Neuroprotective potential of sesamol and its loaded solid lipid nanoparticles in ICV-STZ-induced cognitive deficits: behavioral and biochemical evidence

Suppression of fecal phenol production by oral supplementation of sesamol: inhibition of tyrosine phenol-lyase by sesamol

Phenol is produced from dietary L-tyrosine by the action of tyrosine phenol-lyase (TPL) of gut bacteria and contributes to various physiological disorders, including skin diseases, certain cancers, and kidney dysfunction. We found that oral supplementation of sesamol (36 or 180 μg mL-1) ad libitum for 14 days in mice significantly suppressed fecal phenol production. Fecal microbiota structure analysis in sesamol-supplemented and control groups revealed that their overall microbiota structures were indistinguishable. To explain the sesamol-induced suppression of fecal phenol production, we characterized inhibition of bacterial TPL by sesamol in vitro. Sesamol specifically inhibited bacterial TPL in a mixed-type fashion (Ki, 135 μM), which was rationalized by computational docking studies using the crystal structure of Pantoea agglomerans TPL that was determined at 1.3 Å resolution. Sesamol was detected at 0-0.295 μmol g-1 feces in the sesamol-supplemented group. Given the Ki value of sesamol for TPL inhibition, these levels may not have been sufficient to fully inhibit TPL and suppress fecal phenol production. Therefore, the observed suppression of fecal phenol production upon oral sesamol supplementation arose not solely from the inhibition of TPL by sesamol, but also potentially from the effects of metabolites derived from sesamol and the antioxidant activities of sesamol and related metabolites. Nevertheless, these findings highlight the potential for using sesamol to prevent physiological disorders associated with phenol production by the gut microbiota.

Progress in the treatment of Alzheimer's disease based on nanosized traditional Chinese medicines

Traditional Chinese medicine (TCM) has been employed for centuries in treating and managing Alzheimer's disease (AD). However, their effective delivery to target sites can be a major challenge. This is due to their poor water solubility, low bioavailability, and potential toxicity. Furthermore, the blood-brain barrier (BBB) is a major obstacle to effective TCM delivery, significantly reducing efficacy. Advancements in nanotechnology and its applications in TCM (nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain area. This review summarizes the recent advances in nanocarrier-based delivery systems for different types of active constituents of TCM for AD, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones. Besides, the main challenges and opportunities for the future development of these advanced TCM nanocarriers are emphasized. In conclusion, this review provides valuable insights and guidance for utilizing nanocarriers to shape future TCM drug delivery.

The prospective therapeutic benefits of sesamol: neuroprotection in neurological diseases

Oxidative stress is recognized as a critical contributor to the advancement of neurological diseases, thereby rendering the alleviation of oxidative stress a pivotal strategy in the therapeutic management of such conditions. Sesamol, the principal constituent of sesame oil, has been the subject of extensive research due to its significant antioxidant properties, especially its ability to effectively counteract oxidative stress within the central nervous system and confer neuroprotection. While sesamol demonstrates potential in the treatment and prevention of neurological diseases, its modulation of oxidative stress is complex and not yet fully understood. This review delves into the neuroprotective effects arising from sesamol's antioxidant properties, analyzing how its antioxidative capabilities impact neurological diseases. It provides a theoretical foundation and unveils potential novel therapeutic applications of sesamol in the treatment of neurological disorders through the modulation of oxidative stress.

Surface-modified liposomal in-situ nasal gel enhances brain targeting of berberine hydrochloride for Alzheimer's therapy: optimization and in vivo studies

This work aimed to formulate surface-modified berberine hydrochloride (BER)-loaded liposomes containing in-situ nasal gel for bran targeting. The liposomes were prepared by ethanol-injection method and optimized following a 32 full-factorial design. Size, morphology, zeta potential, ex-vivo permeation, and in-vitro release were estimated. The surface of optimized liposome was modified with ascorbic acid. The size of surface-modified liposomes was bigger (191.4 nm) than the unmodified liposomes (171 nm). Surface-modified liposomes were embedded in in-situ gel using poloxamer and Carbopol 934P. Liposomal in-situ gel showed higher permeation (71.94%) in contrast to the plain gel (46.64%). In-vivo pharmacokinetic examination of payload from liposomal in-situ gel displayed higher concentration in brain (Cmax of 93.50 ng/mL). The liposomal in-situ nasal gel had a higher drug targeting efficiency (138.43%) and a higher drug targeting potential (27.77%) confirming improved brain targeting. In male Wistar rats, the pharmacodynamic parameters (path length and escape latency) were evaluated with trimethyl tin-induced neurodegeneration. Animals treated with BER-loaded in-situ gel significantly decreased escape latency and path length in comparison to the control group. Histopathological assessment showed that the formulated gel was safe for intranasal administration. The developed formulation has the potential to effectively enhance the efficacy of BER in Alzheimer's disease management.

Nanoparticle-Based Drug Delivery Systems Enhance Treatment of Cognitive Defects

Nanoparticle-based drug delivery presents a promising solution in enhancing therapies for neurological diseases, particularly cognitive impairment. These nanoparticles address challenges related to the physicochemical profiles of drugs that hinder their delivery to the central nervous system (CNS). Benefits include improved solubility due to particle size reduction, enhanced drug penetration across the blood-brain barrier (BBB), and sustained release mechanisms suitable for long-term therapy. Successful application of nanoparticle delivery systems requires careful consideration of their characteristics tailored for CNS delivery, encompassing particle size and distribution, surface charge and morphology, loading capacity, and drug release kinetics. Literature review reveals three main types of nanoparticles developed for cognitive function enhancement: polymeric nanoparticles, lipid-based nanoparticles, and metallic or inorganic nanoparticles. Each type and its production methods possess distinct advantages and limitations. Further modifications such as coating agents or ligand conjugation have been explored to enhance their brain cell uptake. Evidence supporting their development shows improved efficacy outcomes, evidenced by enhanced cognitive function assessments, modulation of pro-oxidant markers, and anti-inflammatory activities. Despite these advancements, clinical trials validating the efficacy of nanoparticle systems in treating cognitive defects are lacking. Therefore, these findings underscore the need for researchers to expedite clinical testing to provide robust evidence of the potential of nanoparticle-based drug delivery systems.

Transformative Impact of Nanocarrier‐Mediated Drug Delivery: Overcoming Biological Barriers and Expanding Therapeutic Horizons

Advancing therapeutic progress is centered on developing drug delivery systems (DDS) that control therapeutic molecule release, ensuring precise targeting and optimal concentrations. Targeted DDS enhances treatment efficacy and minimizes off‐target effects, but struggles with drug degradation. Over the last three decades, nanopharmaceuticals have evolved from laboratory concepts into clinical products, highlighting the profound impact of nanotechnology in medicine. Despite advancements, the effective delivery of therapeutics remains challenging because of biological barriers. Nanocarriers offer a solution with a small size, high surface‐to‐volume ratios, and customizable properties. These systems address physiological and biological challenges, such as shear stress, protein adsorption, and quick clearance. They allow targeted delivery to specific tissues, improve treatment outcomes, and reduce adverse effects. Nanocarriers exhibit controlled release, decreased degradation, and enhanced efficacy. Their size facilitates cell membrane penetration and intracellular delivery. Surface modifications increase affinity for specific cell types, allowing precise treatment delivery. This study also elucidates the potential integration of artificial intelligence with nanoscience to innovate future nanocarrier systems.

