The Existing Drug Nifuroxazide as an Antischistosomal Agent: In Vitro, In Vivo, and In Silico Studies of Macromolecular Targets

Schistosomiasis is a parasitic disease that afflicts approximately 250 million people worldwide. There is an urgent demand for new antiparasitic agents because praziquantel, the only drug available for the treatment of schistosomiasis, is not universally effective and may derail current progress toward the WHO goal of eliminating this disease as a public health problem by 2030. Nifuroxazide (NFZ), an oral nitrofuran antibiotic, has recently been explored to be repurposed for parasitic diseases. Here, in vitro, in vivo, and in silico studies were conducted to evaluate the activity of NFZ on Schistosoma mansoni. The in vitro study showed significant antiparasitic activity, with 50% effective concentration (EC50) and 90% effective concentration (EC90) values of 8.2 to 10.8 and 13.7 to 19.3 μM, respectively. NFZ also affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg of body weight) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden (~40%). In patent infection, NFZ achieved a high reduction in the number of eggs (~80%), but the drug caused a low reduction in the egg burden of animals with prepatent infection. Finally, results from in silico target fishing methods predicted that serine/threonine kinases could be one of the potential targets for NFZ in S. mansoni. Overall, the present study revealed that NFZ possesses antischistosomal properties, mainly in terms of egg burden reduction in animals with patent S. mansoni infection. IMPORTANCE The increasing recognition of the burden imposed by helminthiasis, associated with the limited therapeutic arsenal, has led to initiatives and strategies to research and develop new drugs for the treatment of schistosomiasis. One of these strategies is drug repurposing, which considers low-risk compounds with potentially reduced costs and shorter time for development. In this study, nifuroxazide (NFZ) was evaluated for its anti-Schistosoma mansoni potential through in vitro, in vivo, and in silico studies. In vitro, NFZ affected worm pairing and egg production and induced severe damage to the tegument of schistosomes. In vivo, a single oral dose of NFZ (400 mg/kg) to mice harboring either prepatent or patent S. mansoni infection significantly reduced the total worm burden and egg production. In silico investigations have identified serine/threonine kinases as a molecular target for NFZ. Collectively, these results implied that NFZ might be a potential therapeutic candidate for the treatment of schistosomiasis.

Ingestion of a moderate dose of alcohol enhances physical exercise-induced changes in blood lactate concentration

The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.

Dietary administration of a commercial mixed-species probiotic improves growth performance and modulates the intestinal immunity of tilapia, Oreochromis niloticus

The growth performance, immunological status, intestinal morphology and microbiology of tilapia, Oreochromis niloticus, were investigated after dietary administration of the commercial probiotic AquaStar(®) Growout. Tilapia (29.02 ± 0.33 g) were split into five treatments; control (CON), 1.5 g kg(-1) probiotic (PRO-1.5), 3 g kg(-1) probiotic (PRO-3), pulsed probiotic feeding (PRO-PULSE) or an initial probiotic feed followed by control feeding (PRO-INI). After six weeks of experimental feeding, fish fed PRO-3 displayed significantly higher final weight, weight gain and SGR compared to the CON or PRO-INI treatments. Supplementation of the probiotic at this dose induced an up-regulation of intestinal caspase-3, PCNA and HSP70 mRNA levels compared to the CON fed fish. Immuno-modulatory pathways were also affected; significantly higher expression of TLR2, pro-inflammatory genes TNFα and IL-1β, and anti-inflammatory genes IL-10 and TGFβ suggest that the probiotic may potentiate a higher state of mucosal tolerance and immuno-readiness. Histological appraisal revealed significantly higher numbers of intraepithelial leucocytes in the intestine of PRO-3 fed fish compared with treatments CON, PRO-PULSE and PRO-INI but not PRO-1.5. Additionally, fish receiving PRO-3 had a significantly higher abundance of goblet cells in their mid-intestine when compared with fish from all other treatments. Together, these data suggest that continuous provision of AquaStar(®) Growout at 3 g kg(-1) can improve tilapia growth and elevate the intestinal immunological status of the host.

