Meloxicam-loaded nanocapsules as an alternative to improve memory decline in an Alzheimer's disease model in mice: involvement of Na(+), K(+)-ATPase

Meloxicam Inhibits Apoptosis in Neurons by Deactivating Tumor Necrosis Factor Receptor Superfamily Member 25, Leading to the Decreased Cleavage of DNA Fragmentation Factor Subunit α in Alzheimer's Disease

Neuronal apoptosis is considered to be a critical cause of Alzheimer's disease (AD). Recently, meloxicam has shown neuroprotective effects; however, the inherent mechanisms are highly overlooked. Using APP/PS1 transgenic (Tg) mice as in vivo animal models, we found that meloxicam inhibits apoptosis in neurons by deactivating tumor necrosis factor receptor superfamily member 25 (TNFRSF25), leading to the suppression of the expression of fas-associated protein with death domain (FADD) and the cleavage of DNA fragmentation factor subunit α (DFFA) and cysteine aspartic acid protease-3 (caspase 3) via β-amyloid protein (Aβ)-depressing mechanisms. Moreover, the meloxicam treatment blocked the effects of β-amyloid protein oligomers (Aβo) on stimulating the synthesis of tumor necrosis factor α (TNF-α) and TNF-like ligand 1A (TL1A) in neuroblastoma (N) 2a cells. TNF-α and TL1A induce apoptosis in neurons via TNFR- and TNFRSF25-dependent caspase 3-activating mechanisms, respectively. Knocking down the expression of TNFRSF25 blocked the effects of TL1A on inducing apoptosis in neurons by deactivating the signaling cascades of FADD, caspase 3, and DFFA. Consistently, TNFRSF25 shRNA blocked the effects of Aβo on inducing neuronal apoptosis, which was corroborated by the efficacy of meloxicam in inhibiting Aβo-induced neuronal apoptosis. By ameliorating neuronal apoptosis, meloxicam improved memory loss in APP/PS1 Tg mice.

Therapeutic nanotechnologies for Alzheimer's disease: a critical analysis of recent trends and findings

Alzheimer's Disease (AD) is an irreversible neurodegenerative disease for which no disease modifying therapies are presently available. Besides the identification of pathological targets, AD presents numerous clinical and pharmacological challenges such as efficient active delivery to the central nervous system, cell targeting, and long-term dosing. Nanoparticles have been explored to overcome some of these challenges as drug delivery vehicles or drugs themselves. However, early promises have failed to materialize as no nanotechnology-based product has been able to reach the market and very few have moved past preclinical stages. In this review, we perform a critical analysis of the past decade's research on nanomedicine-based therapies for AD at the preclinical and clinical stages. The main obstacles to nanotechnology products and the most promising approaches were also identified, including renewed promise with gene editing, gene modulation, and vaccines.

Protective Effects of Inosine on Memory Consolidation in a Rat Model of Scopolamine-Induced Cognitive Impairment: Involvement of Cholinergic Signaling, Redox Status, and Ion Pump Activities

This study investigated the effects of inosine on memory acquisition and consolidation, cholinesterases activities, redox status and Na⁺, K⁺-ATPase activity in a rat model of scopolamine-induced cognitive impairment. Adult male rats were divided into four groups: control (saline), scopolamine (1 mg/kg), scopolamine plus inosine (50 mg/kg), and scopolamine plus inosine (100 mg/kg). Inosine was pre-administered for 7 days, intraperitoneally. On day 8, scopolamine was administered pre (memory acquisition protocol) or post training (memory consolidation protocol) on inhibitory avoidance tasks. The animals were subjected to the step-down inhibitory avoidance task 24 hours after the training. Scopolamine induced impairment in the acquisition and consolidation phases; however, inosine was able to prevent only the impairment in memory consolidation. Also, scopolamine increased the activity of acetylcholinesterase and reduced the activity of Na⁺, K⁺-ATPase and the treatment with inosine protected against these alterations in consolidation protocol. In the animals treated with scopolamine, inosine improved the redox status by reducing the levels of reactive oxygen species and thiobarbituric acid reactive substances and restoring the activity of the antioxidant enzymes, superoxide dismutase and catalase. Our findings suggest that inosine may offer protection against scopolamine-induced memory consolidation impairment by modulating brain redox status, cholinergic signaling and ion pump activity. This compound may provide an interesting approach in pharmacotherapy and as a prophylactic against neurodegenerative mechanisms involved in Alzheimer's disease.

