The impact of yeast-encapsulated orange oil in Aedes aegypti oviposition.

The yeast-encapsulated orange oil (YEOO) is a novel larvicide under development against vector mosquitoes. Despite its efficiency against Aedes aegypti (L.) in small scale experiments, its applicability in vector control can be influenced by other effects on mosquito behaviour or physiology. For this reason, the impact of YEOO particles in mosquito oviposition was evaluated in laboratory and semi-field conditions. Oviposition assays with one gravid Aedes aegypti female were carried under laboratory and semi-field conditions with natural light and temperature fluctuation. For all ovitraps, the number of eggs was manually counted in the wooden paddle and in the solution of each ovitrap. The proportion of eggs between substrates (wooden paddle and solution) varied between conditions, with females in laboratory presenting a lower preference to lay eggs in paddles when compared with studies in semi-field. This behaviour shifts in laboratory can create challenges to extrapolate results from laboratory to the field. Here, studies in both conditions indicate a similar impact of YEOO particles in Aedes aegypti oviposition. The potential treatment concentration of YEOO particles presents a strong repellent/deterrent effect (-0.559 > OAI > -0.760) within the initial 72h of application when compared with water, and weak repellent/deterrent signal (OAI = -0.220) when compared against inactivated yeast. Control ovitraps with water were more positive for egg presence than treated ovitraps, while ovitraps with YEOO particles and inactivated yeast present similar number of positive ovitraps. It is possible that the repellent/deterrent action is partially driven by the delivery system, since most times Citrus sinensis EO oviposition repellent/deterrent signal is weak, and it seem influenced by solvent/delivery used. However, it is unclear how the yeast wall that protect/surrounds the orange oil will negatively affect oviposition since live yeast are normally consider an attractant for mosquito oviposition.

Sub-lethal doses of Nucleopolyhedrosis Virus and synthetic insecticides alter the biological parameters of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae).

Resistance management is very important for devising control strategies of polyphagous insect-pests like Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). Considering the importance of resistance management, demographic features of selected and unselected populations of H. armigera were studied in 6 different treatments viz. emamectin benzoate, Helicoverpa armigera Nucleopolyhedrosis Virus (HaNPV), emamectin benzoate+HaNPV, spinetoram, spinetoram+HaNPV and control. Higher values for fecundity, intrinsic rate, the finite rate of increase (λ) were recorded in the control of selected as compared to the rest of treatment. Similarly, higher values for these population parameters viz. oviposition days, fecundity, intrinsic rate, the finite rate of increase were calculated in the unselected control. Similarly, net reproductive rate (R0) for selected and unselected control was higher as compared to the rest of the treatments. It may happen because these kinds of selection pressures can result in decreased fitness of the test insect thus decreased fitness of H. armigera in different treatments was observed as compared to the control. Additionally, quicker development of susceptible insects was observed because susceptible insects were growing without any stressor (xenobiotics) as compared to the rest which contributed to their faster development.

Intergenerational Transmission of Resistance of Callosobruchus maculatus to Essential Oil Treatment.

Due to the rise of numerous legal restrictions as well as the increasing emergence of resistant populations, the number of available pesticides is decreasing significantly. One of the potential alternatives often described in the literature are essential oils (EOs). However, there is a lack of research addressing the potential emergence of resistance to this group of substances. In this paper, we investigated the multi-generational effects of sublethal concentrations of rosemary oil (Rosmarinus officinalis) on physiological and biochemical parameters of the cowpea weevil (Callosobruchus maculatus) such as egg laying, hatchability, oxygen consumption and acetylcholinesterase activity. Imago, which as larvae were exposed to EO at concentrations equivalent to LC25, showed significantly lower mortality. The results obtained indicate the potential development of resistance in insects exposed to EO in concentrations corresponding to LC25. In addition, in the case of the group treated with an EO concentration corresponding to LC3.12, a stimulation effect of the above-mentioned parameters was observed, which may indicate the occurrence of a hormesis effect. The obtained results may be an important reference for the development of future guidelines and EO-based insecticides.

Attraction of Brown Marmorated Stink Bugs, Halyomorpha halys, to Blooming Sunflower Semiochemicals.

