Metals in species of the Cambeva (Teleostei: Trichomycteridae) genus of the Iguaçu River basin (Brazil).

The population growth is connected to the demand for resources and waste disposal in water. Metals are among several pollutants affecting aquatic ecosystems, posing risks to biota when in high concentrations. Metals can present a great danger to the aquatic ecosystem because they are not degradable and can bioaccumulate. Many rivers are already considered highly polluted. Among them is the Iguaçu River, located in southern Brazil, which is recognized for the Iguaçu Falls and its rate of endemism. One species of the Cambeva genus is among the endemic species found in the Iguaçu River and is threatened with extinction due to anthropization. Thus, we aimed to evaluate and compare the concentrations of copper, zinc, iron, lead, manganese, and cadmium in Cambeva stawiarski and Cambeva sp. 1 in four different streams of the Iguaçu River (Brazil). We collected 20 fish in two municipalities along the Iguaçu River tributaries. The results showed a statistical difference in the metal concentrations in different species and locations, mainly manganese, iron, and copper, observed in both species and municipalities and cadmium, which showed a statistical difference only for C. sp1. Fish from agricultural regions generally had the highest concentrations of metals, some above the permitted limits. Cadmium was found at high concentrations, generating great ecological concern since it is one of the most toxic metals, even in small quantities. The lack of limits in Brazilian legislation makes it challenging to predict the long-term effects of iron.

Imidacloprid: Impact on Africanized Apis mellifera L. (Hymenoptera: Apidae) workers and honey contamination.

Apis mellifera L. (Hymenoptera: Apidae) is fundamental in the production chain, ensuring food diversity through the ecosystem service of pollination. The aim of this work was to evaluate the impact of imidacloprid, orally, topically, and by contact, on A. mellifera workers and to verify the presence of this active ingredient in honey. Toxicity levels were verified by bioassays. In bioassay 1, the levels correspond to the percentages of 100, 10, 1, 0.1, and 0.01% of the recommended concentration for field application of the commercial product Nortox® (active ingredient imidacloprid), with which we obtained the mean lethal concentration (LC50) in 48 h for A. mellifera, determining the concentration ranges to be used in the subsequent bioassays. Bioassays 2 and 3 followed the guidelines of the Organization for Economic Cooperation and Development, which specify the LC50 (48 h). In bioassay 4, the LC50 (48 h) and the survival rate of bees for a period of 120 h were determined by contact with a surface contaminated with imidacloprid, and in bioassay 5, the interference of the insecticide with the flight behavior of bees was evaluated. Honey samples were collected in agroecological and conventional georeferenced apiaries and traces of the imidacloprid were detected by means of high-performance liquid chromatography (HPLC-UV) with extraction by SPE C18. Bee survival was directly affected by the concentration and exposure time, as well behavioral performance, demonstrating the residual effect of imidacloprid on A. mellifera workers. Honey samples from a conventional apiary showed detection above the maximum residue limits (MRL) allowed by the European Union (0.05 µg mL-1), but samples from other apiaries showed no traces of this insecticide. Imidacloprid affects the survival rate and behavior of Africanized A. mellifera and honey quality.

Lipid profile and fatty acid composition of marine fish species from Northeast coast of Brazil.

Total lipid content, fatty acid composition and nutritional profile of lipid fraction of fourteen fish species from the Brazilian Northeastern coast were evaluated. Lipid content was determined by Bligh and Dyer methodology, whereas the fatty acid composition was determined by gas chromatography with flame ionization detector. The indices of atherogenicity, thrombogenicity and hypocholesterolemic/hypercholesterolemic ratio were used to evaluate the nutritional quality of lipid fraction. The total lipid content ranged from 0.25 to 3.09%, with higher values in L. synagris. A significant difference (p < 0.05) were noted in fatty acids composition between the fourteen fish species. PUFA were the major fatty acids in twelve of fourteen species and C. leiarchus showed the highest content. The n-3 content ranged from 69.83 to 270.62 mg g-1 of total lipids, being EPA and DHA the major fatty acids in most of the species studied. The species L. synagris, M. bonaci and S. brasiliensis exceeded the WHO daily intake recommendation of 250 mg per day from those fatty acids. The quality indexes of the lipid fraction as well as the n-6/n-3 and PUFA/SFA ratios indicated that all fish species can be healthy nutritional options, and can bring many benefits to human health. The principal component analysis resulted in a two-principal-component model that described 79.78% of data variance. Also, it highlighted that despite the differences between the breeding strategies of fish families, the species could be grouped according to their similarity in fatty acids composition.

