Lipid nanocarrier of selegiline augmented anti-Parkinson's effect via P-gp modulation using quercetin

The Advances in Antipsychotics-Induced Dyskinesia Rodent Models: Benefits of Antioxidant Supplementation

After 70 years of clinical practice with antipsychotics in the treatment of some specific serious mental disorders, much information has been accumulated considering their efficiency as a first-line evidence-based schizophrenia therapy, but also on their adverse effects within the range from minor to life-threatening issues. In this paper, we highlight motor impairment as a frequent limiting factor. Despite the diversity of side effects following antipsychotics usage, many of those who suffer share the same pathophysiological background issues, such as oxidative damage, neuroinflammation, apoptosis, and neurodegeneration (observed in the brain regions involved in motor control). The obvious need to solve these limitations is facing restraints in clinical studies due to the ethical issues. Therefore, it seems reasonable to address the importance of preclinical investigations to overcome the adverse effects of antipsychotics. For that purpose, we analyzed the antipsychotics-induced dyskinesia seen in rodent models, with a special focus on attempts to highlight the benefits of antioxidant supplementation. Our analysis has revealed that antioxidant supplementation, with various antioxidant-rich compounds, confirms the clear neuroprotective effects of the therapy of this iatrogenic dyskinesia. Given their accessibility and safety, it seems that the administration of antioxidant-rich compounds in various forms, as an adjuvant therapy, may be beneficial in patients by lowering the risk of secondary Parkinsonism. Also, it seems that the strategy for further investigations in this field of preclinical studies should be standardized and should include more antipsychotics employed in the clinical practice.

A Comprehensive Review on Repurposing the Nanocarriers for the Treatment of Parkinson's Disease: An Updated Patent and Clinical Trials

Parkinson's Disease (PD) is a progressive neurodegenerative disorder marked by the deterioration of dopamine-producing neurons, resulting in motor impairments like tremors and rigidity. While the precise cause remains elusive, genetic and environmental factors are implicated. Mitochondrial dysfunction, oxidative stress, and protein misfolding contribute to the disease's pathology. Current therapeutics primarily aim at symptom alleviation, employing dopamine replacement and deep brain stimulation. However, the quest for disease-modifying treatments persists. Ongoing clinical trials explore novel approaches, such as neuroprotective agents and gene therapies, reflecting the evolving PD research landscape. This review provides a comprehensive overview of PD, covering its basics, causal factors, major pathways, existing treatments, and a nuanced exploration of ongoing clinical trials. As the scientific community strives to unravel PD's complexities, this review offers insights into the multifaceted strategies pursued for a better understanding and enhanced management of this debilitating condition.

Lipid and Transcriptional Regulation in a Parkinson's Disease Mouse Model by Intranasal Vesicular and Hexosomal Plasmalogen-Based Nanomedicines

Plasmalogens (vinyl-ether phospholipids) are an emergent class of lipid drugs against various diseases involving neuro-inflammation, oxidative stress, mitochondrial dysfunction, and altered lipid metabolism. They can activate neurotrophic and neuroprotective signaling pathways but low bioavailabilities limit their efficiency in curing neurodegeneration. Here, liquid crystalline lipid nanoparticles (LNPs) are created for the protection and non-invasive intranasal delivery of purified scallop-derived plasmalogens. The in vivo results with a transgenic mouse Parkinson's disease (PD) model (characterized by motor impairments and α-synuclein deposition) demonstrate the crucial importance of LNP composition, which determines the self-assembled nanostructure type. Vesicle and hexosome nanostructures (characterized by small-angle X-ray scattering) display different efficacy of the nanomedicine-mediated recovery of motor function, lipid balance, and transcriptional regulation (e.g., reduced neuro-inflammation and PD pathogenic gene expression). Intranasal vesicular and hexosomal plasmalogen-based LNP treatment leads to improvement of the behavioral PD symptoms and downregulation of the Il6, Il33, and Tnfa genes. Moreover, RNA-sequencing and lipidomic analyses establish a dramatic effect of hexosomal nanomedicines on PD amelioration, lipid metabolism, and the type and number of responsive transcripts that may be implicated in neuroregeneration.

