Potential Role of Nanoparticles in Treating the Accumulation of Amyloid-Beta Peptide in Alzheimer's Patients

Breaking Barriers in Alzheimer's Disease: the Role of Advanced Drug Delivery Systems

Alzheimer's disease (AD), characterized by cognitive impairment, brain plaques, and tangles, is a global health concern affecting millions. It involves the build-up of amyloid-β (Aβ) and tau proteins, the formation of neuritic plaques and neurofibrillary tangles, cholinergic system dysfunction, genetic variations, and mitochondrial dysfunction. Various signaling pathways and metabolic processes are implicated in AD, along with numerous biomarkers used for diagnosis, risk assessment, and research. Despite these, there is no cure or effective treatment for AD. It is critically important to address this immediately to develop novel drug delivery systems (NDDS) capable of targeting the brain and delivering therapeutic agents to modulate the pathological processes of AD. This review summarizes AD, its pathogenesis, related signaling pathways, biomarkers, conventional treatments, the need for NDDS, and their application in AD treatment. It also covers preclinical, clinical, and ongoing trials, patents, and marketed AD formulations.

Neuroprotective efficiency of celecoxib vesicular bilosomes for the management of lipopolysaccharide-induced Alzheimer in mice employing 23 full factorial design

The aim of this study was to develop and evaluate bilosomes loaded with Celecoxib (CXB) for the efficient treatment of Alzheimer. The thin-film hydration approach was utilized in the formulation of CXB bilosomes (CXB-BLs). The study used a 23-factorial design to investigate the impact of several formulation variables. Three separate parameters were investigated: bile salt type (X1), medication amount (X2), and lipid-bile salt ratio (X3). The dependent responses included entrapment efficiency (Y1: EE %), particle size (Y2: PS), and zeta potential (Y3: ZP). The formulation factors were statistically optimized using the Design-Expert® program. The vesicles demonstrated remarkable CXB encapsulation efficiency, ranging from 94.16 ± 1.91 to 98.38 ± 0.85%. The vesicle sizes ranged from 241.8 ± 6.74 to 352 ± 2.34 nm. The produced formulations have high negative zeta potential values, indicating strong stability. Transmission electron microscopy (TEM) revealed that the optimized vesicles had a spherical form. CXB release from BLs was biphasic, with the release pattern following Higuchi's model. In vivo studies confirmed the efficiency of CXB-BLs in management of lipopolysaccharide-induced Alzheimer as CXB-BLs ameliorated cognitive dysfunction, decreased acetylcholinesterase (AChE), and inhibited neuro-inflammation and neuro-degeneration through reducing Toll-like receptor (TLR4), and Interleukin-1β (IL-1β) levels. The findings suggested that the created CXB-BLs could be a potential drug delivery strategy for Alzheimer's treatment.

Navigating the Maze of Alzheimer's disease by exploring BACE1: Discovery, current scenario, and future prospects

Alzheimer's disease (AD) is a chronic neurological condition that has become a leading cause of cognitive decline in elder individuals. Hardly any effective medication has been developed to halt the progression of AD due to the disease's complexity. Several theories have been put forward to clarify the mechanisms underlying AD etiology. The identification of amyloid plaques as a hallmark of AD has sparked the development of numerous drugs targeting the players involved in the amyloidogenic pathway, such as the β-site of amyloid precursor protein cleavage enzyme 1 (BACE1) blockers. Over the last ten years, preclinical and early experimental research has led several pharmaceutical companies to prioritize producing BACE1 inhibitors. Despite all these efforts, earlier discovered inhibitors were discontinued in consideration of another second-generation small molecules and recent BACE1 antagonists failed in the final stages of clinical trials because of the complications associated either with toxicity or effectiveness. In addition to discussing the difficulties associated with development of BACE1 inhibitors, this review aims to provide an overview of BACE1 and offer perspectives on the causes behind the failure of five recent BACE1 inhibitors, that would be beneficial for choosing effective treatment approaches in the future.

