Hesperetin Nanocrystals Improve Mitochondrial Function in a Cell Model of Early Alzheimer Disease

Comprehensive review of Hesperetin: Advancements in pharmacokinetics, pharmacological effects, and novel formulations

Hesperetin is a flavonoid compound naturally occurring in the peel of Citrus fruits from the Rutaceae family. Previous studies have demonstrated that hesperetin exhibits various pharmacological effects, such as anti-inflammatory, anti-tumor, antioxidative, anti-aging, and neuroprotective properties. In recent years, with the increasing prevalence of diseases and the rising awareness of traditional Chinese medicine, hesperetin has garnered growing attention for its wide-ranging pharmacological effects. To substantiate its health benefits and elucidate potential mechanisms, knowledge of pharmacokinetics is crucial. However, the limited solubility of hesperetin restricts its bioavailability, thereby diminishing its efficacy as a beneficial health agent. To enhance the bioavailability of hesperetin, various novel formulations have been developed, including nanoparticles, liposomes, and cyclodextrin inclusion complexes. This article reviews recent advances in the pharmacokinetics of hesperetin and methods to improve its bioavailability, as well as its pharmacological effects and mechanisms, aiming to provide a theoretical basis for clinical applications.

Latest Perspectives on Alzheimer's Disease Treatment: The Role of Blood-Brain Barrier and Antioxidant-Based Drug Delivery Systems

There has been a growing interest recently in exploring the role of the blood-brain barrier (BBB) in the treatment of Alzheimer's disease (AD), a neurodegenerative disorder characterized by cognitive decline and memory loss that affects millions of people worldwide. Research has shown that the BBB plays a crucial role in regulating the entry of therapeutics into the brain. Also, the potential benefits of using antioxidant molecules for drug delivery were highlighted in Alzheimer's treatment to enhance the therapeutic efficacy and reduce oxidative stress in affected patients. Antioxidant-based nanomedicine shows promise for treating AD by effectively crossing the BBB and targeting neuroinflammation, potentially slowing disease progression and improving cognitive function. Therefore, new drug delivery systems are being developed to overcome the BBB and improve the delivery of therapeutics to the brain, ultimately improving treatment outcomes for AD patients. In this context, the present review provides an in-depth analysis of recent advancements in AD treatment strategies, such as silica nanoparticles loaded with curcumin, selenium nanoparticles loaded with resveratrol, and many others, focusing on the critical role of the BBB and the use of antioxidant-based drug delivery systems.

Development of nanomedicines for the treatment of Alzheimer's disease: Raison d'être, strategies, challenges and regulatory aspects

Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by progressive loss of memory. Presently, AD is challenging to treat with current drug therapy as their delivery to the brain is restricted by the presence of the blood-brain barrier. Nanomedicines, due to their size, high surface volume ratio, and ease of tailoring drug release characteristics, showed their potential to treat AD. The nanotechnology-based formulations for brain targeting are expected to enter the market in the near future. So, regulatory frameworks are required to ensure the quality, safety, and effectiveness of the nanomedicines to treat AD. In this review, we discuss different strategies, in-vitro blood-brain permeation models, in-vivo permeation assessment, and regulatory aspects for the development of nanomedicine to treat AD.

Natural polyphenol: Their pathogenesis-targeting therapeutic potential in Alzheimer's disease

Alzheimer's disease (AD) is a detrimental neurodegenerative disease affecting the elderly. Clinically, it is characterized by progressive memory decline and subsequent loss of broader cognitive functions. Current drugs provide only symptomatic relief but do not have profound disease-modifying effects. There is an unmet need to identify novel pharmacological agents for AD therapy. Neuropathologically, the characteristic hallmarks of the disease are extracellular senile plaques containing amyloid β-peptides and intracellular neurofibrillary tangles containing hyperphosphorylated microtubule-associated protein tau. Simultaneously, oxidative stress, neuroinflammation and mitochondrial dysfunction in specific brain regions are early events during the process of AD pathologic changes and are associated with Aβ/tau toxicity. Here, we first summarized probable pathogenic mechanisms leading to neurodegeneration and hopefully identify pathways that serve as specific targets to improve therapy for AD. We then reviewed the mechanisms that underlie disease-modifying effects of natural polyphenols, with a focus on nuclear factor erythroid 2-related factor 2 activators for AD treatment. Lastly, we discussed challenges in the preclinical to clinical translation of natural polyphenols. In conclusion, there is evidence that natural polyphenols can be therapeutically useful in AD through their multifaceted mechanism of action. However, more clinical studies are needed to confirm these effects.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Reactive oxygen species (ROS) scavenging biomaterials for anti-inflammatory diseases: from mechanism to therapy

