ABSTRACT
Metals exert detrimental effects on various systems within the body, including the nervous system. Nevertheless, the dose-response relationship concerning the administration of low doses of metal mixtures remains inadequately explored. The assessment of neurotoxic effects of lead, cadmium, mercury, and arsenic mixture (MIX) administered at low dose ranges, was conducted using an in vivo approach. A subacute study was conducted on a rat model consisting of a control and five treatment groups subjected to oral exposure with gradually increasing doses (from MIX 1 to MIX 5). The results indicated that behavioural patterns in an already developed nervous system displayed a reduced susceptibility to the metal mixture exposure with tendency of higher doses to alter short term memory. However, the vulnerability of the mature brain to even minimal amounts of the investigated metal mixture was evident, particularly in the context of oxidative stress. Moreover, the study highlights superoxide dismutase's sensitivity as an early-stage neurotoxicity marker, as indicated by dose-dependent induction of oxidative stress in the brain revealed through Benchmark analysis. The narrowest Benchmark Dose Interval (BMDI) for superoxide dismutase (SOD) activity (1e-06 - 3.18e-05 mg As/kg b.w./day) indicates that arsenic may dictate the alterations in SOD activity when co-exposed with the other examined metals. The predicted Benchmark doses for oxidative stress parameters were very low, supporting "no-threshold" concept. Histopathological alterations were most severe in the groups treated with higher doses of metal mixture. Similarly, the brain acetylcholinesterase (AChE) activity demonstrated a dose-dependent decrease significant in higher doses, while BMDI suggested Cd as the main contributor in the examined metal mixture. These findings imply varying susceptibility of neurotoxic endpoints to different doses of environmentally relevant metal mixtures, advocating for risk assessment and regulatory measures to address metal pollution and enhance remediation strategies.
Subject(s)
Dose-Response Relationship, Drug , Animals , Rats , Male , Environmental Pollutants/toxicity , Brain/drug effects , Metals, Heavy/toxicity , Neurotoxicity Syndromes/etiology , Rats, Wistar , Arsenic/toxicity , Oxidative Stress/drug effects , Superoxide Dismutase/metabolismABSTRACT
Recycling of electric and electronic waste products (e-waste) which amounted to more than 50 million metric tonnes per year worldwide is a massive and global operation. Unfortunately, an estimated 70-80% of this waste has not been properly managed because the waste went from developed to low-income countries to be dumped into landfills or informally recycled. Such recycling has been carried out either directly on landfill sites or in small, often family-run recycling shops without much regulations or oversights. The process traditionally involved manual dismantling, cleaning with hazardous solvents, burning and melting on open fires, etc., which would generate a variety of toxic substances and exposure/hazards to applicators, family members, proximate residents and the environment. The situation clearly calls for global responsibility to reduce the impact on human health and the environment, especially in developing countries where poor residents have been shouldering the hazardous burden. On the other hand, formal e-waste recycling has been mainly conducted in small scales in industrialized countries. Whether the latter process would impose less risk to populations and environment has not been determined yet. Therefore, the main objectives of this review are: 1. to address current trends and emerging threats of not only informal but also formal e-waste management practices, and 2. to propose adequate measures and interventions. A major recommendation is to conduct independent surveillance of compliance with e-waste trading and processing according to the Basel Ban Amendment. The recycling industry needs to be carefully evaluated by joint effort from international agencies, producing industries and other stakeholders to develop better processes. Subsequent transition to more sustainable and equitable e-waste management solutions should result in more effective use of natural resources, and in prevention of adverse effects on health and the environment.
Subject(s)
Electronic Waste , Waste Management , Electronic Waste/analysis , Electronics , Humans , RecyclingABSTRACT
The current study describes the experimental design guided development of PEGylated nanoemulsions as parenteral delivery systems for curcumin, a powerful antioxidant, as well as the evaluation of their physicochemical characteristics and antioxidant activity during the two years of storage. Experimental design setup helped development of nanoemulsion templates with critical quality attributes in line with parenteral application route. Curcumin-loaded nanoemulsions showed mean droplet size about 105 nm, polydispersity index <0.15, zeta potential of -40 mV, and acceptable osmolality of about 550 mOsm/kg. After two years of storage at room temperature, all formulations remained stable. Moreover, antioxidant activity remained intact, as demonstrated by DPPH (IC50 values 0.078-0.075 mg/mL after two years) and FRAPS assays. In vitro release testing proved that PEGylated phospholipids slowed down the curcumin release from nanoemulsions. The nanoemulsion carrier has been proven safe by the MTT test conducted with MRC-5 cell line, and effective on LS cell line. Results from the pharmacokinetic pilot study implied the PEGylated nanoemulsions improved plasma residence of curcumin 20 min after intravenous administration, compared to the non-PEGylated nanoemulsion (two-fold higher) or curcumin solution (three-fold higher). Overall, conclusion suggests that developed PEGylated nanoemulsions present an acceptable delivery system for parenteral administration of curcumin, being effective in preserving its stability and antioxidant capacity at the level highly comparable to the initial findings.
