Neuromodulation of Acid-Sensitive Ion Channels (ASICs) and Anti-Inflammatory Potential by Lichenxanthone in Adult Zebrafish (Danio rerio): Experimental and Docking Studies.

The xanthone lichenxanthone did not show toxic effects (LC50>1.0 mg/mL). lichenxanthone prevented nociceptive behavior induced by acidic saline, and its analgesic effect was blocked by amiloride, highlighting the involvement of neuromodulation of acid-sensitive ion channels (ASICs). In the analysis of anti-inflammatory activity, concentrations of 0.1 and 0.5 mg/mL of lichenxanthone reduced the edema induced by k-carrageenan 3.5 %, observed from the fourth hour of analysis. This effect was similar to that observed with ibuprofen (positive control). No leukocyte infiltrates were observed in lichenxanthone, suggesting that the compound acts in the acute inflammatory response. The results of the molecular docking study revealed that lichenxanthone exhibited better affinity energy when compared to the ibuprofen control against the two targets evaluated.

Protective effect of Bougainvillea glabra Choisy bract in toxicity induced by Paraquat in Drosophila melanogaster.

Paraquat (PQ) is a herbicide widely used in agriculture to control weeds. The damage caused to health through intoxication requires studies to combating its damage to health. Bougainvillea glabra Choisy is a plant native to South America and its bracts contain a variety of compounds, including betalains and phenolic compounds, which have been underexplored about their potential applications and benefits for biological studies to neutralize toxicity. In this study, we evaluated the antioxidant and protective potential of the B. glabra bracts (BBGCE) hydroalcoholic extract against Paraquat-induced toxicity in Drosophila melanogaster. BBGCE demonstrated high antioxidant capacity in vitro through the assays of ferric-reducing antioxidant power (FRAP), radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), free radical ABTS and quantification of phenolic compounds, confirmed through identifying the main compounds. Wild males of D. melanogaster were exposed to Paraquat (1.75 mM) and B. glabra Choisy (1, 10, 50 and 100 µg/mL) in agar medium for 4 days. Flies exposed to Paraquat showed a reduction in survival rate and a significant decrease in climbing capacity and balance test when compared to the control group. Exposure of the flies to Paraquat caused a reduction in acetylcholinesterase activity, an increase in lipid peroxidation and production of reactive species, and a change in the activity of the antioxidant enzymes. Co-exposure with BBGCE was able to block toxicity induced by PQ exposure. Our results demonstrate that bract extract has a protective effect against PQ on the head and body of flies, attenuating behavioral deficit, exerting antioxidant effects and blocking oxidative damage in D. melanogaster.

Voluntary physical activity mitigates alveolar bone loss in mice with ligature-induced experimental periodontitis.

OBJECTIVE: To investigate the effect of voluntary physical activity (VPA) on inflammatory profile and the progression of experimental periodontal disease (PD) in mice. METHODS: Male C57BL/6 mice were randomly distributed into Control; VPA; PD and PD/VPA groups. We registered VPA (total volume of revolutions) and average speed (revolutions/minute) in a free running wheel for 30 days. On the 15th day, animals from the PD and PD/VPA groups received ligatures on the upper second molars bilaterally. On the 30th day animals were euthanized, and PD progression was assessed by measuring alveolar bone loss (ABL - the linear distance between the cemento-enamel junction and the alveolar bone crest on the teeth buccal surface). Gene expression of RANKL (kappa nuclear factor B receptor) OPG (osteoprotegerin), IL-1ß (interleukin 1 beta), IL-6 (interleukin 6) and TNF-α (tumor necrosis factor alpha) were evaluated by real-time PCR (quantitative Polymerase Chain Reaction - relative gene expression). RESULTS: The total volume of physical activity and the activity speed decreased along the seven days after ligature-placement (p < 0.05), returning to a similar pattern in relation to VPA group. Ligature placement produced significant bone resorption, and increased RANKL, IL-1ß, IL-6 and TNF-α expression. VPA reduced ABL (p < 0,05) and the expression of TNF-α and IL-1ß, whereas increased OPG expression. CONCLUSION: Animals induced to PD with access to the VPA wheel presented both lower gingival inflammation and less alveolar bone resorption in comparison to animals without access to the wheel.

Recapitulation of Retinal Damage in Zebrafish Larvae Infected with Zika Virus.

