New curcumin-loaded nanocapsules as a therapeutic alternative in an amnesia model

This study aimed to investigate the action of two different formulations of curcumin (Cur)-loaded nanocapsules (Nc) (Eudragit [EUD] and poly (ɛ-caprolactone) [PCL]) in an amnesia mice model. We also investigated the formulations' effects on scopolamine-induced (SCO) depressive- and anxiety-like comorbidities, the cholinergic system, oxidative parameters, and inflammatory markers. Male Swiss mice were randomly divided into five groups (n = 8): group I (control), group II (Cur PCL Nc 10 mg/kg), group III (Cur EUD Nc 10 mg/kg), group IV (free Cur 10 mg/kg), and group V (SCO). Treatments with Nc or Cur (free) were performed daily or on alternate days. After 30 min of treatment, the animals received the SCO and were subjected to behavioral tests 30 min later (Barnes maze, open-field, object recognition, elevated plus maze, tail suspension tests, and step-down inhibitory avoidance tasks). The animals were then euthanized and tissue was removed for biochemical assays. Our results demonstrated that Cur treatment (Nc or free) protected against SCO-induced amnesia and depressive-like behavior. The ex vivo assays revealed lower acetylcholinesterase (AChE) and catalase (CAT) activity, reduced thiobarbituric species (TBARS), reactive species (RS), and non-protein thiols (NSPH) levels, and reduced interleukin-6 (IL-6) and tumor necrosis factor (TNF) expression. The treatments did not change hepatic markers in the plasma of mice. After treatments on alternate days, Cur Nc had a more significant effect than the free Cur protocol, implying that Cur may have prolonged action in Nc. This finding supports the concept that it is possible to achieve beneficial effects in nanoformulations, and treatment on alternate days differs from the free Cur protocol regarding anti-amnesic effects in mice.

4-(Phenylselanyl)-2H-chromen-2-one-Loaded Nanocapsule Suspension-A Promising Breakthrough in Pain Management: Comprehensive Molecular Docking, Formulation Design, and Toxicological and Pharmacological Assessments in Mice

Therapies for the treatment of pain and inflammation continue to pose a global challenge, emphasizing the significant impact of pain on patients' quality of life. Therefore, this study aimed to investigate the effects of 4-(Phenylselanyl)-2H-chromen-2-one (4-PSCO) on pain-associated proteins through computational molecular docking tests. A new pharmaceutical formulation based on polymeric nanocapsules was developed and characterized. The potential toxicity of 4-PSCO was assessed using Caenorhabditis elegans and Swiss mice, and its pharmacological actions through acute nociception and inflammation tests were also assessed. Our results demonstrated that 4-PSCO, in its free form, exhibited high affinity for the selected receptors, including p38 MAP kinase, peptidyl arginine deiminase type 4, phosphoinositide 3-kinase, Janus kinase 2, toll-like receptor 4, and nuclear factor-kappa β. Both free and nanoencapsulated 4-PSCO showed no toxicity in nematodes and mice. Parameters related to oxidative stress and plasma markers showed no significant change. Both treatments demonstrated antinociceptive and anti-edematogenic effects in the glutamate and hot plate tests. The nanoencapsulated form exhibited a more prolonged effect, reducing mechanical hypersensitivity in an inflammatory pain model. These findings underscore the promising potential of 4-PSCO as an alternative for the development of more effective and safer drugs for the treatment of pain and inflammation.

Synthesis and investigation of new indole-containing vinyl sulfide derivatives: In silico and in vitro studies for potential therapeutic applications

Indoles featuring organosulfur compounds serve as privileged structural scaffolds in various biologically active compounds. This study investigates the biological properties of five synthetic sulphenyl vinyl indoles (3 a-e) using both in silico and in vitro methods. Computational analyses employing Swiss ADME and Molinspiration software reveal the remarkable inhibitory activity of compound 3 d against proteases and kinases (scores of 0.18 and 0.06, respectively). Furthermore, it demonstrates the ability to modulate ionic and G protein-coupled receptors (scores: -0.06 and 0.31, respectively) and serves as a ligand for nuclear receptors (score 0.15). In vitro investigations highlight the compounds' efficacy in countering ABTS+ radical attacks and reducing lipid peroxidation levels. Particularly noteworthy is the superior efficacy of compounds 3 a, 3 b, and 3 e in DPPH (EC50 3 a: 268.5 μM) and TEAC assays (EC50 3 a: 49.9 μM; EC50 3 b: 133.4 μM, and EC50 3 e: 84.9 μM), as well as TBARS levels. Compound 3 c significantly reduces acetylcholinesterase activity, positioning itself as a noteworthy enzyme inhibitor. This study emphasizes the versatile biological potential of synthetic indole derivatives, suggesting their applicability for therapeutic purposes.

The Antinociceptive Responses of MTDZ to Paclitaxel-Induced Peripheral Neuropathy and Acute Nociception in Mice: Behavioral, Pharmacological, and Biochemical Approaches

The efficacy of 5-((4-methoxyphenyl)thio)benzo[c][1,2,5] thiodiazole (MTDZ) in mitigating paclitaxel (PTX)-induced peripheral neuropathy was investigated in male and female Swiss mice. The study examined the effects of MTDZ on various pathways, including transient receptor potential cation channel subfamily V member 1 (TRPV1), glutamatergic, nitrergic, guanylate cyclase (cGMP), serotonergic, and opioidergic. Mice received intraperitoneal PTX (2 mg/kg) or vehicle on days 1, 2, and 3, followed by oral MTDZ (1 mg/kg) or vehicle from days 3 to 14. Mechanical and thermal sensitivities were assessed using Von Frey and hot plate tests on days 8, 11, and 14. The open field test evaluated locomotion and exploration on day 12. On day 15, nitrite and nitrate (NOx) levels and Ca2+-ATPase activity in the cerebral cortex and spinal cord were measured after euthanizing the animals. MTDZ administration reversed the heightened mechanical and thermal sensitivities induced by PTX in male and female mice without affecting locomotion or exploration. MTDZ also modulated multiple pathways, including glutamatergic, NO/L-arginine/cGMP, serotonergic (5-HT1A/1B), opioid, and TRPV1 pathways. Additionally, MTDZ reduced NOx levels and modulated Ca2+-ATPase activity. In conclusion, MTDZ effectively alleviated PTX-induced peripheral neuropathy and demonstrated multi-targeted modulation of pain-related pathways. Its ability to modulate multiple pathways, reduce NOx levels, and modulate Ca2+-ATPase activity makes it a potential pharmacological candidate for peripheral neuropathy, acute nociceptive, and inflammatory conditions. Further research is needed to explore its therapeutic potential in these areas.

Development and In Vivo Assessment of 4-Phenyltellanyl-7-chloroquinoline-loaded Polymeric Nanocapsules in Alzheimer's Disease Models

Alzheimer's disease (AD) is the most common form of dementia in older people, and available treatments are palliative and produce undesirable side effects. The 4-phenyltellanyl-7-chloroquinoline (TQ) is an organochalcogen compound studied due to its pharmacological properties, particularly its antioxidant potential. However, TQ possesses some drawbacks such as low aqueous solubility and high toxicity, thus warranting the search for tools that improve the safety and effectiveness of new compounds. Here, we developed and investigated the biological effects of TQ-loaded polymeric nanocapsules (NCTQ) in an AD model in transgenic Caenorhabditis elegans expressing human Aβ_1-42 in their body-wall muscles and Swiss mice injected with Aβ_25-35. The NCTQ displayed good physicochemical properties, including nanometer size and maximum encapsulation capacity. The treatment showed low toxicity, reduced Aβ peptide-induced paralysis, and activated an endoplasmic reticulum chaperone in the C. elegans model. The Aβ injection in mice caused memory impairment, which NCTQ mitigated by improving working, long-term, and aversive memory. Additionally, no changes in biochemical markers were evidenced in mice, demonstrating that there was no hepatotoxicity in the tested doses. Altogether, these findings provide insights into the neuroprotective effects of TQ and indicate that NCTQ is a promising candidate for AD treatment.