Subject(s)
Antioxidants , Curcumin , Drug Carriers , Nanostructures , Animals , Antioxidants/chemistry , Antioxidants/pharmacokinetics , Antioxidants/pharmacology , Biological Availability , Cell Line, Tumor , Curcumin/chemistry , Curcumin/pharmacokinetics , Curcumin/pharmacology , Drug Carriers/chemistry , Drug Carriers/pharmacology , Emulsions , Humans , Male , Nanostructures/chemistry , Nanostructures/therapeutic use , Pilot Projects , Rats , Rats, Sprague-DawleyABSTRACT
Waste electrical and electronic equipment (WEEE) represent one of the growing waste streams in Europe, whose content of hazardous substances and valuable materials focus on how it is handled. However, there are differences between countries regarding e-waste management system in Europe. This paper analyses and presents data regarding the e-waste management system in Italy, one of the founding countries of the EU and Serbia - EU candidate country. Within this work, the following aspects were considered: legislative framework and EU directive goals in terms of e-waste, institutional setup, collection system, and existing recycling and treatment technologies. In addition, material flow analysis is used to model mass balance within WEEE treatment plants in both countries. Finally, through assessment and comparison of current systems in both countries, problems and shortages of Serbia's e-waste management system are addressed.
Subject(s)
Electronic Waste , Waste Management , Electronic Waste/analysis , Electronics , Italy , Recycling , SerbiaABSTRACT
Efficient collection systems and information about the characteristics and quality of collected secondary plastic waste flows are of fundamental importance for the development of circular economies. In order to assess the effectiveness of the implementation of separate collection systems for plastic packaging, especially polyethylene terephthalate (PET) bottles, characteristic of the collected PET bottles in street mesh containers were studied in the city of Perm, Russia. The share of extraneous fractions was assessed and differentiation was carried out by volume, type of product, label presence, shape, content of solid and liquid impurities and colour. These results indicate that PET composition in different seasons is very similar, despite the assumption that the consumption of PET bottles in the spring and autumn seasons varies. In the mesh containers, up to 34% of the items were foreign objects, considering that only PET bottles should be collected. In each dimensional flow of PET bottles, the proportion of transparent bottles prevailed; it ranged from 31% to 70%. Based on the results of the experiment, almost all PET bottle categories had a standard shape, except packaging for food products and household chemicals, in which 26-27% of PET bottles had a non-standard shape. The results about charactersitic of source-separated PET bottles are fundamental for goal-oriented design and implementation of collection, recycling technologies, secondary separation facilities, the economics of recycling intitatives and reverse vending machines for collecting materials.
Subject(s)
Polyethylene Terephthalates , Recycling , Cities , Plastics , RussiaABSTRACT
Magnesium (Mg), is not only a modulator of the glutamatergic NMDA receptors' affinity, it also prevents HPA axis hyperactivity, thus possibly being implicated in neurobiological features of mood disorders. Further uncovering of molecular mechanisms underlying magnesium's proposed effects is needed due to the recent shift in research of treatment resistant depression (TRD) towards glutamatergic pathways. Here, we applied Mg via drinking water for 28â¯days (50â¯mg/kg/day), in ACTH-treated rats, an established animal model of depression resistant to tricyclic antidepressants. Using this model in male rats we measured (1) changes in hippocampal neurogenesis and behavioral alterations, (2) adrenal hormones response to acute stress challenge and (3) levels of biometals involved in regulation of monoamines turnover in rat prefrontal cortex. Our results support beneficial behavioral impact of Mg in TRD model together with increased hippocampal neurogenesis and BDNF expression. Furthermore, Mg prevented ACTH-induced disruption in HPA axis function, by normalizing the levels of plasma ACTH, corticosterone and interleukin-6, and by increasing the peripheral release of adrenaline, noradrenaline and serotonin after the acute stress challenge. Finally, the influence on copper/zinc ratio suggested probable magnesium's involvement in monoamine turnover in PFC. Our findings provide further insights into the possible pathways implicated in the behavioral modulation effects of Mg, as well as its central and peripheral effects in ACTH-induced TRD model. Thus, further investigation of molecular signaling related to the glutamatergic transmission and role of Mg, could reveal prospects to novel treatment strategies that could be of particular importance for patients suffering from TRD.