Neuroprotective effect of omega-3 polyunsaturated fatty acids in the 6-OHDA model of Parkinson's disease is mediated by a reduction of inducible nitric oxide synthase.

OBJECTIVE: Parkinson's disease (PD) is characterized by deterioration of the nigrostriatal system and associated with chronic neuroinflammation. Glial activation has been associated with regulating the survival of dopaminergic neurons and is thought to contribute to PD through the release of proinflammatory and neurotoxic factors, such as reactive nitric oxide (NO) that triggers or exacerbates neurodegeneration in PD. Polyunsaturated fatty acids (PUFAs) exert protective effects, including antiinflammatory, antiapoptotic, and antioxidant activity, and may be promising for delaying or preventing PD by attenuating neuroinflammation and preserving dopaminergic neurons. The present study investigated the effects of fish oil supplementation that was rich in PUFAs on dopaminergic neuron loss, the density of inducible nitric oxide synthase (iNOS)-immunoreactive cells, and microglia and astrocyte reactivity in the substantia nigra pars compacta (SNpc) and striatal dopaminergic fibers. METHODS: The animals were supplemented with fish oil for 50 days and subjected to unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-induced lesions as a model of PD. RESULTS: Fish oil mitigated the loss of SNpc neurons and nerve terminals in the striatum that was caused by 6-OHDA. This protective effect was associated with reductions of the density of iNOS-immunoreactive cells and microglia and astrocyte reactivity. DISCUSSION: These results suggest that the antioxidant and antiinflammatory properties of fish oil supplementation are closely related to a decrease in dopaminergic damage that is caused by the 6-OHDA model of PD.

Evaluation of solvent effect on the extraction of phenolic compounds and antioxidant capacities from the berries: application of principal component analysis.

BACKGROUND: This study evaluated the effect of the solvent on the extraction of antioxidant compounds from black mulberry (Morus nigra), blackberry (Rubus ulmifolius) and strawberry (Fragaria x ananassa). Different extracts of each berry were evaluated from the determination of total phenolic content, anthocyanin content and antioxidant capacity, and data were applied to the principal component analysis (PCA) to gain an overview of the effect of the solvent in extraction method. RESULTS: For all the berries analyzed, acetone/water (70/30, v/v) solvent mixture was more efficient solvent in the extracting of phenolic compounds, and methanol/water/acetic acid (70/29.5/0.5, v/v/v) showed the best values for anthocyanin content. Mixtures of ethanol/water (50/50, v/v), acetone water/acetic acid (70/29.5/0.5, v/v/v) and acetone/water (50/50, v/v) presented the highest antioxidant capacities for black mulberries, blackberries and strawberries, respectively. CONCLUSION: Antioxidants extractions are extremely affected by the solvent combination used. In addition, the obtained extracts with the organic solvent-water mixtures were distinguished from the extracts obtained with pure organic solvents, through the PCA analysis.

Effect of dietary replacement of sunflower oil with perilla oil on the absolute fatty acid composition in Nile tilapia (GIFT).

This study evaluated the effect of the dietary replacement of sunflower oil with perilla oil in Nile tilapia (GIFT strain) at 0, 10, 20 and 30 days. There was an increase in total omega 3 fatty acids (n-3) in muscle tissue (from 63.6 to 181.5 mg g(-1)) and a decrease in total concentration of omega 6 fatty acids (n-6) ranging between 255.6 and 196.1 mgg(-1). Amongst the n-3 fatty acids, the concentrations of alpha-linolenic acid (18:3n-3) and docosahexaenoic acid (20:6n-3) increased by 9.4 and 1.9 times, respectively, after 30 days for the perilla oil-enriched diet. The n-6/n-3, polyunsaturated and saturated fatty acids (PUFA/SFA), and polyunsaturated and monounsaturated fatty acids (PUFA/MUFA) ratios tended to stabilize after 20 days under the perilla oil-enriched diet. Incorporation of perilla oil as a lipid source in the diet of tilapia for 20 or 30 days resulted in significant changes in the fatty acid composition of the fish muscle tissue, contributing to increase its nutritional value.