Treating atopic-dermatitis-like skin lesions in mice with gelatin-alginate films containing 1,4-anhydro-4-seleno-d-talitol (SeTal)

New compounds and pharmacological strategies offer alternatives for treating chronic skin diseases, such as atopic dermatitis (AD). Here, we investigated the incorporation of 1,4-anhydro-4-seleno-d-talitol (SeTal), a bioactive seleno-organic compound, in gelatin and alginate (Gel-Alg) polymeric films as a strategy for improving the treatment and attenuation of AD-like symptoms in a mice model. Hydrocortisone (HC) or vitamin C (VitC) were incorporated with SeTal in the Gel-Alg films, and their synergy was investigated. All the prepared film samples were able to retain and release SeTal in a controlled manner. In addition, appreciable film handling facilitates SeTal administration. A series of in-vivo/ex-vivo experiments were performed using mice sensitized with dinitrochlorobenzene (DNCB), which induces AD-like symptoms. Long-term topical application of the loaded Gel-Alg films attenuated disease symptoms and pruritus, with suppression of the levels of inflammatory markers, oxidative damage, and the skin lesions associated with AD. Moreover, the loaded films showed superior efficiency in attenuating the analyzed symptoms when compared to hydrocortisone (HC) cream, a traditional AD-treatment, and decreased the inherent drawbacks of this compound. In short, incorporating SeTal (by itself or with HC or VitC) in biopolymeric films provides a promising alternative for the long-term treatment of AD-type skin diseases.

Novel Pullulan/Gellan Gum Bilayer Film as a Vehicle for Silibinin-Loaded Nanocapsules in the Topical Treatment of Atopic Dermatitis

In this study a novel gellan gum/pullulan bilayer film containing silibinin-loaded nanocapsules was developed for topical treatment of atopic dermatitis (AD). The bilayer films were produced by applying a pullulan layer on a gellan gum layer incorporated with silibinin nanocapsules by two-step solvent casting method. The bilayer formation was confirmed by microscopic analysis. In vitro studies showed that pullulan imparts bioadhesitvity for the films and the presence of nanocapsules increased their occlusion factor almost 2-fold. Besides, the nano-based film presented a slow silibinin release and high affinity for cutaneous tissue. Moreover, this film presented high scavenger capacity and non-hemolytic property. In the in vivo study, interestingly, the treatments with vehicle film attenuated the scratching behavior and the ear edema in mice induced by 2,4-dinitrochlorobenzene (DNCB). However, the nano-based film containing silibinin modulated the inflammatory and oxidative parameters in a similar or more pronounced way than silibinin solution and vehicle film, as well as than hydrocortisone, a classical treatment of AD. In conclusion, these data suggest that itself gellan gum/pullulan bilayer film might attenuate the effects induced by DNCB, acting together with silibinin-loaded nanocapsules, which protected the skin from oxidative damage, improving the therapeutic effect in this AD-model.

SAFETY PROFILE AND PREVENTION OF COGNITIVE DEFICIT IN ALZHEIMER’S DISEASE MODEL OF GRAPHENE FAMILY NANOMATERIALS, TUCUMA OIL (Astrocaryum vulgare) AND ITS SYNERGISMS

Alzheimer's disease is a worldwide health issue, and there are currently no treatments that can stop this disease. Oxidized graphene derivatives have gained prominence in use in biological systems due to their excellent physical-chemical characteristics, biocompatibility and ability to overcome the blood-brain barrier. Other substances highlighted are those of natural origin from the Amazon biome, such as tucuma, a fruit whose oil has been widely studied in therapeutic applications. Thus, the aim of this study was to investigate the action of graphene oxide, reduced graphene oxide and tucuma oil, isolated and combined, as an alternative for treatment of Alzheimer's disease through studies in silico, in vitro, in vivo and ex vivo. Computational simulation via docking was used to verify the affinity of the substances with the proteins β-amyloid and acetylcholinesterase, in which the reduced graphene oxide was the one that showed the most favorable interaction. The results of the ab initio simulation showed that the synergism between the nanostructures and the oil occurs through physical adsorption. The experimental results revealed that the substances and their combinations were nontoxic, both at the cellular and systemic level. In general, all treatments had positive results against induced memory deficit, but reduced graphene oxide was the most prominent, as it was able to protect against memory damage in all behavioral tests performed, with anticholinesterase activity and antioxidant effect. In conclusion, the reduced graphene oxide is, among the treatments studied, the one with great therapeutic potential to be investigated in the treatment of this disease.

Synthesis and Evaluation of Antioxidant, Anti-Edematogenic and Antinociceptive Properties of Selenium-Sulfa Compounds

Herein we describe results for the synthesis and synthetic application of 4-amino-3-(arylselenyl)benzenesulfonamides, and preliminary evaluation of antioxidant, anti-edematogenic and antinociceptive properties. This class of compounds was synthesized in good yields by a reaction of commercially available sulfanilamide and diorganyl diselenides in the presence of 10 mol% of I2 . Furthermore, the synthesized compound 4-amino-3-(phenylselenyl)benzenesulfonamide (3 a) was evaluated on complete Freund's adjuvant (CFA)-induced acute inflammatory pain. Dose- and time-response curves of antinociceptive effect of compound 3 a were performed using this experimental model. Also, the effect of compound 3 a was monitored in a hot-plate test to evaluate the acute non-inflammatory antinociception. The open-field test was performed to evaluate the locomotor and exploratory behaviors of mice. Oxidative stress markers, such as glutathione peroxidase activity; reactive species, non-protein thiols, and lipid peroxidation levels were performed to investigate the antioxidant action of compound 3 a. Our findings suggest that the antioxidant effect of compound 3 a may contribute to reducing the nociception and suppress the signaling pathways of inflammation on the local injury induced by CFA. Thus, compound 3 a reduced the paw edema as well as the hyperalgesic behavior in mice, being a promising therapeutic agent for the treatment of painful conditions.

Transdermal release of methotrexate by cationic starch/poly(vinyl alcohol)-based films as an approach for rheumatoid arthritis treatment

Methotrexate (MTX) is a common drug used for rheumatoid arthritis (RA) treatment; however, a series of adverse effects associated with its oral or subcutaneous administration is reported. Transdermal delivery of MTX is an alternative to abate these issues, and the use of drug delivery systems (DDS) based on polymeric films presents an impressive potential for this finality. Based on this, in this study, we report the preparation of films made by cationic starch (CSt), poly(vinyl alcohol) (PVA), and chondroitin sulfate (ChS) to incorporate and release MTX, as well as the in vivo evaluation in model of rheumatoid arthritis in mice. CSt/PVA and CSt/PVA/ChS-based films (with and without MTX) were prepared using a simple protocol under mild conditions. The films loaded with 5 w/w-% of MTX exhibited appreciable drug loading efficiency and distribution. The MTX permeation through the layers of porcine skin demonstrated that most of the drug permeated was detected in the medium, suggesting that the formulation can provide a systemic absorption of the MTX. In vivo studies performed in an arthritis-induced model in mice demonstrated that the MTX-loaded films were able to treat and attenuate the symptoms and the biochemical alterations related to RA (inflammatory process, oxidative stress, and nociceptive behaviors). Besides, the pharmacological activity of MTX transdermally delivery by the CSt/PVA and CSt/PVA/ChS films was comparable to the MTX orally administered. Based on these results, it can be inferred that both films are prominent materials for incorporation and transdermal delivery of MTX in a practical and non-invasive manner.

Contribution of antioxidant action of 7-chloro-4-(phenylselanyl) quinoline to treat streptozotocin-induced diabetic neuropathy in mice

Hyperglycemia caused by diabetes mellitus contributes to complications such as diabetic neuropathy (DN), and its high prevalence and consequent economic costs make developing alternative therapies crucial. Given this scenario, this...

Prospecting for a quinoline containing selenium for comorbidities depression and memory impairment induced by restriction stress in mice

RATIONALE

Depression is often associated with memory impairment, a clinical feature of Alzheimer's disease (AD), but no effective treatment is available. 7-Chloro-4-(phenylselanyl) quinoline (4-PSQ) has been studied in experimental models of diseases that affect the central nervous system.