Subject(s)
Antidepressive Agents, Tricyclic/therapeutic use , Behavior, Animal/drug effects , Depression , Magnesium/pharmacology , Neurosecretory Systems/drug effects , Adrenocorticotropic Hormone , Animals , Corticosterone/blood , Depression/chemically induced , Depression/drug therapy , Depression/pathology , Disease Models, Animal , Drug Resistance/drug effects , Hypothalamo-Hypophyseal System/drug effects , Hypothalamo-Hypophyseal System/metabolism , Magnesium/administration & dosage , Male , Neurogenesis/drug effects , Neurosecretory Systems/physiology , Pituitary-Adrenal System/drug effects , Pituitary-Adrenal System/metabolism , Rats , Rats, Wistar , Time Factors , Treatment FailureABSTRACT
This paper outlines the approach that can assist decision makers to have first preliminary insights regarding costs of complying with requested European Union municipal waste management goals in transition and developing countries. Serbia, as a joining member of European Union, must confront itself with the challenges resulting from European Union waste management directives. Implementation of waste separation units and the construction of sanitary landfills is already in place in Serbia. However, new waste management practice will need additional transformation and will require implementation of waste treatment technologies for additional management of generated waste. Implementation of analyzed best available technology/techniques for waste treatment can support the country's effort in reaching the policy goals. However, the question here is how much will the implementation of additional waste treatments influence the overall waste management costs? Results of the scenario's financial viability show that composting and sanitary landfill are the most viable solutions regarding the costs, even under increasing discount rates. Although different discount rates influence the overall gate fees and net present values, the level of affordability for different scenarios remains the same.
Subject(s)
Waste Disposal Facilities , Waste Management/economics , Waste Management/methods , European Union , Goals , Refuse Disposal/economics , Refuse Disposal/instrumentation , Serbia , Waste Management/instrumentationABSTRACT
In this paper, attention is shifted from larger cities and regions to the important role of small municipalities in large-scale capacity waste management systems. The motivation of this analysis is to understand how small municipalities can be prepared for future inclusion in regional waste management. For the first time, solutions that include integrated treatment of municipal, agricultural, and industrial waste generated by small-scale municipalities are developed and assessed. For this purpose, five small Serbian municipalities with populations up to 30,000 inhabitants were chosen as case studies. The methodology integrates field data with material flow analysis (MFA) to analyze and evaluate future scenarios. A set of indicators which reflect the goals of waste management, including the total costs, was chosen for scenario comparison and evaluation. It was found that delivering generated waste to regional waste management centers can result in the most affordable environmental benefits for the representative municipalities. More advanced solutions, which include composting and joint treatment of municipal, agricultural, and industrial waste, can contribute to reaching waste management goals, but are more costly (217% and 652% comparing to delivering generated waste to regions). These results can be regarded as a representative for similar municipalities and can serve to support pre-planning decisions in other countries with problems in establishing regional waste management systems.
Subject(s)
Decision Support Techniques , Models, Theoretical , Solid Waste/analysis , Waste Management/methods , Refuse Disposal , SerbiaABSTRACT
Open dumping and landfilling have represented the predominant method of waste management in Serbia during the past decades. This practice resulted in over 3600 waste disposal sites distributed all over the country. The locations of the sites and their characteristics have been determined in the framework of the presented study. The vast majority of disposal sites (up to 3300) are characterized by small deposition depth of waste and total waste volumes of less than 10,000 m(3). Only about 50 landfills in Serbia contain more than 100,000 m(3) of waste. These large landfills are responsible for more than 95% of the total CH(4) emissions from waste disposal, which was assessed as 60,000 tons of CH(4) in 2010. The evaluation of different measures [soil cover, compost cover and landfill gas (LFG) systems] for mitigating greenhouse gas emissions from Serbian landfills indicated that enhanced microbial CH(4) oxidation (using a compost cover), as well as the installation of LFG systems, could generate net revenues as saved CH(4) emissions are creditable for the European Greenhouse Gas Emissions Trading Scheme. In total between 4 and 7 million tons of CO(2) equivalent emissions could be avoided within the next 20 years by mitigating CH(4) emissions from Serbian landfills.