The polyphagous invasive brown marmorated stink bug, Halyomorpha halys, reportedly discriminates among phenological stages of host plants. To determine whether olfaction is involved in host plant stage discrimination, we selected (dwarf) sunflower, Helianthus annuus, as a model host plant species. When adult females of a still-air laboratory experiment were offered a choice of four potted sunflowers at distinct phenological stages (vegetative, pre-bloom, bloom, seeding), most females settled onto blooming plants but oviposited evenly on plants of all four stages. In moving-air two-choice olfactometer experiments, we then tested each plant stage versus filtered air and versus one another, for attraction of H. halys females. Blooming sunflowers performed best overall, but no one plant stage was most attractive in all experiments. Capturing and analyzing (by GC-MS) the headspace odorants of each plant stage revealed a marked increase of odorant abundance (e.g., monoterpenes) as plants transitioned from pre-bloom to bloom. Analyzing the headspace odorant blend of blooming sunflower by gas chromatographic-electroantennographic detection (GC-EAD) revealed 13 odorants that consistently elicited responses from female H. halys antennae. An 11-component synthetic blend of these odorants attracted H. halys females in laboratory olfactometer experiments. Furthermore, in field settings, the synthetic blend enhanced the attractiveness of synthetic H. halys pheromone as a trap lure, particularly in spring (April to mid-June). A simpler yet fully effective sunflower semiochemical blend could be developed and coupled with synthetic H. halys aggregation pheromones to improve monitoring efforts or could improve the efficacy of modified attract-and-kill control tactics for H. halys.

Honey bee queen health is unaffected by contact exposure to pesticides commonly found in beeswax.

Honey bee queen health is crucial for colony health and productivity, and pesticides have been previously associated with queen loss and premature supersedure. Prior research has investigated the effects of indirect pesticide exposure on queens via workers, as well as direct effects on queens during development. However, as adults, queens are in constant contact with wax as they walk on comb and lay eggs; therefore, direct pesticide contact with adult queens is a relevant but seldom investigated exposure route. Here, we conducted laboratory and field experiments to investigate the impacts of topical pesticide exposure on adult queens. We tested six pesticides commonly found in wax: coumaphos, tau-fluvalinate, atrazine, 2,4-DMPF, chlorpyriphos, chlorothalonil, and a cocktail of all six, each administered at 1, 4, 8, 16, and 32 times the concentrations typically found in wax. We found no effect of any treatment on queen mass, sperm viability, or fat body protein expression. In a field trial testing queen topical exposure of a pesticide cocktail, we found no impact on egg-laying pattern, queen mass, emergence mass of daughter workers, and no proteins in the spermathecal fluid were differentially expressed. These experiments consistently show that pesticides commonly found in wax have no direct impact on queen performance, reproduction, or quality metrics at the doses tested. We suggest that previously reported associations between high levels of pesticide residues in wax and queen failure are most likely driven by indirect effects of worker exposure (either through wax or other hive products) on queen care or queen perception.

Induction of reproductive activity and egg production by gonadotropin-releasing hormone in non-laying hens.

The current study was conducted to evaluate the effects of gonadotropin-releasing hormone (GnRH) analogue (Receptal) injection on reproductive traits of fully mature layers hens (32 weeks) suffered from inactive ovaries. Ninety-six non-laying hens (TETRA-SL brown egg layers), selected from a commercial flock, with similar body weight, were randomly assigned to four groups (n = 24). Hens in the 1st group served as a control. Hens of the 2nd, 3rd and 4th groups were individually intramuscularly injected every 4 days with 50, 100 and 150 µl of Receptal solution, respectively, for two times. The results stated that the injection of Receptal induced the non-laying hens to produce eggs, but control birds did not produce eggs during the experimental period. The distance between pelvic bones and between the pelvic bone and keel bone of hens was significantly improved (p < .001) in groups received different GnRH levels compared with the control group. The best results were observed in the group injected with 100 µl Receptal. Levels of LH, FSH, oestrogen and progesterone hormones were significantly (p < .05) higher in Receptal-treated groups than in the control group. Hens injected with Receptal had an increase in ovary%, yellow follicles number, oviduct% and oviduct length (p < .001) compared with the control. It was concluded that treating inactive ovaries in non-laying hens with GnRH injections for two times, 4-day intervals, is an effective procedure for inducing egg production and useful in cost reduction in layer farms, and the group treated with 100 µl Receptal had the best results.