The Emerging Role of COX-2, 15-LOX and PPARγ in Metabolic Diseases and Cancer: An Introduction to Novel Multi-target Directed Ligands (MTDLs)

Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro- and antitumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarizing the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.

A comparison study of lipid and polymeric nanoparticles in the nasal delivery of meloxicam: Formulation, characterization, and in vitro evaluation

With the increasingly widespread of central nervous system (CNS) disorders and the lack of sufficiently effective medication, meloxicam (MEL) has been reported as a possible medication for Alzheimer's disease (AD) management. Unfortunately, following the conventional application routes, the low brain bioavailability of MEL forms a significant limitation. The intranasal (IN) administration route is considered revolutionary for CNS medications delivery. The objective of the present study was to develop two types of nanocarriers, poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) and solid lipid nanoparticles (SLNs), for the IN delivery of MEL adapting the Quality by Design approach (QbD). Turning then to further enhance the optimized nanoformulation behavior by chitosan-coating. SLNs showed higher encapsulation efficacy (EE) and drug loading (DL) than PLGA NPs 87.26% (EE) and 2.67% (DL); 72.23% (EE) and 2.55% (DL), respectively. MEL encapsulated into the nanoformulations improved in vitro release, mucoadhesion, and permeation behavior compared to the native drug with greater superiority of chitosan-coated SLNs (C-SLNs). In vitro-in vivo correlation (IVIVC) results estimated a significant in vivo brain distribution of the nanoformulations compared to native MEL with estimated greater potential in the C-SLNs. Hence, MEL encapsulation into C-SLNs towards IN route can be promising in enhancing its brain bioavailability.

Development of In Situ Gelling Meloxicam-Human Serum Albumin Nanoparticle Formulation for Nose-to-Brain Application

The aim of this study was to develop an intranasal in situ thermo-gelling meloxicam-human serum albumin (MEL-HSA) nanoparticulate formulation applying poloxamer 407 (P407), which can be administered in liquid state into the nostril, and to increase the resistance of the formulation against mucociliary clearance by sol-gel transition on the nasal mucosa, as well as to improve drug absorption. Nanoparticle characterization showed that formulations containing 12-15% w/w P407 met the requirements of intranasal administration. The Z-average (in the range of 180-304 nm), the narrow polydispersity index (PdI, from 0.193 to 0.328), the zeta potential (between -9.4 and -7.0 mV) and the hypotonic osmolality (200-278 mOsmol/L) of MEL-HSA nanoparticles predict enhanced drug absorption through the nasal mucosa. Based on the rheological, muco-adhesion, drug release and permeability studies, the 14% w/w P407 containing formulation (MEL-HSA-P14%) was considered as the optimized formulation, which allows enhanced permeability of MEL through blood-brain barrier-specific lipid fraction. Cell line studies showed no cell damage after 1-h treatment with MEL-HSA-P14% on RPMI 2650 human endothelial cells' moreover, enhanced permeation (four-fold) of MEL from MEL-HSA-P14% was observed in comparison to pure MEL. Overall, MEL-HSA-P14% can be promising for overcoming the challenges of nasal drug delivery.

Abcg2 transporter affects plasma, milk and tissue levels of meloxicam

ATP-binding cassette (ABCG2) is an efflux transporter that extrudes xenotoxins from cells in liver, intestine, mammary gland, brain and other organs, affecting the pharmacokinetics, brain accumulation and secretion into milk of several compounds, including antitumoral, antimicrobial and anti-inflammatory drugs. The aim of this study was to investigate whether the widely used anti-inflammatory drug meloxicam is an Abcg2 sustrate, and how this transporter affects its systemic distribution. Using polarized ABCG2-transduced cell lines, we found that meloxicam is efficiently transported by murine Abcg2 and human ABCG2. After oral administration of meloxicam, the area under the plasma concentration-time curve in Abcg2^-/- mice was 2-fold higher than in wild type mice (146.06 ± 10.57 µg·h/ml versus 73.80 ± 10.00 µg·h/ml). Differences in meloxicam distribution were reported for several tissues after oral and intravenous administration, with a 20-fold higher concentration in the brain of Abcg2^-/- after oral administration. Meloxicam secretion into milk was also affected by the transporter, with a 2-fold higher milk-to-plasma ratio in wild-type compared with Abcg2^-/- lactating female mice after oral and intravenous administration. We conclude that Abcg2 is an important determinant of the plasma and brain distribution of meloxicam and is clearly involved in its secretion into milk.