Subject(s)
Environmental Monitoring/methods , Methane/chemistry , Refuse Disposal/methods , Carbon Dioxide , Gases , Refuse Disposal/economics , Serbia , SoilABSTRACT
Positive allosteric modulators (PAMs) of α5GABAA receptors (α5GABAARs) are emerging as potential therapeutics for a range of neuropsychiatric disorders. However, their role in memory processing of healthy animals is not sufficiently examined. We tested the effects of MP-III-022 (1 mg/kg, 2.5 mg/kg and 10 mg/kg), a PAM known to be selective for α5GABAARs and devoid of prominent side-effects, in different behavioral paradigms (Morris water maze, novel object recognition test and social novelty discrimination) and on GABRA5 expression in Wistar rats, 30 min and 24 h after intraperitoneal treatment administration. The lowest dose tested worsened short-term object memory. The same dose, administered two times in a span of 24 h, improved spatial and impaired object and, at a trend level, social memory. The highest dose had a detrimental effect on all types of long-term memory (object memory at a trend level) and short-term spatial memory, but improved short-term object and social memory. Distinct sets of expression changes were detected in both prefrontal cortex and two regions of the hippocampus, but the latter ones could be assessed as more consequential. An increase of GABRA5 mRNA in CA2 occurred in parallel with improvement of object and social, but impairment of spatial memory, while the opposite happened with a trend level change in CA1. Our study demonstrates the variability of the roles of the α5GABAAR based on its level of expression and localization, in dependence on the type and protocol of cognitive tasks, as well as the respective timing of pharmacological modulation and testing.
Subject(s)
Hippocampus/drug effects , Memory, Long-Term/drug effects , Memory, Short-Term/drug effects , Prefrontal Cortex/drug effects , Receptors, GABA-A/metabolism , Spatial Memory/drug effects , Animals , Dose-Response Relationship, Drug , Male , Rats , Rats, Wistar , Recognition, Psychology/drug effectsABSTRACT
Autism spectrum disorder (ASD), as a common neurodevelopmental disorder that encompasses impairments in social communication and interaction, as well as repetitive and restrictive behavior, still awaits an effective treatment strategy. The involvement of GABAergic neurotransmission, and especially a deficit of GABAA receptors that contain the α5 subunits, were implicated in pathogenesis of ASD. Therefore, we tested MP-III-022, a positive allosteric modulator (PAM) selective for α5GABAA receptors, in Wistar rats prenatally exposed to valproic acid, as an animal model useful for studying ASD. Postweaning rats of both sexes were treated for 7 days with vehicle or MP-III-022 at two doses pharmacokinetically determined as selective, and thereafter tested in a behavioral battery (social interaction test, elevated plus maze, spontaneous locomotor activity, and standard and reverse Morris water maze). Additional rats were used for establishing a primary neuronal culture and performing calcium imaging, and determination of hippocampal mRNA levels of GABRA5, NKCC1, and KCC2. MP-III-022 prevented impairments in many parameters connected with social, repetitive and restrictive behavioral domains. The lower and higher dose was more effective in males and females, respectively. Intriguingly, MP-III-022 elicited certain changes in control animals similar to those manifested in valproate animals themselves. Behavioral results were mirrored in GABA switch and spontaneous neuronal activity, assessed with calcium imaging, and also in expression changes of three genes analyzed. Our data support a role of α5GABAA receptors in pathophysiology of ASD, and suggest a potential application of selective PAMs in its treatment, that needs to be researched in a sex-specific manner. LAY SUMMARY: In rats prenatally exposed to valproate as a model of autism, a modulator of α5GABAA receptors ameliorated social, repetitive and restrictive impairments, and, intriguingly, elicited certain autism-like changes in control rats. Behavioral results were mirrored in GABA switch and spontaneous neuronal activity, and partly in gene expression changes. This shows a role of α5GABAA receptors in pathophysiology of ASD, and a potential application of their selective modulators in its treatment.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Prenatal Exposure Delayed Effects , Receptors, GABA-A , Animals , Autism Spectrum Disorder/chemically induced , Autism Spectrum Disorder/drug therapy , Behavior, Animal/physiology , Calcium/metabolism , Calcium/pharmacology , Disease Models, Animal , Female , Male , Pregnancy , Rats , Rats, Wistar , Receptors, GABA-A/metabolism , Social Behavior , Valproic Acid/pharmacology , gamma-Aminobutyric AcidABSTRACT
