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Coastal and estuarine areas can be impacted by several sources of anthropogenic activities derived from industries, agriculture, sewage and harbor activities. Two Brazilian estuarine areas (Piraquê-ES e Paranaguá-PR) located close to harbours, industries and sewage from urban centers were evaluated through analysis of somatic indexes, histopathological, biochemical and genetic biomarkers on fish. Histopathological lesions as lamellar fusion, hyperplasia, epithelial lifting, and second lamellae disorganization were found in gills. Necrosis was the main alteration observed in the liver of sampled animals and the occurrence of melano-macrophages in Cathorops spixii was similar among the evaluated areas. Cholinesterase activity increased in most of the contaminated areas. Genotoxic responses as micronucleus induction and occurrence of DNA strand breaks were detected in Piraquê and Paranaguá estuaries in all sampling seasons. Our results suggest that these areas are impacted by anthropogenic activities and that a multi-biomarker approach is valuable and recommended for environmental pollution evaluation.

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The beneficial effect of polyphenols and magnesium­(II) against oxidative stress motivated our research group to explore the antioxidant activity of phenMgIso, an aqueous soluble magnesium­(II) complex containing 1,10-phenanthroline (phen) and isovanillic acid (Iso) as ligands. Combined electrospray ionization–mass spectrometry and DOSY-NMR techniques identified two complexes in methanolic solution: hexacoordinated [Mg­(phen)2(Iso)]+ and tetracoordinated [Mg­(phen)­(Iso)]+. The cyclic voltammogram of phenMgIso in the anodic region showed a cyclic process that interrupts the isovanillic acid degradation, probably by stabilization of the corresponding phenoxyl radical via complexation with Mg­(II), which is interesting for antioxidant applications. phenMgIso competes with 2,2,6,6-tetramethylpiperidine by 1O2 with IC50(1O2) = 15 μg m–1 and with nitrotetrazolium blue chloride by superoxide ions (IC50(O2 •–) = 3.6 μg mL–1). Exposure of both zebrafish (2 mg L–1) and wistar male rats (3 mg kg–1 day–1 dose for 21 days) to phenMgIso does not cause mortality or visual changes compared with the respective control groups, thus phenMgIso could be considered safe under the conditions of this study. Moreover, no significant changes in comparison to both control groups were observed in the biochemical parameters on the brain-acetylcholinesterase activity, digestive tract enzyme catalase, and glutathione-S-transferase. Conversely, the performance of superoxide dismutase activity in wistar male rats increased in the presence of a complex, resulting in enhanced capacity of rats for superoxide radical enzymatic scavenging. The synergistic action of phenMgIso may be explained by the strong electrostatic interaction between Mg­(II) and the O,O­(phenolate) group, which makes the Iso ligand easier to oxidize and deprotonate, generating a cyclic stable species under oxidative conditions.

The oriental fruit moth, Grapholita molesta (Busk, 1916), is one of the most important pests in apple orchards in southern Brazil. Chemical control is still the most commonly used strategy for pest control. The aim of this study was to determine the resistance evolution of seven South Brazilian populations to four insecticides (chlorantraniliprole, lufenuron, chlorpyrifos, and fenitrothion). Bioassays were paired with metabolic analyses of glutathione-S-transferase (GST), carboxylesterases (α-NA and β-NA), and acetylcholinesterase (AChE) to understand the possible role with phytosanitary strategies in the insects’ susceptibility. Insect populations were collected in the municipalities of Campo do Tenente, Lapa and Porto Amazonas, Fraiburgo, São Joaquim, and Vacaria and multiplied in the laboratory. Two susceptible and two resistant populations were used as references. The bioassays showed that five populations were considered more resistant to organophosphates, six to lufenuron and two to chlorantraniliprole when compared with the sensitive population. None of the field populations had greater resistance than the resistant laboratory population. The enzymatic activity of AChE and GST was elevated in most of the populations that were less susceptible to organophosphates and lufenuron. The populations originating from orchards that used sexual confusion techniques had the greatest susceptibility based on toxicological and biochemical bioassays. Populations under pressure from various compounds had high GST, α and β-NA activity. There is evidence that a diversity of control strategies can provide better resistance management.

A multi-biomarker approach was used to evaluate the liver health of two Neotropical fish species (Cathorops spixii and Atherinella brasiliensis) that inhabit two different sites of the Paranaguá bay (Paraná-Brazil) and a reference site in the Garatuba bay. Fish were sampled during summer and winter, so the variation of the responses can reflect the actual conditions of sampling sites. Data showed that fish from both sites of the Paranaguá bay are affected by the presence of pollutants from different sources. Both fish species presented adverse biomarker responses mainly in the summer, probably due to the increased human population during the period. Chronic effects in the liver related with the contamination. Thus, the results demonstrated that pollution in Paranaguá bay induce liver damage in fish that inhabit this area.

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