Progress in the Treatment of Central Nervous System Diseases Based on Nanosized Traditional Chinese Medicine

Traditional Chinese Medicine (TCM) is widely used in clinical practice to treat diseases related to central nervous system (CNS) damage. However, the blood-brain barrier (BBB) constitutes a significant impediment to the effective delivery of TCM, thus substantially diminishing its efficacy. Advances in nanotechnology and its applications in TCM (also known as nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain region. This review provides an overview of the physiological and pathological mechanisms of the BBB and systematically classifies the common TCM used to treat CNS diseases and types of nanocarriers that effectively deliver TCM to the brain. Additionally, drug delivery strategies for nano-TCMs that utilize in vivo physiological properties or in vitro devices to bypass or cross the BBB are discussed. This review further focuses on the application of nano-TCMs in the treatment of various CNS diseases. Finally, this article anticipates a design strategy for nano-TCMs with higher delivery efficiency and probes their application potential in treating a wider range of CNS diseases.

Preparation and evaluation of antidiabetic activity of mangiferin-loaded solid lipid nanoparticles

This study aimed to develop and optimize mangiferin-loaded solid lipid nanoparticles (MG-SLNs) using the microemulsion technique and ultrasonication. The MG-SLNs were composed of Labrafil M 2130 CS, MG, ethanol, Tween 80, and water. The optimized MG-SLNs exhibited a particle size of 138.37 ± 3.39 nm, polydispersity index of 0.247 ± 0.023, entrapment efficiency of 84.37 ± 2.43 %, and zeta potential of 18.87 ± 2.42 mV. Drug release studies showed a two-fold increase in the release of MG from SLNs compared to the solution. Confocal images indicated deeper permeation of MG-SLNs, highlighting their potential. Molecular docking confirmed mangiferin's inhibitory activity against α-amylase, consistent with previous findings. In vitro studies showed that MG-SLNs inhibited α-amylase activity by 55.43 ± 6.11 %, α-glucosidase activity by 68.76 ± 3.14 %, and exhibited promising antidiabetic activities. In a rat model, MG-SLNs significantly and sustainably reduced blood glucose levels for up to 12 h. Total cholesterol and triglycerides decreased, while high-density lipoprotein cholesterol increased. Both MG-SOL and MG-SLNs reduced SGOT and SGPT levels, with MG-SLNs showing a more significant reduction in SGOT compared to MG-SOL. Overall, the biochemical results indicated that both formulations improved diabetes-associated alterations. In conclusion, the study suggests that loading MG in SLNs using the newly developed approach could be an efficient oral treatment for diabetes, offering sustained blood glucose reduction and positive effects on lipid profiles and liver enzymes.

Fabrication of TPGS decorated Etravirine loaded lipidic nanocarriers as a neoteric oral bioavailability enhancer for lymphatic targeting

Etravirine (ERVN) is a potential NNRTI (non-nucleoside reverse transcriptase inhibitor) in treating HIV infection. It possesses extremely low oral bioavailability. The present research aims to optimize the formulation and characterization of TPGS-enriched ERVN-loaded lipid-based nanocarriers (NLCs) for HIV-infected patients. The formulation, ERVN-TPGS-NLCs, was optimized by central composite rotational design using a modified-solvent emulsification process. Various characterization parameters of NLCs were evaluated, including globule size of 121.56 ± 2.174 nm, PDI of 0.172 ± 0.042, the zeta potential of - 7.32 ± 0.021 mV, %EE of 94.42 ± 8.65% of ERVN and %DL was 8.94 ± 0.759% of ERVN and spherical shape was revealed by TEM. PXRD was also performed to identify the crystallinity of the sample. In-vitro drug release showed % a cumulative drug release of 83.72 ± 8.35% at pH 1.2 and 90.61 ± 9.11% at pH 6.8, respectively, whereas the % cumulative drug release from drug suspension (ERVN-S) was found to be 21.13 ± 2.01% at pH 1.2 and 24.84 ± 2.51 at pH 6.8 at the end of 48 h. Further, the intestinal permeation study and confocal microscope showed approximately three-fold and  two-fold increased permeation in ERVN-TPGS-NLCs and ERVN-NLCs across the gut sac compared to ERVN-S. Hemolysis compatibility and lipolysis studies were performed to predict the in-vivo fate of the formulation. The pharmacokinetic study revealed a 3.13-fold increment in the relative bioavailability, which agrees with the ex-vivo studies, and lymphatic uptake was validated by using cycloheximide along with designed formulation, which showed the impact of lymphatic uptake in AUC. This study ensures that ERVN-TPGS-NLCs take lymphatic uptake to minimize the first-pass metabolism followed by improved oral bioavailability of ERVN. Thus, the enhanced bioavailability of ERVN can reduce the high dose of ERVN to minimize the adverse effects related to dose-related burden.