Inflammation is a fundamental defensive response to harmful stimuli, but the overactivation of inflammatory responses is associated with most human diseases. Reactive oxygen species (ROS) are a class of chemicals that are generated after the incomplete reduction of molecular oxygen. At moderate levels, ROS function as critical signaling molecules in the modulation of various physiological functions, including inflammatory responses. However, at excessive levels, ROS exert toxic effects and directly oxidize biological macromolecules, such as proteins, nucleic acids and lipids, further exacerbating the development of inflammatory responses and causing various inflammatory diseases. Therefore, designing and manufacturing biomaterials that scavenge ROS has emerged an important approach for restoring ROS homeostasis, limiting inflammatory responses and protecting the host against damage. This review systematically outlines the dynamic balance of ROS production and clearance under physiological conditions. We focus on the mechanisms by which ROS regulate cell signaling proteins and how these cell signaling proteins further affect inflammation. Furthermore, we discuss the use of potential and currently available-biomaterials that scavenge ROS, including agents that were engineered to reduce ROS levels by blocking ROS generation, directly chemically reacting with ROS, or catalytically accelerating ROS clearance, in the treatment of inflammatory diseases. Finally, we evaluate the challenges and prospects for the controlled production and material design of ROS scavenging biomaterials.

Transcript-Level In Silico Analysis of Alzheimer's Disease-Related Gene Biomarkers and Their Evaluation with Bioactive Flavonoids to Explore Therapeutic Interactions

Alzheimer's disease (AD) is a progressive brain disorder that can significantly affect the quality of life. We used a variety of in silico tools to investigate the transcript-level mutational impact of exonic missense rare variations (single nucleotide polymorphisms, SNPs) on protein function and to identify potential druggable protein cavities that correspond to potential therapeutic targets for the management of AD. According to the NIA-AA (National Institute on Aging-Alzheimer's Association) framework, we selected three AD biomarker genes (APP, NEFL, and MAPT). We systematically screened transcript-level exonic rare SNPs from these genes with a minor allele frequency of 1% in 1KGD (1000 Genomes Project Database) and gnomAD (Genome Aggregation Database). With downstream functional effect predictions, a single variation (rs182024939: K > N) of the MAPT gene with nine transcript SNPs was identified as the most pathogenic variation from the large dataset of mutations. The machine learning consensus classifier predictor categorized these transcript-level SNPs as the most deleterious variations, resulting in a large decrease in protein structural stability (ΔΔG kcal/mol). The bioactive flavonoid library was screened for drug-likeness and toxicity risk. Virtual screening of eligible flavonoids was performed using the MAPT protein. Identification of druggable protein-binding cavities showed VAL305, GLU655, and LYS657 as consensus-interacting residues present in the MAPT-docked top-ranked flavonoid compounds. The MM/PB(GB)SA analysis indicated hesperetin (-5.64 kcal/mol), eriodictyol (-5.63 kcal/mol), and sakuranetin (-5.60 kcal/mol) as the best docked flavonoids with the near-native binding pose. The findings of this study provide important insights into the potential of hesperetin as a promising flavonoid that can be utilized for further rational drug design and lead optimization to open new gateways in the field of AD therapeutics.