Lead (Pb) is a toxic metal that affects almost all human's system and organs, with the nervous system as the most sensitive. Better understanding of the Pb neurobehavioral effects and neurotoxicity requires realistic study scenarios based on low level exposure. The aim of this study was to determine neurotoxic effects and mechanisms of Pb in six low doses and to establish dose-response relationship for these effects and related Benchmark dose (BMD). Forty-two, male albino Wistar rats were randomized into seven groups, control and Pb-exposed: 0.1, 0.5, 1, 3, 7 and 15 mg Pb/kg body weight/day (oral gavage) for 28 days. Behavioural tests (Elevated plus maze test, Spontaneous locomotor activity test and Novel object recognition test) were conducted in the last week of experiment, in the control, lower (0.5 mg Pb/kg), middle (3 mg Pb/kg) and higher (15 mg Pb/kg) dose groups. The acetylcholinesterase activity, oxidative status and essential elements levels (Cu, Zn, Mn and Fe) were measured in brain tissue along with histological analyses. External and internal dose-response analyses were performed using PROASTweb 70.1 software. The results have shown that subacute exposure to very low doses of Pb resulted in memory deficits in rats that was accompanied with acetylcholinesterase enzyme activity decrease. The observed hyperactive behaviour was accompanied by dose-dependent induction of brain oxidative stress and Zn elevation. The histological alterations in Purkinje cells were only detected in the group treated with the highest Pb dose. The lowest BMD considering entire oxidative status was calculated based on total oxidative status (4.5e-06 mg Pb/kg b.w./day). The findings reported in our study may be beneficial in further evaluating the health consequences and human health risk assessment of low-level Pb exposure.
Subject(s)
Acetylcholinesterase , Neurotoxicity Syndromes , Animals , Benchmarking , Lead/toxicity , Male , Neurotoxicity Syndromes/etiology , Oxidative Stress , Rats , Rats, WistarABSTRACT
AIMS: GABAergic modulation involved in cognitive processing appears to be substantially changed in Alzheimer's disease (AD). In a widely used 5xFAD model of AD, we aimed to assess if negative and positive allosteric modulators of α5 GABAA receptors (NAM and PAM, respectively) would affect social interaction, social, object and spatial memory, and neuroinflammation. METHODS: After 10-day treatment with PAM, NAM, or solvent, 6-month-old transgenic and non-transgenic 5xFAD mice underwent testing in a behavioral battery. Gene expressions of IL-1ß, IL-6, TNF-α, GFAP, and IBA-1 were determined in hippocampus and prefrontal cortex by qPCR. RESULTS: PAM treatment impaired spatial learning in transgenic females compared to solvent-treated transgenic females, and social recognition in transgenic and non-transgenic males. NAM treatment declined social interaction in transgenic and non-transgenic males, while had beneficial effect on cognitive flexibility in non-transgenic males compared to solvent-treated non-transgenic males. Transgenic animals have not fully displayed cognitive symptoms, but neuroinflammation was confirmed. NAM reduced proinflammatory gene expressions in transgenic females and astrogliosis in transgenic males compared to pathological controls. CONCLUSION: PAM and NAM failed to exert favorable behavioral effects in transgenic animals. Suppression of neuroinflammation obtained with NAM calls for more studies with GABAergic ligands in amyloid beta- and/or tau-dependent models with prominent neuroinflammation.
Subject(s)
Alzheimer Disease , Alzheimer Disease/drug therapy , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Disease Models, Animal , Female , Interleukin-6/metabolism , Male , Memory , Mice , Mice, Transgenic , Neuroinflammatory Diseases , Receptors, GABA-A/genetics , Social Interaction , Solvents , Tumor Necrosis Factor-alpha/metabolism , gamma-Aminobutyric AcidABSTRACT
Intranasal treatment with oxytocin showed beneficial effects in post-traumatic stress disorder and autism spectrum disorders; however, it was not investigated as much in depression. Keeping in mind the favorable effects of oxytocin on animal models of anxiety and depression, we postulated that synergy between prescribed first choice drugs, selective serotonin reuptake inhibitors (SSRIs) and oxytocin could improve the treatment outcome compared with SSRI monotherapy. Our previous in vitro genome-wide transcriptomic study on human lymphoblastoid cell lines exposed to paroxetine resulted in increase of integrin ß3 (ITGB3) gene expression, and further, ITGB3/CHL1 expression ratio was hypothesized to influence the sensitivity to SSRIs. The aim of this report was to explore molecular mechanisms behind the antidepressant-like oxytocin effect, alone and in synergy with citalopram, on behavioral and molecular level in corticosterone treated rats, a paradigm used to model anxiety and depression in animals. Oxytocin treatment (1) ameliorated corticosterone-induced reduction of neurogenesis and number of parvalbumin-positive interneurons in the hippocampal CA1 region, (2) enhanced anxiolytic- and antidepressant-like effects of citalopram in the open field test, and (3) the SSRI/oxytocin synergy persisted in reversing the reduction of the Itgb3 gene expression and increased Itgb3/Chl1 ratio in the prefrontal cortices. These results support the existence of synergy between citalopram and oxytocin in reversing the molecular and behavioral changes induced by corticosterone treatment and point to possible molecular mechanisms behind antidepressant-like effect of oxytocin.