Insights on Quercetin Therapeutic Potential for Neurodegenerative Diseases and its Nano-technological Perspectives

The neurodegeneration process begins in conjunction with the aging of the neurons. It manifests in different parts of the brain as Aβ plaques, neurofibrillary tangles, Lewy bodies, Pick bodies, and other structures, which leads to progressive loss or death of neurons. Quercetin (QC) is a flavonoid compound found in fruits, tea, and other edible plants have antioxidant effects that have been studied from subcellular compartments to tissue levels in the brain. Also, quercetin has been reported to possess a neuroprotective role by decreasing oxidative stress-induced neuronal cell damage. The use of QC for neurodegenerative therapy, the existence of the blood-brain barrier (BBB) remains a significant barrier to improving the clinical effectiveness of the drug, so finding an innovative solution to develop simultaneous BBB-crossing ability of drugs for treating neurodegenerative disorders and improving neurological outcomes is crucial. The nanoparticle formulation of QC is considered beneficial and useful for its delivery through this route for the treatment of neurodegenerative diseases seems necessary. Increased QC accumulation in the brain tissue and more significant improvements in tissue and cellular levels are among the benefits of QC-involved nanostructures.

Thermosensitive Micelles Gel to Deliver Quercetin Locally for Enhanced Antibreast Cancer Efficacy: An In Vitro Evaluation

Although quercetin is low cytotoxicity to normal human cells, quercetin is effective against the growth of some tumors. Given the poor blood stability in vivo, insolubility, low delivery efficiency, and poor medicinal properties of quercetin, we developed a local drug delivery system comprising quercetin core's polymer micelles and F127 hydrogel stroma. In vitro evaluation revealed that quercetin core's polymer micelles have excellent antitumor activity and could inhibit the multiplication of 4T1 breast cancer cells through the apoptosis pathway. Meanwhile, a rheological study revealed that the quercetin core's micelles gel possessed excellent properties of hydrogel formation and injectability of liquid preparation as a local drug delivery system after the quercetin core's polymer micelles were loaded into the F127 hydrogel stroma. Our study findings indicated that the drug stability and stable release capacity of quercetin were vastly improved with the composite formulation of the micelles gel. This not only realized drug injectability but also drug storage in the semisolid form, which is a more comfortable and slower drug-releasing form that will eventually exert a proper therapeutic effect. In conclusion, quercetin micellar hydrogel system has better antitumor activity and excellent hydrogel properties.

