Francine R. Ianiski

Protective effect of meloxicam-loaded nanocapsules against amyloid-β peptide-induced damage in mice

The objective of present study was to investigate the protective effect of M-NC against aβ (25-35) peptide-induced damage in mice, as the first step to evaluate their potential value for the treatment of AD. Moreover, we compared the effects of M-NC with free meloxicam (M-F). Mice were divided into six groups: (I) sham, (II) aβ, (III) M-NC, (IV) M-F, (V) M-NC+aβ and (VI) M-F+aβ. Mice were pre-treated with M-NC (5mg/kg, by gavage), M-F (5mg/kg, by gavage) or blank nanocapsules (B-NC). Thirty minutes after treatments, aβ peptide (3nmol) or filtered water were i.c.v. injected. Learning and memory were assessed with the Morris water maze (MWM) (days 4-7) and step-down-type passive-avoidance (SDPA) (days 7-8) tasks. At the end of the experimental protocol (day 8), animals were euthanized and brains were removed for biochemical determinations (reactive species (RS), non-protein thiols (NPSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST)) and histological examination. Our results confirmed that aβ peptide caused learning and memory deficits in mice. Histological analysis demonstrated neuronal loss, intense cellular accumulation and chromatolysis caused by aβ peptide. Furthermore, this study showed that oxidative stress was increased in mice that received aβ peptide. An important finding of the present study was the protective effect of M-NC in damage induced by aβ peptide. However, M-F did not have protective effect. In summary, the data reported herein clearly demonstrate that meloxicam carried by polymeric nanocapsules protected against learning and memory impairments, loss neuronal and oxidative stress in a mouse model of AD induced by aβ peptide.

Meloxicam-loaded nanocapsules have antinociceptive and antiedematogenic effects in acute models of nociception.

AIMS The development of new treatments for inflammation and pain continues to be of high interest, since long-acting effect is critical for patients. The present study investigated whether the polymeric nanocapsules, a drug delivery system, have pharmacological effect on acute nociceptive and inflammatory models in mice. MAIN METHODS Swiss mice (20-25 g) were previously pre-treated with meloxicam-loaded nanocapsules (M-NC) or free meloxicam (M-F) or suspension without drug (B-NC), at a dose of 5 mg/kg (per oral) at different times (0.5-120 h). Antinociceptive and antiedematogenic effects were evaluated by chemical (acetic acid-induced abdominal writhing, nociception and paw edema induced by formalin and glutamate, croton oil-induced ear edema) and thermal (tail immersion and hot-plate) tests. KEY FINDINGS M-NC reduced the licking time- and paw edema-induced by glutamate and formalin, while M-F did not have an effect. In the acetic acid-induced abdominal writhing and croton oil-induced ear edema, analysis of time-course revealed that M-NC showed a response more prolonged than M-F. In the hot-plate test, a thermal test, the time-course analysis indicated a similar increase in the latency response to thermal stimuli of M-NC and M-F, while in the tail-immersion test M-F had an effect at 0.5 h and M-NC at 24 h. SIGNIFICANCE Polymeric nanoparticles had antinociceptive, anti-inflammatory and antiedematogenic effects in the formalin and glutamate tests, and prolonged the effect in acetic acid and croton oil tests, but not in thermal tests, supporting the idea that the inflammatory process in tissues facilitates the vectoring of polymeric nanoparticles.

Relationship between behavioral alterations and activities of adenylate kinase and creatine kinase in brain of rats infected by Trypanosoma evansi

The aim of this study was to investigate the behavioral assessment and activities of important enzymes involved in the phosphoryl transfer network in rat brains that were experimentally infected with Trypanosoma evansi. Behavioral assessment (cognitive performance), pro-inflammatory cytokines in serum and activities of adenylate kinase (AK), pyruvate kinase (PK), and creatine kinase (CK) in brain were evaluated at 5 and 15 days post-infection (PI). Here we demonstrate a cognitive impairment in the rats infected with T. evansi. At 5 and 15 days PI, a memory deficit and a depressant activity were demonstrated by an inhibition avoidance test and increase in the immobility time in a tail suspension test, respectively. On day 5 PI, a decrease in the CK activity and an increase in the AK activity were observed. On day 15 PI, an increase in the CK activity and a decrease in the AK activity were observed. Considering the importance of energy metabolism for brain functioning, it is possible that the changes in the activity of enzymes involved in the cerebral phosphotransfer network and an increase in the proinflammatory cytokines (TNF and IFN) may be involved at least in part in the cognitive impairment in infected rats with T. evansi.