Subject(s)
Antidepressive Agents/pharmacology , Anxiety/drug therapy , Cell Adhesion Molecules/metabolism , Citalopram/pharmacology , Depression/drug therapy , Integrin beta3/metabolism , Oxytocin/pharmacology , Selective Serotonin Reuptake Inhibitors/pharmacology , Animals , Anxiety/chemically induced , Cell Adhesion Molecules/genetics , Citalopram/therapeutic use , Corticosterone , Depression/chemically induced , Disease Models, Animal , Drug Synergism , Integrin beta3/genetics , Interneurons/drug effects , Male , Neurogenesis/drug effects , Oxytocin/therapeutic use , Prefrontal Cortex/drug effects , Prefrontal Cortex/metabolism , Rats , Rats, WistarABSTRACT
BACKGROUND: Positive and negative allosteric modulators of α5 GABAA receptors (PAM and NAM, respectively) are worthy of investigation as putative treatments of Alzheimer's disease (AD). However, their potential to modify a dynamic range of behaviors in AD models needs to be systematically examined. OBJECTIVE: The study aimed to assess effects of MP-III-022 as PAM and PWZ-029 as NAM on emotional reactivity, motivation, and motor function, as well as on gene expression of GABRA2, GABRA3 and GABRA5 subunit of GABAA receptors in prefrontal cortex (PFC) and hippocampus (HC) in 5xFAD mice, as an early-onset transgenic AD model. METHODS: The 6-month-old 5xFAD transgenic and non-transgenic mice of both genders underwent a battery of reflexes and behavioral tests (sensorimotor tests, elevated plus maze, and open field) after 10-day intraperitoneal treatment with MP-III-022, PWZ-029, or solvent. The behavioral battery was followed by qPCR analysis of gene expression. RESULTS: MP-III-022 induced a decline in motor function, while PWZ-029 further decreased emotionality of transgenic males, as compared to the transgenic control. No interfering effects on non-cognitive behavior were observed in female mice. In HC, both treatments reversed reciprocal GABRA2 and GABRA3 changes in transgenic females. In PFC, MP-III-022 decreased GABRA5 in both genders, while PWZ-029 increased GABRA2 in male transgenic animals. CONCLUSION: Gender-dependent protracted effects of PAMs and NAMs in AD model, with detrimental impact on motor capabilities of PAM, and attenuation of emotionality elicited by NAM in transgenic males, were revealed. This favors future research of α5 GABAA receptor modulation in females as more promising.
Subject(s)
Alzheimer Disease/metabolism , Benzodiazepines/administration & dosage , Hippocampus/metabolism , Motivation , Receptors, GABA-A/metabolism , Animals , Benzodiazepines/pharmacology , Disease Models, Animal , Female , Male , Maze Learning , Mice , Mice, TransgenicABSTRACT
Over the last years, emerging incentives for secondary production of high tech-metals, found in e-waste, are created because of their increasing demand and economic issues associated with their primary production. Due to the very low share of these metals in e-waste, pre-treatment methods can result in an output fraction rich in the metals of interest and may, therefore, be essential. To this scope, the present article evaluates and compares the efficiency of four different pre-treatment approaches containing various steps for recovering indium (In) from liquid crystal displays (LCDs) in laptop computers. The pre-treatment steps, used in various combinations, are (a) dry mechanical crushing and sieving, (b) pyrolysis, (c) thermal shock and (d) gravimetric process. Also, in all approaches, liquid crystals were removed from the samples, before applying the mechanical crushing step, as these are toxic and potentially harmful to human health and the environment. The removal was achieved by ultrasonic irradiation or mild agitation and optimized in terms of time, temperature and solvent type and concentration. Then, the feasibility of each pre-treatment approach was evaluated based on two parameters: (a) the content of In in the resulting sample after pre-treatment and (b) the separated mass share (%) with larger indium content as compared to the original LCD panel. The results showed that In is highly liberated in the fractions consisting of finest particles (<25⯵m and <53⯵m) after dry mechanical crushing and sieving with a maximum content of 234â¯mg/kg, which is twice as much as in the raw material. However, these particles represented only about 14â¯wt% of the original LCD panel mass. On the contrary, thermal shock results indicated that this was the most efficient pre-treatment approach, as both the content of In and the separated LCD mass (%) remained in high levels. Finally, some economic aspects associated with the processes are presented.