Intranasal inorganic cerium oxide nanoparticles ameliorate oxidative stress induced motor manifestations in haloperidol-induced parkinsonism

Cerium oxide nanoparticles (CONPs), owing to their radical scavenging property, have recently emerged as a therapeutic candidate for oxidative stress-mediated neurological diseases. However, oral and intravenous administration of CONPs is limited due to their poor physicochemical characteristics, low bioavailability, rapid systemic clearance, poor blood-brain penetration and dose-dependent toxicity. To overcome these challenges, we developed intranasal CONPs and evaluated their potential in the experimental PD model. CONPs were prepared by homogenous precipitation using tween 80 as a stabilizer and methanol/water as solvent. The optimization was done using Central Composite Design (CCD). The CONPs synthesis was confirmed by UV and FTIR. The optimized CONPs were small-sized (105.1 ± 5.78 nm), spherical (TEM), uniform (PDI, 0.119 ± 0.006) and stable (ZP, -22.7 ± 1.02 mV). Energy-dispersive X-ray analysis showed characteristic signals of Ce in developed CONPs. The X-ray diffraction pattern described the cubic fluorite structure and nano-crystalline nature of CONPs. The CONP anti-oxidant activity was found to be 93.60 ± 0.32% at 25 µg/mL concentration. Finally, motor manifestation studies like the forced swim test, locomotor test, akinesia, catalepsy, and muscle coordination test were conducted to assess the motor dysfunctions and behavioral activity in all four animal groups. Results of the in vivo motor manifestation studies in the haloperidol-induced PD rat model showed that co-administration of intranasal CONPs along with a half dose of levodopa resulted in significant protection, and results were significantly different from the untreated group but not significantly different from the healthy group. In conclusion, intranasal CONPs can be useful in ameliorating oxidative stress through their antioxidant effect and could be prospective therapeutics for the treatment of motor manifestations in Parkinson's disease.

Quality-by-Design-Assisted Optimization of Carvacrol Oil-Loaded Niosomal Gel for Anti-Inflammatory Efficacy by Topical Route

Niosomes are multilamellar vesicles that effectively transfer active ingredients into the skin's layers. To improve the active substance's penetration across the skin, these carriers are frequently utilized as topical drug delivery systems. Essential oils (EOs) have garnered significant interest in the field of research and development owing to their various pharmacological activities, cost-effectiveness, and simple manufacturing techniques. However, these ingredients undergo degradation and oxidation over time, leading to a loss of functionality. Niosome formulations have been developed to deal with these challenges. The main goal of this work was to create a niosomal gel of carvacrol oil (CVC) to improve its penetration into the skin for anti-inflammatory actions and stability. By changing the ratio of drug, cholesterol and surfactant, various formulations of CVC niosomes were formulated using Box Behnken Design (BBD). A thin-film hydration technique using a rotary evaporator was employed for the development of niosomes. Following optimization, the CVC-loaded niosomes had shown: 180.23 nm, 0.265, -31.70 mV, and 90.61% of vesicle size, PDI, zeta potential, and EE%. An in vitro study on drug release discovered the rates of drug release for CVC-Ns and CVC suspension, which were found to be 70.24 ± 1.21 and 32.87 ± 1.03, respectively. The release of CVC from niosomes best fit the Higuchi model, and the Korsmeyer-Peppas model suggests that the release of the drug followed the non-Fickian diffusion. In a dermatokinetic investigation, niosome gel significantly increased CVC transport in the skin layers when compared to CVC-conventional formulation gel (CVC-CFG). Confocal laser scanning microscopy (CLSM) of rat skin exposed to the rhodamine B-loaded niosome formulation showed a deeper penetration of 25.0 µm compared to the hydroalcoholic rhodamine B solution (5.0 µm). Additionally, the CVC-N gel antioxidant activity was higher than that of free CVC. The formulation coded F4 was selected as the optimized formulation and then gelled with carbopol to improve its topical application. Niosomal gel underwent tests for pH determination, spreadability, texture analysis, and CLSM. Our findings imply that the niosomal gel formulations could represent a potential strategy for the topical delivery of CVC in the treatment of inflammatory disease.

pH-Responsive and Mucoadhesive Nanoparticles for Enhanced Oral Insulin Delivery: The Effect of Hyaluronic Acid with Different Molecular Weights

