Effect of digestible protein on intermediate metabolism, hepatic enzyme activities, energy reserves, and growth performance of pacu (Piaractus mesopotamicus) in the finishing growth phase.

This study investigated the effect of different levels of digestible protein (DP) on blood metabolites, hepatic enzyme activity of glycolysis and amino acid metabolism, energy reserves, and the production characteristics of pacu (Piaractus mesopotamicus) during the finishing growth phase. Six semi purified and isoenergetic diets, containing 16.3, 20.1, 23.8, 27.2, 31.5, and 34.8% of balanced DP, provided with essential amino acid balance, were hand-fed to pacu (1100.0 ± 10.3 g, initial weight) three times daily for 7 weeks. The experiment consisted of six treatments, with three randomly arranged replicates (tanks) per treatment. The data obtained from this experiment were analyzed by one-way analysis of variance (ANOVA), and significant differences (p < 0.05) between treatments were determined using Tukey's test. Blood metabolites, except serum ammonia and the hepatic enzymes activities of glycolysis and amino acid metabolism, except hexokinase activity were affected (p < 0.05) by balanced DP. The energy reserve indices, except hepatic total lipid content, were also found associated (p < 0.05) with balanced DP. The test diets significantly (p < 0.05) affected growth performance parameters. Higher dietary proteins led to a greater energy uptake by fish from the protein in feed. Overall, fish fed the intermediate level (23.8%) of balanced DP with digestible energy of 17.95 MJ kg-1 showed better production traits and physio-biochemical health markers. This information could help nutritionists and farmers to develop nutritionally balanced and economically and environmentally sustainable aquafeed for promoting healthy and sustainable production of pacu in intensive culture systems.

Limonoids and insecticidal activity on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) of Trichilia catigua A. Juss. (Meliaceae).

The aim of the study was to evaluate the effects of the seeds, exocarp and aril extracts from Trichilia catigua A. Juss. (Meliaceae) against Spodoptera frugiperda and present the phytochemical study carried out with the aril extract of T. catigua. Limonoids were isolated from the aril of T. catigua through chromatographic techniques and their structures were proposed by spectroscopic analysis and comparison with literature data. The effects of the seeds, exocarp and aril extracts from T. catigua against S. frugiperda were evaluated considering as parameters the duration and mortality of the larval phase, in addition to the pupal weight. Phytochemical investigation of the aril extracts of T. catigua has led to the identification of the limonoids 6α-O-acetyl-7-deacetyl-14,15-dihydro-15-oxo-nimocinol (1), cedrelone (2) and 6α-O-acetyl-7-deacetylnimocinol (3). The hexane and CH2Cl2 extracts of the aril showed a high rate of larval mortality (100 and 90%, respectively). In addition, a prolongation of larval phase and a reduction in the pupal weight were observed for insects treated with hexane, CH2Cl2 and methanol extracts of seeds and with CH2Cl2 extract of exocarp of T. catigua.

MALDI-TOF Mass Spectrometry for the Diagnosis of Citrus Canker Caused by Xanthomonas citri subsp. citri.

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a disease that causes serious problems to the global citrus industry. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry (MS) has been used in human medicine to diagnose various diseases caused by both fungi and bacteria. In agriculture, this technique has potential for the diagnosis of diseases due to the low cost of large-scale analysis and quickness. This study showed that MALDI-TOF MS combined with chemometric analysis was effective for differentiating the macromolecule profile of orange leaves with canker lesions, healthy leaves, and leaves with phytotoxicity symptoms, proving that this technique may be used for the rapid diagnosis of citrus canker.

Exploring chemical diversity in Glycine max cultivars: A multivariate approach in the search for bioactive compounds against Spodoptera cosmioides.

Soybean crop is regulated by abiotic and biotic stresses with great potential in reducing grain yield and quality. The selection of resistant cultivars is a promising approach for mitigating these damages. We evaluated the chemical profile of Glycine max leaves from different cultivars in order to explore their defense mechanisms against Spodoptera cosmioides caterpillars. We optimized solid-liquid extraction techniques using ultrasound bath and static headspace extraction. Additionally, we developed an approach based on liquid and gas chromatography for analyzing the chemical profile of G. max cultivars. The principal component analysis allowed the classification of transgenic cultivars, which are classified as susceptible to S. cosmioides, from those obtained by genetic improvement and resistant to the insect. Differences were observed in the abundance of phenolic glycosides, lipids, aldehydes, and alcohols. More specifically, S. cosmioides resistant cultivars presented molecules related to the jasmonic and salicylic acid pathways. Such data can contribute to a molecular understanding of phenotypic diversity in soybean cultivars, from plant quality to resistance mechanisms and adaptation, to environmental stress and herbivory.