OBJECTIVES

The pharmacological activity of 4-PSQ in depressive-like behavior associated with memory impairment induced by acute restraint stress (ARS) in male Swiss mice was evaluated.

METHODS

ARS is an unavoidable stress model that was applied for a period of 240 min. Ten minutes after ARS, animals were intragastrically treated with canola oil (10 ml/kg) or 4-PSQ (10 mg/kg) or positive controls (paroxetine or donepezil) (10 mg/kg). Then, after 30 min, mice were submitted to behavioral tests. Corticosterone levels were evaluated in plasma and oxidative stress parameters; monoamine oxidase (MAO)-A and MAO -B isoform activity; mRNA expression levels of kappa nuclear factor B (NF-κB); interleukin (IL)-1β, IL-18, and IL-33; phosphatidylinositol-se-kinase (PI3K); protein kinase B (AKT2), as well as acetylcholinesterase activity were evaluated in the prefrontal cortex and hippocampus.

RESULTS

4-PSQ attenuated the depressive-like behavior, self-care, and memory impairment caused by ARS. Based on the evidence, we believe that effects of 4-PSQ may be associated, at least in part, with the attenuation of HPA axis activation, attenuation of alterations in the monoaminergic system, modulation of oxidative stress, reestablishment of AChE activity, modulation of the PI3K/AKT2 pathway, and reduction of neuroinflammation.

CONCLUSIONS

These results suggested that 4-PSQ exhibited an antidepressant-like effect and attenuated the memory impairment induced by ARS, and it is a promising molecule to treat these comorbidities.

Synthesis and biological evaluation of 5-chalcogenyl-benzo[h]quinolines via photocyclization of arylethynylpyridine derivatives

A new and efficient method for the synthesis of 6-organyl-5-(arylselanyl)benzo[h]quinolines via visible light-promoted intramolecular ortho-cyclization of 2-aryl-3-(organylethynyl)pyridines has been achieved. The reaction was promoted by radical organochalcogen species generated in...

Target enzymes in oxaliplatin-induced peripheral neuropathy in Swiss mice: A new acetylcholinesterase inhibitor as therapeutic strategy

In the present study it was hypothesized that 5-((4-methoxyphenyl)thio)benzo[c][1,2,5] thiodiazole (MTDZ), a new acetylcholinesterase inhibitor, exerts antinociceptive action and reduces the oxaliplatin (OXA)-induced peripheral neuropathy and its comorbidities (anxiety and cognitive deficits). Indeed, the acute antinociceptive activity of MTDZ (1 and 10 mg/kg; per oral route) was observed for the first time in male Swiss mice in formalin and hot plate tests and on mechanical withdrawal threshold induced by Complete Freund's Adjuvant (CFA). To evaluate the MTDZ effect on OXA-induced peripheral neuropathy and its comorbidities, male and female Swiss mice received OXA (10 mg/kg) or vehicle intraperitoneally, on days 0 and 2 of the experimental protocol. Oral administration of MTDZ (1 mg/kg) or vehicle was performed on days 2-14. OXA caused cognitive impairment, anxious-like behaviour, mechanical and thermal hypersensitivity in animals, with females more susceptible to thermal sensitivity. MTDZ reversed the hypersensitivity, cognitive impairment and anxious-like behaviour induced by OXA. Here, the negative correlation between the paw withdrawal threshold caused by OXA and acetylcholinesterase (AChE) activity was demonstrated in the cortex, hippocampus, and spinal cord. OXA inhibited the activity of total ATPase, Na⁺ K⁺ - ATPase, Ca²⁺ - ATPase and altered Mg²⁺ - ATPase in the cortex, hippocampus, and spinal cord. OXA exposure increased reactive species (RS) levels and superoxide dismutase (SOD) activity in the cortex, hippocampus, and spinal cord. MTDZ modulated ion pumps and reduced the oxidative stress induced by OXA. In conclusion, MTDZ is an antinociceptive molecule promising to treat OXA-induced neurotoxicity since it reduced nociceptive and anxious-like behaviours, and cognitive deficit in male and female mice.

Organoselenium-chitosan derivative: Synthesis via "click" reaction, characterization and antioxidant activity

The derivatization of chitosan (CS) is widely exploited to endow this polysaccharide with enhanced physicochemical and biological properties. Beyond the synthetic route, the nature of the compounds used to functionalize the CS-derivatives exerts a pivotal role in their final properties. Making use of a simple "click" reaction, we synthesized for the first time an organoselenium-CS derivative through a 1,2,3-triazole formation. The product (CS-TSe) was characterized in detail by FTIR, NMR (¹H, ¹³C, and ⁷⁷Se) and UV-Vis techniques, and SEM microscopy. The antioxidant activity of CS-TSe was examined by ABTS⁺ and DPPH (free radical-scavenging) assays. Experimentally, it was demonstrated that CS-TSe has superior antioxidant activity compared with raw CS and "free" organoselenium compound, suggesting a benign and synergistic effect due to the derivatization. In short, the antioxidant property of CS-TSe combined with the other attractive properties of CS and selenium could be useful in the formulation of advanced materials for biomedical and packaging applications.

Pullulan film incorporated with nanocapsules improves pomegranate seed oil anti-inflammatory and antioxidant effects in the treatment of atopic dermatitis in mice

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.

A new arylsulfanyl-benzo-2,1,3-thiadiazoles derivative produces an anti-amnesic effect in mice by modulating acetylcholinesterase activity

The aim of the present study was investigate the binding affinity of 5-((4-methoxyphenyl)thio)benzo[c][1,2,5]thiadiazole (MTDZ) with acetylcholinesterase (AChE). We also evaluated the effect of MTDZ against scopolamine (SCO)-induced amnesia in mice and we looked at the toxicological potential of this compound in mice. The binding affinity of MTDZ with AChE was investigated by molecular docking analyses. For an experimental model, male Swiss mice were treated daily with MTDZ (10 mg/kg, intragastrically (i.g.)) or canola oil (10 ml/kg, i.g.), and induced, 30 min later, with injection of SCO (0.4 mg/kg, intraperitoneally (i.p.)) or saline (0.9%, 5 ml/kg, i.p.) daily. From day 1 to day 10, mice were submitted to the behavioral tasks (Barnes maze, open-field, object recognition and location, Y-maze and step-down inhibitory avoidance tasks), 30 min after induction with SCO. On the tenth day, the animals were euthanized and blood was collected for the analysis of biochemical markers (creatinine, aspartate (AST), and alanine (ALT) aminotransferase). MTDZ interacts with residues of the AChE active site. SCO caused amnesia in mice by changing behavioral tasks. MTDZ treatment attenuated the behavioral changes caused by SCO. In ex vivo assay, MTDZ also protected against the alteration of AChE activity, reactive species (RS) levels, thiobarbituric acid reative species (TBARS) levels, catalase (CAT) activity in tissues, as well as in transaminase activities of plasma caused by SCO in mice. In conclusion, MTDZ presented anti-amnesic action through modulation of the cholinergic system and provided protection from kidney and liver damage caused by SCO.

