Effects of subchronic exposure to environmentally relevant concentrations of the herbicide atrazine in the Neotropical fish Astyanax altiparanae

Atrazine (ATZ) is among the most widely used herbicides in the world, and yet it has a potential to contaminate aquatic environments due to pesticide leaching from agricultural areas. In the Neotropical region, studies about the effects of this herbicide in native aquatic wildlife is scarce.Our study aimed at investigating the effects of a 30-day exposure to a commercial atrazine formulation on oxidative stress parameters, histopathology in testis and liver, and hormone levels in males and female of yellow-tailed tetra fish (Astyanax altiparanae). Adults were exposed to low but environmentally relevant concentrations of atrazine as follows: 0 (CTL-control), 0.5 (ATZ0.5), 1 (ATZ1), 2 (ATZ2) and 10 (ATZ10) μg/L. Our results showed decreased GST activity in gills in all groups of exposed animals and increased CAT activity in gills from the ATZ10 group. In the liver, there was an increase in lipid peroxidation in fish from ATZ1 and ATZ2 groups. Histological analysis of the liver showed increased percentage of sinusoid capillaries in ATZ2 fish, increased vascular congestion in ATZ1 and increased leukocyte infiltration in the ATZ10 group. Hepatocyte diameter analysis revealed a decrease in cell size in all groups exposed to ATZ, and a decrease in hepatocyte nucleus diameter in ATZ1, ATZ2 and ATZ10 groups. Endocrine parameters did not show significant changes following ATZ exposure, although an increase of triiodothyronine/thyroxine (T₃/T₄) ratio was observed in ATZ2 fish. Our results provide evidence that even low, environmentally relevant concentrations of ATZ produced oxidative damage and histological alterations in adult yellow-tailed tetra.

Aspects regarding renal morphophysiology of fruit-eating and vampire bats

Bats have adapted to many different feeding habits, which are known to induce morphophysiological adaptations in several tissues, especially those particularly involved with absorption, metabolism and excretion. The common vampire bat (Desmodus rotundus) has a very unique diet (blood), which, among other challenges, seems to pose a risk to their kidneys, due to the increased nitrogen excretion imposed by their remarkably high protein meal. Fruit-eating bats (Artibeus lituratus) consume a high carbohydrate diet and may be taken as a suitable species for this dietary comparative study. Here we aimed at investigating the renal morphology and stereology, kidneys antioxidant capacity, and plasma antidiuretic hormone (ADH) concentrations in adult fruit-eating and vampire bats. Sixteen animals were captured and used in this study, being 8 adult males from each species. Our results showed higher morphological standards of glomerular area, volumetric density of glomeruli, and renal somatic index for vampire bats, as well as higher reactive species of oxygen (ROS) production, such as nitric oxide (NO), higher plasma iron reduction ability (FRAP), higher activity of the antioxidant enzyme glutathione-S-transferase (GST) and a higher malondialdehyde production (MDA) in vampires' kidneys, compared to the fruit-eating species. The activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were higher in fruit-eating bats. Plasma ADH concentrations were not different between species. Taken together, the renal morphophysiology conditions presented by vampire bats might be associated with a high demand for nitrogenous products excretion imposed by protein and iron overload. These features may play an important role on preventing protein-overload nephropathy, allowing vampires to survive under such a unique diet.

Feed contaminated by fumonisin (Fusarium spp.) in chicks has a negative influence on oxidative stress and performance, and the inclusion of curcumin-loaded nanocapsules minimizes these effects

The aim of this study was to determine whether the addition of curcumin (free and encapsulated) to chick feed would minimize the negative effects on health and performance caused by daily intake of fumonisin. We used 50 birds, divided into five treatments: CP, basal diet with 600 mg/kg of fumonisin, with antibiotic and coccidiostatic agent; CU, 600 mg/kg of fumonisin and 50 mg/kg of curcumin; NC5, feed with 600 mg/kg of fumonisin and 5 mg of nano-curcumin/kg of feed; NC10, feed with 600 mg/kg of fumonisin and 10 mg of nano-curcumin/kg of feed; and CN, fumonisin-free diet, with antibiotic and coccidiostatic. We measured weights, weight gain, and serum biochemistry, as well as antioxidant and oxidant activities. Lower body weight and weight gain were observed in chicks that received feed with fumonisin; curcumin did not minimize this negative effect. Lower glucose and triglyceride levels were also observed in the NC10 group, while the highest cholesterol levels were observed in all groups of birds that consumed fumonisin compared to the CN group. Uric acid levels were significantly lower in CP than in CN. Levels of liver enzymes were higher in CP than in CN. The highest levels of thiobarbituric acid reactive substances were found in CP and CU, whereas ROS was higher in CU compared to CN. Superoxide dismutase activity was significantly lower in CP, while glutathione S-transferase activity was higher in the CP group. Catalase activity was lower in groups of birds that consumed fumonisin compared to CN. Taken together, these findings suggest that intake of curcumin-loaded nanocapsules (10 mg/kg) had hepaprotective and antioxidant effects in chicks artificially intoxicated with fumonisin, minimizing the negative effects caused by this mycotoxin.