Liver dysfunction and energy storage mobilization in traíra, Hoplias malabaricus (Teleostei, Erythrinidae) induced by subchronic exposure to toxic cyanobacterial crude extract.

Microcystins (MC) are hepatotoxic for organisms. Liver MC accumulation and structural change are intensely studied, but the functional hepatic enzymes and energy metabolism have received little attention. This study investigated the liver and hepatocyte structures and the activity of key hepatic functional enzymes with emphasis on energetic metabolism changes after subchronic fish exposure to cyanobacterial crude extract (CE) containing MC. The Neotropical erythrinid fish, Hoplias malabaricus, were exposed intraperitoneally to CE containing 100 µg MC-LR eq kg-1 for 30 days and, thereafter, the plasma, liver, and white muscle was sampled for analyses. Liver tissue lost cellular structure organization showing round hepatocytes, hyperemia, and biliary duct obstruction. At the ultrastructural level, the mitochondria and the endoplasmic reticulum exhibited disorganization. Direct and total bilirubin increased in plasma. In the liver, the activity of acid phosphatase (ACP) increased, and the aspartate aminotransferase (AST) decreased; AST increased in plasma. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were unchanged in the liver, muscle, and plasma. Glycogen stores and the energetic metabolites as glucose, lactate, and pyruvate decrease in the liver; pyruvate decreased in plasma and lactate decreased in muscle. Ammonia levels increased and protein concentration decreased in plasma. CE alters liver morphology by causing hepatocyte intracellular disorder, obstructive cholestasis, and dysfunction in the activity of key liver enzymes. The increasing energy demand implies glucose mobilization and metabolic adjustments maintaining protein preservation and lipid recruitment to supply the needs for detoxification allowing fish survival.

Nanoparticles Loaded with Essential Oil from Zanthoxylum riedelianum Engl. Leaves: Characterization and Effects on Bemisia tabaci Middle-East Asia Minor 1.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle-East Asia Minor 1 is a major pest of agricultural production systems. It is controlled by synthetic insecticides. Essential oils are promising eco-friendly alternatives. This study developed and characterized nanoparticles loaded with essential oils of Zanthoxylum riedelianum Engl. (Rutaceae) leaves and evaluated their potential for B. tabaci management. The essential oil exhibited an average yield of 0.02% (w w-1) and showed as major components γ-elemene (24.81%), phytol (18.16%), bicyclogermacrene (16.18%), cis-nerolidol (8.26%), and D-germacrene (6.52%). Characterization of the nanoparticles showed a pH between 4.5 and 6.7, a zeta potential of approximately - 25 mV, particle-size distribution ranging from 450 to 550 nm, and encapsulation efficiency close to 98%. The nanoencapsulation was an efficient process that provided photostability against photodegradation. Bioassays with crude and nanoencapsulated essential oils significantly reduced the number of nymphs and eggs of B. tabaci, with the best results observed at concentrations of 5 and 2% (v v-1). Our results demonstrated that essential oils from Z. riedelianum can be nanoformulated resulting in a stable product while maintaining their biological activity against B. tabaci Middle-East Asia Minor 1.

Dynamics of Growth and Egg Traits in Three Dietary Balanced Protein Scenarios Applied for Laying Hens.

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids. Then, two experimental feeds were formulated to contain 20% above or below the dietary BP used in the standard feed. The responses evaluated were cumulated feed intake (g), daily feed intake (g/day), body weight (g), body composition (g of protein, fat, and ash), hen-housed egg production (%/hen-housed), egg production (%), egg weight (g), egg mass (g), and egg components (percentages of yolk, albumen, and eggshell). The dietary BP influenced the body composition, egg production, egg weight, and egg mass of white laying hens. The increase in dietary BP was related to an increase in body contents and egg weight, whereas hens consuming the low dietary balanced protein presented a lower body weight, leaner, and produced smaller eggs.

Insecticidal activity of copper (II) complexes with flavanone derivatives.