Nanomaterials that Aid in the Diagnosis and Treatment of Alzheimer's Disease, Resolving Blood-Brain Barrier Crossing Ability

As a form of dementia, Alzheimer's disease (AD) suffers from no efficacious cure, yet AD treatment is still imperative, as it ameliorates the symptoms or prevents it from deteriorating or maintains the current status to the longest extent. The human brain is the most sensitive and complex organ in the body, which is protected by the blood-brain barrier (BBB). This yet induces the difficulty in curing AD as the drugs or nanomaterials that are much inhibited from reaching the lesion site. Thus, BBB crossing capability of drug delivery system remains a significant challenge in the development of neurological therapeutics. Fortunately, nano-enabled delivery systems possess promising potential to achieve multifunctional diagnostics/therapeutics against various targets of AD owing to their intriguing advantages of nanocarriers, including easy multifunctionalization on surfaces, high surface-to-volume ratio with large payloads, and potential ability to cross the BBB, making them capable of conquering the limitations of conventional drug candidates. This review, which focuses on the BBB crossing ability of the multifunctional nanomaterials in AD diagnosis and treatment, will provide an insightful vision that is conducive to the development of AD-related nanomaterials.

Sesamol as a potent anticancer compound: from chemistry to cellular interactions

Sesamol (SM), a well-known component isolated from sesame seeds (Sesamum indicum), used in traditional medicines in treating numerous ailments. However, numerous molecular investigations revealed the various mechanisms behind its activity, emphasizing its antiproliferative, anti-inflammatory, and apoptosis-inducing properties, preventing cancer cell spread to distant organs. In several cells derived from various malignant tissues, SM-regulated signal transduction pathways and cellular targets have been identified. This review paper comprehensively describes the anticancer properties of SM and SM-viable anticancer drugs. Additionally, the interactions of this natural substance with standard anticancer drugs are examined, and the benefits of using nanotechnology in SM applications are explored. This makes SM a prime example of how ethnopharmacological knowledge can be applied to the development of contemporary drugs.

Sesamol: A Phenolic Compound of Health Benefits and Therapeutic Promise in Neurodegenerative Diseases

Sesamol, one of the key bioactive ingredients of sesame seeds (Sesamum indicum L.), is responsible for many of its possible nutritional benefits. Both the Chinese and Indian medical systems have recognized the therapeutic potential of sesame seeds. It has been shown to have significant therapeutic potential against oxidative stress, inflammatory diseases, metabolic syndrome, neurodegeneration, and mental disorders. Sesamol is a benign molecule that inhibits the expression of inflammatory indicators like numerous enzymes responsible for inducing inflammation, protein kinases, cytokines, and redox status. This review summarises the potential beneficial effects of sesamol against neurological diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Recently, sesamol has been shown to reduce amyloid peptide accumulation and attenuate cognitive deficits in AD models. Sesamol has also been demonstrated to reduce the severity of PD and HD in animal models by decreasing oxidative stress and inflammatory pathways. The mechanism of sesamol's pharmacological activities against neurodegenerative diseases will also be discussed in this review.

Nano biomaterials based strategies for enhanced brain targeting in the treatment of neurodegenerative diseases: an up-to-date perspective

Neurons and their connecting axons gradually degenerate in neurodegenerative diseases (NDs), leading to dysfunctionality of the neuronal cells and eventually their death. Drug delivery for the treatment of effected nervous system is notoriously complicated because of the presence of natural barriers, i.e., the blood-brain barrier and the blood cerebrospinal fluid barrier. Palliative care is currently the standard care for many diseases. Therefore, treatment programs that target the disease's origin rather than its symptoms are recommended. Nanotechnology-based drug delivery platforms offer an innovative way to circumvent these obstacles and deliver medications directly to the central nervous system, thereby enabling treatment of several common neurological problems, i.e., Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. Interestingly, the combination of nanomedicine and gene therapy enables targeting of selective mutant genes responsible for the progression of NDs, which may provide a much-needed boost in the struggle against these diseases. Herein, we discussed various central nervous system delivery obstacles, followed by a detailed insight into the recently developed techniques to restore neurological function via the differentiation of neural stem cells. Moreover, a comprehensive background on the role of nanomedicine in controlling neurogenesis via differentiation of neural stem cells is explained. Additionally, numerous phytoconstituents with their neuroprotective properties and molecular targets in the identification and management of NDs are also deliberated. Furthermore, a detailed insight of the ongoing clinical trials and currently marketed products for the treatment of NDs is provided in this manuscript.

Harnessing role of sesamol and its nanoformulations against neurodegenerative diseases

Sesamol is a lignan of sesame seeds and a natural phenolic molecule that has emerged as a useful medical agent. Sesamol is a non-toxic phytoconstituent, which exerts certain valuable effects in the management of cancer, diabetes, cardiovascular diseases, neurodegenerative diseases (NDs), etc. Sesamol is known to depict its neuroprotective role by various mechanisms, such as metabolic regulators, action on oxidative stress, neuroinflammation, etc. However, its poor oral bioavailability, rapid excretion (as conjugates), and susceptibility to gastric irritation/toxicity (particularly in rats' forestomach) may restrict its effectiveness. To overcome the associated limitations, novel drug delivery system-based formulations of sesamol are emerging and being researched extensively. These can conjugate with sesamol and enhance the bioavailability and solubility of free sesamol, along with delivery at the target site. In this review, we have summarized various research works highlighting the role of sesamol on various NDs, including Alzheimer's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Parkinson's disease. Moreover, the formulation strategies and neuroprotective role of sesamol-based nano-formulations have also been discussed.

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

The protective effects of sesamol and/or the probiotic, Lactobacillus rhamnosus, against aluminum chloride-induced neurotoxicity and hepatotoxicity in rats: Modulation of Wnt/β-catenin/GSK-3β, JAK-2/STAT-3, PPAR-γ, inflammatory, and apoptotic pathways

Introduction: Aluminium (Al) is accumulated in the brain causing neurotoxicity and neurodegenerative disease like Alzheimer's disease (AD), multiple sclerosis, autism and epilepsy. Hence, attenuation of Al-induced neurotoxicity has become a "hot topic" in looking for an intervention that slow down the progression of neurodegenerative diseases. Objective: Our study aims to introduce a new strategy for hampering aluminum chloride (AlCl3)-induced neurotoxicity using a combination of sesamol with the probiotic bacteria; Lactobacillus rhamnosus (L. rhamnosus) and also to test their possible ameliorative effects on AlCl3-induced hepatotoxicity. Methods: Sprague-Dawley male rats were randomly divided into five groups (n = 10/group) which are control, AlCl3, AlCl3 + Sesamol, AlCl3 + L. rhamnosus and AlCl3 + Sesamol + L. rhamnosus. We surveilled the behavioral, biochemical, and histopathological alterations centrally in the brain and peripherally in liver. Results: This work revealed that the combined therapy of sesamol and L. rhamnosus produced marked reduction in brain amyloid-β, p-tau, GSK-3β, inflammatory and apoptotic biomarkers, along with marked elevation in brain free β-catenin and Wnt3a, compared to AlCl3-intoxicated rats. Also, the combined therapy exerted pronounced reduction in hepatic expressions of JAK-2/STAT-3, inflammatory (TNF-α, IL-6, NF-κB), fibrotic (MMP-2, TIMP-1, α-SMA) and apoptotic markers, (caspase-3), together with marked elevation in hepatic PPAR-γ expression, compared to AlCl3 -intoxicated rats. Behavioral and histopathological assessments substantiated the efficiency of this combined regimen in halting the effect of neurotoxicity. Discussion: Probiotics can be used as an add-on therapy with sesamol ameliorate AlCl3 -mediated neurotoxicity and hepatotoxicity.