Brazilin-7-2-butenoate inhibits amyloid β-protein aggregation, alleviates cytotoxicity, and protects Caenorhabditis elegans

The fibrillogenesis of amyloid β-protein (Aβ) gradually accumulates to form neurotoxic Aβ aggregates in the human brain, which is the direct cause of Alzheimer's disease (AD) related symptoms. There are currently no effective therapies for AD. Brazilin, a natural polyphenol, inhibits Aβ fibrillogenesis, disrupts the mature fibrils and alleviates the corresponding cytotoxicity, but it also has the high toxic. Therefore, brazilin-7-2-butenoate (B-7-2-B), a brazilin derivative, was designed and synthesized. B-7-2-B exhibited lower toxicity and stronger inhibitory effect on Aβ aggregation than brazilin. B-7-2-B could prevent the formation of Aβ fibrils and oligomers, and depolymerize pre-formed aggregates in a dose-dependent manner. Furthermore, B-7-2-B prominently alleviated the cytotoxicity and the oxidative stress induced by Aβ aggregates in PC12 cells. The protective impacts of B-7-2-B were further demonstrated by using the Caenorhabditis elegans model, including decreasing the extent of Aβ aggregation, improving the motility and sensation disorders. Eventually, B-7-2-B was proven to be no apparent damage to worms. In summarize, it can be concluded that B-7-2-B has the potential as a drug for treating AD.

Unravelling the in vitro and in vivo potential of selenium nanoparticles in Alzheimer's disease: A bioanalytical review

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and the accumulation of beta-amyloid plaques and tau tangles in the brain. Current therapies have limited efficacy, prompting the search for novel treatments. Selenium nanoparticles (SeNPs) have emerged as promising candidates for AD therapy due to their unique physicochemical properties and potential therapeutic effects. This review provides an overview of SeNPs and their potential application in AD treatment, as well as the main bioanalytical techniques applied in this field. SeNPs possess antioxidant and anti-inflammatory properties, making them potential candidates to combat the oxidative stress and neuroinflammation associated with AD. Moreover, SeNPs have shown the ability to cross the blood-brain barrier (BBB), allowing them to target brain regions affected by AD pathology. Various methods for synthesizing SeNPs are explored, including chemical, physical and biological synthesis approaches. Based on the employment of algae, yeast, fungi, and plants, green methods offer a promising and biocompatible alternative for SeNPs production. In vitro studies have demonstrated the potential of SeNPs in reducing beta-amyloid aggregation and inhibiting tau hyperphosphorylation, providing evidence of their neuroprotective effects on neuronal cells. In vivo studies using transgenic mouse models and AD-induced symptoms have shown promising results, with SeNPs treatment leading to cognitive improvements and reduced amyloid plaque burden in the hippocampus. Looking ahead, future trends in SeNPs research involve developing innovative brain delivery strategies to enhance their therapeutic potential, exploring alternative animal models to complement traditional mouse studies, and investigating multi-targeted SeNPs formulations to address multiple aspects of AD pathology. Overall, SeNPs represent a promising avenue for AD treatment, and further research in this field may pave the way for effective and much-needed therapeutic interventions for individuals affected by this debilitating disease.

Ion-activated In Situ Gel of Gellan Gum Containing Chrysin for Nasal Administration in Parkinson's Disease

INTRODUCTION

This study focused on creating an innovative treatment approach for Parkinson's disease (PD), a progressive neurodegenerative condition characterized by the loss of specific neurons in the brain.

AIM

The research aimed to develop a nasal gel using gellan gum containing a complex of chrysin with hydroxypropyl-β-cyclodextrin (HP-β-CD) to enhance the drug's solubility and stability.

METHOD

The formulation process involved utilizing central composite design (CCD) to optimize the concentrations of gellan gum and HPMC E5, with viscosity and mucoadhesive strength as key factors. The resulting optimized In Situ gel comprised 0.7% w/v gellan gum and 0.6% w/v HPMC E5, exhibiting desirable viscosity levels for both sol and gel states, along with robust mucoadhesive properties. The formulated gel underwent comprehensive evaluation, including assessments for gelation, drug content, in vitro drug release, ex vivo permeation, and histopathology.

