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.

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.

Mechanistic pathways of fibromyalgia induced by intermittent cold stress in mice is sex-dependently.

Fibromyalgia results from a complex interplay of biochemical and neurobiological elements mediated sensitization of nociceptive pathways. Despite the symptoms of fibromyalgia negatively affect the quality of life of patients, the pathophysiology of this disease remains inconclusive, which difficult the development of an appropriate treatment. The present study investigated the involvement of the serotonergic receptors, the N-methyl-D-aspartate (NMDA)/ nitric oxide (NO)/ cyclic guanosine monophosphate (cGMP) pathway and the oxidative stress in an animal model of fibromyalgia induced by intermittent cold stress (ICS), considering the specificities of male and female Swiss mice. The ICS exposure increased mechanical and thermal sensitivities, and decreased muscle strength in mice of both sexes. Female mice exhibited a longer-lasting mechanical sensitivity than male mice exposed to ICS along with an enhancement of the Na+, K+-ATPase activity in the spinal cord and cerebral cortex. Conversely, an inhibition in the Na+, K+-ATPase and glutathione peroxidase activities accompanied by an increase in the reactive species levels in the cerebral cortex of male mice were observed. The treatment with different serotonergic antagonists (pindolol, ketanserin and ondasetron) reversed the mechanical sensitivity in mice of both sexes, after the ICS exposure. The administration of MK-801, L-arginine and methylene blue also blocked the mechanical sensitivity in female mice exposed to ICS. Except L-arginine, MK-801 and methylene blue also attenuated this nociceptive signal in male mice, after ICS exposure. In conclusion, the modulation of serotonergic receptors, the NMDA/NO/cGMP pathway, and the oxidative stress seems contribute to nociceptive behaviors induced by ICS exposure sex-dependent.

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)-1ß, 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 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.

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.

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.

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.

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.

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.

Biopolymeric films as delivery vehicles for controlled release of hydrocortisone: Promising devices to treat chronic skin diseases.

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease with nasty effects on the psychosocial wellbeing of patients. Overall, glucocorticoids, such as hydrocortisone (HC), are the primary pharmacologic drugs used to treat AD and its symptoms. However, the long-term treatment with HC is often accompanied by severe adverse effects. So, this study reports the encapsulation of HC in polymeric films based on gelatin (Gel) and gelatin/starch (Gel/St) and investigates their potential to treat and attenuate 2,4-Dinitrochlorobenzene (DNCB)-induced AD-like symptoms in BALB/c mice model. The prepared films were characterized by different techniques, which indicated that HC was physically entrapped into the polymer matrices. In vitro experiments indicate that the HC release process occurs in a controlled manner (up to 48 h) for both films. Regarding the in vivo experiments, HC-loaded films (Gel@HC and Gel/St@HC), unloaded films (Gel and Gel/St) and HC cream (1%) (as reference) were applied topically on the back of the DNCB-sensitized animals and skin severity scores and scratching behavior were determined. Ex-vivo experiments were done to quantify inflammatory and/or biochemical parameters. As assessed, the topical application of the biopolymeric films (loaded or not with HC) improved the inflammatory parameters, while a lower corticosterone level was observed for the animals treated with Gel and Gel@HC films. In summary, the HC-loaded films showed superior efficiency to treat/attenuate the analyzed parameter than the HC cream (1%). Further, no death or sign of toxicity was observed in animals exposed to HC-loaded films. Thus, the encapsulation of HC in biopolymeric films seems to be a promising alternative for the treatment of injuries caused by chronic skin diseases that require prolonged use of glucocorticoids.

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.

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.

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 GABAA 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.

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.

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.

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.