Zebrafish are increasingly being utilized as a model to investigate infectious diseases and to advance the understanding of pathogen-host interactions. Here, we take advantage of the zebrafish to recapitulate congenital ZIKV infection and, for the first time, demonstrate that it can be used to model infection and reinfection and monitor anti-viral and inflammatory immune responses, as well as brain growth and eye abnormalities during embryonic development. By injecting a Brazilian strain of ZIKV into the yolk sac of one-cell stage embryos, we confirmed that, after 72 h, ZIKV successfully infected larvae, and the physical condition of the virus-infected hosts included gross morphological changes in surviving embryos (84%), with a reduction in larval head size and retinal damage characterized by increased thickness of the lens and inner nuclear layer. Changes in locomotor activity and the inability to perceive visual stimuli are a result of changes in retinal morphology caused by ZIKV. Furthermore, we demonstrated the ability of ZIKV to replicate in zebrafish larvae and infect new healthy larvae, impairing their visual and neurological functions. These data reinforce the deleterious activity of ZIKV in the brain and visual structures and establish the zebrafish as a model to study the molecular mechanisms involved in the pathology of the virus.

Early-life mice housed in standard stocking density reduce the spontaneous physical activity and increase visceral fat deposition before reaching adulthood.

Laboratory rodents spend the entire day housed in standard cages that provide a restricted area for movements and might, therefore, limit physical activity. However, it has not been tested in immature rodents of ages ranging from weaning to adulthood (adolescence period) whether the restricted area per animal does actually reduce physical activity and impact the body composition. We analyzed the spontaneous physical activity and feeding behavior during the adolescence of mice kept in two different housing conditions (standard stocking density (SSD) versus low stocking density (LSD)). We aimed to compare the body composition between SSD and LSD groups before they reached adulthood. Differential housing began at four weeks of age and was maintained for four weeks until euthanasia at eight weeks of age. The SSD group had a floor space of 88 cm2 available per animal, while LSD mice were housed with a floor space of 320 cm2 per animal, increasing the individual radius for movement more than three-fold compared with standard requirements. Mice kept in SSD exhibit lower spontaneous physical activity than mice kept in LSD. Early-life exposure to reduced physical activity in mice housed in SSD resulted in greater visceral fat accumulation before adulthood. An environment enabling/stimulating physical activity should be established for rodents as early as possible. This study will be helpful in showing that mice kept in SSD are early exposed to a reduced physical activity already in the adolescence period. Our findings could raise reflections about the translatability of rodents kept in SSD to healthy active humans.

Effect of Illicium verum (Hook) essential oil on cholinesterase and locomotor activity of Alphitobius diaperinus (Panzer).

The aim of this work was to test the insecticidal effect of the essential oil of Illicium verum (Hook) by observing the survival, biochemical parameters (acetylcholinesterase (AChE) activity, glutathione s-transferase (GST) activity and the concentration of reactive oxygen species (ROS)) and locomotor capacity of the Coleoptera Alphitobius diaperinus (Panzer), a pest of beef poultry. The sublethal concentrations (100% survival of A. diaperinus during 96 h of exposure) of I. verum essential oil selected for analysis were 0.5% and 1%. The selected sublethal concentrations did not show significant increases in ROS levels after 24 h of exposure to the essential oil. However, increases in GST activity were seen following exposure to 0.5% I. verum essential oil, while decreases in AChE activity were observed following exposure to concentrations of 0.5% and 1%. These results correlate with the observed behavior of A. diaperinus; when placed into an arena, these insects typically demonstrate aversion to stimuli and refuge-seeking behavior. Following exposure to 0.5% I. verum essential oil, the insects showed loss of refuge-seeking capacity and, following exposure to a concentration of 1%, loss of locomotor capacity. Overall, these results indicate that I. verum essential oil can be used as an alternative to conventional insecticides.

Relationship between toxicity and oxidative stress of the nanoencapsulated colchicine in a model of Drosophila melanogaster.

Drug repurposing allows searching for new biological targets, especially against emerging diseases such as Covid-19. Drug colchicine (COL) presents recognized anti-inflammatory action, while the nanotechnology purpose therapies with low doses, efficacy, and decrease the drug's side-effects. This study aims to evaluate the effects of COL and colchicine nanocapsules (NCCOL) on survival, LC50, activity locomotor, and oxidative stress parameters, elucidating the toxicity profile in acute and chronic exposure in Drosophila melanogaster. Three-day-old flies were investigated into groups: Control, 0.001, 0.0025, 0.005, and 0.010 mg/mL of COL or NCCOL. The survival rate, open field test, LC50, oxidative stress markers (reactive species (RS) production, thiobarbituric acid reactive substances), antioxidant enzyme activity (catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase), protein thiols, nonprotein thiols, acetylcholinesterase activity, and cell viability were measured. As a result, acute exposure to the COL decreases the number of crosses in the open field and increases CAT activity. NCCOL reduced RS levels, increased lipoperoxidation and SOD activity. Chronic exposure to the COL and NCCOL in high concentrations implied high mortality and enzymatic inhibition of the CAT and AChE, and only the COL caused locomotor damage in the open field test. Thus, NCCOL again reduced the formation of RS while COL increased. In this comparative study, NCCOL was less toxic to the antioxidant system than COL and showed notable involvement of oxidative stress as one of their toxicity mechanisms. Future studies are needed to elucidate all aspects of nanosafety related to the NCCOL.