RESULT

The findings demonstrated superior drug release from the In Situ gel compared to standalone chrysin. Ex vivo studies revealed effective drug permeation through nasal mucosa without causing harm. Moreover, experiments on neuronal cells exposed to oxidative stress (H2O2- induced) showcased significant neuroprotection conferred by chrysin and its formulations. These treatments exhibited notable enhancements in cell viability and reduced instances of apoptosis and necrosis, compared to the control group. The formulations exhibited neuroprotective properties by mitigating oxidative damage through mechanisms, like free radical scavenging and restoration of antioxidant enzyme activity.

CONCLUSION

In conclusion, this developed In situ gel formulation presents a promising novel nasal delivery system for PD therapy. By addressing challenges related to drug properties and administration route, it holds the potential to enhance treatment outcomes and improve the quality of life for individuals with Parkinson's disease.

Drug Repositioning: A Monetary Stratagem to Discover a New Application of Drugs

Drug repurposing, also referred to as drug repositioning or drug reprofiling, is a scientific approach to the detection of any new application for an already approved or investigational drug. It is a useful policy for the invention and development of new pharmacological or therapeutic applications of different drugs. The strategy has been known to offer numerous advantages over developing a completely novel drug for certain problems. Drug repurposing has numerous methodologies that can be categorized as target-oriented, drug-oriented, and problem-oriented. The choice of the methodology of drug repurposing relies on the accessible information about the drug molecule and like pharmacokinetic, pharmacological, physicochemical, and toxicological profile of the drug. In addition, molecular docking studies and other computer-aided methods have been known to show application in drug repurposing. The variation in dosage for original target diseases and novel diseases presents a challenge for researchers of drug repurposing in present times. The present review critically discusses the drugs repurposed for cancer, covid-19, Alzheimer's, and other diseases, strategies, and challenges of drug repurposing. Moreover, regulatory perspectives related to different countries like the United States (US), Europe, and India have been delineated in the present review.

Neuronanomedicine for Alzheimer's and Parkinson's disease: Current progress and a guide to improve clinical translation

Neuronanomedicine is an emerging multidisciplinary field that aims to create innovative nanotechnologies to treat major neurodegenerative disorders, such as Alzheimer's (AD) and Parkinson's disease (PD). A key component of neuronanomedicine are nanoparticles, which can improve drug properties and demonstrate enhanced safety and delivery across the blood-brain barrier, a major improvement on existing therapeutic approaches. In this review, we critically analyze the latest nanoparticle-based strategies to modify underlying disease pathology to slow or halt AD/PD progression. We find that a major roadblock for neuronanomedicine translation to date is a poor understanding of how nanoparticles interact with biological systems (i.e., bio-nano interactions), which is partly due to inconsistent reporting in published works. Accordingly, this review makes a set of specific recommendations to help guide researchers to harness the unique properties of nanoparticles and thus realise breakthrough treatments for AD/PD.

Nanoparticles loaded with natural medicines for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that disrupts cognitive function and severely affects the quality of life. Existing drugs only improve cognitive function and provide temporary relief of symptoms but do not stop or delay disease progression. Recently, natural medicines, especially Chinese herbal medicines, have gained attention in the treatment of AD due to their antioxidant, anti-inflammatory, and neuroprotective effects. However, conventional oral dosage forms lack brain specificity and have side effects that lead to poor patient compliance. Utilizing nanomedicine is a promising approach to improve brain specificity, bioavailability, and patient compliance. This review evaluates recent advances in the treatment of AD with nanoparticles containing various natural medicines. This review highlights that nanoparticles containing natural medicines are a promising strategy for the treatment of AD. It is believed that this technology can be translated into the clinic, thereby providing opportunities for AD patients to participate in social activities.