In this work, we describe the insecticidal activity against Spodoptera frugiperda of flavanone derivatives (naringin, naringenin and hesperidin) complexed to copper (II). For the assays, the compounds were incorporated into an artificial diet and offered to S. frugiperda during its larval period. The duration of larval and pupal phases, the weight of pupae and the percentage of dead insects at the end of the larval phase were evaluated. Among the tested compounds, the free flavanones 1 and 3 and the complexes 4 and 6 showed a shortening of the larval phase when compared to the control. Complex 9 showed the highest toxicity, with 96.66% larval mortality. This is the first report on the insecticidal activity of the Cu2+ complexes of the flavanones naringin, naringenin and hesperidin.[Formula: see text].

Effect of feed restriction on the maintenance energy requirement of broiler breeders.

OBJECTIVE: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition. METHODS: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO2/VO2 ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software. RESULTS: The daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg0.75/d) and CO2 production (+2.2 L/kg0.75/d). That resulted in a higher FHP 359±14 kJ/kg0.75/d for T2 than T1 296±17.23 kJ/kg0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1. CONCLUSION: The birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

Encapsulation of B. bassiana in Biopolymers: Improving Microbiology of Insect Pest Control.

The fungus Beauveria bassiana is widely used for pest control; however, biostability and dispersion for broth pulverization are limiting factors for its application in the field. In this context, formulation techniques such as microencapsulation are viable alternatives. The aim of this work is to optimize B. bassiana formulations by spray dryer and evaluate its stability and biological activity against Spodoptera cosmioides compared to ionic gelatinization formulations. The fungus was biocompatible with all evaluated biopolymers (lignin, cellulose, starch, humic substances, and alginate). The encapsulation by spray drying was optimized by factorial design in an inlet and outlet air temperature of 120°C and 68°C, respectively; aspirator rate of 35 m3·h-1, feed flow rate of 12 mL·min-1; and drying gas flow at 35 L·h-1. The ionic gelation capsules were obtained using a 0.5% quantity of conidia in a 1% sodium alginate solution dropped into a 0.5 mol·L-1 CaCl2 solution using a peristaltic pump. Spray drying provided smaller microcapsules than those by ionic gelation. Both techniques produced more stable conidia when exposed to temperature and UV-radiation than non-formulated B. bassiana. The formulations prepared by spray drying showed gains at aqueous dispersion. Biological assays against Spodoptera cosmioides showed a mortality rate of up to 90%. These results demonstrate the suitability of encapsulating B. bassiana conidia stably in aqueous dispersion without loss of viability and virulence.

Octahedral ruthenium and magnesium naringenin 5-alkoxide complexes: NMR analysis of diastereoisomers and in-vivo antibacterial activity against Xylella fastidiosa.

Although many copper-based antimicrobial compounds have been developed to control pathogenic bacteria and fungi in plants and applied for crop protection, there is evidence that several plant pathogens have developed resistance to copper-based antimicrobial compounds, including some Xanthomonas species. Xylella is a bacterial genus belonging to the Xanthomonas family; and X. fastidiosa, which is responsible for citrus variegated chlorosis (CVC) in sweet orange, may develop resistance to one or more copper-based antimicrobials. Because of the time required for the development and approval of new antimicrobials for commercial use, the discovery of novel bactericidal compounds is essential before the development of resistance to the antimicrobials currently in use becomes widespread. Here, we explored the antimicrobial potential of two newly synthesized antimicrobials complexes and one natural compound against X. fastidiosa. Several nuclear magnetic resonance (NMR) assays with high resolution and sensitivity were developed to identify new diastereoisomers in the context of octahedral ruthenium - [Ru(narin)(phen)2]PF6-and magnesium naringenin 5-alkoxide - [Mg(narin)(phen)2]OAc - complexes, obtained in the present work. The NMR assays proved to be powerful tools for the identification of isomers in metal complexes. Moreover, a protocol for the in-vivo determination of the effects of these complexes against X. fastidiosa was developed. The main trunks of X. fastidiosa infected plants were injected with the two complexes as well as with the limonoid azadirachtin using a syringe; the number of bacterial cells in the plants following treatment was estimated via real-time quantitative PCR (qPCR). Importantly, the administration of both complexes and of azadirachtin drastically reduced the number of X. fastidiosa cells in vivo.

Lycium barbarum polysaccharide fraction associated with photobiomodulation protects from epithelium thickness and collagen fragmentation in a model of cutaneous photodamage.