Diets Containing α-Linolenic (ω3) or Oleic (ω9) Fatty Acids Rescues Obese Mice From Insulin Resistance

Subclinical systemic inflammation is a hallmark of obesity and insulin resistance. The results obtained from a number of experimental studies suggest that targeting different components of the inflammatory machinery may result in the improvement of the metabolic phenotype. Unsaturated fatty acids exert antiinflammatory activity through several distinct mechanisms. Here, we tested the capacity of ω3 and ω9 fatty acids, directly from their food matrix, to exert antiinflammatory activity through the G protein-coupled receptor (GPR)120 and GPR40 pathways. GPR120 was activated in liver, skeletal muscle, and adipose tissues, reverting inflammation and insulin resistance in obese mice. Part of this action was also mediated by GPR40 on muscle, as a novel mechanism described. Pair-feeding and immunoneutralization experiments reinforced the pivotal role of GPR120 as a mediator in the response to the nutrients. The improvement in insulin sensitivity in the high-fat substituted diets was associated with a marked reduction in tissue inflammation, decreased macrophage infiltration, and increased IL-10 levels. Furthermore, improved glucose homeostasis was accompanied by the reduced expression of hepatic gluconeogenic enzymes and reduced body mass. Thus, our data indicate that GPR120 and GPR40 play a critical role as mediators of the beneficial effects of dietary unsaturated fatty acids in the context of obesity-induced insulin resistance.

CARACTERIZAÇÃO FÍSICO-QUÍMICA E BACTERIOLÓGICA DOS RESÍDUOS DE ETA: A IMPORTÂNCIA DO SEU ESTUDO

The treatment of water from Anapolis - GO generates as major waste sludge in the decanter after alkalinization, coagulation, flocculation and sedimentation, and washing water after backwashing of the filters themselves. This work was carried out physical-chemical and bacterial waste by means of the methods prescribed in Standard Methods for the Examination of Water and Wastewater. The results indicate the need for treatment and proper disposal of sludge to the decanter, as its parameters do not meet the standards required for discharge of effluents into water bodies. While the characteristics of the wash water filters are close to the standards of water quality class 2, set by the CONAMA Resolution 357. These results demonstrate the need and the importance to waste characterization.

Hypothalamic AMPK activation blocks lipopolysaccharide inhibition of glucose production in mice liver

Endotoxic hypoglycaemia has an important role in the survival rates of septic patients. Previous studies have demonstrated that hypothalamic AMP-activated protein kinase (hyp-AMPK) activity is sufficient to modulate glucose homeostasis. However, the role of hyp-AMPK in hypoglycaemia associated with endotoxemia is unknown. The aims of this study were to examine hyp-AMPK dephosphorylation in lipopolysaccharide (LPS)-treated mice and to determine whether pharmacological hyp-AMPK activation could reduce the effects of endotoxemia on blood glucose levels. LPS-treated mice showed reduced food intake, diminished basal glycemia, increased serum TNF-α and IL-1β levels and increased hypothalamic p-TAK and TLR4/MyD88 association. These effects were accompanied by hyp-AMPK/ACC dephosphorylation. LPS-treated mice also showed diminished liver expression of PEPCK/G6Pase, reduction in p-FOXO1, p-AMPK, p-STAT3 and p-JNK level and glucose production. Pharmacological hyp-AMPK activation blocked the effects of LPS on the hyp-AMPK phosphorylation, liver PEPCK expression and glucose production. Furthermore, the effects of LPS were TLR4-dependent because hyp-AMPK phosphorylation, liver PEPCK expression and fasting glycemia were not affected in TLR4-mutant mice. These results suggest that hyp-AMPK activity may be an important pharmacological target to control glucose homeostasis during endotoxemia.

Hypothalamic inhibition of acetyl-CoA carboxylase stimulates hepatic counter-regulatory response independent of AMPK activation in rats

BACKGROUND

Hypothalamic AMPK acts as a cell energy sensor and can modulate food intake, glucose homeostasis, and fatty acid biosynthesis. Intrahypothalamic fatty acid injection is known to suppress liver glucose production, mainly by activation of hypothalamic ATP-sensitive potassium (K(ATP)) channels. Since all models employed seem to involve malonyl-CoA biosynthesis, we hypothesized that acetyl-CoA carboxylase can modulate the counter-regulatory response independent of nutrient availability.

METHODOLOGY/PRINCIPAL FINDINGS

In this study employing immunoblot, real-time PCR, ELISA, and biochemical measurements, we showed that reduction of the hypothalamic expression of acetyl-CoA carboxylase by antisense oligonucleotide after intraventricular injection increased food intake and NPY mRNA, and diminished the expression of CART, CRH, and TRH mRNA. Additionally, as in fasted rats, in antisense oligonucleotide-treated rats, serum glucagon and ketone bodies increased, while the levels of serum insulin and hepatic glycogen diminished. The reduction of hypothalamic acetyl-CoA carboxylase also increased PEPCK expression, AMPK phosphorylation, and glucose production in the liver. Interestingly, these effects were observed without modification of hypothalamic AMPK phosphorylation.