Tanshinone-IIA mediated neuroprotection by modulating neuronal pathways

The progression of neurological diseases is mainly attributed to oxidative stress, apoptosis, inflammation, and trauma, making them a primary public concern. Since no drugs can stop these neurological disorders from happening, active phytochemical intervention has been suggested as a possible treatment. Among the several phytochemicals being studied for their potential health advantages, tanshinone-IIA (Tan-IIA ) stands out due to its wide range of therapeutic effects. Tan-IIA, derived from the Salvia miltiorrhiza plant, is a phenanthrenequinone. The pharmacological characteristics of Tan-IIAagainst various neurodegenerative and neuropsychiatric illnesses have led researchers to believe that the compound possesses neuroprotective potential. Tan-IIA has therapeutic potential in treating neurological diseases due to its capacity to cross the blood-brain barrier and its broad range of activities. In treating neurological disorders, Tan-IIA has been shown to have neuroprotective effects such as anti-apoptotic, anti-inflammatory, BBB protectant, and antioxidant properties. This article concisely summarises the latest scientific findings about the cellular and molecular aspects of Tan-IIA neuroprotection in relation to various neurological diseases. The results of preclinical studies on Tan-IIA provide insight into its potential application in future therapeutic development. This molecule rapidly establishes as a prominent bioactive compound for clinical research.

Photobiomodulation in Alzheimer's Disease-A Complementary Method to State-of-the-Art Pharmaceutical Formulations and Nanomedicine?

Alzheimer's disease (AD), as a neurodegenerative disorder, usually develops slowly but gradually worsens. It accounts for approximately 70% of dementia cases worldwide, and is recognized by WHO as a public health priority. Being a multifactorial disease, the origins of AD are not satisfactorily understood. Despite huge medical expenditures and attempts to discover new pharmaceuticals or nanomedicines in recent years, there is no cure for AD and not many successful treatments are available. The current review supports introspection on the latest scientific results from the specialized literature regarding the molecular and cellular mechanisms of brain photobiomodulation, as a complementary method with implications in AD. State-of-the-art pharmaceutical formulations, development of new nanoscale materials, bionanoformulations in current applications and perspectives in AD are highlighted. Another goal of this review was to discover and to speed transition to completely new paradigms for the multi-target management of AD, to facilitate brain remodeling through new therapeutic models and high-tech medical applications with light or lasers in the integrative nanomedicine of the future. In conclusion, new insights from this interdisciplinary approach, including the latest results from photobiomodulation (PBM) applied in human clinical trials, combined with the latest nanoscale drug delivery systems to easily overcome protective brain barriers, could open new avenues to rejuvenate our central nervous system, the most fascinating and complex organ. Picosecond transcranial laser stimulation could be successfully used to cross the blood-brain barrier together with the latest nanotechnologies, nanomedicines and drug delivery systems in AD therapy. Original, smart and targeted multifunctional solutions and new nanodrugs may soon be developed to treat AD.

A Nanoenzyme Constructed from Manganese and Strandberg-Type Phosphomolybdate with Versatility in Antioxidant and Modulating Conformation of Aβ Protein Misfolding Aggregates In Vitro

Amyloid β-peptide (Aβ) misfolding aggregates with β-sheet structures and surplus reactive oxygen species (ROS) are both considered to be the culprit of neuronal toxicity in Alzheimer's disease (AD). Therefore, modulating the misfolding mode of Aβ and inhibiting ROS simultaneous has become an important method for anti-AD. Herein, a nanoscale manganese-substituted polyphosphomolybdate (H₂en)₃[Mn(H₂O)₄][Mn(H₂O)₃]₂[P₂Mo₅O₂₃]₂·14.5H₂O (abbreviated as MnPM) (en = ethanediamine) was designed and synthesized by single crystal to single crystal transformation method. MnPM can modulate the β-sheet rich conformation of Aβ aggregates, and thus reduce the formation of toxic species. Moreover, MnPM also possesses the ability to eliminate the free radicals produced by Cu²⁺-Aβ aggregates. It can inhibit the cytotoxicity of β-sheet-rich species and protect synapses of PC12 cells. MnPM combines the conformation modulating ability of Aβ and anti-oxidation ability, which makes a promising multi-funcational molecular with a composite mechanism for the new conceptual designing in treatment of such protein-misfolding diseases.