Successful Treatment of Pneumothorax in a Dog With Sterile Pleural Fibrosis Caused by Chylothorax

A 2-year-old, 12 kg, intact male crossbreed dog was presented with respiratory distress, exercise intolerance, and gagging. Plain thoracic radiographs revealed severe pleural effusion. Although bilateral needle thoracocentesis and chest tube placement were performed, no re-expansion of the lung lobes occurred. Pleural effusion was of chylous quality and led to lung entrapment. Computer tomography revealed a highly atrophic and atelectatic right middle lung lobe. The remaining lung lobes were only expanded to ~40%. Visceral pleura and pericardium showed a heterogeneous thickening consistent with pleural fibrosis. Partial pericardiectomy with resection of the middle lung lobe through a right lateral thoracotomy was performed. Ligation of the thoracic duct and ablation of the cisterna chyli was achieved through a single paracostal approach. Histopathology revealed chronic-active proliferative beginning granulomatous pleuritis, fibrotic pericarditis, and partial coagulative necrosis with incomplete granulomatous sequestration in the resected middle lung lobe. Chylothorax resolved after surgical intervention. Active pleural effusion resolved, and lung entrapment changed to trapped lung disease. The remaining lung lobes re-expanded to ~80% over the following 6 days. The dog was discharged 10 days later. Mild to moderate pleural effusion of non-chylic quality was present during the following 4 months. Meloxicam was administered for 4 months because of its anti-fibrotic and anti-inflammatory properties. Fifteen months later, thoracic radiographs revealed full radiologic expansion of the lungs with persistent mild pleural fibrosis. To the authors' knowledge, this is the first case report of pneumothorax due pleural fibrosis caused by chylothorax in a dog with an excellent clinical outcome.

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.

A novel albumin wrapped nanosuspension of meloxicam to improve inflammation-targeting effects

Background

The objective of this study was to develop a more bio-available and safe nanosuspension of meloxicam (MX), which could dramatically improve inflammation targeting.

Methods and results

MX-loaded bovine serum albumin (BSA) nanosuspensions were prepared using acid–base neutralization in aqueous solution and the prepared nanosuspensions were characterized. The results obtained showed that the prepared nanosuspensions had a narrow size distribution with a mean particle size of 78.67±0.22 nm, a polydispersity index of 0.133±0.01, and a zeta potential of −11.87±0.91 mV. The prepared MX nanosuspensions were spherically wrapped by BSA with a smooth surface as shown by transmission electron microscopy. Stability studies showed that the nanosuspensions were physically stable at 4°C with a shelf life of at least 6 months. In the in vitro dissolution test, the MX-loaded BSA nanosuspension (MX-BSA-NS) exhibited sustained release. In addition, an in vivo pharmacokinetic study in rats following intravenous injection showed that the half-life (t_1/2), mean residence time (MRT), and area under the concentration–time curve (AUC_0–∞) of MX-BSA-NS was increased by 169.83%, 150.13%, and 148.80%, respectively, in comparison with MX conventional solution (MX solution). Furthermore, results from inflammation targeting studies showed that the concentration of MX increased significantly in inflamed tissues but was reduced in normal tissues compared with the MX solution group after injection of MX-BSA-NS.

Conclusion

The prepared MX-BSA-NS significantly increased the inflammation-targeting properties and bioavailability of MX, suggesting its potential as a promising formulation for the targeted drug delivery of MX in future clinical applications.