Posterity of nanoscience as lipid nanosystems for Alzheimer's disease regression

Alzheimer's disease (AD) is a type of dementia that affects a vast number of people around the world, causing a great deal of misery and death. Evidence reveals a relationship between the presence of soluble Aβ peptide aggregates and the severity of dementia in Alzheimer's patients. The BBB (Blood Brain Barrier) is a key problem in Alzheimer's disease because it prevents therapeutics from reaching the desired places. To address the issue, lipid nanosystems have been employed to deliver therapeutic chemicals for anti-AD therapy in a precise and targeted manner. The applicability and clinical significance of lipid nanosystems to deliver therapeutic chemicals (Galantamine, Nicotinamide, Quercetin, Resveratrol, Curcumin, HUPA, Rapamycin, and Ibuprofen) for anti-AD therapy will be discussed in this review. Furthermore, the clinical implications of the aforementioned therapeutic compounds for anti-AD treatment have been examined. Thus, this review will pave the way for researchers to fashion therodiagnostics approaches based on nanomedicine to overcome the problems of delivering therapeutic molecules across the blood brain barrier (BBB).

Development of Atomoxetine-Loaded NLC In Situ Gel for Nose-to-Brain Delivery: Optimization, In Vitro, and Preclinical Evaluation

The present study investigates the brain-targeted efficiency of atomoxetine (AXT)-loaded nanostructured lipid carrier (NLC)-laden thermosensitive in situ gel after intranasal administration. AXT-NLC was prepared by the melt emulsification ultrasonication method and optimized using the Box-Behnken design (BBD). The optimized formulation (AXT-NLC) exhibited particle size PDI, zeta potential, and entrapment efficiency (EE) of 108 nm, 0.271, -42.3 mV, and 84.12%, respectively. The morphology of AXT-NLC was found to be spherical, as confirmed by SEM analysis. DSC results displayed that the AXT was encapsulated within the NLC matrix. Further, optimized NLC (AXT-NLC13) was incorporated into a thermosensitive in situ gel using poloxamer 407 and carbopol gelling agent and evaluated for different parameters. The optimized in situ gel (AXT-NLC13G4) formulation showed excellent viscosity (2532 ± 18 Cps) at 37 °C and formed the gel at 28-34 °C. AXT-NLC13-G4 showed a sustained release of AXT (92.89 ± 3.98% in 12 h) compared to pure AXT (95.47 ± 2.76% in 4 h). The permeation flux through goat nasal mucosa of AXT from pure AXT and AXT-NLC13-G4 was 504.37 µg/cm²·h and 232.41 µg/cm²·h, respectively. AXT-NLC13-G4 intranasally displayed significantly higher absolute bioavailability of AXT (1.59-fold higher) than intravenous administration. AXT-NLC13-G4 intranasally showed 51.91% higher BTP than pure AXT (28.64%) when administered via the same route (intranasally). AXT-NLC13-G4 showed significantly higher BTE (207.92%) than pure AXT (140.14%) when administered intranasally, confirming that a high amount of the AXT reached the brain. With the disrupted performance induced by L-methionine, the AXT-NLC13-G4 showed significantly (p < 0.05) better activity than pure AXT as well as donepezil (standard). The finding concluded that NLC in situ gel is a novel carrier of AXT for improvement of brain delivery by the intranasal route and requires further investigation for more justification.

Role of Tau in Various Tauopathies, Treatment Approaches, and Emerging Role of Nanotechnology in Neurodegenerative Disorders

A few protein kinases and phosphatases regulate tau protein phosphorylation and an imbalance in their enzyme activity results in tau hyper-phosphorylation. Aberrant tau phosphorylation causes tau to dissociate from the microtubules and clump together in the cytosol to form neurofibrillary tangles (NFTs), which lead to the progression of neurodegenerative disorders including Alzheimer's disease (AD) and other tauopathies. Hence, targeting hyperphosphorylated tau protein is a restorative approach for treating neurodegenerative tauopathies. The cyclin-dependent kinase (Cdk5) and the glycogen synthase kinase (GSK3β) have both been implicated in aberrant tau hyperphosphorylation. The limited transport of drugs through the blood-brain barrier (BBB) for reaching the central nervous system (CNS) thus represents a significant problem in the development of drugs. Drug delivery systems based on nanocarriers help solve this problem. In this review, we discuss the tau protein, regulation of tau phosphorylation and abnormal hyperphosphorylation, drugs in use or under clinical trials, and treatment strategies for tauopathies based on the critical role of tau hyperphosphorylation in the pathogenesis of the disease. Pathology of neurodegenerative disease due to hyperphosphorylation and various therapeutic approaches including nanotechnology for its treatment.

Synaptic loss and gliosis in the nucleus tractus solitarii with streptozotocin-induced Alzheimer's disease

Obstructive sleep apnea is highly prevalent in Alzheimer's disease (AD). However, brainstem centers controlling respiration have received little attention in AD research, and mechanisms behind respiratory dysfunction in AD are not understood. The nucleus tractus solitarii (nTS) is an important brainstem center for respiratory control and chemoreflex function. Alterations of nTS integrity, like those shown in AD patients, likely affect neuronal processing and adequate control of breathing. We used the streptozotocin-induced rat model of AD (STZ-AD) to analyze cellular changes in the nTS that corroborate previously documented respiratory dysfunction. We used 2 common dosages of STZ (2 and 3 mg/kg STZ) for model induction and evaluated the early impact on cell populations in the nTS. The hippocampus served as control region to identify site-specific effects of STZ. There was significant atrophy in the caudal nTS of the 3 mg/kg STZ-AD group only, an area known to integrate chemoafferent information. Also, the hippocampus had significant atrophy with the highest STZ dosage tested. Both STZ-AD groups showed respiratory dysfunction along with multiple indices for astroglial and microglial activation. These changes were primarily located in the caudal and intermediate nTS. While there was no change of astrocytes in the hippocampus, microglial activation was accompanied by a reduction in synaptic density. Together, our data demonstrate that STZ-AD induces site-specific effects on all major cell types, primarily in the caudal/intermediate nTS. Both STZ dosages used in this study produced a similar outcome and can be used for future studies examining the initial symptoms of STZ-AD.