Impact of nanoparticles on amyloid β-induced Alzheimer's disease, tuberculosis, leprosy and cancer: a systematic review

Nanotechnology is an interdisciplinary domain of science, technology and engineering that deals with nano-sized materials/particles. Usually, the size of nanoparticles lies between 1 and 100 nm. Due to their small size and large surface area-to-volume ratio, nanoparticles exhibit high reactivity, greater stability and adsorption capacity. These important physicochemical properties attract scientific community to utilize them in biomedical field. Various types of nanoparticles (inorganic and organic) have broad applications in medical field ranging from imaging to gene therapy. These are also effective drug carriers. In recent times, nanoparticles are utilized to circumvent different treatment limitations. For example, the ability of nanoparticles to cross the blood-brain barrier and having a certain degree of specificity towards amyloid deposits makes themselves important candidates for the treatment of Alzheimer's disease. Furthermore, nanotechnology has been used extensively to overcome several pertinent issues like drug-resistance phenomenon, side effects of conventional drugs and targeted drug delivery issue in leprosy, tuberculosis and cancer. Thus, in this review, the application of different nanoparticles for the treatment of these four important diseases (Alzheimer's disease, tuberculosis, leprosy and cancer) as well as for the effective delivery of drugs used in these diseases has been presented systematically. Although nanoformulations have many advantages over traditional therapeutics for treating these diseases, nanotoxicity is a major concern that has been discussed subsequently. Lastly, we have presented the promising future prospective of nanoparticles as alternative therapeutics. In that section, we have discussed about the futuristic approach(es) that could provide promising candidate(s) for the treatment of these four diseases.

Influence of TiO2 and ZnO Nanoparticles on α-Synuclein and β-Amyloid Aggregation and Formation of Protein Fibrils

The most common neurological disorders, i.e., Parkinson's disease (PD) and Alzheimer's disease (AD), are characterized by degeneration of cognitive functions due to the loss of neurons in the central nervous system. The aggregation of amyloid proteins is an important pathological feature of neurological disorders.The aggregation process involves a series of complex structural transitions from monomeric to the formation of fibrils. Despite its potential importance in understanding the pathobiology of PD and AD diseases, the details of the aggregation process are still unclear. Nanoparticles (NPs) absorbed by the human circulatory system can interact with amyloid proteins in the human brain and cause PD. In this work, we report the study of the interaction between TiO₂ nanoparticles (TiO₂-NPs) and ZnO nanoparticles (ZnO-NPs) on the aggregation kinetics of β-amyloid fragment 1-40 (βA) and α-synuclein protein using surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS). The characterizations of ZnO-NPs and TiO₂-NPs were evaluated by X-ray diffraction (XRD) spectrum, atomic force microscopy (AFM), and UV-Vis spectroscopy. The interaction of nanoparticles with amyloid proteins was investigated by SERS. Our study showed that exposure of amyloid protein molecules to TiO₂-NPs and ZnO-NPs after incubation at 37 °C caused morphological changes and stimulated aggregation and fibrillation. In addition, significant differences in the intensity and location of active Raman frequencies in the amide I domain were found. The principal component analysis (PCA) results show that the effect of NPs after incubation at 4 °C does not cause changes in βA structure.

Anti-Caspr-conjugated gold nanoparticles emergence as a novel approach in the treatment of EAE animal model

Multiple sclerosis (MS) is a chronic autoimmune disorder of central nervous system which is increasing worldwide. Although immunosuppressive agents are used for the treatment of MS disease, nevertheless the lack of non-toxic and efficient therapeutic method is perceptible. Hence, this study aims to evaluate the effect of Contactin-associated protein (Caspr) antibody-, poly ethylene glycol (PEG)- and exosome combined gold nanoparticles (GNPs) in comparison to Glatiramer acetate as a selective treatment of MS disease in the experimental autoimmune encephalomyelitis (EAE) mouse model. EAE was induced in female C57BL/6 mice and 25-day treatment with anti-Caspr-, PEG- and exosome combined GNPs was evaluated. Histopathological examination of spinal cord, regulatory T cells as well as inflammatory pathway including IFN-ɣ and IL-17 and mir-326 were investigated. The results showed the severity of MS symptoms was significantly decreased in all treated groups. Histological examination of the spinal cord indicated the reduced demyelination and immune cell infiltration. Besides, regulatory T cells were significantly increased following all treatments. Remarkably, the cytokine levels of IFN-ɣ and IL-17 as well as mir-326 is altered in treated groups. Taken together, the obtained findings demonstrate that the administration of anti-Caspr-, PEG- and exosome combined GNPs can be considered a potential treatment in MS disease.