Recapitulation of retinal damage in zebrafish larvae infected with Zika virus

Zebrafish are increasingly being utilized as a model to investigate infectious diseases and to advance the understanding of pathogen–host interactions. Here, we take advantage of the zebrafish to recapitulate congenital ZIKV infection and, for the first time, demonstrate that it can be used to model infection and reinfection and monitor anti-viral and inflammatory immune responses, as well as brain growth and eye abnormalities during embryonic development. By injecting a Brazilian strain of ZIKV into the yolk sac of one-cell stage embryos, we confirmed that, after 72 h, ZIKV successfully infected larvae, and the physical condition of the virus-infected hosts included gross morphological changes in surviving embryos (84%), with a reduction in larval head size and retinal damage characterized by increased thickness of the lens and inner nuclear layer. Changes in locomotor activity and the inability to perceive visual stimuli are a result of changes in retinal morphology caused by ZIKV. Furthermore, we demonstrated the ability of ZIKV to replicate in zebrafish larvae and infect new healthy larvae, impairing their visual and neurological functions. These data reinforce the deleterious activity of ZIKV in the brain and visual structures and establish the zebrafish as a model to study the molecular mechanisms involved in the pathology of the virus.

Aerobic training associated with an active lifestyle exerts a protective effect against oxidative damage in hypothalamus and liver: The involvement of energy metabolism.

BACKGROUND: Oxidation resistance protein 1 (OXR1) is of scientific interest due its role in protecting tissues against oxidative stress, DNA mutations and tumorigenesis, but little is known regarding strategies to increase OXR1 in different tissues. As an improved antioxidant defense may result from a high total amount of physical activity, the present study was designed to determine whether an active lifestyle including aerobic training exercise and spontaneous physical activity (SPA) can increase OXR1. We have built a large cage (LC) that allows animals to move freely, promoting an increase in SPA in comparison to a small cage (SC). METHODS: We examined the effects of aerobic training applied for 8 weeks on SPA and OXR1 of C57BL/6 J mice living in two types of housing (SC and LC). OXR1 protein was studied in hypothalamus, muscle and liver, which were chosen due to their important role in energy and metabolic homeostasis. RESULTS: LC-mice were more active than SC-mice as determined by SPA values. Despite both trained groups exhibiting similar gains in aerobic capacity, only trained mice kept in a large cage (but not for trained mice housed in SC) exhibited high OXR1 in the hypothalamus and liver. Trained mice housed in LC that exhibited an up-regulation of OXR1 also were those who exhibited an energy-expensive metabolism (based on metabolic parameters). CONCLUSIONS: These results suggest that aerobic training associated with a more active lifestyle exerts a protective effect against oxidative damage and may be induced by changes in energy metabolism.

Exercise associated with γ-oryzanol supplementation suppresses oxidative stress and prevents changes in locomotion in Drosophila melanogaster.

Association to early mortality and sedentarism was already demonstrated in the literature; nevertheless, some possible biochemical mechanisms around physical inactivity still need answers. The use of an invertebrate model, such as Drosophila melanogaster, can reproduce reliable responses in inducing an exercise protocol with exogenous antioxidant supplementation. This study main evaluates the effect of exercise (EXE) associated with γ-oryzanol (ORY) supplementation to improve locomotor behavior, antioxidant defenses, and survival in Drosophila melanogaster. Two-day old flies were submitted to a protocol for seven days, divided into five groups: Control, Movement-Limited Flies (MLF), EXE, ORY [25 µM], and EXE + ORY [25 µM]. The survival rate was evaluated, followed by open field and negative geotaxis. Flies were euthanized and subjected to analysis for acetylcholinesterase (AChE) and antioxidant enzymes activity, glycidic and lipid parameters, body weight, reactive species (RS), and lipid peroxidation. EXE and EXE + ORY flies showed increased survival and locomotor activity, improved glycidic and lipid parameters, with a lower RS production, and increased antioxidant defenses compared to Control, and EXE + ORY when compared to the EXE group, obtained an increase in the ratio of protein levels/body weight, decreased ratio of triglyceride levels/body weight and decreased lipid peroxidation. However, MLF showed less survival and decreased locomotor activity, possibly due to increased AChE activity and reduced antioxidant defenses. The EXE and EXE + ORY demonstrate effective results in maintaining endogenous defenses, with increased locomotor activity, supporting evidence on EXE benefits, and supplementation with antioxidant compounds face of health paradigms.HighlightsNew protocol system of exercise on Drosophila melanogaster model.ORY demonstrates synergistic effect with EXE.Exercise with ORY supplementation increases locomotor behavior.Exercise with ORY supplementation decrease oxidative damages on flies.