Drug degradation at low pH and rapid clearance from intestinal absorption sites are the main factors limiting the development of oral macromolecular delivery systems. Based on the pH responsiveness and mucosal adhesion of hyaluronic acid (HA) and poly[2-(dimethylamino)ethyl methacrylate] (PDM), we prepared three HA–PDM nano-delivery systems loaded with insulin (INS) using three different molecular weights (MW) of HA (L, M, H), respectively. The three types of nanoparticles (L/H/M-HA–PDM–INS) had uniform particle sizes and negatively charged surfaces. The optimal drug loadings of the L-HA–PDM–INS, M-HA–PDM–INS, H-HA–PDM–INS were 8.69 ± 0.94%, 9.11 ± 1.03%, and 10.61 ± 1.16% (w/w), respectively. The structural characteristics of HA–PDM–INS were determined using FT-IR, and the effect of the MW of HA on the properties of HA–PDM–INS was investigated. The release of INS from H-HA–PDM–INS was 22.01 ± 3.84% at pH 1.2 and 63.23 ± 4.10% at pH 7.4. The protective ability of HA–PDM–INS with different MW against INS was verified by circular dichroism spectroscopy and protease resistance experiments. H-HA–PDM–INS retained 45.67 ± 5.03% INS at pH 1.2 at 2 h. The biocompatibility of HA–PDM–INS, regardless of the MW of HA, was demonstrated using CCK-8 and live–dead cell staining. Compared with the INS solution, the transport efficiencies of L-HA–PDM–INS, M-HA–PDM–INS, and H-HA–PDM–INS increased 4.16, 3.81, and 3.10 times, respectively. In vivo pharmacodynamic and pharmacokinetic studies were performed in diabetic rats following oral administration. H-HA–PDM–INS exhibited an effective hypoglycemic effect over a long period, with relative bioavailability of 14.62%. In conclusion, these simple, environmentally friendly, pH-responsive, and mucoadhesive nanoparticles have the potential for industrial development. This study provides preliminary data support for oral INS delivery.

The Impact of P-Glycoprotein on Opioid Analgesics: What's the Real Meaning in Pain Management and Palliative Care?

Opioids are widely used in cancer and non-cancer pain management. However, many transporters at the blood-brain barrier (BBB), such as P-glycoprotein (P-gp, ABCB1/MDR1), may impair their delivery to the brain, thus leading to opioid tolerance. Nonetheless, opioids may regulate P-gp expression, thus altering the transport of other compounds, namely chemotherapeutic agents, resulting in pharmacoresistance. Other kinds of painkillers (e.g., acetaminophen, dexamethasone) and adjuvant drugs used for neuropathic pain may act as P-gp substrates and modulate its expression, thus making pain management challenging. Inflammatory conditions are also believed to upregulate P-gp. The role of P-gp in drug-drug interactions is currently under investigation, since many P-gp substrates may also act as substrates for the cytochrome P450 enzymes, which metabolize a wide range of xenobiotics and endobiotics. Genetic variability of the ABCB1/MDR1 gene may be accountable for inter-individual variation in opioid-induced analgesia. P-gp also plays a role in the management of opioid-induced adverse effects, such as constipation. Peripherally acting mu-opioid receptors antagonists (PAMORAs), such as naloxegol and naldemedine, are substrates of P-gp, which prevent their penetration in the central nervous system. In our review, we explore the interactions between P-gp and opioidergic drugs, with their implications in clinical practice.

Central Composite Design Implemented Azilsartan Medoxomil Loaded Nanoemulsion to Improve Its Aqueous Solubility and Intestinal Permeability: In Vitro and Ex Vivo Evaluation