Protective effect of ((4-tert-butylcyclohexylidene) methyl) (4-methoxystyryl) sulfide, a novel unsymmetrical divinyl sulfide, on an oxidative stress model induced by sodium nitroprusside in mouse brain: involvement of glutathione peroxidase activity

In this study, the antioxidant action of ((4‐tert‐butylcyclohexylidene) methyl) (4‐methoxystyryl) sulfide, a novel unsymmetrical divinyl sulfide, against oxidative damage induced by sodium nitroprusside (SNP) in brains of mice was investigated.

Organosulfur compound protects against memory decline induced by scopolamine through modulation of oxidative stress and Na + /K + ATPase activity in mice

The present study investigated the possible effect of BMMS in protecting against memory impairment in an Alzheimer’s disease model induced by scopolamine in mice. Another objective was to evaluate the involvement of oxidative stress and Na+/K+ ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were divided into four groups: groups I and III received canola oil (10 ml/kg, intragastrically (i.g.)), while groups II and IV received BMMS (10 mg/kg, i.g.). Thirty minutes after treatments, groups III and IV received scopolamine (1 mg/kg, intraperitoneal (i.p.)), while groups I and II received saline (5 ml/kg, i.p.). Behavioral tests were performed thirty minutes after scopolamine or saline injection. Cerebral cortex and hippocampus were removed to determine the thiobarbituric acid reactive species (TBARS) levels, non-protein thiols (NPSH) content, catalase (CAT) and Na+/K+ ATPase activities. The results showed that BMMS pretreatment protected against the reduction in alternation and latency time induced by scopolamine in the Y-maze test and step-down inhibitory avoidance, respectively. In the Barnes maze, the latency to find the escape box and the number of holes visited were attenuated by BMMS. Locomotor and exploratory activities were similar in all groups. BMMS pretreatment protected against the increase in the TBARS levels, NPSH content and CAT activity, as well as the inhibition on the Na+/K+ ATPase activity caused by scopolamine in the cerebral cortex. In the hippocampus, no significant difference was observed. In conclusion, the present study revealed that BMMS protected against the impairment of retrieval of short-term and long-term memories caused by scopolamine in mice. Moreover, antioxidant effect and protection on the Na+/K+ ATPase activity are involved in the effect of compound against memory impairment in AD model induced by scopolamine.

Antinociceptive property of vinyl sulfides in spite of their weak antioxidant activity

Vinyl sulfides (a–c), a new class of organosulfur compounds, were screened for antioxidant and antinociceptive activities. In view of this, in vitro antioxidant effect was investigated through the determination of the thiobarbituric acid reactive substances and protein carbonyl levels in rat brain homogenate. Considering the results obtained in vitro, antinociceptive activity of vinyl sulfides (a–c) (5–50 mg/kg, intragastrically) was investigated in a model of nociception induced by glutamate (20 μmol/paw, 20 μl, intraplantar) in mice. A close inspection of the results revealed that unsymmetrical substituted vinyl sulfides (compounds a–c) presented weak antioxidant activity against lipid peroxidation and protein carbonilation in vitro. In vivo experiments showed that compounds a, b, and c, at all doses (5–50 mg/kg), caused an inhibition of the licking and edema induced by glutamate in mice. However, antinociceptive action of sulfides was not dose-dependent, as well as the antioxidant effect was not concentration-dependent. Thus, chemical structure of vinyl sulfides is not related with pharmacological effects. The results demonstrated that vinyl sulfides presented weak antioxidant effect and potent antinociceptive and antiedematogenic effect.

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.

Amyloid-β peptide absence in short term effects on kinase activity of energy metabolism in mice hippocampus and cerebral cortex

Considering that Alzheimers disease is a prevalent neurodegenerative disease worldwide, we investigated the activities of three key kinases: creatine kinase, pyruvate kinase and adenylate kinase in the hippocampus and cerebral cortex in Alzheimers disease model. Male adult Swiss mice received amyloid-β or saline. One day after, mice were treated with blank nanocapsules (17 ml/kg) or meloxicam-loaded nanocapsules (5 mg/kg) or free meloxicam (5 mg/kg). Treatments were performed on alternating days, until the end of the experimental protocol. In the fourteenth day, kinases activities were performed. Amyloid-β did not change the kinases activity in the hippocampus and cerebral cortex of mice. However, free meloxicam decrease the creatine kinase activity in mitochondrial-rich fraction in the group induced by amyloid-β, but for the cytosolic fraction, it has raised in the activity of pyruvate kinase activity in cerebral cortex. Further, meloxicam-loaded nanocapsules administration reduced adenylate kinase activity in the hippocampus of mice injected by amyloid-β. In conclusion we observed absence in short-term effects in kinases activities of energy metabolism in mice hippocampus and cerebral cortex using amyloid-β peptide model. These findings established the foundation to further study the kinases in phosphoryltransfer network changes observed in the brains of patients post-mortem with Alzheimers disease.