Induced Hatching of Quiescent Aedes aegypti (Diptera: Culicidae) Eggs by Labile Glutathione-Stabilizable Compounds From Yeast Extract.

Aedes aegypti (Linnaeus, 1762) is the insect vector that transmits several deadly human diseases. Although the egg stage is an important phase of its life cycle, the biology of mosquito egg remains poorly understood. Here, we report our investigations on the chemical factors that induced hatching of Ae. aegypti eggs. Commercial yeast extracts were able to increase egg hatching rate in a dose-dependent manner, with a hatching rate that ranged from approximately 10% with 1 g/liter to 80% with 20 g/liter of yeast extract. Notably, the addition of glutathione, a reducing agent that showed no significant effect on egg hatching by itself, enhanced and stabilized the activity of yeast extract for at least 70 h. Because dissolved oxygen in different treatments was maintained at high levels in a narrow range (92-95%), we proposed that yeast extract contains hatching inducing compound (HIC) which is able to trigger egg hatching independent of dissolved oxygen level. The HIC in yeast extract could prove to be a potential starting point to design an effective tool to forcefully induce mosquito eggs to hatch under unfavorable conditions, functioning as a novel method for vector control.

Effects of magnolol on egg production, egg quality, antioxidant capacity, and intestinal health of laying hens in the late phase of the laying cycle.

Magnolol is a multifunctional plant polyphenol. To evaluate the effects of magnolol on laying hens in the late laying period, 360 (50-week-old) laying hens were randomly assigned to 4 dietary treatments: a non-supplemented control diet (C), and control diets supplemented with 100, 200, and 300 mg/kg of magnolol (M100, M200, and M300), respectively. Each treatment had 6 replicates with 15 hens per replicate. Results showed that dietary supplementation of 200 and 300 mg/kg of magnolol increased the laying rate and the M200 group had a lower feed conversion ratio (P < 0.05). Magnolol supplementation (200 and 300 mg/kg) could linearly increase albumen height and Haugh unit of fresh eggs in the late phase of the laying cycle (P < 0.01). And magnolol linearly alleviated the decline of the albumen height and Haugh unit of eggs stored for 14 d (P < 0.01). The total superoxide dismutase activity in the ovaries of M100 group was greater than that in the other treatments (P < 0.05). As dietary magnolol levels increased, villus height of jejunum and ileum linearly increased (P < 0.01). M200 and M300 groups had higher expression level of occludin in the ileum compared with group C (P < 0.01). The level of nitric oxide production and inducible nitric oxide synthase expression in the ileum of M200 group were lower than that in the C group (P < 0.05). In conclusion, dietary supplementation of 200 and 300 mg/kg magnolol can improve hen performance, albumen quality of fresh and storage eggs, and hepatic lipid metabolism in the late laying cycle. Also, magnolol has a good effect on increasing villi and improving the intestinal mucosal mechanical barrier function.

Effects of developmental exposure to pesticides in wax and pollen on honey bee (Apis mellifera) queen reproductive phenotypes.

Stressful conditions during development can have sub-lethal consequences on organisms aside from mortality. Using previously reported in-hive residues from commercial colonies, we examined how multi-pesticide exposure can influence honey bee (Apis mellifera) queen health. We reared queens in beeswax cups with or without a pesticide treatment within colonies exposed to treated or untreated pollen supplement. Following rearing, queens were open-mated and then placed into standard hive equipment in an "artificial swarm" to measure subsequent colony growth. Our treated wax had a pesticide Hazard Quotient comparable to the average in beeswax from commercial colonies, and it had no measurable effects on queen phenotype. Conversely, colonies exposed to pesticide-treated pollen had a reduced capacity for viable queen production, and among surviving queens from these colonies we observed lower sperm viability. We found no difference in queen mating number across treatments. Moreover, we measured lower brood viability in colonies later established by queens reared in treated-pollen colonies. Interestingly, royal jelly from colonies exposed to treated pollen contained negligible pesticide residues, suggesting the indirect social consequences of colony-level pesticide exposure on queen quality. These findings highlight how conditions during developmental can impact queens long into adulthood, and that colony-level pesticide exposure may do so indirectly.