Effects of dexamethasone and meloxicam on Borrelia burgdorferi-induced inflammation in glial and neuronal cells of the central nervous system

Background

Lyme neuroborreliosis (LNB), caused by the spirochete Borrelia burgdorferi (Bb), affects both the central and peripheral nervous systems. Previously, we reported that in a model of acute LNB in rhesus monkeys, treatment with the anti-inflammatory drug dexamethasone significantly reduced both pleocytosis and levels of cerebrospinal fluid (CSF) immune mediators that were induced by Bb. Dexamethasone also inhibited the formation of inflammatory, neurodegenerative, and demyelinating lesions in the brain and spinal cord of these animals. In contrast, these signs were evident in the infected animals that were left untreated or in those that were treated with meloxicam, a non-steroidal anti-inflammatory drug.

Methods

To address the differential anti-inflammatory effects of dexamethasone and meloxicam in the central nervous system (CNS), we evaluated the potential of these drugs to alter the levels of Bb-induced inflammatory mediators in culture supernatants of rhesus frontal cortex (FC) explants, primary rhesus astrocytes and microglia, and human oligodendrocytes. We also ascertained the potential of dexamethasone to modulate Bb-induced apoptosis in rhesus FC explants. As meloxicam is a known COX-2 inhibitor, we evaluated whether meloxicam altered the levels of COX-2 as induced by live Bb in cell lysates of primary rhesus astrocytes and microglia.

Results

Dexamethasone but not meloxicam significantly reduced the levels of several Bb-induced immune mediators in culture supernatants of FC explants, astrocytes, microglia, and oligodendrocytes. Dexamethasone also had a protective effect on Bb-induced neuronal and oligodendrocyte apoptosis in rhesus FC explants. Further, meloxicam significantly reduced the levels of Bb-induced COX-2 in microglia, while both Bb and meloxicam were unable to alter the constitutive levels of COX-2 in astrocytes.

Conclusions

These data indicate that dexamethasone and meloxicam have differential anti-inflammatory effects on Bb-induced inflammation in glial and neuronal cells of the CNS and help explain the in vivo findings of significantly reduced inflammatory mediators in the CSF and lack of inflammatory neurodegenerative lesions in the brain and spinal cord of Bb-infected animals that were treated with dexamethasone but not meloxicam. Signaling cascades altered by dexamethasone could serve as possible therapeutic targets for limiting CNS inflammation and tissue damage in LNB.

Nerolidol-loaded nanospheres prevent behavioral impairment via ameliorating Na+, K+-ATPase and AChE activities as well as reducing oxidative stress in the brain of Trypanosoma evansi-infected mice

The aim of this study was to investigate the effect of nerolidol-loaded nanospheres (N-NS) on the treatment of memory impairment caused by Trypanosoma evansi in mice, as well as oxidative stress, and Na⁺, K⁺-ATPase and acetylcholinesterase (AChE) activities in brain tissue. Animals were submitted to behavioral tasks (inhibitory avoidance task and open-field test) 4 days postinfection (PI). Reactive oxygen species (ROS) and thiobarbituric acid-reactive substance (TBARS) levels and catalase (CAT), superoxide dismutase (SOD), Na⁺, K⁺-ATPase and AChE activities were measured on the fifth-day PI. T. evansi-infected mice showed memory deficit, increased ROS and TBARS levels and SOD and AChE activities, and decreased CAT and Na⁺, K⁺-ATPase activities compared to uninfected mice. N-NS prevented memory impairment and oxidative stress parameters (except SOD activity), while free nerolidol (N-F) restored only CAT activity. Also, N-NS treatment was able to prevent alterations in Na⁺, K⁺-ATPase and AChE activities caused by T. evansi infection. A significantly negative correlation was observed between memory and ROS production (p < 0.001; r = -0.941), as well as between memory and AChE activity (p < 0.05; r = -0.774). On the contrary, a significantly positive correlation between memory and Na⁺, K⁺-ATPase activity was observed (p < 0.01; r = 0.844). In conclusion, N-NS was able to reverse memory impairment and to prevent increased ROS and TBARS levels due to amelioration of Na⁺, K⁺-ATPase and AChE activities and to activation of the antioxidant enzymes, respectively. These results suggest that N-NS treatment may be a useful strategy to treat memory dysfunction and oxidative stress caused by T. evansi infection.