Endothelial Dysfunction in Neurodegenerative Diseases

The cerebral vascular system stringently regulates cerebral blood flow (CBF). The components of the blood-brain barrier (BBB) protect the brain from pathogenic infections and harmful substances, efflux waste, and exchange substances; however, diseases develop in cases of blood vessel injuries and BBB dysregulation. Vascular pathology is concurrent with the mechanisms underlying aging, Alzheimer's disease (AD), and vascular dementia (VaD), which suggests its involvement in these mechanisms. Therefore, in the present study, we reviewed the role of vascular dysfunction in aging and neurodegenerative diseases, particularly AD and VaD. During the development of the aforementioned diseases, changes occur in the cerebral blood vessel morphology and local cells, which, in turn, alter CBF, fluid dynamics, and vascular integrity. Chronic vascular inflammation and blood vessel dysregulation further exacerbate vascular dysfunction. Multitudinous pathogenic processes affect the cerebrovascular system, whose dysfunction causes cognitive impairment. Knowledge regarding the pathophysiology of vascular dysfunction in neurodegenerative diseases and the underlying molecular mechanisms may lead to the discovery of clinically relevant vascular biomarkers, which may facilitate vascular imaging for disease prevention and treatment.

Sesamol inhibits proliferation, migration and invasion of triple negative breast cancer via inactivating Wnt/β-catenin signaling

Triple negative breast cancer (TNBC), a particularly aggressive breast cancer subtype without estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (HER2) expression, possesses highly invasive capacity, uncontrolled proliferative phenotype and poor clinical prognosis. Sesamol enriched in sesame seeds has been widely reported as a metabolic modulator due to its anti-aging, anti-hepatotoxic and cardio-protective properties. In this study, we found that sesamol significantly inhibited proliferation, migration and invasion of TNBC cells via attenuating PCNA, CyclinD1 expression and reversion of epithelial-mesenchymal transition (EMT) characterized by increased epithelial marker E-cadherin and decreased mesenchymal marker N-cadherin, Vimentin, Snail expression. Moreover, sesamol inactivated Wnt/β-catenin signaling and Wnt agonist 1 AMBMP application reversed the inhibition of proliferation, migration and invasion of TNBC by sesamol administration. Subsequently, our data showed that sesamol induced Wnt inhibitory factor 1 (WIF1), an endogenous inhibitor of Wnt/β-catenin pathway, expression and WIF1 artificial knockdown abrogated the inactivation of Wnt/β-catenin signaling by sesamol exposure in TNBC cells. And we found that promoter region de-methylation was responsible for WIF1 up-regulation by sesamol administration. Finally, with the xenograft assay using nude mice, we also found that sesamol inhibited proliferation and metastasis of TNBC via WIF1-induced inactivation of Wnt/β-catenin signaling in vivo. Collectively, these data added novel understandings and evidences to the anti-cancer properties of sesamol.

Sesamol protects against liver fibrosis induced in rats by modulating lysophosphatidic acid receptor expression and TGF-β/Smad3 signaling pathway

The present study aimed to investigate the hepatoprotective effect of sesamol (SML), a nutritional phenolic compound obtained from sesame seeds, in liver fibrosis induced by thioacetamide (TAA) in rats and to explore the underlying mechanisms. Thirty-two male Sprague-Dawley rats were equally divided into four groups: control, TAA, TAA + SML 50 mg/kg, and TAA + SML 100 mg/kg groups. Liver functions and hepatic contents of glutathione (GSH) and malondialdehyde (MDA) were measured colorimetrically. Gene expressions of lysophosphatidic acid receptor (LPAR)-1 and -3, connective tissue growth factor (CTGF), transforming growth factor (TGF)-β1, small mothers against decapentaplegic (Smad)-3 and -7, α-smooth muscle actin (α-SMA), and cytokeratin 19 (CK19) were analyzed by qRT-PCR. Moreover, phosphorylated Smad3 (pSmad3) was quantified by ELISA. Additionally, TGF-β1, α-SMA, CK19, and vascular endothelial growth factor (VEGF) protein concentrations were semi-quantitatively analyzed by immunostaining of liver sections. SML treatment markedly improved liver index and liver functions. Moreover, SML protected against liver fibrosis in a dose-dependent manner as indicated by down-regulation of LPAR1, LPAR3, CTGF, TGF-β1/Smad3, and α-SMA expressions and a decrease in pSmad3 level, as well as an up-regulation of Smad7 expression. In addition, SML suppressed ductular reaction hinted by the decrease in CK19 expression. These results reveal the anti-fibrotic effect of SML against liver fibrosis that might be attributed to down-regulation of LPAR1/3 expressions, inhibition of TGF-β1/Smad3 pathway, and ductular reaction.

Inorganic Nanomaterials versus Polymer-Based Nanoparticles for Overcoming Neurodegeneration

Neurodegenerative disorders (NDs) affect a great number of people worldwide and also have a significant socio-economic impact on the aging population. In this context, nanomedicine applied to neurological disorders provides several biotechnological strategies and nanoformulations that improve life expectancy and the quality of life of patients affected by brain disorders. However, available treatments are limited by the presence of the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B-CSFB). In this regard, nanotechnological approaches could overcome these obstacles by updating various aspects (e.g., enhanced drug-delivery efficiency and bioavailability, BBB permeation and targeting the brain parenchyma, minimizing side effects). The aim of this review is to carefully explore the key elements of different neurological disorders and summarize the available nanomaterials applied for neurodegeneration therapy looking at several types of nanocarriers. Moreover, nutraceutical-loaded nanoparticles (NPs) and synthesized NPs using green approaches are also discussed underling the need to adopt eco-friendly procedures with a low environmental impact. The proven antioxidant properties related to several natural products provide an interesting starting point for developing efficient and green nanotools useful for neuroprotection.

A novel multi-target strategy for Alzheimer's disease treatment via sublingual route: Donepezil/memantine/curcumin-loaded nanofibers

Drug delivery systems that not only show efficacy through multiple therapeutic pathways but also facilitate patient drug use and exhibit a high bioavailability profile represent a promising strategy in the treatment of Alzheimer's disease (AD). Here, donepezil (DO)/memantine (MM)/curcumin (CUR)-loaded electrospun nanofibers (NFs) were produced for the treatment of AD. DSC, XRD, and FT-IR studies demonstrated the complete incorporation of the drug into PVA/PVP NFs. The disintegration profile was improved by loading the drugs in PVA/PVP with fast wetting (less than 1 s), the start of disintegration (21 s), and dispersion in 110 s. The desired properties for sublingual application were achieved with the dissolution of NFs in 240 s. The cell viability in DO/MM/CUR-loaded NFs was similar to the control group after 48 h in the cell culture. DO/MM/CUR-loaded NFs enhanced the expressions of BDNF (13.5-fold), TUBB3 (8.9-fold), Neurog2 (5.6-fold), NeuroD1 (5.8-fold), Nestin (166-fold), and GFAP (115-fold). DO/MM/CUR-loaded NFs and powder of these drugs contained in these fibers were daily administered sublingually to intracerebroventricular-streptozotocin (icv-STZ) treated rats. DO/MM/CUR-loaded NFs treatment improved the short-term memory damage and enhanced memory, learning ability, and spatial exploration talent. Results indicated that the levels of Aβ, Tau protein, APP, GSK-3β, AChE, and TNF-α were significantly decreased, and BDNF was increased by DO/MM/CUR-loaded NFs treatment compared to the AD group. In the histopathological analysis of the hippocampus and cortex, neuritic plaques and neurofibrillary nodes were not observed in the rats treated with DO/MM/CUR-loaded NFs. Taken together, the sublingual route delivery of DO/MM/CUR-loaded NFs supports potential clinical applications for AD.