Recent Advancements in Nanocarrier-assisted Brain Delivery of Phytochemicals Against Neurological Diseases

Despite ongoing advancements in research, the inability of therapeutics to cross the blood-brain barrier (BBB) makes the treatment of neurological disorders (NDs) a challenging task, offering only partial symptomatic relief. Various adverse effects associated with existing approaches are another significant barrier that prompts the usage of structurally diverse phytochemicals as preventive/therapeutic lead against NDs in preclinical and clinical settings. Despite numerous beneficial properties, phytochemicals suffer from poor pharmacokinetic profile which limits their pharmacological activity and necessitates the utility of nanotechnology for efficient drug delivery. Nanocarriers have been shown to be proficient carriers that can enhance drug delivery, bioavailability, biocompatibility, and stability of phytochemicals. We, thus, conducted a meticulous literature survey using several electronic databases to gather relevant studies in order to provide a comprehensive summary about the use of nanocarriers in delivering phytochemicals as a treatment approach for NDs. Additionally, the review highlights the mechanisms of drug transport of nanocarriers across the BBB and explores their potential future applications in this emerging field.

Herbal Medicine Nanocrystals: A Potential Novel Therapeutic Strategy

Herbal medicines have gained recognition among physicians and patients due to their lower adverse effects compared to modern medicines. They are extensively used to treat various diseases, including cancer, cardiovascular issues, chronic inflammation, microbial contamination, diabetes, obesity, and hepatic disorders, among others. Unfortunately, the clinical application of herbal medicines is limited by their low solubility and inadequate bioavailability. Utilizing herbal medicines in the form of nanocrystals (herbal medicine nanocrystals) has shown potential in enhancing solubility and bioavailability by reducing the particle size, increasing the specific surface area, and modifying the absorption mechanisms. Multiple studies have demonstrated that these nanocrystals significantly improve drug efficacy by reducing toxicity and increasing bioavailability. This review comprehensively examines therapeutic approaches based on herbal medicine nanocrystals. It covers the preparation principles, key factors influencing nucleation and polymorphism control, applications, and limitations. The review underscores the importance of optimizing delivery systems for successful herbal medicine nanocrystal therapeutics. Furthermore, it discusses the main challenges and opportunities in developing herbal medicine nanocrystals for the purpose of treating conditions such as cancer, inflammatory diseases, cardiovascular disorders, mental and nervous diseases, and antimicrobial infections. In conclusion, we have deliberated regarding the hurdles and forthcoming outlook in the realm of nanotoxicity, in vivo kinetics, herbal ingredients as stabilizers of nanocrystals, and the potential for surmounting drug resistance through the utilization of nanocrystalline formulations in herbal medicine. We anticipate that this review will offer innovative insights into the development of herbal medicine nanocrystals as a promising and novel therapeutic strategy.

Combination of Secondary Plant Metabolites and Micronutrients Improves Mitochondrial Function in a Cell Model of Early Alzheimer's Disease

Alzheimer's disease (AD) is characterized by excessive formation of beta-amyloid peptides (Aβ), mitochondrial dysfunction, enhanced production of reactive oxygen species (ROS), and altered glycolysis. Since the disease is currently not curable, preventive and supportive approaches are in the focus of science. Based on studies of promising single substances, the present study used a mixture (cocktail, SC) of compounds consisting of hesperetin (HstP), magnesium-orotate (MgOr), and folic acid (Fol), as well as the combination (KCC) of caffeine (Cof), kahweol (KW) and cafestol (CF). For all compounds, we showed positive results in SH-SY5Y-APP695 cells-a model of early AD. Thus, SH-SY5Y-APP695 cells were incubated with SC and the activity of the mitochondrial respiration chain complexes were measured, as well as levels of ATP, Aβ, ROS, lactate and pyruvate. Incubation of SH-SY5Y-APP695 cells with SC significantly increased the endogenous respiration of mitochondria and ATP levels, while Aβ1-40 levels were significantly decreased. Incubation with SC showed no significant effects on oxidative stress and glycolysis. In summary, this combination of compounds with proven effects on mitochondrial parameters has the potential to improve mitochondrial dysfunction in a cellular model of AD.