Neuroprotective activity of selenium nanoparticles against the effect of amino acid enantiomers in Alzheimer's disease

Alzheimer's disease (AD), the most prevalent neurodegenerative disease, is characterized by extracellular accumulation of amyloid-beta protein (Aβ), which is believed to be the very starting event of AD neurodegeneration. In this work, D-Phe, D-Ala, and D-Glu amino acids, which are the non-occurring enantiomeric form in the human body, and also D-Asp and DL-SeMet, have proved to be amyloidogenic regarding Aβ₄₂ aggregation in TEM studies. These amyloidogenic amino acid enantiomers also widened Aβ₄₂ fibrils up to 437% regarding Aβ₄₂ alone, suggesting that Aβ₄₂ aggregation is enantiomerically dependent. To inhibit enantiomeric-induced amyloid aggregation, selenium nanoparticles stabilized with chitosan (Ch-SeNPs) were successfully synthesized and employed. Thus, Ch-SeNPs reduced and even completely inhibited Aβ₄₂ aggregation produced in the presence of some amino acid enantiomers. In addition, through UV-Vis spectroscopy and fluorescence studies, it was deduced that Ch-SeNPs were able to interact differently with amino acids depending on their enantiomeric form. On the other hand, antioxidant properties of amino acid enantiomers were evaluated by DPPH and TBARS assays, with Tyr enantiomers being the only ones showing antioxidant effect. All spectroscopic data were statistically analysed through experimental design and response surface analysis, showing that the interaction between the Ch-SeNPs and the amino acids studied was enantioselective and allowing, in some cases, to establish the concentration ratios in which this interaction is maximum.

GSH-AuNP anti-oxidative stress, ER stress and mitochondrial dysfunction in amyloid-beta peptide-treated human neural stem cells

Amyloid-beta (Aβ) peptides have a role in the pathogenesis of Alzheimer's disease (AD) and are thought to promote oxidative stress, endoplasmic reticulum (ER) stress and mitochondrial deficiency, causing neuronal loss in the AD brain. The potential applications of glutathione conjugated gold nanoparticles (GSH-AuNPs) suggest they might have therapeutic value. Several studies have demonstrated that the effects of nanoparticles could provide protective roles in AD. Here, we showed that GSH-AuNPs mediate the viability of human neural stem cells (hNSCs) with Aβ, which was correlated with decreased caspase 3 and caspase 9. Importantly, hNSCs co-treated with GSH-AuNPs were significantly protected from Aβ-induced oxidative stress, as detected using the DCFH-DA, DHE, and MitoSOX staining assays. Furthermore, hNSCs co-treated with GSH-AuNPs were significantly protected from the Aβ-induced reduction in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2 downstream antioxidant target genes (SOD-1, SOD-2, Gpx, Catalase, and HO-1). In addition, GSH-AuNPs rescued the expression levels of ER stress-associated genes (Bip, CHOP, and ASK1) in Aβ-treated hNSCs. GSH-AuNPs normalized ER calcium and mitochondrial cytochrome c homeostasis in Aβ-treated hNSCs. Furthermore, treatment with GSH-AuNPs restored the levels of ATP, D-loop, mitochondrial mass, basal respiration, ATP-linked reparation, maximal respiration capacity, COX activity, mitochondrial membrane potential, and mitochondrial genes (PGC1α, NRF-1 and Tfam) in Aβ-treated hNSCs. Taken together, these findings extend our understanding of the protective effects of GSH-AuNPs against oxidative stress, ER stress and mitochondrial dysfunction in hNSCs with Aβ.