Subject(s)
Electronic Waste , Liquid Crystals , Indium , Recycling , UltrasonicsABSTRACT
Although a magnesium-mediated attenuation of memory deficits was reported in animal models of ageing and traumatic brain injury, a possible memory enhancement in healthy subjects has not been investigated yet. We used novel object recognition test (NORT) to examine the effects of acute (30 mg/kg) and chronic (50 mg/kg, 28 days) Mg-sulfate treatment on the long-term memory (LTM) in healthy adult male rats, and to test the sustainability of magnesium effects in the models of acute and chronic (21 days) ACTH administration (10 µg/animal), mimicking the stress- and depression-like conditions. A single dose of Mg-sulfate enhanced the LTM retrieval in the 24 h inter-trial NORT protocol, in healthy, as well as in rats acutely treated with ACTH. Memory enhancement was also detected after 4-week long Mg-sulfate intake, in both healthy and rats chronically treated with ACTH. While the present findings on procognitive effects of chronic Mg-sulfate treatment corroborate with those from studies on the therapeutic potential of Mg-threonate, the current study is the first to report on memory enhancement induced by a single dose of magnesium.
Subject(s)
Adrenocorticotropic Hormone/pharmacology , Magnesium/administration & dosage , Magnesium/pharmacology , Memory, Long-Term/drug effects , Recognition, Psychology/drug effects , Adrenocorticotropic Hormone/blood , Animals , Brain/metabolism , Dose-Response Relationship, Drug , Male , Rats, WistarABSTRACT
This study aimed to investigate the potential of lecithin-based nanoemulsions costabilized by sucrose esters, with and without skin pretreatment with stainless steel microneedles, to improve delivery of aceclofenac, as a model drug, into/across the skin. The characterization revealed favorable droplet size (about 180â¯nm), narrow size distribution (<0.15), high surface charge (about -40â¯mV) and satisfying long-term stability (one year at 4⯱â¯1⯰C) of the formulation costabilized by sucrose palmitate, demonstrating a similar trend observed for the reference stabilized by widely used lecithin/polysorbate 80 combination. In vitro release/permeation testing and differential stripping on the porcine ear proved the superiority of the sucrose ester- over polysorbate-based nanoemulsion. However, in vitro findings were not fully indicative of the in vivo performances - no significant differences were observed between investigated formulations in pharmacokinetic profile and total amount of aceclofenac deposited in the rat skin 24â¯h after dosing, simultaneously pointing to delayed aceclofenac delivery into the systemic circulation. In addition, the ratio of plasma concentrations of aceclofenac and its major metabolite in rats, diclofenac, was remarkably changed after topical application of tested nanoemulsions compared to intravenous administration of aceclofenac solution. Finally, skin pretreatment with microneedles improved aceclofenac delivery into/across the rat skin from tested formulations, resulting in 1.4-2.1-fold increased bioavailability and 1.2-1.7-fold enhanced level of aceclofenac retained in the skin, as measured 24â¯h after administration. Moreover, the plasma concentrations of aceclofenac 24â¯h after application of tested formulations (lecithin/sucrose palmitate vs. lecithin/polysorbate 80) combined with microneedles (173.37⯱â¯40.50â¯ng/ml vs. 259.23⯱â¯73.18â¯ng/ml) were significantly higher than those obtained through intact skin (105.69⯱â¯19.53â¯ng/ml vs. 88.38⯱â¯14.46â¯ng/ml). However, obtained results suggest that combination of microneedles and sucrose palmitate-costabilized nanoemulsion could be useful to attain higher skin concentration, while combination of microneedles with polysorbate 80-costabilized nanoemulsion could be a preferable option for enhancing drug delivery into the bloodstream.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Diclofenac/analogs & derivatives , Drug Delivery Systems , Nanoparticles/administration & dosage , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Biological Transport , Diclofenac/administration & dosage , Diclofenac/pharmacokinetics , Drug Liberation , Emulsions , Microinjections , Needles , Rats, Wistar , Skin/metabolism , Skin Absorption , Sucrose/administration & dosage , Sucrose/analogs & derivatives , Sucrose/pharmacokinetics , SwineABSTRACT