Se-[(2,2-Dimethyl-1,3-dioxolan-4-yl)methyl] 4-Chlorobenzoselenolate Attenuates Inflammatory Response, Nociception, and Affective Disorders Related to Rheumatoid Arthritis in Mice

Despite major advances, not all patients achieve rheumatoid arthritis (RA) remission, thus highlighting a pressing need for new therapeutic treatments. Given this scenario, this study sought to evaluate Se-[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl] 4-chlorobenzoselenolate (Se-DMC) potential on a complete Freund's adjuvant (CFA)-induced unilateral arthritis model. The effects of Se-DMC (5 mg/kg; oral dose) and meloxicam (5 mg/kg; oral dose), both administered to animals daily for 14 days, on paw edema, mechanical sensitivity, neurobehavioral deficits (anxiogenic- and depressive-like behaviors), Na⁺/K⁺-ATPase activity, oxidative stress, and inflammation were evaluated in male Swiss mice exposed to CFA (intraplantar injection of 0.1 mL; 10 mg/mL). Se-DMC reduced the paw withdrawal threshold and CFA-induced paw edema. Histopathological results revealed the antiedematogenic potential of the compound, which was evidenced by lower quantities of dilated lymphatic vessels compared with the CFA group. Se-DMC reduced mRNA relative expression levels of tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB) in the hippocampus and paw of CFA mice. The CFA-induced anxiogenic- and depressive-like behaviors were reversed by Se-DMC to the control levels in the elevated plus-maze and tail suspension tests. Se-DMC reduced the paw reactive species levels and restored the superoxide dismutase (hippocampus and paw) and Na⁺/K⁺-ATPase (hippocampus) activities previously increased by CFA. Moreover, CFA administration inhibited serum creatinine kinase activity, albeit the Se-DMC effects did not appear to involve the modulation of this enzyme and were equal to or greater than meloxicam. Se-DMC attenuates CFA-induced inflammatory response, nociception, and neurobehavioral deficits in mice.

4-Phenylselanyl-7-chloroquinoline attenuates hepatic injury triggered by neonatal exposure to monosodium glutamate in rats

AIMS

Obesity is associated with a spectrum of hepatic abnormalities that can be experimentally induced by injections of monosodium glutamate (MSG) in neonatal rodents. We investigated the protective actions of the repeated therapy with 4-phenylselenyl-7-chloroquinoline (4-PSQ), a quinoline derivative containing selenium, on damage to the liver triggered by early postnatal administration of MSG in male Wistar rats.

MAIN METHODS

Neonatal rats received MSG (4 g/kg, subcutaneous route) or saline (1 ml/kg) from 5 to 14 postnatal day (PND) to induce obesity with consequent damages in the liver. 4-PSQ treatment (5 mg/kg) or canola oil (1 ml/kg) was administered from 60 to 76 PND by the intragastric route. On 76 PND, animals were anesthetized for blood and liver collection. Plasma markers of hepatic function, hepatic lipoperoxidation levels and histology analysis of liver tissue were assessed.

KEY FINDINGS

Our data revealed that treatment with 4-PSQ reverted the increase in plasma transaminases activities observed in MSG rats. Treatment with 4-PSQ reduced plasma lactate levels in obese rats. In the liver, MSG elevated the content of lipoperoxidation which was reverted by 4-PSQ administrations. Lastly, 4-PSQ therapy attenuated the histological alterations induced by MSG.

SIGNIFICANCE

Together, the results indicate a hepatoprotective action of repeated treatment with 4-PSQ in obese rats.

Suppressive effect of 1,4-anhydro-4-seleno-D-talitol (SeTal) on atopic dermatitis-like skin lesions in mice through regulation of inflammatory mediators

BACKGROUND

Atopic dermatitis (AD) is a multifactorial chronic inflammatory disease that affects ∼20 % of children and 3% of adults globally and is generally treated by the topical application of steroidal drugs that have undesirable side-effects. The development of alternative therapies is therefore an important objective. The present study investigated the effects of topical treatment with a novel water-soluble selenium-containing carbohydrate derivative (4-anhydro-4-seleno-D-tatitol, SeTal) on the symptoms and inflammatory parameters in an AD mouse model.

METHODS

Mice were sensitized by applying 2,4-dinitrochlorobenzene (DNCB) to their dorsal skin on days 1-3, then further challenged on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. SeTal (1 and 2%) or hydrocortisone (1%) was applied topically to the backs of the mice from days 14-29, and skin severity scores and scratching behavior determined on day 30. The mice were euthanized, and their ears and dorsal skin removed to quantify inflammatory parameters, edema, myeloperoxidase (MPO) activity, and AD-associated cytokines (tumor necrosis factor alpha (TNF-α), interleukins (IL)-18, and IL-33).

RESULTS

DNCB treatment induced skin lesions and increased the scratching behavior, ear edema, MPO activity (ear and dorsal skin), and cytokine levels in dorsal skin. Topical application of SeTal improved inflammatory markers (cytokine levels and MPO activity), cutaneous severity scores, and scratching behavior.

CONCLUSION

The efficacy of SeTal was satisfactory in the analyzed parameters, showing similar or better results than hydrocortisone. SeTal appears to be therapeutically advantageous for the treatment and control of AD.

The neurotherapeutic role of a selenium-functionalized quinoline in hypothalamic obese rats

RATIONALE

Obesity is considered one of the major global health problems and increases the risk of several medical complications, such as diabetes and mental illnesses.

OBJECTIVE

The present study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on obesity parameters, behavioral and neurochemical alterations in hypothalamic obese rats.

METHODS

Male Wistar rats received subcutaneous neonatal injections of monosodium glutamate (MSG, 4g/kg) or saline. After the Lee Index evaluation, rats were divided into groups and treated with 4-PSQ (5 mg/kg, intragastric route) or canola oil once a day (post-natal days (PND) 60→76). Open-field, elevated plus-maze, forced swim task, object recognition/location memory, and stepdown inhibitory avoidance tasks were conducted from PND 66 to 74. On PND 76, rats were euthanized and epididymal fat, blood, cerebral cortex, andhippocampus were removed. Blood biochemical parameters and cortical/hippocampal acetylcholinesterase (AChE) and Na /K -ATPase activities were assessed.

RESULTS

MSG increased the Lee Index characterizing the chemically induced hypothalamic obesity model. 4-PSQ reversed the increases of epididymal fat, blood glucose, and triglyceride levels caused by MSG exposure. 4-PSQ attenuated anxiety-like and depression-like behaviors induced by neonatal administrations of MSG. Memory deficits found in MSG-obese rats were reversed by treatment with 4-PSQ. Neurochemical alterations produced by MSG evidenced by stimulation ofNa⁺/K⁺-ATPase and AChE activities in the cerebral cortex and hippocampus of rats were normalized by 4-PSQ treatment.

CONCLUSIONS

In brief, 4-PSQ therapy improved hypothalamic obesity-related parameters, as well as psychiatric symptoms, cognitive impairment, and neurochemical alterations found in obese rats.

Bis-(3-amino-2-pyridine) diselenide improves psychiatric disorders -atopic dermatitis comorbidity by regulating inflammatory and oxidative status in mice

Suppressive effect of bis (3-amino-2-pyridine) diselenide (BAPD) on psychiatric disorders - atopic dermatitis (AD) comorbidity in mice was investigated. To sensitize the animals, 2,4-dinitrochlorobenzene (DNCB) was applied to their dorsal skin on days 1-3. Mice were challenged with DNCB on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. BAPD and Dexamethasone were administered to the animals, from days 14-29, and skin severity scores and behavioral tests were determined. Oxidative stress and inflammatory parameters were evaluated on the dorsal skin of mice. Na⁺, K⁺-ATPase activity and corticosterone levels were determined in hippocampus/cerebral cortex and plasma of mice, respectively. BAPD improved cutaneous damage, scratching behavior, inflammatory and oxidative stress markers. BAPD showed anxiolytic- and antidepressant-like effects and restored Na⁺, K⁺-ATPase activity and corticosterone levels. The present study was performed using female mice due the susceptibility for this disease. But, the evaluation of AD model in male mice would help to verify whether the male gender has the same predisposition to present this pathology. Our data demonstrated the suppressive effect of BAPD on psychiatric disorders - AD comorbidity by regulating inflammatory and oxidative status in mice.