Influence of maternal labor time on delta-aminolevulinate dehydratase enzyme activity and markers of oxidative stress in newborns

The purpose is to determine markers of oxidative stress related to the longer and shorter duration of labor (DOL) of pregnant women in the umbilical cord blood of neonates, not yet studied. Blood samples from the umbilical cord were collected from pregnant women with normal delivery and classified according to DOL in two groups: a group with DOL less than 310 min (n = 33) and a group with DOL greater than or equal to 310 min (n = 35). The oxidative stress parameters were analyzed by the quantification of thiobarbituric acid reactive substances (TBARS), nitrate/nitrite (NOx), protein thiol groups (P-SH) and non-protein (NP-SH), vitamin C and plasma iron reduction capacity (FRAP), in addition to the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D). The activity of the δ-ALA-D enzyme was shown to be decreased in longer DOL, however, the oxidant parameters and antioxidants were higher in the longer DOL, with the exception of NP-SH that was lower. The longer maternal DOL time is related to the alteration of δ-ALA-D enzyme activity and other parameters in neonates, suggesting an increase in the passage of maternal oxidative markers by umbilical cord blood.

In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits

The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro application was done in five replicates for each concentration in petri dishes in the laboratory. The treated mites were observed at 1, 12, and 24 h post application (PA) for lemon oil effect. In addition, oxidative stress profile was evaluated for the treated mite. Dependent on in vitro results, 20 % lemon oil was used in vivo trial. Twenty-four naturally infected rabbits were divided into three groups of eight: 20 % lemon oil, deltamethrin, and untreated control. The infected parts of rabbits were treated topically once a week for four successive weeks. In vitro application results showed that lemon oil 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h PA. The oxidative stress profile revealed that mites treated with 20 % lemon oil had significantly (P < 0.05) higher hydrogen peroxide and malondialdehyde when compared with mites treated with deltamethrin or distilled water. In vivo application of 20 % lemon oil on naturally infected rabbits showed complete recovery from clinical signs, absence of mite in microscopic examination from the second week of treatment. In addition, productive performance was significantly better than infected untreated group. Also, the treated tissue showed stoppage of scale formation and hair growth faster than deltamethrin-treated rabbits. Consequently, lemon oil has remarkable miticidal activity in vitro and in vivo applications.

Acute exposure to the biopesticide azadirachtin affects parameters in the gills of common carp (Cyprinus carpio)

The biopesticide, azadirachtin (Aza) is less hazardous to the environment, but may cause several toxic effects in aquatic organisms. The Cyprinus carpio (n=12, for all concentrations) after 10days of acclimation under controlled conditions, were exposed at 20, 40, and 60μL/L of Aza during 96h. After this period, fish were anesthetized and euthanized then mucus layer and gills collected. In this study, the effects of exposure to different Aza concentrations were analysed through a set of biomarkers: Na(+)/K(+-)ATPase, lipid peroxidation (TBARS), protein carbonyl (PC), superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase (CAT), glutathione peroxidase (GPx), non-protein thiols (NPSH), ascorbic acid (AsA) and histological parameters and, yet, protein and glucose concentration in the surface area of mucous layer. Na(+)K(+-)ATPase was inhibited at 40 and 60μL/L compared to control. TBARS decreased at 40μL/L compared to control. PC, SOD and GST increased at 60μL/L in comparison to control. CAT increased at 20 and 60μL/L, and GPx increased in all Aza concentrations compared to control. NPSH decreased and AsA increased in all concentrations in comparison to control. Histological analyses demonstrated an increase in the intensity of the damage with increasing Aza concentration. Alterations in histological examination were elevation and hypertrophy of the epithelial cells of the secondary filament, hypertrophy and hyperplasia of the mucous and chlorate cells and lamellar aneurism. Glucose and protein concentrations in mucus layer increased at 60μL/L compared to control. In general, we suggest that 60μL/L Aza concentration affected several parameters causing disruptions carp metabolism.

Dehydroepiandrosterone and 7-oxo-dehydroepiandrosterone in male reproductive health: Implications of differential regulation of human Sertoli cells metabolic profile

Dehydroepiandrosterone (DHEA) is a precursor of androgen synthesis whose action is partially exerted through its metabolites. 7-Oxo-dehydroepiandrosterone (7-oxo-DHEA) is a common DHEA metabolite, non-convertible to androgens, which constitutes a promising therapeutic strategy for multiple conditions. Sertoli cells (SCs) are responsible for the support of spermatogenesis, having unique metabolic characteristics strongly modulated by androgens. Consequently, disruptions in androgen synthesis compromise SCs function and hence male fertility. We aimed to evaluate the effects of DHEA and 7-oxo-DHEA in human SCs (hSCs) metabolism and oxidative profile. To do so, hSCs were exposed to increasing concentrations of DHEA and 7-oxo-DHEA (0.025, 1 and 50 μM) that revealed to be non-cytotoxic in these experimental conditions. We measured hSCs metabolites consumption/production by (1)H NMR, the protein expression levels of key players of the glycolytic pathway by Western blot as well as the levels of carbonyl groups, nitration and lipid peroxidation by Slot blot. The obtained data demonstrated that 7-oxo-DHEA is a more potent metabolic modulator than DHEA since it increased hSCs glycolytic flux. DHEA seem to redirect hSCs metabolism to the Krebs cycle, while 7-oxo-DHEA has some inhibitory effect in this path. The highest 7-oxo-DHEA concentrations (1 and 50 μM) also increased lactate production, which is of extreme relevance for the successful progression of spermatogenesis in vivo. None of these steroids altered the intracellular oxidative profile of hSCs, illustrating that, at the concentrations used they do not have pro- nor antioxidant actions in hSCs. Our study represents a further step in the establishment of safe doses of DHEA and 7-oxo-DHEA to hSCs, supporting its possible use in hormonal and non-hormonal therapies against male reproductive problems.