Precision and Advanced Nano-Phytopharmaceuticals for Therapeutic Applications

Phytopharmaceuticals have been widely used globally since ancient times and acknowledged by healthcare professionals and patients for their superior therapeutic value and fewer side-effects compared to modern medicines. However, phytopharmaceuticals need a scientific and methodical approach to deliver their components and thereby improve patient compliance and treatment adherence. Dose reduction, improved bioavailability, receptor selective binding, and targeted delivery of phytopharmaceuticals can be likely achieved by molding them into specific nano-formulations. In recent decades, nanotechnology-based phytopharmaceuticals have emerged as potential therapeutic candidates for the treatment of various communicable and non-communicable diseases. Nanotechnology combined with phytopharmaceuticals broadens the therapeutic perspective and overcomes problems associated with plant medicine. The current review highlights the therapeutic application of various nano-phytopharmaceuticals in neurological, cardiovascular, pulmonary, and gastro-intestinal disorders. We conclude that nano-phytopharmaceuticals emerge as promising therapeutics for many pathological conditions with good compliance and higher acceptance.

PLGA-Based Curcumin Delivery System: An Interesting Therapeutic Approach in the Treatment of Alzheimer's Disease

Progressive degeneration and dysfunction of the nervous system because of oxidative stress, aggregations of misfolded proteins, and neuroinflammation are the key pathological features of neurodegenerative diseases. Alzheimer's disease is a chronic neurodegenerative disorder driven by uncontrolled extracellular deposition of β-amyloid (Aβ) in the amyloid plaques and intracellular accumulation of hyperphosphorylated tau protein. Curcumin is a hydrophobic polyphenol with noticeable neuroprotective and anti-inflammatory effects that can cross the blood-brain barrier. Therefore, it is widely studied for the alleviation of inflammatory and neurological disorders. However, the clinical application of curcumin is limited due to its low aqueous solubility and bioavailability. Recently, nano-based curcumin delivery systems are developed to overcome these limitations effectively. This review article discusses the effects and potential mechanisms of curcumin-loaded PLGA nanoparticles in Alzheimer's disease.

Mechanisms Involved in Microglial-Interceded Alzheimer's Disease and Nanocarrier-Based Treatment Approaches

Alzheimer's disease (AD) is a common neurodegenerative disorder accountable for dementia and cognitive dysfunction. The etiology of AD is complex and multifactorial in origin. The formation and deposition of amyloid-beta (Aβ), hyperphosphorylated tau protein, neuroinflammation, persistent oxidative stress, and alteration in signaling pathways have been extensively explored among the various etiological hallmarks. However, more recently, the immunogenic regulation of AD has been identified, and macroglial activation is considered a limiting factor in its etiological cascade. Macroglial activation causes neuroinflammation via modulation of the NLRP3/NF-kB/p38 MAPKs pathway and is also involved in tau pathology via modulation of the GSK-3β/p38 MAPK pathways. Additionally, microglial activation contributes to the discrete release of neurotransmitters and an altered neuronal synaptic plasticity. Therefore, activated microglial cells appear to be an emerging target for managing and treating AD. This review article discussed the pathology of microglial activation in AD and the role of various nanocarrier-based anti-Alzeihmenr's therapeutic approaches that can either reverse or inhibit this activation. Thus, as a targeted drug delivery system, nanocarrier approaches could emerge as a novel means to overcome existing AD therapy limitations.

Neuroprotective Potential of Chrysin: Mechanistic Insights and Therapeutic Potential for Neurological Disorders

Chrysin, a herbal bioactive molecule, exerts a plethora of pharmacological effects, including anti-oxidant, anti-inflammatory, neuroprotective, and anti-cancer. A growing body of evidence has highlighted the emerging role of chrysin in a variety of neurological disorders, including Alzheimer's and Parkinson's disease, epilepsy, multiple sclerosis, ischemic stroke, traumatic brain injury, and brain tumors. Based on the results of recent pre-clinical studies and evidence from studies in humans, this review is focused on the molecular mechanisms underlying the neuroprotective effects of chrysin in different neurological diseases. In addition, the potential challenges, and opportunities of chrysin's inclusion in the neurotherapeutics repertoire are critically discussed.