It is unclear whether GABAA receptors (GABAARs) that contain the α3-subunit are substantially involved in the anxiolytic effects of benzodiazepines (BDZs). In the present study, we tested YT-III-31, a newer BDZ ligand with functional preference for α3ßγ2 GABAARs, in two paradigms of unconditioned anxiety, the open field and elevated plus maze in rats. The effective dose of YT-III-31 (2â¯mg/kg) displayed a clear anxiolytic-like profile, unhampered by sedative action, in both tests. At a higher dose (10â¯mg/kg), YT-III-31 induced ataxia in the rotarod and sedation in spontaneous locomotor activity test. The latter effect was preventable by flumazenil and ßCCt, the non-selective and α1ßγ2 GABAAR affinity-selective antagonist, respectively, demonstrating that sedative properties of YT-III-31, when attained, are mediated by the α1γ2 site. To elucidate the receptor substrate of subtle behavioral differences between YT-III-31 and diazepam, we approximated in vivo receptor potentiation for both ligands, based on estimated unbound concentrations in rat brains. Far different from diazepam, YT-III-31 has significantly lower affinity for the α1γ2 over other BDZ-sensitive sites, and at lower doses (1-2â¯mg/kg) was devoid of potentiation at α1ßγ2 GABAARs. The approximation approach revealed a modest selectivity of YT-III-31 for α3γ2- in comparison to α2γ2 and α5γ2 binding sites, suggesting that its anxiolytic-like activity may not necessarily or predominantly reflect potentiation at α3ßγ2 GABAARs. Nonetheless, as the anxiolytic effects are achievable at a dose devoid of any sedative potential, and having favorable safety (cytotoxicity) and metabolic stability profile, YT-III-31 represents a valuable candidate for further translational research.
Subject(s)
GABA Agents/pharmacology , Receptors, GABA-A/metabolism , Animals , Anti-Anxiety Agents/pharmacology , Anxiety/drug therapy , Anxiety/metabolism , Benzodiazepines/pharmacology , Binding Sites , Binding, Competitive , Brain/drug effects , Brain/metabolism , Dose-Response Relationship, Drug , Hypnotics and Sedatives/pharmacology , Male , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Motor Activity/drug effects , Motor Activity/physiology , Rats, WistarABSTRACT
We previously demonstrated that lipopolysaccharide (LPS) administered intraperitoneally (i.p.) to pregnant Wistar rat dams, at embryonic days 15 and 16 (E15/16), induced a decrease of baseline locomotor activity and diminished reactivity to amphetamine in adult female offspring. In the present study we aimed to assess the duration of LPS-induced maternal immune activation (MIA) and investigate possible changes in levels of main neurotransmitters in fetal brain during MIA. We hypothesized that the observed behavioral changes may be linked with MIA-induced disturbance of prenatal GABAergic system development, especially with α5 GABAA receptors (α5GABAARs), expression of which takes place between E14 and E17. Thereafter, we set to investigate if later potentiation of α5GABAARs in offspring's preadolescence (from postnatal day 22-28) could prevent the deficit in locomotor reactivity to amphetamine observed in adulthood, at postnatal day P60. The elevation of IL-6 in amniotic fluid 6h after LPS treatment (100µg/kg, i.p.) at E15 was concurrent with a significant increase of GABA and decrease of glutamate concentration in fetal brain. Moreover, repeated administration of MP-III-022, a selective positive allosteric modulator of α5GABAARs, at a dose (2mg/kg daily, i.p.) derived from a separate pharmacokinetic study, prevented the LPS-induced decrease in locomotor reactivity to amphetamine (0.5mg/kg, i.p.) in adult females. These results were not mirrored in the parallel set of experiments with male offspring from LPS-treated rats. The results suggest that pharmacological potentiation of α5GABAARs activity in preadolescence may ameliorate at least some of adverse consequences of exposure to MIA in utero.