Ultraviolet radiation (UVR) is the major etiologic agent of cutaneous photoaging, and different strategies are used to prevent and treat this condition. The polysaccharide fraction (LBPF) isolated from Lycium Barbarum fruits (goji berry) contains several active ingredients with antioxidant, immune system modulation, and antitumor effects. In addition, the photobiomodulation (PBM) is widely applied in photoaging treatment. This study investigated the effects of LBPF and PBM against the UVR-induced photodamage in the skin of hairless mice. The mice were photoaged for 6 weeks in a chronic and cumulative exposure regimen using a 300-W incandescent lamp that simulates the UVR effects. From the third to the sixth week of photoaging induction, the animals received topical applications of LBPF and PBM, singly or combined, in different orders (first LBPF and then PBM and inversely), three times per week after each session of photoaging. After completion of experiments, the dorsal region skin was collected for the analysis of thickness, collagen content, and metalloproteinases (MMP) levels. A photoprotective potential against the increase of the epithelium thickness and the fragmentation of the collagen fibers was achieved in the skin of mice treated with LBPF or PBM singly, as well as their combination. All treatments maintained the skin collagen composition, except when PBM was applied after the LBPF. However, no treatment protected against the UVR-induced MMP increase. Taken together, we have shown that the LBPF and PBM promote a photoprotective effect in hairless mice skin against epidermal thickening and low collagen density. Both strategies, singly and combined, can be used to reduce the UVR-induced cutaneous photoaging.

Avocado kernels, an industrial residue: a source of compounds with insecticidal activity against silverleaf whitefly.

Fruit processing waste, such as kernels (endocarp + seed) of avocado [Persea americana Mill. (Lauraceae)], could be used as raw material in the preparation of botanical insecticides. In light of this potential, this study assessed the insecticidal action of extracts and fractions from kernels of two avocado cultivars (Breda and Margarida) on Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B, an important pest species in tropical conditions. Ethanolic and aqueous extracts prepared from kernels of P. americana, regardless of the plant cultivar used, caused promising insecticidal activity to whitefly nymphs. Based on yield in crude extracts [10.32 and 9.85% (w/w), respectively, for cultivars Breda and Margarida], on the bioassay results with crude extracts and on the chemical profiles, the ethanolic extract of kernels of P. americana cv. Breda was chose for the continuation of the study. Thus, the ethanolic extract of kernels of cv. Breda (LC50 = 197.84 ppm and LC90 = 567.19 ppm) was selected and subjected to fractionation by the liquid-liquid partition technique. The hexane and dichloromethane fractions of this extract caused significant mortality of nymphs. The analysis using the ultraviolet (UV) and hydrogen nuclear magnetic resonance (1H NMR) showed the presence of long-chain aliphatic compounds (alkanols or acetogenins of Lauraceae), alkylfurans (or avocadofurans), and unsaturated fatty acids in these fractions, which are possibly related to bioactivity observed in B. tabaci, besides saccharides. The results show that kernels of P. americana are promising sources of compounds with insecticidal action for the control of B. tabaci biotype B, a great opportunity to transform environmental problems into eco-friendly solutions to agriculture.

Multi-biomarkers approach to access the impact of novel metal-insecticide based on flavonoid hesperidin on fish.

Aquatic ecosystem health is the main concern to increasing pesticides application to control agricultural pests as it is the ultimate receptor of such materials. This study evaluated the impact of new metal-insecticide, the [Mg(hesp)2(phen)], referred as MgHP, on fish using physiological, genetic, biochemical, and morphological biomarkers. The fish, Prochilodus lineatus, was exposed to 0 (control), 1, 10, 100, 1000 µg L-1 MgHP, for 24 and 96 h. MgHP was not lethal but caused genotoxicity, altered hematological variables and, the activity of antioxidant and biotransformation enzymes and histology of liver, depending on concentration and time exposure. Hematocrit and erythrocyte number (RBC) increased without change hemoglobin content resulting in changes in hematimetric indexes after 24 h; after 96 h, only RBC was changed. Erythrocyte nuclear abnormalities and crenate cells increased after 24 h but, not after 96 h. Erythrocytes and hepatocytes indicated instability in DNA integrity however, the absence of micronuclei suggested DNA damage repairment. After 24 h, the antioxidant defense system and the phase II biotransformation enzyme was responsiveness and catalase activity decreased at high MgHP concentrations; the antioxidant response was triggered after 96 h. Hepatocyte hypertrophy, intracellular cytoplasmic substances, cytoplasm degeneration, melanomacrophage and hyperemia increased in fish exposed from 10 µg L-1 to higher MgHP concentrations; the organ alteration index increased as MgHP concentration increased showing dose-dependence. Most of hematological and genotoxic effects occurred after 24 h exposure evidencing potential recover capability of organism by activation of the antioxidant defense system and DNA repairment mechanisms. Nevertheless, the histopathological changes in the liver was maintained over time at high MgHP concentrations, a concentration usually no environmental relevant. In conclusion, this data reinforced the importance of continuing research on MgHP effects in other organisms considering the promising use of such compound to control the leaf-cutter ants and other insects.