The AMPK-SIRT1-FoxO1-NF-κB signaling pathway participates in hesperetin-mediated neuroprotective effects against traumatic brain injury via the NLRP3 inflammasome

BACKGROUND

Traumatic brain injury (TBI) induces inflammations that lead to secondary damage. Hesperetin (Hes) exerts anti-inflammatory activities against central nervous system (CNS) diseases. This article probes the possible neuroprotective effect and mechanism of Hes on TBI-induced acute cerebral damage.

METHODS

Male C57BL/6J mice were subjected to controlled cortical impingement (CCI) and Hes (50 mg/kg) treatment after the surgery. Short-term neurological deficits were assessed with the modified neurological severity score (mNSS) and the Rota-rod test. The brain edema was tested by the wet/dry method. Neuron apoptosis was evaluated by Nissl staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The blood-brain barrier (BBB) integrity was measured by Evans' blue staining, and immunohistochemistry (IHC) was conducted to study BV2 microglial activation. BV2 microglia and HT22 neuronal cells were stimulated by oxygen-glucose deprivation followed by recovery (OGD/R) and processed with Hes. Quantitative real-time-polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were implemented to gauge the expression of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-β (IL-1-β) and interleukin-6 (IL-6). Western blot (WB) was performed to check AMPK-SIRT1-FoxO1 both in vitro and in vivo.

RESULTS

Hes eased neurological deficits, cerebral edema, and neuronal apoptosis in mice following TBI. Hes hampered microglial activation and pro-inflammatory cytokines production. Hes promoted AMPK and SIRT1 expression, whereas repressed the phosphorylation of FoxO1-NF-κB, and inhibited NLRP3 expression. The AMPK inhibitor Compound C markedly reversed Hes-mediated anti-inflammatory and neuron-protective effects.

CONCLUSION

Hes curbs microglial activation-mediated inflammation via the AMPK-SIRT1-FoxO1-NF-κB axis, thereby improving neurobehavioral function after TBI.

Rejuvenation: Turning Back Time by Enhancing CISD2

The aging human population with age-associated diseases has become a problem worldwide. By 2050, the global population of those who are aged 65 years and older will have tripled. In this context, delaying age-associated diseases and increasing the healthy lifespan of the aged population has become an important issue for geriatric medicine. CDGSH iron-sulfur domain 2 (CISD2), the causative gene for Wolfram syndrome 2 (WFS2; MIM 604928), plays a pivotal role in mediating lifespan and healthspan by maintaining mitochondrial function, endoplasmic reticulum integrity, intracellular Ca²⁺ homeostasis, and redox status. Here, we summarize the most up-to-date publications on CISD2 and discuss the crucial role that this gene plays in aging and age-associated diseases. This review mainly focuses on the following topics: (1) CISD2 is one of the few pro-longevity genes identified in mammals. Genetic evidence from loss-of-function (knockout mice) and gain-of-function (transgenic mice) studies have demonstrated that CISD2 is essential to lifespan control. (2) CISD2 alleviates age-associated disorders. A higher level of CISD2 during natural aging, when achieved by transgenic overexpression, improves Alzheimer's disease, ameliorates non-alcoholic fatty liver disease and steatohepatitis, and maintains corneal epithelial homeostasis. (3) CISD2, the expression of which otherwise decreases during natural aging, can be pharmaceutically activated at a late-life stage of aged mice. As a proof-of-concept, we have provided evidence that hesperetin is a promising CISD2 activator that is able to enhance CISD2 expression, thus slowing down aging and promoting longevity. (4) The anti-aging effect of hesperetin is mainly dependent on CISD2 because transcriptomic analysis of the skeletal muscle reveals that most of the differentially expressed genes linked to hesperetin are regulated by hesperetin in a CISD2-dependent manner. Furthermore, three major metabolic pathways that are affected by hesperetin have been identified in skeletal muscle, namely lipid metabolism, protein homeostasis, and nitrogen and amino acid metabolism. This review highlights the urgent need for CISD2-based pharmaceutical development to be used as a potential therapeutic strategy for aging and age-associated diseases.