Combating silver nanoparticle-mediated toxicity in Drosophila melanogaster with curcumin.

Nanoscale materials display unique physical and chemical properties that enable their assimilation into a variety of industrial and consumer products. Amongst the widely used nanomaterials, silver nanoparticles (AgNPs) have gained tremendous recognition for various applications, owing to their extraordinary plasmonic and bactericidal properties. Despite of the extensive usage of AgNPs in various sectors, its impact on human health remains ambiguous. Several studies have established that higher doses of AgNPs are detrimental to organismal health. In order to attain the best from these versatile nanoparticles, a recent advent of green nanotechnology, that is, employment of metal nanoparticles synthesized using plant extracts, has emerged. Here, using Drosophila as a model system, we tested if adding curcumin, a biologically active polyphenolic compound present in turmeric, having multitudes of therapeutic properties, could mitigate AgNP-mediated biotoxicity. We found that co-administration of AgNPs with curcumin in the fly food could alleviate several harmful effects evoked by AgNPs ingestion in Drosophila model. Addition of curcumin superseded reduction in feeding, pupation, eclosion, pigmentation, and fertility caused by AgNPs ingestion. Interestingly, impairment in ovary development observed in flies reared on AgNPs-supplemented food was also partially restored by co-administration of AgNPs with curcumin. Furthermore, substantial alleviation of reactive oxygen species level and cell death was observed in larval tissues upon co-supplementation of AgNPs with curcumin. We therefore propose that curcumin, when administered with AgNPs, can abrogate the toxic manifestations of AgNPs ingestion and hence can be incorporated in various consumer products encompassing it.

Understanding the potential impact of continued seed treatment use for resistance management in Cry51Aa2.834_16 Bt cotton against Frankliniella fusca.

Transgenic cotton expressing Cry51Aa2.834_16 Bt toxin (hereafter referred to as MON 88702) has the potential to be an important tool for pest management due to its unique activity against tobacco thrips, Frankliniella fusca. Unlike other Bt toxins targeting lepidopteran cotton pests, MON 88702 does not cause direct mortality but has an antixenotic effect that suppresses F. fusca oviposition. Previous work has shown neonicotinoid seed treated (NST) crops have similar behavioral effects on thrips. This study used non-choice and common garden experiments to examine how the presence of MON 88702 cotton and soybean (another F. fusca host) with and without NSTs might alter F. fusca infestation distributions. In a no-choice environment, significant larval establishment differences were observed, with untreated soybean plants becoming most heavily infested. In choice experiments, plants expressing MON 88702 or were neonicotinoid treated had significantly lower larval establishment. Larval density decreased as dispersal distance increased, suggesting reproductive decisions were negatively related to distance from the release point. Understanding how F. fusca responds to MON 88702 in an environment where adults can choose among multiple host plants will provide valuable context for projections regarding design of MON 88702 resistance refuges. Reduced larval establishment on NST cotton and soybean suggests that area-wide use of NSTs could reduce the number of susceptible F. fusca generated in unstructured crop refuges for MON 88702. These results also suggest that although the presence of NST MON 88702 could suppress reproduction and resistance selection, over time this benefit could erode resulting in increased larval establishment on NST cotton and soybean due to increased frequency of neonicotinoid resistant F. fusca populations.

Lethal concentration of Cymbopogon citratus (Poaceae) essential oil for Dolops discoidalis and Argulus sp. (Crustacea: Argulidae).

This study investigated the acute toxicity (LC50-24 hr ) effects of the essential oil of Cymbopogon citratus for adult Argulus sp. and Dolops discoidalis, before and during oviposition. In vitro acute toxicity (LC50-24 hr ) was tested using 20, 40, 60, 80, 100, 120, 140 and 160 µg/L of C. citratus essential oil, and two control groups (one with cultivation tank water and one with cultivation tank water + alcohol) were used. Specimens of Argulus sp. and D. discoidalis submitted to acute toxicity were evaluated using histological procedures. The major chemical compounds of C. citratus essential oil were geranial (47.5%), neral (35.6%) and myrcene (6.7%). The LC50-24 hr for Argulus sp. adults was 67.97 µg/L, while for D. discoidalis it was 59.55 µg/L. In the oviposition of both species of argulids, maximum mortality began with treatments of 140 µg/L, while the LC50-24 hr for Argulus sp. and D. discoidalis was 83.98 µg/L and 82.48 µg/L, respectively. In both argulid species exposed to C. citratus essential oil, morphological alterations were observed only in the eyes, and they occurred in the ommatidium and rhabdomeres and were dependent on the concentration of C. citratus essential oil and the parasite species.