Biochemical and morphological biomarker responses in the gills of a Neotropical fish exposed to a new flavonoid metal-insecticide.

The flavonoid metal-insecticide [Mg(hesp)2(phen)], denominated MgHP, has high potential for controlling agricultural pests. If applied in large scale, it may reach aquatic ecosystems and be harmful to the biota. This study evaluated the effects of MgHP in the gills of the Neotropical fish, Prochilodus lineatus by determining the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione s-transferase (GST), and the levels of glutathione (GSH) and lipid peroxidation (LPO) after 24 and 96 h exposure to 0, 1, 10, 100 and 1000 µg L-1. The histopathological changes with emphases to mitochondria-rich cells (MRC) were evaluated as well. After 24 h exposure the enzyme activities and the GSH and LPO levels were unchanged however, after 96 h exposure to high MgHP concentration (1000 µg L-1), the GST activity and GSH levels increased. Oxidative stress measured as LPO levels did not occur after MgHP exposure in both periods. Gill tissue alterations increased after MgHP exposure to 10, 100 and 1000 µg L-1. Cellular atrophy, pillar cells changes, filament epithelium hyperplasia and hypertrophy, lamellar epithelium hyperplasia were the most frequent histopathology. MRC in the filament epithelium decreased after exposure to 24 h and increased after 96 h indicating possible transitory osmo-ionic disruption. P. lineatus exhibited high tolerance to MgHP. The increased GST activity and GSH levels after 96 h exposure suggested possible MgHP accumulation and concentration- and time-dependent response. Histopathology in the gills of exposed fish occurred at high MgHP concentrations. These results suggested that the MgHP into water, at high concentrations, affect the gills by changing GST activity, GSH levels and histology being useful biomarkers for MgHP water contamination.

Evaluation of the microencapsulation of orange essential oil in biopolymers by using a spray-drying process.

Essential oils are volatile compounds commonly used by several industries, easily degradable, which restrains their applications. Therefore, we developed and validated a methodology for producing microcapsules loaded with orange essential oil, using a spray-drying process. The experimental design results showed that the combination between a low flow transfer rate (0.15 L h-1) of the colloidal suspension, a higher drying air flow rate (536 L h-1), and an inlet air temperature of 150 °C to the spray-dryer were the most important parameters for the atomization efficiency. The method optimization resulted in microcapsules with powder recovery between 7.6 and 79.9% (w w-1), oil content ranging from 8.9 to 90.4% (w w-1), encapsulation efficiency between 5.7 and 97.0% (w w-1), and particle sizes with a high frequency of distribution less than 4 µm. In these experiments, gelatin and lignin were evaluated as biopolymers of encapsulation. We also developed an analytical method using headspace gas chromatography. The matrix effects could be addressed by using matrix-matched calibration curves. The chromatographic analysis was linear and selective for D-limonene between 0.025 and 3.00 µg mL-1, with correlation coefficients higher than 0.99. The analytical method had limits of detection and quantitation of 0.024 and 0.073 mg g-1 for gelatin and 0.039 and 0.119 mg g-1 for lignin, respectively.

Polysaccharide-rich hydrogel formulation combined with photobiomodulation repairs UV-induced photodamage in mice skin.