CONCLUSION/SIGNIFICANCE

Hypothalamic ACC inhibition can activate hepatic counter-regulatory response independent of hypothalamic AMPK activation.

Solidago chilensis Meyen hydroalcoholic extract reduces JNK/IκB pathway activation and ameliorates insulin resistance in diet-induced obesity mice

Hydroalcoholic extract of Solidago chilensis (Sc) is employed in popular medicine to treat inflammatory disease. The low-grade proinflammatory state and the activation of serine/threonine kinases in adipose tissue, like c-jun kinase (JNK) and IKK, and transcription factors, have an important role in obesity-associated insulin resistance. The aim of this study was to further investigate the effects of the Sc extract on glucose homeostasis in diet-induced obesity mice. Male Swiss mice were randomized to three groups: a control group (C) fed with standard laboratory chow; a group with an experimental high-fat diet (HFD); and a group fed with a high-fat (45% kcal from fat) diet + extract of Sc (via intraperitoneal, 3 mg/kg) (ScHFD). The dietary treatment lasted for eight weeks. Subsequently, the expression and phosphorylation of proteins of interest in the liver, hypothalamus and skeletal muscle were evaluated by Western blot analysis. Body weight, epididymal fat pad mass and liver triglycerides were higher in HFD than in control mice, but these parameters were reduced by intraperitoneal administration of the extracts (3 mg/kg) to the HFD group. AKT phosphorylation stimulated by insulin in the liver, hypothalamus and skeletal muscle was higher in ScHFD as compared with HFD mice. Additionally, liver expression of phosphoenolpyruvate carboxykinase (PEPCK) and fatty acid synthase were lower in ScHFD as compared with HFD mice. Nuclear factor κB, p-IκB and p-JNK levels were higher in HFD when compared with control mice, but they were lowered by treatment with extract (ScHFD). In addition, in db/db mice, Sc extract also improved liver AKT phosphorylation stimulated by insulin and reduced PEPCK expression. The data presented herein show that Sc improves AKT activation. This effect may be promoted by reduction of the proinflammatory pathway in the liver and hypothalamus. Therefore, systemic action of the Sc components may contribute to improve obesity-associated pathophysiology.

Central leptin action improves skeletal muscle AKT, AMPK, and PGC1 alpha activation by hypothalamic PI3K-dependent mechanism

Central leptin action requires PI3K activity to modulate glucose homeostasis and peripheral metabolism. However, the mechanism behind this phenomenon is not clearly understood. We hypothesize that hypothalamic PI3K activity is important for the modulation of the AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) pathway, PGC1 alpha, and AKT in skeletal muscle (SM). To address this issue, we injected leptin into the lateral ventricle of rats. Hypothalamic JAK2 and AKT were activated by intracerebroventricular (ICV) injection of leptin in a time-dependent manner. Central leptin improved tolerance to glucose (GTT), increased PGC1 alpha expression, and AKT, AMPK, ACC and JAK2 phosphorylation in the soleus muscle. Previous ICV administration of either LY294002 or propranolol (IP) blocked these effects. We concluded that the activation of the hypothalamic PI3K pathway is important for leptin-induced AKT phosphorylation, as well as for active catabolic pathway through AMPK and PGC1 alpha in SM. Thus, a defective leptin signalling PI3K pathway in the hypothalamus may contribute to peripheral resistance to insulin associated to diet-induced obesity.

Utilization of the sex-linked gene for imperfect albinism (S*ALS). 2. Yolk sac lipid utilization