Consequences of various housing systems and dietary supplementation of thymol, carvacrol, and euganol on performance, egg quality, blood chemistry, and antioxidant parameters.

The present work was carried out to investigate the influences of housing system and dietary essential oils (EOs) supplementation to laying hens on the productive performance, egg quality, immunity, antioxidant parameters, and hematology. A factorial arrangement (2 × 4) was performed, including 2 housing systems and 4 different types of EOs (without EOs, thymol, carvacrol, and euganol) during the production stages (from 28-78 wk of age). Birds were randomly divided into 2 groups with each of 2,000 birds. The first group was moved to laying cages while the second group was a floor reared. Each group was randomly divided into 4 groups (5 replicates of 100 birds each): The first were considered as a control group, and the second, third, and fourth groups were treated with thymol, carvacrol, and euganol EO, respectively. The results showed that hens reared in cage system had higher egg weight (P < 0.05), egg production, egg mass, and feed intake and better feed conversion ratio (P < 0.001) than those reared in the floor system. Blood picture values (except white blood cells), phagocytic index, phagocytic activity, and blood chemistry parameters (except calcium, phosphorus, and urea values) of laying hens were not affected (P > 0.05) by housing system. The groups fed EOs showed a rapid improvement (P < 0.001) in the egg production%, egg weight, egg mass, and egg quality. Thymol group had the highest egg production (P < 0.001). Thymol and eugenol groups had the highest egg weight, egg mass, and egg quality (P < 0.001). The groups fed diets containing thymol or eugenol consumed lower feed and had better feed conversion ratio (P < 0.001) than the control group. Immunity indices (phagocytic activity [P < 0.05], avian influenza [AIH5 and AIH9], P < 0.001) were improved with the presence of EOs in the laying hen diet. These results strongly suggest that dietary EO supplementation could be a successful attempt to improve the productive performance, egg quality, and immunity of laying hens.

Pharmacological inhibition of lysine-specific demethylase 1 (LSD1) induces global transcriptional deregulation and ultrastructural alterations that impair viability in Schistosoma mansoni.

Treatment and control of schistosomiasis still rely on only one effective drug, praziquantel (PZQ) and, due to mass treatment, the increasing risk of selecting for schistosome strains that are resistant to PZQ has alerted investigators to the urgent need to develop novel therapeutic strategies. The histone-modifying enzymes (HMEs) represent promising targets for the development of epigenetic drugs against Schistosoma mansoni. In the present study, we targeted the S. mansoni lysine-specific demethylase 1 (SmLSD1), a transcriptional corepressor, using a novel and selective synthetic inhibitor, MC3935, which was used to treat schistosomula and adult worms in vitro. By using cell viability assays and optical and electron microscopy, we showed that treatment with MC3935 affected parasite motility, egg-laying, tegument, and cellular organelle structures, culminating in the death of schistosomula and adult worms. In silico molecular modeling and docking analysis suggested that MC3935 binds to the catalytic pocket of SmLSD1. Western blot analysis revealed that MC3935 inhibited SmLSD1 demethylation activity of H3K4me1/2. Knockdown of SmLSD1 by RNAi recapitulated MC3935 phenotypes in adult worms. RNA-Seq analysis of MC3935-treated parasites revealed significant differences in gene expression related to critical biological processes. Collectively, our findings show that SmLSD1 is a promising drug target for the treatment of schistosomiasis and strongly support the further development and in vivo testing of selective schistosome LSD1 inhibitors.

Investigation of the ability of the oviposition-stimulant lectin from Moringa oleifera seeds (WSMoL) to bind with membrane proteins present in the legs of Aedes aegypti.