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.

Nanoparticles in Combating Neuronal Dysregulated Signaling Pathways: Recent Approaches to the Nanoformulations of Phytochemicals and Synthetic Drugs Against Neurodegenerative Diseases

As the worldwide average life expectancy has grown, the prevalence of age-related neurodegenerative diseases (NDDs) has risen dramatically. A progressive loss of neuronal function characterizes NDDs, usually followed by neuronal death. Inflammation, apoptosis, oxidative stress, and protein misfolding are critical dysregulated signaling pathways that mainly orchestrate neuronal damage from a mechanistic point. Furthermore, in afflicted families with genetic anomalies, mutations and multiplications of α-synuclein and amyloid-related genes produce some kinds of NDDs. Overproduction of such proteins, and their excessive aggregation, have been proven in various models of neuronal malfunction and death. In this line, providing multi-target therapies carried by novel delivery systems would pave the road to control NDDs through simultaneous modulation of such dysregulated pathways. Phytochemicals are multi-target therapeutic agents, which employ several mechanisms towards neuroprotection. Besides, the blood-brain barrier (BBB) is a critical issue in managing NDDs since it inhibits the accessibility of drugs to the brain in sufficient concentration. Besides, discovering novel delivery systems is vital to improving the efficacy, bioavailability, and pharmacokinetic of therapeutic agents. Such novel formulations are also employed to improve the drug's biodistribution, allow for the co-delivery of several medicines, and offer targeted intracellular delivery against NDDs. The present review proposes nanoformulations of phytochemicals and synthetic agents to combat NDDs by modulating neuroinflammation, neuroapoptosis, neuronal oxidative stress pathways and protein misfolding.

Sesamol Attenuates Amyloid Peptide Accumulation and Cognitive Deficits in APP/PS1 Mice: The Mediating Role of the Gut-Brain Axis

Alzheimer's disease (AD), a neurodegenerative disease, is the leading cause of dementia. Sesamol is a lignan extracted from sesame oil and has been found to exert neuroprotective effects. The present study aimed to investigate the neuroprotective effects of sesamol on APPswe/PS1dE9 transgenic AD mice. The AD mice were fed with a diet supplemented with sesamol (0.075 w/w %). Sesamol treatment improved spatial memory and learning ability in AD mice, improved neuronal damage, and decreased Aβ accumulation. Sesamol protected the synaptic ultrastructure and inhibited neuroinflammatory responses in the brain of AD mice. Sesamol also significantly inhibited the overactivated microglia and reduced the overexpression of TNF-α and IL-1β in the brain of AD mice. Notably, sesamol reshaped gut microbiota by significantly decreasing the relative abundance of Helicobacter hepaticus, Clostridium, and Bacillaceae, enhancing the relative abundance of Rikenellaceae and Bifidobacterium in AD mice. It has been found that sesamol protected the gut barrier integrity and prevented the LPS leakage into the serum. Importantly, sesamol remarkably enhanced the content of SCFAs, including acetate, propionate, isobutyrate, butyrate, and valerate, in AD mice. Correlation analysis indicated that there was a strong correlation between the levels of SCFAs and cognitive functions. These results demonstrated that sesamol attenuated AD-related cognitive dysfunction and neuroinflammatory responses, which could be partly explained by its role in mediating the gut microbe-SCFA-brain axis. Thus, sesamol is a promising nutritional intervention strategy to prevent AD via the microbiota-gut-brain axis.

Emerging Novel Approaches for the Enhanced Delivery of Natural Products for the Management of Neurodegenerative Diseases

Neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington disease, amyotrophic lateral sclerosis, and prion disease affect any part of the brain. The complete mechanism of ND is unknown, but there are some molecular mechanism and chemical process. Natural compounds have better compatibility with the human body along with lesser side effects. Moreover, several studies showed that various natural compounds have significant neuroprotective, potent antioxidant, and anti-inflammatory properties, which are effective for treating the different type of ND. In ND, natural compounds act by various mechanisms such as preventing the generation of reactive oxygen species (ROS), eliminating destructed biomolecules before their accumulation affects cell metabolism, and improving the disease conditions. But due to the presence of the blood-brain barrier (BBB) layer and unfavorable pharmacokinetic properties of natural compounds, their delivery into the brain is limited. To minimize this problem and enhance drug delivery into the brain with an effective therapeutic dose, there is a need to develop a practical novel approach. The various studies showed that nanoformulations and microneedles (MN) containing natural compounds such as quercetin, curcumin, resveratrol, chrysin, piperine, ferulic acid, huperzine A, berberine, baicalein, hesperetin, and retinoic acid effectively improved many ND. In this review, the effect of such natural drug-loaded nanoformulation and MN patches on ND management is discussed, along with their merits and demerits. This review aims to introduce different novel approaches for enhancing natural drug delivery into the brain to manage various neurodegenerative diseases.

Neuroprotective effect of sesamol against aluminum nanoparticle-induced toxicity in rats

Alumina nanoparticles (ALNPs) are widely used causing neurobehavioral impairment in intoxicated animals and humans. Sesamol (SML) emerged as a natural phytochemical with potent antioxidant and anti-inflammatory properties. However, no study has directly tested the potential of SML to protect against AlNP-induced detrimental effects on the brain. AlNPs (100 mg/kg) were orally administered to rats by gavage with or without oral sesamol (100 mg/kg) for 28 days. In AlNP-intoxicated group, the brain AChE activity was elevated. The concentrations of MDA and 8-OHdG were increased suggesting lipid peroxidation and oxidative DNA damage. GSH depletion with inhibited activities of CAT and SOD were demonstrated. Serum levels of IL-1β and IL-6 were elevated. The expressions of GST, TNF-α, and caspase-3 genes in the brain were upregulated. Histopathologically, AlNPs induced hemorrhages, edema, neuronal necrosis, and/or apoptosis in medulla oblongata. The cerebellum showed loss of Purkinje cells, and the cerebrum showed perivascular edema, neuronal degeneration, necrosis, and neuronal apoptosis. However, concomitant administration of SML with AlNPs significantly ameliorated the toxic effects on the brain, reflecting antioxidant, anti-inflammatory, and anti-apoptotic effects of SML. Considering these results, sesamol could be a promising phytochemical with neuroprotective activity against AlNP-induced neurotoxicity.