Effect of a purine derivative containing selenium to improve memory decline and anxiety through modulation of the cholinergic system and Na+/K+-ATPase in an Alzheimer's disease model

Alzheimer's disease (AD) is a worldwide problem, and there are currently no treatments that can stop this disease. To investigate the binding affinity of 6-((4-fluorophenyl) selanyl)-9H-purine (FSP) with acetylcholinesterase (AChE), to verify the effects of FSP in an AD model in mice and to evaluate the toxicological potential of this compound in mice. The binding affinity of FSP with AChE was investigated by molecular docking analyses. The AD model was induced by streptozotocin (STZ) in Swiss mice after FSP treatment (1 mg/kg, intragastrically (i.g.)), 1st-10th day of the experimental protocol. Anxiety was evaluated in an elevated plus maze test, and memory impairment was evaluated in the Y-maze, object recognition and step-down inhibitory avoidance tasks. The cholinergic system was investigated based on by looking at expression and activity of AChE and expression of choline acetyltransferase (ChAT). We evaluated expression and activity of Na⁺/K⁺-ATPase. For toxicological analysis, animals received FSP (300 mg/kg, i.g.) and aspartate aminotransferase, alanine aminotransferase activities were determined in plasma and δ-aminolevulinate dehydratase activity in brain and liver. FSP interacts with residues of the AChE active site. FSP mitigated the induction of anxiety and memory impairment caused by STZ. FSP protected cholinergic system dysfunction and reduction of activity and expression of Na⁺/K⁺-ATPase. FSP did not modify toxicological parameters evaluated and did not cause the death of mice. FSP protected against anxiety, learning and memory impairment with involvement of the cholinergic system and Na⁺/K⁺-ATPase in these actions.

7-Chloro-4-(phenylselanyl) quinoline reduces renal oxidative stress induced by oxaliplatin in mice

The object of this study was to evaluate the relationship between oxidative damage induced by oxaliplatin (OXA) and the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) in kidney of mice. Mice received OXA (10 mg/kg) or vehicle intraperitoneally (days 0 and 2). Oral administration of 4-PSQ (1 mg/kg) or vehicle was performed on days 2 to 14. On day 15 the animals were euthanized and the kidneys and blood were collected. The effect of OXA and (or) 4-PSQ on urea, thiobarbituric acid reactive species, nonprotein thiol (NPSH), and protein carbonyl (PC) levels were investigated. Moreover, renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), δ-aminolevulinic acid dehydratase (δ-ALA-D), and Na⁺,K⁺ ATPase activities were evaluated. Our findings revealed an increase on urea levels and significant renal oxidative damage in OXA-induced mice. OXA exposure increased SOD, GPx, and GST activities and caused a reduction on NPSH levels and CAT and GR activities. Na⁺,K⁺ ATPase and δ-ALA-D activities were reduced by OXA. 4-PSQ decreased plasmatic urea levels and renal oxidative damage. SOD, GPx, CAT, GR, and Na⁺,K⁺ ATPase activities were restored by 4-PSQ. 4-PSQ may be a good prototype for the treatment of OXA-induced renal injury.

Detection of SARS-CoV-2 virus using an alternative molecular method and evaluation of biochemical, hematological, inflammatory, and oxidative stress in healthcare professionals

In early December 2019, an outbreak of coronavirus disease 2019 caused by a new strain of coronavirus (SARS-CoV-2), occurred in the city of Wuhan, Hubei Province, China. On January 30, 2020, the World Health Organization (WHO) declared the outbreak a public health emergency of international concern. Since then, frontline healthcare professionals have been experiencing extremely stressful situations and damage to their physical and mental health. These adverse conditions cause stress and biochemical, hematological, and inflammatory changes, as well as oxidative damage, and could be potentially detrimental to the health of the individual. The study population consisted of frontline health professionals working in BHU in a city in southern Brazil. Among the 45 participants, two were infected with the SARS-CoV-2 virus and were diagnosed using immunochromatographic tests such as salivary RT-LAMP and qRT-PCR. We also evaluated biochemical, hematological, inflammatory, and oxidative stress markers in the participants. The infected professionals (CoV-2-Prof) showed a significant increase in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, lactic dehydrogenase, lymphocytes, and monocytes. In this group, the levels of uric acid, triglycerides, leukocytes, neutrophils, hemoglobin, hematocrit, and platelets decreased. In the group of uninfected professionals (NoCoV-2-Prof), significant increase in HDL levels and the percentages of eosinophils and monocytes, was observed. Further, in this group, uric acid, LDH, triglyceride, and cholesterol levels, and the hematocrit count and mean corpuscular volume were significantly reduced. Both groups showed significant inflammatory activity with changes in the levels of C-reactive protein and mucoprotein. The NoCoV-2-Prof group showed significantly elevated plasma cortisol levels. To our kowledge, this study is the first to report the use of the RT-LAMP method with the saliva samples of health professionals, to evalute of SARS-CoV-2.

Co-nanoencapsulated meloxicam and curcumin improves cognitive impairment induced by amyloid-beta through modulation of cyclooxygenase-2 in mice

Alzheimer’s disease (AD) is a progressive brain disorder and complex mechanisms are involved in the physiopathology of AD. However, there is data suggesting that inflammation plays a role in its development and progression. Indeed, some non-steroidal anti-inflammatory drugs, such as meloxicam, which act by inhibiting cyclooxygenase-2 (COX-2) have been used as neuroprotective agents in different neurodegenerative disease models. The purpose of this study was to investigate the effects of co-nanoencapsulated curcumin and meloxicam in lipid core nanocapsules (LCN) on cognitive impairment induced by amyloid-beta peptide injection in mice. LCN were prepared by the nanoprecipitation method. Male Swiss mice received a single intracerebroventricular injection of amyloid-beta peptide aggregates (fragment 25–35, 3 nmol/3 μL) or vehicle and were subsequently treated with curcumin-loaded LCN (10 mg/kg) or meloxicam-loaded LCN (5 mg/kg) or meloxicam + curcumin-co-loaded LCN (5 and 10 mg/kg, respectively). Treatments were given on alternate days for 12 days (i.e., six doses, once every 48 hours, by intragastric gavage). Our data showed that amyloid-beta peptide infusion caused long-term memory deficits in the inhibitory avoidance and object recognition tests in mice. In the inhibitory avoidance test, both meloxicam and curcumin formulations (oil or co-loaded LCN) improved amyloid-beta-induced memory impairment in mice. However, only meloxicam and curcumin-co-loaded LCN attenuated non-aversive memory impairment in the object recognition test. Moreover, the beneficial effects of meloxicam and curcumin-co-loaded LCN could be explained by the anti-inflammatory properties of these drugs through cortical COX-2 downregulation. Our study suggests that the neuroprotective potential of meloxicam and curcumin co-nanoencapsulation is associated with cortical COX-2 modulation. This study was approved by the Committee on Care and Use of Experimental Animal Resources, the Federal University of Pampa, Brazil (approval No. 02-2015) on April 16, 2015.

Advances in the Understanding of Oxaliplatin-Induced Peripheral Neuropathy in Mice: 7-Chloro-4-(Phenylselanyl) Quinoline as a Promising Therapeutic Agent

In this study, the deposition of platinum in oxaliplatin (OXA)-exposed mice and the effects of the oxidative damage on the central nervous system were investigated. The relationship between the reactive species (RS) levels as well as the expression and activity of enzymes, such as catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and acetylcholinesterase (AChE), in the development of peripheral neuropathy after OXA exposure, was evidenced. The effects of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) on OXA-induced peripheral neuropathy was also investigated. Swiss mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed on days 2 to 14. Behavioural tasks started on day 9, after the first OXA administration. It was observed that 4-PSQ reduced the mechanical and thermal hypersensitivity induced by OXA. 4-PSQ and OXA did not affect locomotor and exploratory activities. The results revealed, for the first time, a high concentration of platinum in the spinal cord of mice exposed to OXA. 4-PSQ reversed the increased levels of RS in the spinal cord, cerebral cortex and hippocampus of mice exposed to OXA. The alterations in the activity and expression of the GPx, SOD, CAT and AChE induced by OXA exposure were normalized by 4-PSQ. Therefore, the 4-PSQ might be a good prototype for the development of a more effective drug for the treatment of OXA-induced peripheral neuropathy. The results obtained by the present study expanded the knowledge about the mechanisms involved in the physiopathology of peripheral neuropathy. Graphical abstract.