The gene for sex-linked imperfect albinism (S*ALS) has been associated with reduced early growth and slow utilization of the yolk sac contents. Neonatal growth was studied using albino and nonalbino full siblings that were dissected at 2-d intervals from Day 16 of incubation to 7 d after hatch. Fatty acid composition of the yolk, yolk sac membrane, and liver was determined to study neonatal lipid metabolism. At hatch, albinos had similar BW and lower (P < 0.01) liver weights, suggesting reduced lipid transfer from the yolk sac during late incubation. Nonalbinos started gaining weight at 3 d after hatch, 1 d earlier than albino chicks. Albinos had reduced growth (P < 0.01), larger yolk sacs (P < 0.05), and similar (P > 0.05) yolk uptake from hatch to 7 d after hatch. Albino chicks also had lower body temperatures (P < 0.05) at 2, 4, and 6 d after hatch. Albinos had a slower rate of transfer of yolk lipids to the developing embryo in the last 2 d of incubation. The fatty acid composition of the yolk and yolk sac membrane was similar for both genotypes during the last 3 d of incubation, except for the level of stearic acid, which was higher (P < 0.05) for nonalbinos on Day 18 of incubation for both tissues and at 1 d after hatch for the yolk. The fatty acid composition of the livers of albinos and nonalbinos were similar (P > 0.05) during the neonatal period. For both genotypes, the hepatic level of oleic acid increased to Day 20 of incubation, remained constant to 1 d after hatch, and decreased sharply thereafter. The major difference between the genotypes was a slower rate of transfer of yolk lipids to the developing albino embryo in the last 2 d of incubation.

Utilization of the sex-linked gene for imperfect albinism (S*ALS). 1. Effect of early weight loss on chick metabolism

The sex-linked gene for imperfect albinism (S*ALS) has been associated with slow early growth in some trials but not in others. Albino (59) and nonalbino (73) chicks were raised to 3 d of age to study early growth. At 3 d of age, plasma beta-hydroxybutyrate (beta-HBA) levels were measured and the chicks were euthanatized and dissected to measure liver, gall bladder, and yolk sac weights. Fatty acids of the liver and the yolk sac were also analyzed. On average, albino chicks lost weight between hatch and 3 d of age and nonalbinos gained weight (-2.41 vs 0.74 g/d, P < 0.01). At 3 d of age, livers from albinos contained higher (P < 0.01) levels of docosahexaenoic acid than those of nonalbinos, likely reflecting the dependence on yolk sac nutrients of albinos and on dietary lipids of nonalbinos at this time. Albinos had lower body temperatures (P < 0.01), liver weights (P < 0.01) and gall bladder weights (P < 0.05), and heavier yolk sacs (P < 0.01) than did nonalbinos. Plasma levels of beta-HBA were higher (P < 0.01) for albinos than for nonalbinos. At similar body weights, chicks of both genotypes had similar body temperatures, gall bladder weights, and plasma beta-HBA levels. Linear regressions indicated that in albinos weight loss is associated with larger yolk sacs, smaller livers, larger gall bladders, lower body temperatures, and higher levels of beta-HBA. Yolk sac utilization seemed to be correlated with activation of the digestive system. The inability of starving chicks to use the yolk sac nutrients while lipolysis is taking place suggests that yolk sac absorption does not respond to lipolytic hormones. Because under certain conditions a large proportion of albinos (90% in this experiment) show the symptoms of the starve-out syndrome, the S*ALS gene could serve as a model for the study of this syndrome.

A method for separating sex-linked imperfect albino (S*ALS) and nonalbino embryos before hatch

The feasibility of using the sex-linked gene for imperfect albinism (S*ALS) to sex chicks during incubation by candling was studied. With this technique, the dark eye of nonalbino embryos can be positively identified. Two trials were performed. In a first trial, 66.5 and 89.5% of the 254 nonalbino and 210 albino chicks produced in four hatches were correctly identified by candling at 7 d of incubation. Of 191 eggs predicted to be nonalbinos, 22 were albinos, resulting in an overall accuracy of 88.5% for identification of nonalbino embryos. In a second trial, the accuracy of the technique from 7 to 10 d of incubation was evaluated. Increased age resulted in a tendency for lower accuracy, but candling at 8, 9, or 10 d of incubation allowed identification of a greater (P < 0.05) proportion of the nonalbino population than at 7 d of incubation. Candling at 8 d of incubation allowed identification of nonalbinos and albinos with an accuracy of 81.3 and 84.9%, respectively, suggesting that the ALS gene could be used to sex chicks during incubation when used in a sex-linked cross. This technique may prove advantageous to the laying industry because of savings of incubator and hatcher space. The males of commercial layer lines are normally killed at hatch. Reducing the number that hatch by eliminating them before 10 d of incubation could diminish animal welfare concerns.

IR studies on carrageenan of Ahnfeltia concinna, a marine red alga

The principal polysaccharide of Ahnfeltia concinna gave IR absorptions at 1240, 930, 845-850, and 805 cm-1, all typical of a carrageenan. The polysaccharide was separated into soluble and insoluble fractions with potassium chloride.