered cutaneously or by injection, with no comparison between two or more routes. The purpose of this study is to assess whether the effect of BαP is influenced by its route of administration, using the response of hepatic biomarkers of Physalaemus nattereri. Specimens (n = 108) were collected and divided into three experimental treatments (cutaneous, injection, and oral) and three experimental times (one, three, and seven days). Specimens received 0.02 ml of pure mineral oil (control) or mineral oil containing 2 mg/kg of BαP. The BαP causes changes in morphological (melanin, hemosiderin, lipofuscin, and mast cells) and biochemical (superoxide dismutase and glutathione S-transferase) hepatic biomarkers. Compared to biochemical, morphological biomarkers underwent a greater number of significant changes due to the treatment with BαP. The route of exposure alters the effects of BαP, mainly seen in morphological biomarkers, especially the pigments melanin, hemosiderin, and lipofuscin. In these pigments, the effect of the exposure pathway changes according to the analyzed biomarker, and the exposure time modulates the exposure pathway effect. These results are unprecedented for anurans and contribute to the field of herpetology and ecotoxicology.

Endophytic fungi isolated from Brazilian medicinal plants as potential producers of antioxidants and their relations with anti-inflammatory activity.

In this study, 19 endophytic fungi were isolated from Lafoensia pacari, Guazuma ulmifolia, Campomanesia xanthocarpa and Siparuna guianensis. Seventeen strains were molecularly identified as belonging to the genera Colletotrichum, Diaporthe, Bjerkandera, Talaromyces, Cochliobolus, Phaeophlebiopsis, Curvularia, and Xylaraceae. Assays for detecting antioxidant activity were performed by free radical scavenging activity using the DDPH and ABTS + methods. Based on the results with DPPH, two strains were selected to evaluate the presence of flavonoids and anti-inflammatory activity. A strong positive correlation was found between these activities and the presence of flavonoids. The anti-inflammatory activity of endophytic fungi is under explored; however, the Talaromyces obtained the best result of 87.33% protection of erythrocytes and Colletotrichium of 60.71%. This study demonstrated that endophytic fungi associated with selected plants are potential sources of novel antioxidant products.

Effects of copper toxicity at different pH and temperatures on the in vitro enzyme activity in blood and liver of fish, Prochilodus lineatus.

Blood and liver from curimbata (Prochilodus lineatus) acclimated at pH 4.5, 7.0 and 8.0 and at 20 and 30 °C were exposed in vitro to different concentrations of copper (Cu): 98 ± 0.8 µg Cu L-1 at pH 4.5 and 16 ± 0.2 µg Cu L-1 at pH 8.0 at 20 °C; 88 ± 0.8 µg Cu L-1 at pH 4.5 and 14 ± 0.5 µg Cu L-1 at pH 8.0 at 30 °C and in 29 µg Cu L-1 at pH 7.0 at 20 and 30 °C for 2 h. The pH affected the levels of glucose and glycogen and in vitro exposure to Cu increased glucose levels and decreased glycogen at 20 and 30 °C. Exposures to acid water and Cu in vitro also resulted in an increase in enzyme activity in the blood, hexokinase (HK), pyruvate kinase (PK) and at pH 8.0 decreased the HK activity and increased PK and lactate dehydrogenase (LDH) activities at 20 °C. Cu caused an increase in the activities of HK (at pH 4.5) and PK in both pH, 4.5 and 8.0 at 30 °C. At 20 °C, HK (pH 8.0) and glycose-6-phosphate dehydrogenase (G6PDH) (pH 4.5) activities increased and PK (pHs 4.5 and 8.0) and LDH decreased (pH 4.5) in the liver. In vitro, exposure to Cu increased HK and G6PDH at pH 8.0 and PK activity increased in both pH values and LDH increased in pH 7.0. Cu exposure in vitro at 30 °C, phosphofructokinase (PFK) and PK activities decreased and LDH activity increased in all pH values when compared to fish from the water from its respective pH values. Interactions occurred in blood and liver between the temperature, pH and exposure to copper in vitro. The in vitro tests may constitute an interesting biological model for experimental and applied toxicology, especially in the case of environmental pollution.

Cardiac biomarkers as sensitive tools to evaluate the impact of xenobiotics on amphibians: the effects of anionic surfactant linear alkylbenzene sulfonate (LAS).

Amphibian populations have been experiencing a drastic decline worldwide. Aquatic contaminants are among the main factors responsible for this decline, especially in the aquatic environment. The linear alkylbenzene sulfonate (LAS) is of particular concern, since it represents 84% of the anionic surfactants' trade. In Brazil, the maximal LAS concentration allowed in fresh waters is 0.5mgL-1, but its potential harmful effects in amphibians remain unknown. Therefore, this study aimed to analyze the effects of a sublethal concentration of LAS (0.5mgL-1) for 96h on sensitive cardiac biomarkers of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802). For this, we measured the activity level (AL - % of animals), in situ heart rate (fH - bpm), relative ventricular mass (RVM - % of body mass), in vitro myocardial contractility and cardiac histology of the ventricles. Tadpoles' AL and fH decreased in LAS group. In contrast, the RVM increased, as a result of a hypertrophy of the myocardium, which was corroborated by the enlargement of the nuclear measures and the increase of myocytes' diameters. These cellular effects resulted in an elevation of the in vitro contractile force of ventricle strips. Acceleration in the contraction (TPT - ms) also occurred, although no alterations in the time to relaxation (THR -ms) were observed. Therefore, it can be concluded that even when exposed to an environmentally safe concentration, this surfactant promotes several alterations in the cardiac function of bullfrog tadpoles that can impair their development, making them more susceptible to predators and less competitive in terms of reproduction success. Thus, LAS concentrations that are considered safe by Brazilian by regulatory agencies must be revised in order to minimize a drastic impact over amphibian populations. This study demonstrates the relevance of employing cardiac biomarkers at different levels (e.g., morphological, physiological and cellular) to evaluate effects of xenobiotics in tadpoles.

Hepatic metallothionein in a teleost (Prochilodus scrofa) exposed to copper at pH 4.5 and pH 8.0.

Copper accumulation and induction of metallothionein (MT) were investigated in the liver of juvenile Prochilodus scrofa exposed to copper (96 h-LC50) at pH 4.5 (LC50=98+/-0.8 microg Cu l(-1)) and pH 8.0 (LC50=16+/-0.5 microg Cu l(-1)) at 20 degrees C. No significant difference was found in copper accumulated in the liver at either pH. The ratio between copper accumulation in the liver after 96 h exposure and the copper in the water at pH 4.5 and 8.0 was 5.1 and 34.4, respectively. MT in the liver of fish exposed to copper was isolated by DEAE-Sepharose chromatography and identified by SDS-PAGE. No MT was identified in the controls. MT concentration was 126.8+/-21.5 and 167.4+/-25.6 microg g(-1) wet mass in fish exposed to copper at pH 4.5 and pH 8.0 (P>0.05), respectively. The results indicate that the pH of the water is a determining factor in copper toxicity, and the increased concentration of MT in the liver of P. scrofa exposed to copper suggests the possibility of using MT as a biomarker to evaluate the biological response of this species to copper contamination in aquatic environments.