The anxiolytic effect of a promising quinoline containing selenium with the contribution of the serotonergic and GABAergic pathways: Modulation of parameters associated with anxiety in mice

Recently, we demonstrated the promising anxiolytic action of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) in mice. For this reason, the objective of this study was to expand our previous findings by investigating the contribution of serotoninergic and GABAergic systems to the anxiolytic action of this compound. Pretreatment with different serotoninergic antagonists (pindolol, WAY100635 and ketanserin) blocked the anxiolytic effect caused by 4-PSQ (50 mg/kg, per oral) in the elevated plus maze (EPM) test. The contribution of the GABAergic system was investigated by pretreatment with pentylenetetrazole (a GABA_A receptor antagonist) (PTZ). 4-PSQ diminished the PTZ-induced anxiety, and did not modify the locomotor, exploratory and motor activities of mice. Later, this group of animals was euthanized and the blood was removed to determine the levels of corticosterone, and cerebral cortex and hippocampus to determine the mRNA expression levels of cAMP response element binding protein (CREB), brain derived neurotrophic factor (BDNF) and nuclear factor kappa B (NF-κB), as well as the Na⁺, K⁺ ATPase activity and reactive species (RS) levels. 4-PSQ was able to significantly reverse the increase in RS and corticosterone levels, as well as the decrease of CREB and BDNF expression in the cerebral structures and increase of NF-κB expression in the hippocampus. Finally, 4-PSQ restored the Na⁺, K⁺ ATPase activity in the cerebral structures evaluated. Here, we showed that the modulation of serotonergic and GABAergic systems, factors related to neurogenesis, oxidative status and Na⁺, K⁺ ATPase activity contributes to the anxiolytic effect of 4-PSQ and reinforces the therapeutical potential of this compound for the treatment of anxiety.

Role of 7-chloro-4-(phenylselanyl) quinoline in the treatment of oxaliplatin-induced hepatic toxicity in mice

There is an increasing incidence of hepatotoxicity induced by oxaliplatin (OXA); therefore, researchers' attention has been drawn to therapeutic alternatives that may decrease OXA-induced hepatotoxicity. Studies indicate that oxidative stress plays a major role in OXA-induced liver injury. As several pharmacological effects of 7-chloro-4-(phenylselanyl) quinole (4-PSQ) involve its antioxidant action, the hypothesis that this organoselenium compound could be promising for the treatment or prevention of hepatotoxicity induced by treatment with OXA was investigated. To test this hypothesis, male Swiss mice received OXA (10 mg·kg^-1) on days 0 and 2, followed by oral administration of 4-PSQ (1 mg·kg^-1) on days 2 to 14. 4-PSQ reduced the plasma aspartate, and alanine aminotransferase activity increased by exposure to OXA. The histopathological examination of the liver showed that 4-PSQ markedly improved OXA-induced hepatic injury. In addition, treatment with 4-PSQ reduced the oxidation of lipids and proteins (thiobarbituric acid reactive species levels and protein carbonyl content) and attenuated the increase of hepatic catalase and glutathione peroxidase activity caused by OXA. The inhibition of hepatic δ-aminolevulinic dehydratase activity induced by OXA was reverted by 4-PSQ. In conclusion, results indicate that 4-PSQ may be a good therapeutic strategy for attenuating OXA-induced liver damage.

Synthesis of 2-Organylchalcogenopheno[2,3-b]pyridines from Elemental Chalcogen and NaBH4 /PEG-400 as a Reducing System: Antioxidant and Antinociceptive Properties

An alternative method to prepare 2-organylchalcogenopheno[2,3-b]pyridines was developed by the insertion of chalcogen species (selenium, sulfur or tellurium), generated in situ, into 2-chloro-3-(organylethynyl)pyridines by using the NaBH₄ /PEG-400 reducing system, followed by an intramolecular cyclization. It was possible to obtain a series of compounds with up to 93 % yield in short reaction times. Among the synthesized products, 2-organyltelluropheno[2,3-b]pyridines have not been described in the literature so far. Moreover, the compounds 2-phenylthieno[2,3-b]pyridine (3 b) and 2-phenyltelluropheno[2,3-b]pyridine (3 c) exhibited significant antioxidant potential in different in vitro assays. Further studies demonstrated that compound 3 b exerted an antinociceptive effect in acute inflammatory and non-inflammatory pain models, thus indicating the involvement of the central and peripheral nervous systems on its pharmacological action. More specifically, our results suggest that the intrinsic antioxidant property of compound 3 b might contribute to attenuating the nociception and inflammatory process on local injury induced by complete Freund's adjuvant (CFA).

Pharmacological modulation of Na+, K+-ATPase as a potential target for OXA-induced neurotoxicity: Correlation between anxiety and cognitive decline and beneficial effects of 7-chloro-4-(phenylselanyl) quinoline

Growing evidence demonstrates that Oxaliplatin (OXA) is commonly associated with neurotoxicity that leads to emotional and cognitive impairments. The aim of the present study was to evaluate the OXA and Na⁺, K⁺-ATPase interaction and to correlate anxious behavior and cognitive impairment induced by this chemotherapeutic in Swiss mice. Also, considering the pharmacological modulation of Na⁺, K⁺-ATPase as a potential target for OXA-induced neurotoxicity, the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) was evaluated. Mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed from days 2-14. Behavioral tasks started from day 12 onwards. On day 15, the animals were sacrificed, and the tissues collected. The effects of OXA and 4-PSQ on activity and expression level of Na⁺, K⁺-ATPase in the hippocampus and cerebral cortex, and the plasmatic corticosterone levels were determined. The findings demonstrated a significant positive correlation between anxious behavior and cognitive impairment induced by OXA. OXA caused an increase on the plasmatic corticosterone levels and reduced activity and expression level of Na⁺, K⁺-ATPase. 4-PSQ reduced both anxious behavior and cognitive impairment induced by OXA. 4-PSQ effect seems to be due to the modulation of Na⁺, K⁺-ATPase and reduction of corticosterone levels. Our results helped to expand knowledge about the mechanisms involved in the physiopathology of the OXA-induced neurotoxicity and strongly indicated that 4-PSQ may be a good prototype for the treatment of anxious behavior and cognitive impairment induced by OXA exposure.

Synthesis, molecular structure and antioxidant activity of bis [L(μ2-chloro)copper(II)] supported by phenoxy/naphthoxy-imine ligands

A new series of Cu(II) complexes [bis[{(μ₂-chloro)-2-MeO-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-OC₆H₂)}Cu(II)] (Cu1); bis[{(μ₂-chloro)-2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(OC₆H₂)}Cu(II)] (Cu2); bis[{(μ₂-chloro)-2-MeO-Ph-CH₂-(N=CH)-2-(OC₁₀H₆)} Cu(II)] (Cu3); bis[{(μ₂-chloro)-2-MeS-Ph-CH₂-(N=CH)-2-(OC₁₀H₆)}Cu(II)] complex (Cu4); bis[{2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(OC₆H₂)}Cu(II)] (Cu5)] have been synthesized and characterized by elemental analysis, IR, UV-Visible and by X-ray crystallography for Cu1, Cu4 and Cu5. In the solid state, Cu1 features of a chloro-bridged dimer complex with κ² coordination of the monoanionic phenoxy-imine ligand onto the copper center. On the other hand, the molecular structure of Cu4 reveals the naphthoxy-imine ligand with pendant S-group coordinated to the copper atom in tridentate meridional fashion. Treatment of [Cu(OAc)₂·H₂O] with two equiv. of [2-MeS-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(HOC₆H₂)] led to a monomeric complex Cu5, with the ONS-donor Schiff base acting as a bidentate ligand. The redox behavior was explored by cyclic voltammetry. The reduction/oxidation potential of Cu(II) complexes depends on the structure and conformation of the central atom in the coordination compounds. Antioxidant activities of the complexes, Cu1 - Cu5, were determined by in vitro assays such as 1,1-diphenyl-2-picryl-hydrazyl free radicals (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS⁺). The dinuclear compounds Cu1-Cu4, from the concentration of 5 μM, presented a good activity in scavenging DPPH radical. In addition, most of the Cu(II) complexes showed ABTS^.+ radical-scavenging activity. The monomeric complex Cu5 at all concentrations tested showed antioxidant inability. The cytotoxicity of the Cu1 and Cu3 was determined in V79 cell line by reduction of 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay.