Haloperidol Interactions with the dop-3 Receptor in Caenorhabditis elegans.

Haloperidol is a typical antipsychotic drug commonly used to treat a broad range of psychiatric disorders related to dysregulations in the neurotransmitter dopamine (DA). DA modulates important physiologic functions and perturbations in Caenorhabditis elegans (C. elegans) and, its signaling have been associated with alterations in behavioral, molecular, and morphologic properties in C. elegans. Here, we evaluated the possible involvement of dopaminergic receptors in the onset of these alterations followed by haloperidol exposure. Haloperidol increased lifespan and decreased locomotor behavior (basal slowing response, BSR, and locomotion speed via forward speed) of the worms. Moreover, locomotion speed recovered to basal conditions upon haloperidol withdrawal. Haloperidol also decreased DA levels, but it did not alter neither dop-1, dop-2, and dop-3 gene expression, nor CEP dopaminergic neurons' morphology. These effects are likely due to haloperidol's antagonism of the D2-type DA receptor, dop-3. Furthermore, this antagonism appears to affect mechanistic pathways involved in the modulation and signaling of neurotransmitters such as octopamine, acetylcholine, and GABA, which may underlie at least in part haloperidol's effects. These pathways are conserved in vertebrates and have been implicated in a range of disorders. Our novel findings demonstrate that the dop-3 receptor plays an important role in the effects of haloperidol.

Housing conditions modulate spontaneous physical activity, feeding behavior, aerobic running capacity and adiposity in C57BL/6J mice.

There is evidence of reduced adiposity in rodents living in a large cages (LC) as compared to animals housed in small cages (SC). Because spontaneous physical activity (SPA) provides an important portion of the total daily energy expenditure, an increase of SPA in rodents kept in LC could explain their reduced body fat accumulation. The relationship between SPA and components of physical fitness (i.e. aerobic and anaerobic fitness and body leanness) has not been previously determined. We examined the effects of eight weeks of LC exposure on SPA, body composition, feeding behavior, as well as aerobic and anaerobic running capacity in adult C57BL/6J mice. Male mice were housed in cages of two different sizes for 8 weeks: a small (SC, n = 10) and large (LC n = 10) cages with 1320 cm2 and 4800 cm2 floor space, respectively. SPA was measured gravimetrically, and food and water intake were recorded daily. Mice had critical velocity (CV) and anaerobic running capacity (ARC) evaluated at the beginning, middle course (4th week) and at the end of study (8th week). Despite non-significant differences in each week LC-mice were more active than SC-mice by considering all SPA values obtained in the entire period of 8 weeks. The difference in SPA over the whole day was mainly due to light phase activity, but also due to activity at dark period (from 6 pm to 9 pm and from 5 am to 6 am). LC-mice also exhibited higher food and water intake over the entire 8-wk period. LC-mice had lower content of fat mass (% of the eviscerated carcass) than SC-mice (SC: 8.4 ±â€¯0.4 vs LC: 6.3 ±â€¯0.3, p < 0.05). LC-mice also exhibited reduced epididymal fat pads (% of body mass) compared to SC-mice (SC: 1.3 ±â€¯0.1 vs LC: 0.9 ±â€¯0.1, p < 0.05) and retroperitoneal fat pads (SC: 0.4 ±â€¯0.05 vs LC: 0.2 ±â€¯0.02, p < 0.05). The LC-group showed significantly higher critical velocity than SC-group at the fourth week (SC: 14.9 ±â€¯0.6 m·min-1 vs LC: 18.0 ±â€¯0.3 m·min-1, p < 0.05) and eighth week (SC: 17.1 ±â€¯0.5 m·min-1 vs LC: 18.8 ±â€¯0.6 m·min-1, p < 0.05). Our findings demonstrate that eight weeks of LC housing increases SPA of C57BL/6J mice, and this may lead to reduced fat accumulation as well as higher aerobic fitness. Importantly, our study implies that SC limits SPA, possibly generating experimental artifacts in long-term rodent studies.