The mosquito Aedes aegypti L. is a vector transmitting diseases such as dengue, chikungunya and Zika virus fever. The water-soluble lectin from Moringa oleifera Lam. seeds (WSMoL) is larvicidal, ovicidal and can stimulate oviposition in A. aegypti. This study aimed to investigate whether WSMoL could bind to membrane proteins from A. aegypti legs. Initially, proteins from the legs were extracted using sodium deoxycholate, digitonin, dodecyl sodium sulfate (SDS) or Triton X-100. The protein concentration was found to be higher in the extract obtained using Triton X-100, which was applied to a WSMoL-Sepharose column. The adsorbed proteins were evaluated using gel filtration chromatography and polyacrylamide gel electrophoresis (PAGE) in presence of SDS. The similarity in the sequences of adsorbed proteins with those available in databases was determined. The proteins adsorbed on the matrix were eluted forming a single peak. Gel filtration chromatography and SDS-PAGE revealed the presence of proteins with molecular masses of approximately 20 kDa and polypeptide bands of 17.0 and 23.7 kDa, respectively. MS/MS analysis indicated similarity between these proteins and ABC carriers, which are expressed in the legs of mosquitos. WSMoL could bind to membrane proteins in the legs of A. aegypti females and induce oviposition through these interactions.

Capsaicin Functions as Drosophila Ovipositional Repellent and Causes Intestinal Dysplasia.

Plants generate a plethora of secondary compounds (toxins) that potently influence the breadth of the breeding niches of animals, including Drosophila. Capsaicin is an alkaloid irritant from hot chili peppers, and can act as a deterrent to affect animal behaviors, such as egg laying choice. However, the mechanism underlying this ovipositional avoidance remains unknown. Here, we report that Drosophila females exhibit a robust ovipositional aversion to capsaicin. First, we found that females were robustly repelled from laying eggs on capsaicin-containing sites. Second, genetic manipulations show that the ovipositional aversion to capsaicin is mediated by activation of nociceptive neurons expressing the painless gene. Finally, we found that capsaicin compromised the health and lifespan of flies through intestinal dysplasia and oxidative innate immunity. Overall, our study suggests that egg-laying sensation converts capsaicin into an aversive behavior for female Drosophila, mirroring an adaptation to facilitate the survival and fitness of both parents and offspring.

The paradoxical effects of progesterone on the eggshell quality of laying hens.

This study demonstrates the effects of progesterone on eggshell quality and ultrastructure by injecting progesterone into laying hens 2 and 5 h post-oviposition, respectively. Progesterone injected 2 h post-oviposition (P4-2 h) improved eggshell quality with a significant decrease (P < 0.01) in the thickness of the mammillary layer and a significant increase (P < 0.01) in the thickness of the effective layer in the eggshell ultrastructure compared to the control. Progesterone injected 5 h post-oviposition (P4-5 h) damaged the eggshell quality by significantly reducing (P < 0.01) the effective layer thickness. Progesterone injected delayed obviously (P < 0.01) the following oviposition. Moreover, the concentrations of Thr, Cys, Leu, Lys, and His in the eggshell membranes were significantly higher (P < 0.05) in the P4-2 h treated hens whereas Val and Lys were significantly lower (P < 0.05) in P4-5 h treated hens compared to the control. Therefore, progesterone shows paradoxical effects on eggshell quality depending on the injection time-points post-oviposition, which could explain the contradictions in previous related reports. P4 injected affected the content of amino acids in eggshell membranes, especially lysine which contributed to eggshell quality. In addition, P4 injected 2 h after oviposition improved eggshell quality by promoting the premature fusion of mammillary knobs. This work contributed to a novel insight to understanding the mechanism of improving eggshell quality.

The phosphodiesterase-4 inhibitor roflumilast impacts Schistosoma mansoni ovipositing in vitro but displays only modest antischistosomal activity in vivo.