Therapeutic potential of selanyl amide derivatives in the in vitro anticholinesterase activity and in in vivo antiamnesic action

The present study evaluated the in vitro acetylcholinesterase (AChE) inhibitor activity of two new selanyl amide derivatives in cerebral structures of mice. Our results demonstrated that N-(2-(3-(phenylselanyl)propoxy)phenyl)furan-2-carboxamide (1) and N-(2-(3-(phenylselanyl)propoxy)phenyl)thiophene-2-carboxamide (2) inhibited the in vitro AChE activity in mice. Another objective was to assess the effect of the best AChE inhibitor in an amnesic model induced by scopolamine (SCO) in male Swiss mice. The involvement of AChE activity and lipid peroxidation in the cerebral structures was investigated. Our results showed that compound 1 (10 mg/kg, intragastrically) attenuated the latency to find the escape box and the number of holes visited in the Barnes maze task, without altering the locomotor and exploratory activities in an open-field test. Compound 1 protected against increasing in lipid peroxidation levels and AChE activity caused by SCO in the cerebral cortex and hippocampus of mice. In conclusion, the present study evidenced the in vitro anticholinesterase effect of two new selanyl amide derivatives in the cerebral structures of mice. Moreover, compound 1, a selanyl amide derivative containing a furan ring, demonstrated antiamnesic action due to its antioxidant and anticholinesterase activities in cerebral structures.

Amnesia-ameliorative effect of a quinoline derivative through regulation of oxidative/cholinergic systems and Na+/K+-ATPase activity in mice

The present study evaluated the anti-amnesic activity of 1-(7-chloroquinolin-4-yl)-5-methyl-N-phenyl-1H-1,2,3-triazole-4-carboxamide (QTCA-1) against scopolamine (SCO)-induced amnesia in mice. It was evaluated cholinergic dysfunction, oxidative stress and Na⁺/K⁺-ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were treated with QTCA-1 (10 mg/kg, intragastrically (i.g.), daily) for nine days. Thirty minutes after the treatment with compound, the animals received a injection of SCO (0.4 mg/kg, intraperitoneally (i.p.)). Mice were submitted to the behavioral tasks 30 min after injection of SCO (Barnes maze, open-field, object recognition and location, and step-down inhibitory avoidance tasks) during nine days. In day 9, cerebral cortex and hippocampus of mice were removed to determine the thiobarbituric acid reactive species (TBARS) levels, and catalase (CAT), Na⁺/K⁺-ATPase and acetylcholinesterase (AChE) activities. SCO caused amnesia in mice for changing in step-down inhibitory avoidance, Barnes maze, and object recognition and object location tasks. QTCA-1 treatment attenuated the behavioral changes caused by SCO. Moreover, SCO increased AChE and CAT activities, decreased Na⁺/K⁺-ATPase activity and increased TBARS levels in the cerebral structures of mice. QTCA-1 protected against these brain changes. In conclusion, QTCA-1 had anti-amnesic action in the experimental model used in the present study, through the anticholinesterase effect, modulation of Na⁺/K⁺-ATPase activity and antioxidant action.

Airborne toluene exposure causes germline apoptosis and neuronal damage that promotes neurobehavioural changes in Caenorhabditis elegans

Toluene is a highly volatile organic solvent present in gasoline. Exposure mainly occurs by absorption via the pulmonary tract and easily reaches the central nervous system, which causes toxic effects. Toluene toxicity has been described but not well established. The present work aimed to evaluate the effects of airborne exposure to toluene, the in vivo model Caenorhabditis elegans was assessed to determine whether nematode could be used to evaluate the effects of exposure to toluene and the possible mechanisms of toxicity of the solvent. Worms at the first or fourth larval stages were exposed to toluene for 48 or 24 h, respectively, in a laboratory-developed vapor chamber at concentrations of 450, 850, 1250 and 1800 ppm. We observed increases in worm mortality and significant developmental delays that occurred in a concentration-dependent manner. An increased incidence of apoptotic events in treated germline cells was shown, which was consistent with observed reductions in reproductive capacity. In addition, toluene promoted significant behavioural changes affecting swimming movements and radial locomotion, which were associated with changes in the fluorescence intensity and morphology of GABAergic and cholinergic neurons. We conclude that toluene exposure was toxic to C. elegans, with effects produced by the induction of apoptosis and neuronal damage.

Se - [(2,2-Dimethyl-1,3-dioxolan-4-yl) methyl] 4-chlorobenzoselenolate reduces the nociceptive and edematogenic response by chemical noxious stimuli in mice: Implications of multi-target actions

BACKGROUND

The present study evaluated the antioxidant, antinociceptive and anti-edematogenic effects of Se-[(2,2-dimethyl-1,3-dioxolan-4-yl) methyl] 4-chlorobenzoselenolate (Se-DMC).

METHODS

In vitro experiments were carried out to evaluate Se-DMC antioxidant action. Thiobarbituric acid reactive species levels, 2,2'-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-thylbenzthiazoline-6-sulfonic acid) radicals scavenging and glutathione S-transferase-like activity were determined. Male Swiss mice were orally pretreated with Se-DMC (1, 10 and 50 mg/kg), meloxicam (50 mg/kg) or vehicle 30 min prior to acetic acid or glutamate test. To extend our knowledge of the pharmacological properties of this compound, it was tested in an inflammatory model through ear edema induced by croton oil. The contribution of glutamatergic and serotonergic systems was also investigated.

RESULTS

In vitro experiments revealed that Se-DMC exerts antioxidant activity. Nociception induced by glutamate or acetic acid was reduced by Se-DMC or meloxicam. Se-DMC diminished the paw edema formation induced by glutamate, while meloxicam did not show any effect. Se-DMC and meloxicam decreased the ear edema formation and protected against the increase in myeloperoxidase activity in mice ear induced by croton oil. The pretreatment of animals with MK-801 did not alter antinociception caused by Se-DMC in the glutamate test. The antinociceptive effect exerted by Se-DMC in the acetic acid test was reverted by the pretreatment of mice with different serotonergic antagonists (WAY100635, ketanserin and pindolol).

CONCLUSIONS

Data presented here showed that the modulation of serotonergic and glutamatergic systems and the anti-inflammatory and antioxidant actions could contribute to the antinociceptive and anti-edematogenic effects of Se-DMC and it supported the therapeutic potential of this compound.

Contribution of serotonergic and nitrergic pathways, as well as monoamine oxidase-a and Na+, K+-ATPase enzymes in antidepressant-like action of ((4-tert-butylcyclohexylidene) methyl) (4-methoxystyryl) sulfide (BMMS)

The present study investigated a possible antidepressant-like effect of ((4-tert-butylcyclohexylidene)methyl) (4-methoxystyryl) sulfide (BMMS) by using the forced swimming test (FST) and the tail suspension test (TST) in Swiss mice. The contribution of serotoninergic, glutamatergic and nitrergic systems in the antidepressant-like activity of BMMS was evaluated. We also examined the involvement of monoamine oxidase (MAO)-A, MAO-B and Na⁺, K⁺-ATPase activities in prefrontal cortex of mice. BMMS, (0.1-10 mg/kg, intragastrically (i.g.)) and fluoxetine (32 mg/kg, i.g.) decreased the immobility time in the FST and TST. The anti-immobility effect of BMMS (10 mg/kg, i.g.) in the TST was prevented by the pretreatment of mice with WAY100635 (0.1 mg/kg, subcutaneously (s.c.), a 5-HT_1A receptor antagonist), ketanserin (5 mg/kg, intraperitoneal (i.p.), a 5-HT_2A/2C receptor antagonist), and partially blocked by ondansetron (1 mg/kg, i.p., a 5-HT₃ receptor antagonist). The anti-immobility effect of BMMS (10 mg / kg, i.g.) was not avoided by pretreatment with MK-801 (0.01 mg/kg, s.c. a non-competitive N-methyl D-Aspartate (NMDA) receptor) in the TST. Pretreatment with L-arginine (500 mg/kg, i.p., a nitric oxide precursor) reversed partially the reduction in the immobility time elicited by BMMS (10 mg/kg, i.g.) in TST. BMMS altered Na⁺,K⁺-ATPase and MAO-A activities in prefrontal cortex of mice, but was not able to change the MAO-B activity. In conclusion, BMMS exerted an antidepressant-like effect in mice and serotonergic and nitrergic systems are involved in the antidepressant-like action of compound. BMMS modulated MAO-A and Na⁺, K⁺- ATPase activities in prefrontal cortex of mice.

