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The present study aimed to characterize in vitro antioxidant properties of red algae (Gracilaria birdiae) powder and to investigate its potential protective and antioxidant effects in male rats, with and without co-exposure to a ternary mixture of agrochemicals. The focus was on reproductive and DNA damage parameters, both known as vulnerable targets for oxidative stress induced by this class of toxicants. It is important to emphasize that the dehydrated powder of G. birdiae used in the present study is already commercialized for food purposes. In vitro tests revealed that G. birdiae dehydrated powder preserves important antioxidant features of the algae, demonstrating potential for use as food supplements. On the other hand, in vivo tests showed that dietary supplementation with 5% of the homogenate of dehydrated G. birdiae, per se, impaired spermatogenesis due to increased cell damage and consequent cell death in the seminiferous epithelium, without interfering with antioxidant enzymes and androgenic status of the animals. In addition, no beneficial or protective effect of G. birdiae homogenate was observed in animals co-exposed to the agrochemical mixture. Contrary to expectation, in the experimental conditions presented here, powder of G. birdiae was able to induce reproductive toxicity and provoke DNA damage. The data obtained call attention to the importance of discussing the use of food supplementation in the prevention and maintenance of health and the need for better regulating the processing procedures and market of natural supplements.

Aedes aegypti is the main mosquito vector of dengue, zika, chikungunya, and yellow fever diseases. The low effectiveness of vector control options is mainly related to the increased insect's resistance and to the toxicity of products used for non-target organisms. The development of new environmentally friendly and safer products is imperative. Technical cashew nut shell liquid (tCNSL), mostly composed by cardanol (C), is an abundant by-product of the cashew (Anacardium occidentale L.) production chain, available at low cost, and with proven larvicidal activity. However, chemical modifications in both tCNSL and cardanol were required to increase their water solubilities. Our objectives were to synthesise and characterise sustainable, low-cost and easy-to-use multiple function products based on tCNSL, cardanol, and the sulphonates obtained from both; and to evaluate all these products efficacy as surfactants, larvicidal, and antimicrobial agents. None of the sulphonates presented antimicrobial and larvicidal activities. tCNSL and cardanol were successfully emulsified with sodium technical cashew nut shell liquid sulphonate (NatCNSLS, complex mixture of surfactants). The emulsions obtained presented larvicidal activity due to the presence of tCNSL and cardanol in their composition. Our results showed that the tCNSL+NatCNSLS mixture emulsion was an effective larvicide and surfactant multiple function product, with high availability and easy-to-use, which can facilitate its large-scale use in different environments. Graphical abstract.

The use of non-plant and plant-derived anesthetics in aquaculture activities is a frequent and necessary practice to maintain fish welfare. Currently anesthetics authorized for use in aquaculture activities are limited, and the use of unauthorized products is common. However, to obtain authorization for use in aquaculture and ensure their safety, anesthetics should be evaluated for their genotoxic potential. Our objective was to evaluate the genotoxicity of three not approved anesthetics commonly used in aquaculture using Astyanax lacustris and Oreochromis niloticus. Both fish species were exposed to six treatments: two with commercial anesthetics (benzocaine and eugenol), one with Lippia alba essential oil (EO), and three controls - negative (without treatment), vehicle (ethanol PA), and positive (cyclophosphamide). Fishes were exposed to all treatments in a water bath for 10 min and were transferred to individual aquariums without anesthetics or controls. Venipuncture of the caudal vein was performed 72 h after the exposure to the anesthetics. Nuclear abnormalities and the micronucleus were analyzed in blood smears, and DNA damage was assessed using comet assay. No genotoxicity effects were verified for fishes exposed to L. alba EO. Eugenol presented genotoxicity to both species. The comet assay showed increased DNA damage in both species induced by benzocaine and eugenol. Thus, L. alba EO was proven to be the safest anesthetic resulting in no genotoxicity and, therefore, may be an interesting alternative to commercial anesthetics used in aquaculture. However, a complete toxicological evaluation is necessary to ensure the safety of its use as an anesthetic.

This study assessed the quality of vegetation cover in the Parque Estadual das Varzeas do Rio Ivinhema (PEVRI, Upper Parana River basin, MS, Brazil), the concentration of metals (Cd, Pb, Cr, Cu, Fe, Zn and Ni) in water and muscle and hepatic tissues of five fish species collected in the PEVRI – Hemiodus orthonops, Leporinus friderici, Prochilodus lineatus, Pterodoras granulosus and Pimelodus maculatus – in addition to non-carcinogenic risk assessment and genotoxicity potential in these species. Regarding vegetation index, we found that only 26.25% of the PEVRI area is occupied by denser vegetation. In the sites analyzed, Cd, Cu, Fe and Ni showed high concentrations in water, above the reference values established by the legislation. In the muscle and hepatic tissues of the fish species analyzed, Cd and Pb values exceeded the reference limits. The genotoxic alterations identified in erythrocytes of the fish species studied were nuclear invagination, nuclear budding, picnosis, binucleated cell and lobulate nucleus. For the non-carcinogenic risk assessment in fish, Cd and Pb presented values greater than 1, indicating risk in the consumption of these fish. In the bioaccumulation factor, Cd and Pb were greater than 100 in all fish species analyzed, except for Pb in L. friderici. The results indicated that the water resources of the PEVRI are being affected by some type of contaminant, probably due to anthropic activities carried out around the park or carried from the upper portions of the basin through the drainage system.