Nanoparticles: A Hope for the Treatment of Inflammation in CNS

Neuroinflammation, an inflammatory response within the central nervous system (CNS), is a main hallmark of common neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), among others. The over-activated microglia release pro-inflammatory cytokines, which induces neuronal death and accelerates neurodegeneration. Therefore, inhibition of microglia over-activation and microglia-mediated neuroinflammation has been a promising strategy for the treatment of neurodegenerative diseases. Many drugs have shown promising therapeutic effects on microglia and inflammation. However, the blood–brain barrier (BBB)—a natural barrier preventing brain tissue from contact with harmful plasma components—seriously hinders drug delivery to the microglial cells in CNS. As an emerging useful therapeutic tool in CNS-related diseases, nanoparticles (NPs) have been widely applied in biomedical fields for use in diagnosis, biosensing and drug delivery. Recently, many NPs have been reported to be useful vehicles for anti-inflammatory drugs across the BBB to inhibit the over-activation of microglia and neuroinflammation. Therefore, NPs with good biodegradability and biocompatibility have the potential to be developed as an effective and minimally invasive carrier to help other drugs cross the BBB or as a therapeutic agent for the treatment of neuroinflammation-mediated neurodegenerative diseases. In this review, we summarized various nanoparticles applied in CNS, and their mechanisms and effects in the modulation of inflammation responses in neurodegenerative diseases, providing insights and suggestions for the use of NPs in the treatment of neuroinflammation-related neurodegenerative diseases.

Sequential delivery of dual drugs with nanostructured lipid carriers for improving synergistic tumor treatment effect

To improve synergistic anticancer efficacy and minimize the adverse effects of chemotherapeutic drugs, temozolomide (TMZ) and curcumin (CUR) co-loaded nanostructured lipid carriers (NLCs) were prepared by microemulsion in this study. And the physicochemical properties, drug release behavior, intracellular uptake efficiency, in vitro and in vivo anticancer effects of TMZ/CUR-NLCs were evaluated. TMZ/CUR-NLCs showed enhanced inhibitory effects on glioma cells compared to single drug loaded NLCs, which may be owing to that the quickly released CUR can sensitize the cancer cells to TMZ. The inhibitory mechanism is a combination of S phase cell cycle arrest associated with induced apoptosis. Notably, TMZ/CUR-NLCs can accumulate at brain and tumor sites effectively and perform a significant synergistic anticancer effect in vivo. More importantly, the toxic effects of TMZ/CUR-NLCs on major organs and normal cells at the same therapeutic dosage were not observed. In conclusion, NLCs are promising nanocarriers for delivering dual chemotherapeutic drugs sequentially, showing potentials in the synergistic treatment of tumors while reducing adverse effects both in vitro and in vivo.

Saroglitazar, a novel dual PPAR-α/γ agonist, reverses high fat-low protein diet-induced metabolic and cognitive aberrations in C57BL/6J male mice

AIMS

Insulin resistance (IR) has become one of the major causative factors for the pathogenesis of various metabolic and neurometabolic diseases. The sedentary lifestyle in association with the consumption of protein-deficient and high-calorie diet results in IR development. This study was aimed to evaluate the neuroprotective effects of Saroglitazar (SGZ), a dual peroxisome-proliferator activated receptor (PPAR-α/γ) in a high fat-low protein diet (HFLPD) fed mouse model of MetS and associated cognitive deficits.

METHODS

Adult male C57BL/6J mice were fed with HFLPD plus 15% oral fructose solution for 16 weeks. Starting at the 13th week, SGZ (5 & 10 mg/kg; p.o.) was administered along with HFLPD for four weeks, i.e., the 12th to 16th week of the study groups. Various physiological, serum metabolic, neurobehavioral, neuroinflammatory, and oxidative stress parameters were assessed. The brain histopathology and mRNA expression of diverse genes in specific brain regions were also estimated.

RESULTS

The treatment with SGZ at both doses have significantly reversed various HFLPD-induced metabolic and cognitive alterations by improving the glucose and lipid profile in the periphery in addition to the enhanced cerebral glucose homeostasis, BBB integrity, reduced oxidative stress, and neuroinflammation. Furthermore, the SGZ improved locomotion and memory retention while reducing the HFLPD-induced anxiety-like behaviors in the mice.

CONCLUSIONS

SGZ treatment showed significant metabo-neuroprotective effects in mice fed with HFLPD, possibly through peripherally mediated activation of PPAR-α/γ and insulin downstream signaling in the cortex and hippocampus.

Sesamin and sesamol attenuate H2O2-induced oxidative stress on human neuronal cells via the SIRT1-SIRT3-FOXO3a signaling pathway

Background: An imbalance of free radicals and antioxidant defense systems in physiological processes can result in protein/DNA damage, inflammation, and cellular apoptosis leading to neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Sesamin and sesamol, compounds derived from sesame seeds and oil, have been reported to exert various pharmacological effects, especially antioxidant activity. However, their molecular mechanisms against the oxidative stress induced by exogenous hydrogen peroxide (H₂O₂) remain to be elucidated. Aim: In this study, neuroprotective effects of sesamin and sesamol on H₂O₂-induced human neuroblastoma (SH-SY5Y) cell death and possible signaling pathways in the cells were explored. Methods: MTT assay and flow cytometry were conducted to determine cell viability and apoptotic profiles of neuronal cells treated with sesamin and sesamol. Carboxy-DCFDA assay was used to measure reactive oxygen species (ROS). Moreover, Western blot analysis was performed to investigate protein profiles associated with neuroprotection. Results: Pretreatment of the cells with 1 µM of sesamin and sesamol remarkably reduced the SH-SY5Y cell death induced by 400 µM H₂O₂ as well as the intracellular ROS production. Moreover, the molecular mechanisms underlying neuroprotection of the compounds were associated with activating SIRT1-SIRT3-FOXO3a expression, inhibiting BAX (proapoptotic protein), and upregulating BCL-2 (anti-apoptotic protein). Conclusion: The findings suggest that sesamin and sesamol are compounds that potentially protect neuronal cells against oxidative stress similar to that of the resveratrol, the reference compound. These antioxidants are thus of interest for further investigation in in vivo models of neuroprotection.

Sesamol alleviates chronic intermittent hypoxia-induced cognitive deficits via inhibiting oxidative stress and inflammation in rats

Chronic intermittent hypoxia (CIH) is a major pathophysiological feature of obstructive sleep apnea (OSA), which can cause oxidative stress and inflammation which can further impair the nervous system. Cognitive impairment is a common complication of the nervous system in OSA. Sesamol, a natural extract from Sesamum plants, is believed to have strong antioxidant and anti-inflammation capacity, which has a powerful neuroprotective function. But whether sesamol can improve CIH-induced cognitive impairment is unclear. This study aimed to explore whether sesamol can improve CIH-induced cognitive impairment and its relative mechanism in the model rats with OSA. Rats were exposed to CIH for 8 h a day for 2, 4, 6, and 8 weeks separately and concurrently were treated with sesamol (20 mg/kg/day, intraperitoneal). The Morris water maze (MWM) test was used to evaluate their learning and memory function. The activity of the superoxide dismutase (SOD) and the level of malondialdehyde were measured to evaluate the oxidative stress in the hippocampus of the rats. The levels of tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in the hippocampus were quantified to analyse neuroinflammation by ELISA. The MWM test showed that sesamol improved learning and memory impairment in CIH-exposed rats. We also found that the sesamol-treated CIH-exposed rats had significantly increased the activity of SOD, as well as reduced the level of malondialdehyde in the hippocampus. In addition, sesamol also reduced the levels of TNF-α and IL-1β in the hippocampus. These data show that sesamol is able to alleviate cognitive impairments in CIH-exposed rats, with its neuroprotective effects likely inhibiting oxidative stress and inflammation.