Prolonged skin exposure to ultraviolet radiation (UVR) induces premature aging in both the epidermis and the dermis. Chronic exposure to UVR induces the activation of mitogen-activated protein kinase (MAPK) signaling pathway, activating c-Jun, c-Fos expression, and transcription factor of AP-1 activating protein. AP-1 activation results in the positive induction of matrix metalloproteinase (MMP) synthesis, which degrade skin collagen fibers. Polysaccharides from the fruit of Lycium barbarum (LBP fraction) have a range of activities and have been demonstrate to repair the photodamage. In different approaches, laser application aims to recover the aged skin without destroying the epidermis, promoting a modulation, called photobiomodulation (PBM), which leads to protein synthesis and cell proliferation, favoring tissue repair. Here we developed a topical hydrogel formulation from a polysaccharide-rich fraction of Lycium barbarum fruits (LBP). This formulation was associated with PBM (red laser) to evaluate whether the isolated and combined treatments would reduce the UVR-mediated photodamage in mice skin. Hairless mice were photoaged for 6 weeks and then treated singly or in combination with LBP and PBM. Histological, immunohistochemistry, and immunofluorescence analyses were used to investigate the levels of c-Fos, c-Jun, MMP-1, -2, and -9, collagen I, III, and FGF2. The combined regimen inhibited UVR-induced skin thickening, decreased the expression of c-Fos and c-Jun, as well as MMP-1, -2, and -9 and concomitantly increased the levels of collagen I, III, and FGF2. The PBM in combination with LBP treatment is a promising strategy for the repair of photodamaged skin, presenting potential clinical application in skin rejuvenation.

Biochemical and genotoxic biomarkers and cell cycle assessment in the zebrafish liver (ZF-L) cell line exposed to the novel metal-insecticide magnesium-hespiridin complex.

The flavonoid metal-insecticide magnesium-hesperidin complex (MgHP) has recently been considered as a novel insecticide to replace some persistent pesticides. However, it is important to evaluate its action on non-target species, mainly those living in an aquatic environment, as these ecosystems are the final receptors of most chemicals. Reactive oxygen species, antioxidant and oxidative stress biomarkers, genotoxicity as well as cell cycle was evaluated in the liver cell line from zebrafish (Danio rerio; ZF-L) exposed to 0, 0.1, 1, 10, 100 and 1000 ng mL-1 MgHP. MgHP affected cell stability by increasing reactive oxygen species (ROS) in both exposure times (24 and 96 h) at high concentrations. Catalase (CAT) activity decreased after 24 h exposure, and glutathione and metallothionein values increased, avoiding the lipid peroxidation. Genotoxicity increased as MgHP concentration increased, after 24 h exposure, exhibiting nuclear abnormalities; it was recovered after 96 h exposure, evidencing possible stimulation of DNA repair mechanisms. The alteration in the cell cycle (increasing in the Sub-G1 phase and decreasing in the S-phase) was associated with chromosomal instability. In conclusion, the responses of ROS and the antioxidant defense system depended on MgHP concentration and time exposure, while DNA exhibited some instability after 24 h exposure, which was recovered after 96 h.

Synthesis, Characterization, and Low-Toxicity Study of a Magnesium(II) Complex Containing an Isovanillate Group.

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.

Mycotoxins from Fusarium proliferatum: new inhibitors of papain-like cysteine proteases.

Papain-like cysteine proteases (PLCPs) in plants are essential to prevent phytopathogen invasion. In order to search for cysteine protease inhibitors and to investigate compounds that could be associated to pineapple Fusarium disease, a chemistry investigation was performed on Fusarium proliferatum isolated from Ananas comosus (pineapple) and cultivated in Czapek medium. From F. proliferatum extracts, nine secondary metabolites were isolated and characterized by nuclear magnetic resonance spectroscopy and mass spectrometry experiments: beauvericin (1), fusaric acid (2), N-ethyl-3-phenylacetamide (3), N-acetyltryptamine (4), cyclo(L-Val-L-Pro) cyclodipeptide (5), cyclo(L-Leu-L-Pro) cyclodipeptide (6), cyclo(L-Leu-L-Pro) diketopiperazine (7), 2,4-dihydroxypyrimidine (8), and 1H-indole-3-carbaldehyde (9). Compounds 1, 3, and 6 showed significant inhibition of papain, with IC50 values of 25.3 ± 1.9, 39.4 ± 2.5, and 7.4 ± 0.5 µM, respectively. Compound 1 also showed significant inhibition against human cathepsins V and B with IC50 of 46.0 ± 3.0 and 6.8 ± 0.7 µM, respectively. The inhibition of papain by mycotoxins (fusaric acid and beauvericin) may indicate a mechanism of Fusarium in the roles of infection process.