The present research attempted to design and develop a nanoemulsion formulation of azilsartan medoxomil to improve its aqueous solubility and intestinal permeability. Based on the solubility profile, ethyl oleate, tween 80, and Transcutol P were selected as the oil phase, surfactant, and co-surfactant, respectively. Central composite design (CCD) suggested an optimized azilsartan medoxomil- nanoemulsion formulation (optimized AZL-NE formulation) with 1.25% oil, 15.73% Smix, and 90 s ultrasonication time; it was found to have the droplet size, percentage transmittance, and % cumulative drug release (%CDR) of 71.5 nm, 93.46 ± 1.13%, and 90.14 ± 0.94%, respectively. Furthermore, it exhibited a 0.141 polydispersity index, 34.05 mV zeta potential, a 1.413 ± 0.03 refractive index, 6.68 ± 0.22 pH, 28.17 ± 0.52 cps viscosity, and a 96.98 ± 0.94% percentage drug content. Transmission electron microscopy (TEM) assessed the nano-sized spherical shape, and a differential scanning calorimeter (DSC) assessed the solubilization of the drug in the optimized formulation. The %CDR was 1.71 times higher and the % cumulative drug permeation was 2.1 times higher for the optimized AZL-NE formulation than for the drug suspension through an intestinal segment of a rat, which was also supported by confocal laser scanning microscopy (CLSM) studies. Thus, the nanoemulsion formulation of azilsartan medoxomil ensured the enhancement of the drug availability in the body.

Nanostructured Lipid Carrier-Based Codelivery of Raloxifene and Naringin: Formulation, Optimization, In Vitro, Ex Vivo, In Vivo Assessment, and Acute Toxicity Studies

This work aimed to develop dual drug-loaded nanostructured lipid carriers of raloxifene and naringin (RLX/NRG NLCs) for breast cancer. RLX/NRG NLCs were prepared using Compritol 888 ATO and oleic acid using a hot homogenization-sonication method and optimized using central composite design (CCD). The optimized RLX/NRG NLCs were characterized and evaluated using multiple technological means. The optimized RLX/NRG NLCs exhibited a particle size of 137.12 nm, polydispersity index (PDI) of 0.266, zeta potential (ZP) of 25.9 mV, and entrapment efficiency (EE) of 91.05% (raloxifene) and 85.07% (naringin), respectively. In vitro release (81 ± 2.2% from RLX/NRG NLCs and 31 ± 1.9% from the RLX/NRG suspension for RLX and 93 ± 1.5% from RLX/NRG NLCs and 38 ± 2.01% from the RLX/NRG suspension for NRG within 24 h). Concurrently, an ex vivo permeation study exhibited nearly 2.3 and 2.1-fold improvement in the permeability profiles of RLX and NRG from RLX/NRG NLCs vis-à-vis the RLX/NRG suspension. The depth of permeation was proved with CLSM images which revealed significant permeation of the drug from the RLX/NRG NLCs formulation, 3.5-fold across the intestine, as compared with the RLX/NRG suspension. An in vitro DPPH antioxidant study displayed a better antioxidant potential of RLX/NRG in comparison to RLX and NRG alone due to the synergistic antioxidant effect of RLX and NRG. An acute toxicity study in Wistar rats showed the safety profile of the prepared nanoformulations and their excipients. Our findings shed new light on how poorly soluble and poorly permeable medicines can be codelivered using NLCs in an oral nanoformulation to improve their medicinal performance.

Lipid-Based Nanocarriers for Neurological Disorders: A Review of the State-of-the-Art and Therapeutic Success to Date

Neurodegenerative disorders including Alzheimer's, Parkinson's, and dementia are chronic and advanced diseases that are associated with loss of neurons and other related pathologies. Furthermore, these disorders involve structural and functional defections of the blood-brain barrier (BBB). Consequently, advances in medicines and therapeutics have led to a better appreciation of various pathways associated with the development of neurodegenerative disorders, thus focusing on drug discovery and research for targeted drug therapy to the central nervous system (CNS). Although the BBB functions as a shield to prevent toxins in the blood from reaching the brain, drug delivery to the CNS is hindered by its presence. Owing to this, various formulation approaches, including the use of lipid-based nanocarriers, have been proposed to address shortcomings related to BBB permeation in CNS-targeted therapy, thus showing the potential of these carriers for translation into clinical use. Nevertheless, to date, none of these nanocarriers has been granted market authorization following the successful completion of all stages of clinical trials. While the aforementioned benefits of using lipid-based carriers underscores the need to fast-track their translational development into clinical practice, technological advances need to be initiated to achieve appropriate capacity for scale-up and the production of affordable dosage forms.