Opening eyes to therapeutic perspectives of bioactive polyphenols and their nanoformulations against diabetic neuropathy and related complications

Introduction: Diabetic neuropathy (DN) is one of the major complications arising from hyperglycaemia in diabetic patients. In recent years polyphenols present in plants have gained attention to treat DN. The main advantages associated with them are their action via different molecular pathways to manage DN and their safety. However, they failed to gain clinical attention due to challenges associated with their formulation development such as lipophilicity,poor bioavailability, rapid systemic elimination, and enzymatic degradation.Area covered: This article includes different polyphenols that have shown their potential against DN in preclinical studies and the research carried out towards development of their nanoformulations in order to overcome aforementioned issues.Expert opinion: In this review various polyphenol based nanoformulations such as nanospheres, self-nanoemulsifying drug delivery systems, niosomes, electrospun nanofibers, metallic nanoparticles explored exclusively to treat DN are discussed. However, the literature available related to polyphenol based nanoformulations to treat DN is limited. Moreover, these experiments are limited to preclinical studies. Hence, more focus is required towards  development of nanoformulations using simple and single step process as well as inexpensive and non-toxic excipients so that a stable, scalable, reproducible and non-toxic formulation could be achieved and clinical trials could be initiated.

Exosomes from human umbilical cord Mesenchymal stem cells attenuates stress-induced hippocampal dysfunctions

Human Mesenchymal Stem Cells (MSCs) especially human umbilical cord MSCs is the novel regenerative cell resource for regenerative therapy. However, the biological underpinning of MSCs in neuroprotections requires deep understanding. Exosomes is an important biological factor due to its multiple types of contents with various biological function. In current study, we collected the exosome from umbilical cord mesenchymal stem cells (hUC-MSCs) and tested the neuroprotective effects to brain stress. Proteomic analysis indicates significant enriched protein components display the functions in metabolic regulation. We then injected the exosome (MSC-Ex) to adult mice by i.v injection. On physiological level, treatment of MSC-Ex increased the adiponectin level in peripheral central nervous system (CNS). Moreover, MSC-Ex significantly accelerated the differentiation of adult neural stem cells but did not benefit the related cognitive behavior. We then created acute brain disorder model with STZ intra-hippocampal injection. Compared with STZ group, treatment of MSC-Ex improved cognitive function. Moreover, MSC-Ex promotes hippocampal neurogenesis that was suppressed by STZ injection. In conclusion, hUC-MSCs derived exosome would exert the neural regenerative effects associating with its metabolism regulatory capacity.

Critical Review of the Alzheimer's Disease Non-Transgenic Models: Can They Contribute to Disease Treatment?

Alzheimer's disease (AD) is a growing neurodegenerative disease without effective treatments or therapies. Despite the use of different approaches and an extensive variety of genetic amyloid based models, therapeutic strategies remain elusive. AD is characterized by three main pathological hallmarks that include amyloid-β plaques, neurofibrillary tangles, and neuroinflammatory processes; however, many other pathological mechanisms have been described in the literature. Nonetheless, the study of the disease and the screening of potential therapies is heavily weighted toward the study of amyloid-β transgenic models. Non-transgenic models may aid in the study of complex pathological states and provide a suitable complementary alternative to evaluating therapeutic biomedical and intervention strategies. In this review, we evaluate the literature on non-transgenic alternatives, focusing on the use of these models for testing therapeutic strategies, and assess their contribution to understanding AD. This review aims to underscore the need for a shift in preclinical research on intervention strategies for AD from amyloid-based to alternative, complementary non-amyloid approaches.

Lipid Nanoparticles as Carriers for the Treatment of Neurodegeneration Associated with Alzheimer's Disease and Glaucoma: Present and Future Challenges

Glaucoma constitutes the second cause of blindness worldwide and it is considered a neurodegenerative disorder. In this sense, Alzheimer's disease, which is the most common type of dementia, also causes neurodegeneration. The association between both diseases remains unknown although it has been hypothesised that a possible connection might exist and it will be analysed throughout the review. In this sense, nanoparticulate systems and specially, lipid nanoparticles could be the key for effective neuroprotection. Lipid nanoparticles are the most recent type of drug nanoparticulate systems. These nanoparticles have shown great potential to encapsulate hydrophobic drugs increasing their bioavailability and being able to deliver them to the target tissue. In addition, they have shown great potential for ocular drug delivery. This review explores the most recent strategies employing lipid nanoparticles for AD and glaucoma.

Lipid Nanoparticles Improve the Uptake of α-Asarone Into the Brain Parenchyma: Formulation, Characterization, In Vivo Pharmacokinetics, and Brain Delivery

Treatment of brain-related diseases is one of the most strenuous challenges in drug delivery research due to numerous hurdles, including poor blood-brain barrier penetration, lack of specificity, and severe systemic toxicities. Our research primarily focuses on the delivery of natural therapeutic compound, α-asarone, for the treatment of brain-related diseases. However, α-asarone has poor aqueous solubility, bioavailability, and stability, all of which are critical issues that need to be addressed. This study aims at formulating a lipid nanoparticulate system of α-asarone (A-LNPs) that could be used as a brain drug delivery system. The physicochemical, solid-state properties, stability, and in vitro and in vivo studies of the A-LNPs were characterized. The release of α-asarone from the A-LNPs was prolonged and sustained. After intravenous administration of A-LNPs or free α-asarone, significantly higher levels of α-asarone from the A-LNPs were detected in murine plasma and brain parenchyma fractions, confirming the ability of A-LNPs to not only maintain a therapeutic concentration of α-asarone in the plasma, but also transport α-asarone across the blood-brain barrier. These findings confirm that lipid nanoparticulate systems enable penetration of natural therapeutic compound α-asarone through the blood-brain barrier and may be a candidate for the treatment of brain-related diseases.

Neuroprotective Potential of Curcumin-Loaded Nanostructured Lipid Carrier in an Animal Model of Alzheimer's Disease: Behavioral and Biochemical Evidence

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is caused by accumulation of amyloid-β (Aβ) peptide and is associated with neurological abnormalities in learning and memory. The protective role of curcumin on nerve cells, along with a potent antioxidant and free radical scavenging activity, has been widely studied. However, its low bioavailability and limited transport ability across the blood-brain barrier are two major drawbacks of its application in the treatment of different neurodegenerative diseases. The present study was designed to improve the effectiveness of curcumin in the treatment of Aβ-induced cognitive deficiencies in a rat model of AD by loading it into nanostructured lipid carriers (NLCs). The accumulation rate of curcumin (505.76±38.4 ng/g-1 h) in rat brain, as well as its serum levels, were significantly increased by using curcumin-loaded NLCs. The effective role of NLCs for brain delivery of curcumin was confirmed by reduced oxidative stress parameters (ROS formation, lipid peroxidation, and ADP/ATP ratio) in the hippocampal tissue and improvement of spatial memory. Also, histopathological studies revealed the potential of Cur-NLCs in decreasing the hallmarks of Aβ in AD in the animal model. The result of studying the neuroprotective potential of Cur-NLC in both pre-treatment and treatment modes showed that loading curcumin in NLCs is an effective strategy for increasing curcumin delivery to the brain and reducing Aβ-induced neurological abnormalities and memory defects and that it can be the basis for further studies in the area of AD prevention and treatment.