Intracerebellar microinjection of histaminergic compounds on locomotor and exploratory behaviors in mice.

The neural histaminergic system innervates the cerebellum, with a high density of fibers in the vermis and flocculus. The cerebellum participates in motor functions, but the role of the histaminergic system in this function is unclear. In the present study, we investigated the effects of intracerebellar histamine injections and H1, H2 and H3 receptor antagonist injections (chlorpheniramine, ranitidine, and thioperamide, respectively) and H4 receptor agonist (VUF-8430) on locomotor and exploratory behaviors in mice. The cerebellar vermis of male mice was implanted with guide cannula. After three days of recovery,the animals received microinjections of saline or histamine (experiment1), saline or chlorpheniramine (experiment 2), saline or ranitidine(experiment 3), saline or thioperamide (experiment 4), and saline or VUF-8430 (experiment 5) in different concentrations. Five minutes postinjection,the open field test was performed. The data were analyzed using one-way ANOVA and Duncan's post hoc test. The microinjections of histamine, ranitidine or thioperamide did not lead any behavioral effects at the used doses. In contrast, animals that received chlorpheniramine at the highest dose (0.16 nmol) and VUF-8430 at the highest dose (1.48 nmol)were more active in the open field apparatus, with an increase in the number of crossed quadrants, number of rearings and time spent in the central area of the arena, suggesting that chlorpheniramine and VUF-8430 modulates locomotor and exploratory behaviors in mice.

Manganese(II) chloride alters behavioral and neurochemical parameters in larvae and adult zebrafish.

Manganese (Mn) is an essential metal for organisms, but high levels can cause serious neurological damage. The aim of this study was to evaluate the effects of MnCl2 exposure on cognition and exploratory behavior in adult and larval zebrafish and correlate these findings with brain accumulation of Mn, overall brain tyrosine hydroxylase (TH) levels, dopamine (DA) levels, 3,4-dihydroxyphenylacetic acid (DOPAC) levels and cell death markers in the nervous system. Adults exposed to MnCl2 for 4days (0.5, 1.0 and 1.5mM) and larvae exposed for 5days (0.1, 0.25 and 0.5mM) displayed decreased exploratory behaviors, such as distance traveled and absolute body turn angle, in addition to reduced movement time and an increased number of immobile episodes in larvae. Adults exposed to MnCl2 for 4days showed impaired aversive long-term memory in the inhibitory avoidance task. The overall brain TH levels were elevated in adults and larvae evaluated at 5 and 7 days post-fertilization (dpf). Interestingly, the protein level of this enzyme was decreased in larval animals at 10dpf. Furthermore, DOPAC levels were increased in adult animals exposed to MnCl2. Protein analysis showed increased apoptotic markers in both the larvae and adult nervous system. The results demonstrated that prolonged exposure to MnCl2 leads to locomotor deficits that may be associated with damage caused by this metal in the CNS, particularly in the dopaminergic system.

The effects of long-term dopaminergic treatment on locomotor behavior in rats.

Long-term treatments with dopaminergic agents are associated with adverse effects, including augmentation. Augmentation consists of an exacerbation of restless legs syndrome (a sleep-related movement disorder) symptoms during treatment compared to those experienced during the period before therapy was initiated. The objective of this study was to examine locomotor activity in rats after long-term dopaminergic treatment and its relationship with expression of the D2 receptor, in addition to demonstrating possible evidence of augmentation. The rats were divided into control (CTRL) and drug (Pramipexole-PPX) groups that received daily saline vehicle and PPX treatments, respectively, for 71 days. The locomotor behavior of the animals was evaluated weekly in the Open Field test for 71 days. The expression of the dopamine D2 receptor was evaluated by Western Blot analysis. The animals that received the PPX demonstrated a significant reduction in locomotor activity from day 1 to day 57 and a significant increase in immobility time from day 1 to day 64 relative to baseline values, but these values had returned to baseline levels at 71 days. No changes in the expression of the D2 receptor were demonstrated after treatment with a dopaminergic agonist. This study suggests changes in locomotor activity in rats after long-term PPX treatment that include an immediate reduction of locomotion and an increase in immobilization, and after 64 days, these values returned to baseline levels without evidence of augmentation. In addition, it was not possible to demonstrate a relationship between locomotor activity and the expression of D2 receptors under these conditions.