Assessing the water quality in a World Heritage Site using biomarkers in top fish predators.

The use of biomarkers in fish for biomonitoring is a valuable approach to reveal effects of human impacts on biota health. Top predator fish are effective models for monitoring human activities' impacts on aquatic ecosystems. The Guaraguaçu River is the largest river-system on coastal region of South Brazil and a World Heritage site. The river receives contaminants from disorderly urban growth, including discharges of domestic sewage and small fishery boats, particularly during the tourist season. Our study aimed to assess impact of anthropogenic activities on water quality in the Guaraguaçu River by analyzing environmental contamination biomarkers in the top fish predator Hoplias malabaricus. Fish were collected using a fyke net trap across sectors representing a gradient of anthropic impact: sector 1 - pristine; sector 2 - impacted; and sector 3 - less impacted. Water samples were collected to analyze the presence of trace elements and pesticide. Biomarkers of the antioxidant system, histopathology, genotoxicity, neurotoxicity, and concentration of trace elements were analyzed in fish tissues. In water samples Al, Fe and Mn were detected, but no pesticides were found. In fish muscle, zinc and iron were detected. Brain acetylcholinesterase activity decreased in impacted sectors, indicating neurotoxic effects. The antioxidant system increased activity in gills and liver, and damage from lipoperoxidation was observed, particularly in sector 2 when compared to sector 1, suggesting oxidative stress. Histopathological biomarkers revealed lesions in the liver and gills of fish in impacted sectors. Micronuclei, a genotoxicity biomarker, were observed in organisms from all sectors. Our results demonstrate detrimental effects of poor water quality on biota health, even when contaminants are not detected in water.

Ripening stage impacts nutritional components, antiglycemic potential, digestibility and antioxidant properties of grumixama (Eugenia brasiliensis Lam.) fruit.

This study aimed to determine the nutritional components (macronutrients ans minerals) and α-amylase inhibition capacity of freeze-dried grumixama (Eugenia brasiliensis Lam) seeds (S) and pulp/peel (P) portions, at ripe and mid-ripe stages. In vitro digestion was also performed on S and P from grumixama to assess the bioaccessibility of total phenolic compound (TPC), flavonoids (TFC), and anthocyanins (TAC), as well as to examine their impact on antioxidant activity (DPPH, ABTS, FRAP). The ripening process impacts the bioactive compounds and individual phenolics of S and P portions. The ripe S was source of myricetin and exhibited higher antioxidant activity, while mid-ripe S was high in flavonoids and cinnamic acid with higher antiglycemic potential. Ripe P showed higher soluble fiber, carbohydrate, TAC, and caffeic acid content, whereas mid-ripe P had increased mineral content (calcium, potassium, manganese), catechin, and TPC. After in vitro digestion, the P portion showed a bioaccessibility of total phenolic content (TPC) and total flavonoid content (TFC) exceeding 40% at intestinal phase. In contrast, the S portions had better release of TPC and TFC and antioxidant activity at gastric phase. Considering the outstanding nutritional and biological properties of grumixama fruit, freeze-dried S and P portions from both ripening stages possess could be explored as valuable sources of nutrients and antioxidant compounds.

Potentiality of Epoxy-Montmorillonite Composite for Stir-Bar Sorptive Extraction for Determination of Atrazine

Abstract A new low-cost material is presented for the first time, aiming to study the sorption process for the stir-bar sorptive extraction (SBSE) technique. The bars were made using a composition of a commercial epoxy resin and montmorillonite, under different compositions and a final ratio of 70% (epoxy) and 30% (montmorillonite) was employed, providing the best mechanical and chemical resistance. A PTFE support was developed to hold the bars permitting the magnetic stirring, without turbulent behavior even under long times of stirring at 1000 rpm. The bars were employed to study the sorption of the herbicide atrazine (ATZ), and the best extraction conditions were: sample volume 20.0 mL, pH 6.0, extraction time of 15 min, room temperature, stirring speed of 100 rpm, and 10.0% (w v-1) NaCl. This preliminary evaluation suggests that the modified bars could be employed for ATZ sorption, affording close to 71% of ATZ removal, and presented robust characteristics to be used at least 80 times.