Computationally Designed Sesamol Derivatives Proposed as Potent Antioxidants

Oxidative stress has been recognized to play an important role in several diseases, such as Parkinson's and Alzheimer's disease, which justifies the beneficial effects of antioxidants in ameliorating the deleterious effects of these health disorders. Sesamol, in particular, has been investigated for the treatment of several conditions because of its antioxidant properties. This article reports a rational computational design of new sesamol derivatives. They were constructed by adding four functional groups (-OH, -NH2, -COOH, and -SH) in three different positions of the sesamol molecular framework. A total of 50 derivatives between mono-, di-, and trisubstituted compounds were obtained. All the derivatives were evaluated and compared with a reference set of commercial neuroprotective drugs. The estimated properties are absorption, distribution, metabolism, excretion, toxicity, and synthetic accessibility. Selection and elimination scores were used to choose a first set of promising candidates. Acid-based properties and reactivity indexes were then estimated using the density functional theory. Four sesamol derivatives were finally selected, which are hypothesized to be potent antioxidants, even better than sesamol and Trolox for that purpose.

Protective Effects of Sesamol on Systemic Inflammation and Cognitive Impairment in Aging Mice

Sesamol, a lignan in sesame, possesses several bioactivities, such as antioxidation, anti-inflammation, and neuroprotective capability. In this study, the effects of sesamol on aging-caused cognitive defects are investigated. Twelve-month-old mice were treated with sesamol (0.1%, w/w) as dietary supplementation for 12 weeks. Behavioral tests revealed that sesamol improved aging-associated cognitive impairments. Sesamol decreased aging-induced oxidative stress via suppression of malondialdehyde production and increased antioxidant enzymes. Histological staining showed that sesamol treatment improved aging-induced neuronal damage and synaptic dysfunction in the hippocampus. Furthermore, sesamol significantly reduced aging-induced neuroinflammation by inhibiting the microglial overactivation and inflammatory cytokine expressions. Meanwhile, the accumulation of Aβ_1-42 was reduced by sesamol treatment. Moreover, sesamol protected the gut barrier integrity and reduced LPS release, which was highly associated with its beneficial effects on behavioral and inflammatory changes. In conclusion, our findings indicated that the use of sesamol is feasible in the treatment of aging-related diseases.

Application of Iron Oxide Nanoparticles in the Diagnosis and Treatment of Neurodegenerative Diseases With Emphasis on Alzheimer's Disease

Neurodegenerative diseases are characterized by chronic progressive degeneration of the structure and function of the nervous system, which brings an enormous burden on patients, their families, and society. It is difficult to make early diagnosis, resulting from the insidious onset and progressive development of neurodegenerative diseases. The drugs on the market cannot cross the blood-brain barrier (BBB) effectively, which leads to unfavorable prognosis and less effective treatments. Therefore, there is an urgent demand to develop a novel detection method and therapeutic strategies. Recently, nanomedicine has aroused considerable attention for diagnosis and therapy of central nervous system (CNS) diseases. Nanoparticles integrate targeting, imaging, and therapy in one system and facilitate the entry of drug molecules across the blood-brain barrier, offering new hope to patients. In this review, we summarize the application of iron oxide nanoparticles (IONPs) in the diagnosis and treatment of neurodegenerative disease, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). We focus on IONPs as magnetic resonance imaging (MRI) contrast agents (CAs) and drug carriers in AD. What most neurodegenerative diseases have in common is that hall marker lesions are represented by protein aggregates (Soto and Pritzkow, 2018). These diseases are of unknown etiology and unfavorable prognosis, and the treatments toward them are less effective (Soto and Pritzkow, 2018). Such diseases usually develop in aged people, and early clinical manifestations are atypical, resulting in difficulty in early diagnosis. Recently, nanomedicine has aroused considerable attention for therapy and diagnosis of CNS diseases because it integrates targeting, imaging, and therapy in one system (Gupta et al., 2019). In this review article, we first introduce the neurodegenerative diseases and commonly used MRI CAs. Then we review the application of IONPs in the diagnosis and treatment of neurodegenerative diseases with the purpose of assisting early theranostics (therapy and diagnosis).

Current insights on lipid nanocarrier-assisted drug delivery in the treatment of neurodegenerative diseases

The central nervous system (CNS) is vulnerable to pathologic processes that lead to the development of neurodegenerative disorders like Alzheimer's, Parkinson's and Huntington's diseases, Multiple sclerosis or Amyotrophic lateral sclerosis. These are chronic and progressive pathologies characterized by the loss of neurons and the formation of misfolded proteins. Additionally, neurodegenerative diseases are accompanied by a structural and functional dysfunction of the blood-brain barrier (BBB). Although serving as a protection for the CNS, the existence of physiological barriers, especially the BBB, limits the access of several therapeutic agents to the brain, constituting a major hindrance in neurotherapeutics advancement. In this regard, nanotechnology-based approaches have arisen as a promising strategy to not only improve drug targeting to the brain, but also to increase bioavailability. Lipid nanocarriers such as liposomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), microemulsions and nanoemulsions, have already proven their potential for enhancing brain transport, crossing more easily into the CNS and allowing the administration of medicines that could benefit the treatment of neurological pathologies. Given the socioeconomic impact of such conditions and the advent of nanotechnology that inevitably leads to more effective and superior therapeutics for their management, it is imperative to constantly update on the current knowledge of these topics. Herein, we provide insight on the BBB and the pathophysiology of the main neurodegenerative disorders. Moreover, this review seeks to highlight the several approaches that can be used to improve the delivery of therapeutic agents to the CNS, while also offering an extensive overview of the latest efforts regarding the use of lipid-based nanocarriers in the management of neurodegenerative diseases.

Novel therapeutic strategies for Alzheimer's disease: Implications from cell-based therapy and nanotherapy

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease which leads to progressive dysfunction of cognition, memory and learning in elderly people. Common therapeutic agents are not only inadequate to suppress the progression of AD pathogenesis but also produce deleterious side effects; hence, development of alternative therapies is required to specifically suppress complications of AD. The current review provides a commentary on conventional as well as novel therapeutic approaches with an emphasis on stem cell and nano-based therapies for improvement and management of AD pathogenesis. According to our overview of the current literature, AD is a multi-factorial disorder with various pathogenic trajectories; hence, a multifunctional strategy to create effective neuroprotective agents is required to treat this disorder.