Synthesis of Isoxazolines by the Electrophilic Chalcogenation of β,γ-Unsaturated Oximes: Fishing Novel Anti-Inflammatory Agents

Herein, we describe a new strategy to prepare chalcogen-functionalized isoxazolines. The strategy involves the reaction of β,γ-unsaturated oximes with electrophilic selenium and tellurium species, affording 19 new selenium- and tellurium-containing isoxazolines in good yields after 1 h at room temperature. The method was efficiently extended to the synthesis of 5 new (bis)isoxazoline ditellurides. One of the prepared compounds, 3-phenyl-5-((phenylselanyl)methyl)-isoxazoline, demonstrated better anti-inflammatory and antiedematogenic effects than the reference drug Celecoxib.

Cationic and anionic unloaded polymeric nanocapsules: Toxicological evaluation in rats shows low toxicity

The experimental design aiming at evaluating the performance of drugs nanoencapsulated involves inclusion of a formulation without drug (unloaded). This formulation has sometimes presented per se effect. In this sense, we sought to evaluate the toxicity of unloaded polymeric nanocapsules (NCs) with different surfaces (cationic and anionic) in male Wistar rats in male Wistar rats. The physicochemical characterization of NCs with different surfaces: polysorbate 80 (P80), polyethylene glycol (PEG), eudragit ®RS 100 (EUD) and chitosan (CS) was performed. Rats were treated with unloaded NCs (P80, PEG, EUD and CS surfaces) daily for 14 days per oral route. 24 h of last treatment, animals were euthanized and organs were removed and weighted. After, biochemical determinations were performed. In general, NCs-surfaces did not cause alterations in body weight, weight of organs and histopathological analysis. PEG-surface NCs did not generate hepatotoxicity. In investigation of lipid profile, the surface with P80 changed TC and HDL-C levels. Besides that, all NCs did not alter oxidative stress markers in organs studied (TBARS and Reactive Species) and CS-surface presented antioxidant activity in kidney. This study demonstrated that NCs-surfaces depending on their physicochemical characteristics had low or no toxicity.

Post-mortem interval estimative through determination of catalase and Δ-aminolevulinate dehydratase activities in hepatic, renal, skeletal muscle and cerebral tissues of Swiss mice

Purpose: Determining the post-mortem interval (PMI) is one of the challenging tasks in forensic science due to the lack of quick and inexpensive methods. Our objective is to develop innovative and alternative means for PMI evaluation. Methods: The relationship between PMI and enzymatic modifications in mice tissues was described. After being sacrificed, Swiss mice were randomly divided into groups according to the time elapsed since death. The activities of catalase (CAT) and δ-aminolevulinate dehydratase (δ-ALA-D) were determined in hepatic, renal, skeletal muscle and cerebral tissues. Results: CAT activity increased in kidney and brain 6 h after death and this increase remained for up to 24 h in the brain and 48 h in the kidney. δ-ALA-D had its activity decreased in the liver and kidneys in 6 h. In the skeletal muscle, δ-ALA-D activity was reduced only 48 h after death. Conversely, an increase on δ-ALA-D activity was observed in the brain at 6 h, followed by its decrease at 24 and 48 h. Conclusion: With the association of this set of results, it is possible to provide an estimate of PMI. Additionally, these results can be used as an auxiliary parameter associated with other methods to estimate PMI.

7-Chloro-4-(Phenylselanyl) Quinoline with Memory Enhancer Action in Aging Rats: Modulation of Neuroplasticity, Acetylcholinesterase Activity, and Cholesterol Levels

This study investigated the effect of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) to restore the cognitive impairment caused by aging in male Wistar rats. Moreover, modulation of neuroplasticity markers, acetylcholinesterase (AChE) activity, and cholesterol levels was performed. Aged rats were intragastrically treated with 4-PSQ (5 mg/kg) for 7 days. Animals were tested in behavioral tasks, and then plasma (to determine cholesterol levels), hippocampus, and cerebral cortex (to determine neural cell adhesion molecule (NCAM) and polysialyltransferase (PST) levels, and AChE activity) were removed. Our findings demonstrated that treatment of aged rats with 4-PSQ restored short-term and long-term memories in the object recognition tests. 4-PSQ treatment did not restore exploratory activity (rearings) but partially restored locomotor activity (crossings) reduced by aging in the open-field test. Moreover, the compound restored the reduction in the NCAM and PST levels, and AChE activity in cerebral structures, as well as the increase in the plasma cholesterol levels, caused by aging in rats. In conclusion, 4-PSQ restored cognitive impairment caused by aging in rats by modulating synaptic plasticity, cholinergic system, and cholesterol levels.

Na+/K+-ATPase, acetylcholinesterase and glutathione S-transferase activities as new markers of postmortem interval in Swiss mice

Determining precisely the postmortem interval (PMI) is a key parameter for forensic researches, given that various physical, biochemical and metabolic changes begin to occur in the body after death. In the present study, the Na⁺/K⁺-ATPase, glutathione S-transferase (GST) and acetylcholinesterase (AChE) activities were evaluated. For this, male adult Swiss mice were killed by isoflurane inhalation anesthesia and divided into four groups according to time of death (0, 6, 24 and 48 h). The brain, liver, kidney and skeletal muscle tissues were removed. Our results revealed that at the time of 6 h, there was a decrease on Na⁺/K⁺-ATPase and GST activities in the brain and liver tissues, respectively. In addition, at this time point, an increase on renal GST activity was verified. At the time of 24 h, an increase on the cerebral AChE and renal GST activities was observed, while the cerebral Na⁺/K⁺-ATPase activity was decreased. Forty-eight hours after death, cerebral Na⁺/K⁺-ATPase and renal GST activities remained decreased and increased, respectively. In addition, no alteration was observed on the GST activity in the skeletal muscle and brain (in PMIs evaluated). The present study revealed that the brain and kidney (at the times of 24 and 48 h) were the tissues that suffered the most changes in almost all the enzymes evaluated. Our results demonstrated that enzyme activity assessments are reliable, easy-to-perform and low-cost determinations, and could be promising postmortem markers.

PEGylated meloxicam-loaded nanocapsules reverse in vitro damage on caspase activity and do not induce toxicity in cultured human lymphocytes and mice

Meloxicam is an anti-inflammatory drug that has a potential protective effect in many common diseases. However, this molecule is quickly eliminated from the body due to it short half-life. One way to overcome this problem is to incorporate meloxicam into lipid-core nanocapsules which may increase it anti-inflammatory effects. In view of this, the objective of this work was to evaluate the potential toxicity and safety of these novel nanomaterials both in vitro and in vivo. Here, we evaluated the effects of uncoated meloxicam-loaded nanocapsules (M-NC), uncoated and not loaded with meloxicam or blank (B-NC), PEGylated meloxicam-loaded lipid-core nanocapsules (M-NCPEG), blank PEGylated lipid-core nanocapsules (B-NCPEG) and free meloxicam (M-F) in vitro through the analysis of cell viability, caspase activity assays and gene expression of perforin and granzyme B. Meanwhile, the in vivo safety was assessed using C57BL/6 mice that received nanocapsules for seven days. Thus, no change in cell viability was observed after treatments. Furthermore, M-NC, M-NCPEG and M-F groups reversed the damage caused by H₂O₂ on caspase-1, 3 and 8 activities. Overall, in vivo results showed a safe profile of these nanocapsules including hematological, biochemical, histological and genotoxicity analysis. In conclusion, we observed that meloxicam nanocapsules present a safe profile to use in future studies with this experimental protocol and partially reverse in vitro damage caused by H₂O₂.