Praziquantel (PZQ) is the sole drug used to treat schistosomiasis, and the probability of developing resistance is growing the longer it is relied upon, justifying the search for alternatives. Phosphodiesterases (PDEs), particularly the PDE4 family, have attracted considerable attention as drug targets, including in Schistosoma mansoni, and especially SmPDE4A. This study investigates the potential antischistosomal activity of human PDE4 and potent SmPDE4A inhibitor roflumilast, either alone or combined with PZQ. In vitro, roflumilast resulted in a significant, concentration-dependent reduction in egg production but not of worm viability. In vitro exposure to roflumilast in combination with a low concentration of PZQ was less effective than PZQ alone, pointing to antagonism. S. mansoni-infected mice treated with roflumilast showed significant reductions in worm burden (27%) as well as hepatic and intestinal egg burdens (~28%) two weeks post treatment. Scanning EM of worms isolated from roflumilast-treated and untreated mice did not reveal noticeable changes to their tegument. S. mansoni-infected mice treated with a fixed dosage of roflumilast and a variable dosage of PZQ resulted in a higher reduction in worm burden, reduced hepatic egg counts, absence of immature eggs and a marked increase in dead eggs, compared to PZQ alone. However, the combination resulted in increased animal mortality, probably attributable to pharmacodynamic interactions between the two drugs. Although this study marks the first report of in vivo antischistosomal potential by a PDE inhibitor, an important proof of concept, we conclude that the antischistosomal effects of roflumilast are insufficient to warrant further development.

Effects of inulin supplementation in laying hens diet on the antioxidant capacity of refrigerated stored eggs.

The effects of inulin supplementation in the diet of laying hens on the antioxidant capacity of refrigerated (0, 2, 4, 6 and 8 weeks) eggs were evaluated. Three hundred commercial laying hens were divided into five treatment groups and fed diets with supplements of 0 (control), 5, 10, 15 or 20 g/kg inulin. The experimental results showed that the use of inulin (15 or 20 g/kg) in the diet for laying hens increased the DPPH and ABTS radical-scavenging activities, total phenolic content and ferric reducing power in the yolks of fresh (stored 0 weeks) and stored eggs (P < 0.05). The antioxidant enzyme (SOD and GSH-Px) activities of the stored egg increased linearly (P < 0.05), and the malonaldehyde (MDA) levels of stored eggs decreased linearly (P < 0.01) as the inulin levels improved at every two weeks of storage. In conclusion, inulin supplementation in the diet of laying hens had the potential to prolong the shelf-life of eggs.

The repositioning of epigenetic probes/inhibitors identifies new anti-schistosomal lead compounds and chemotherapeutic targets.

BACKGROUND: Praziquantel represents the frontline chemotherapy used to treat schistosomiasis, a neglected tropical disease (NTD) caused by infection with macro-parasitic blood fluke schistosomes. While this drug is safe, its inability to kill all schistosome lifecycle stages within the human host often requires repeat treatments. This limitation, amongst others, has led to the search for novel anti-schistosome replacement or combinatorial chemotherapies. Here, we describe a repositioning strategy to assess the anthelmintic activity of epigenetic probes/inhibitors obtained from the Structural Genomics Consortium. METHODOLOGY/PRINCIPLE FINDINGS: Thirty-seven epigenetic probes/inhibitors targeting histone readers, writers and erasers were initially screened against Schistosoma mansoni schistosomula using the high-throughput Roboworm platform. At 10 µM, 14 of these 37 compounds (38%) negatively affected schistosomula motility and phenotype after 72 hours of continuous co-incubation. Subsequent dose-response titrations against schistosomula and adult worms revealed epigenetic probes targeting one reader (NVS-CECR2-1), one writer (LLY-507 and BAY-598) and one eraser (GSK-J4) to be particularly active. As LLY-507/BAY-598 (SMYD2 histone methyltransferase inhibitors) and GSK-J4 (a JMJD3 histone demethylase inhibitor) regulate an epigenetic process (protein methylation) known to be critical for schistosome development, further characterisation of these compounds/putative targets was performed. RNA interference (RNAi) of one putative LLY-507/BAY-598 S. mansoni target (Smp_000700) in adult worms replicated the compound-mediated motility and egg production defects. Furthermore, H3K36me2, a known product catalysed by SMYD2 activity, was also reduced by LLY-507 (25%), BAY-598 (23%) and siSmp_000700 (15%) treatment of adult worms. Oviposition and packaging of vitelline cells into in vitro laid eggs was also significantly affected by GSK-J4 (putative cell permeable prodrug inhibitor of Smp_034000), but not by the related structural analogue GSK-J1 (cell impermeable inhibitor). CONCLUSION/SIGNIFICANCE: Collectively, these results provide further support for the development of next-generation drugs targeting schistosome epigenetic pathway components. In particular, the progression of histone methylation/demethylation modulators presents a tractable strategy for anti-schistosomal control.