Caenorhabditis elegans as a Model for the Effects of Phytochemicals on Mitochondria and Aging

The study of aging is an important topic in contemporary research. Considering the demographic changes and the resulting shifts towards an older population, it is of great interest to preserve youthful physiology in old age. For this endeavor, it is necessary to choose an appropriate model. One such model is the nematode Caenorhabditis elegans (C. elegans), which has a long tradition in aging research. In this review article, we explore the advantages of using the nematode model in aging research, focusing on bioenergetics and the study of secondary plant metabolites that have interesting implications during this process. In the first section, we review the situation of aging research today. Conventional theories and hypotheses about the ongoing aging process will be presented and briefly explained. The second section focuses on the nematode C. elegans and its utility in aging and nutrition research. Two useful genome editing methods for monitoring genetic interactions (RNAi and CRISPR/Cas9) are presented. Due to the mitochondria's influence on aging, we also introduce the possibility of observing bioenergetics and respiratory phenomena in C. elegans. We then report on mitochondrial conservation between vertebrates and invertebrates. Here, we explain why the nematode is a suitable model for the study of mitochondrial aging. In the fourth section, we focus on phytochemicals and their applications in contemporary nutritional science, with an emphasis on aging research. As an emerging field of science, we conclude this review in the fifth section with several studies focusing on mitochondrial research and the effects of phytochemicals such as polyphenols. In summary, the nematode C. elegans is a suitable model for aging research that incorporates the mitochondrial theory of aging. Its living conditions in the laboratory are optimal for feeding studies, thus enabling bioenergetics to be observed during the aging process.

Medicinal plants' proposed nanocomposites for the management of endocrine disorders

Extensive attention has been focused on herbal medicine for the treatment of different endocrine disorders. In fact, compelling scientific evidence indicates that natural compounds might act as endocrine modulators by mimicking, stimulating, or inhibiting the actions of different hormones, such as thyroid, sex, steroidal, and glucose regulating hormones. These potentials might be effectively employed for therapeutic purposes related to the endocrine system as novel complementary choices. Nevertheless, despite the remarkable therapeutic effects, inadequate targeting efficiency and low aqueous solubility of the bioactive components are still essential challenges in their clinical accreditation. On the other hand, nanotechnology has pushed the wheels of combining inorganic nanoparticles with biological structures of medicinal bioactive compounds as one of the utmost exciting fields of research. Nanoparticle conjugations create an inclusive array of applications that provide greater compliance, higher bioavailability, and lower dosage. This can safeguard the global availability of these wealthy natural sources, regardless of their biological occurrence. This review inspects future challenges of medicinal plants in various endocrine disorders for safe and alternative treatments with examples of their nanoparticle formulations.

Redox Active α-Lipoic Acid Differentially Improves Mitochondrial Dysfunction in a Cellular Model of Alzheimer and Its Control Cells

Introduction: Alpha lipoic acid (ALA) is a sulphur-containing organic compound, derived from octanoic acid, and an important cofactor for mitochondrial respiratory enzymes. It has strong antioxidant properties that improve mitochondrial function. We investigated if ALA improves mitochondrial dysfunction in a cellular model of Alzheimer’s disease (AD). Methods: SH-SY5Y-APP₆₉₅ cells were used as a model for an early stage of AD. Vector-transfected SH-SY5Y-MOCK cells served as controls. Using these cells, we investigated mitochondrial respiration (OXPHOS), mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) production, and citrate synthase activity (CS) in cells treated with ALA. Cells were treated for 24 h with different concentrations of ALA and with or without the complex I inhibitor rotenone. Results: Incubation with ALA showed a significant increase in ATP levels in both SH-SY5Y-APP₆₉₅ and SH-SY5Y-MOCK cells. MMP levels were elevated in SH-SY5Y-MOCK cells, treatment with rotenone showed a reduction in MMP, which could be partly alleviated after incubation with ALA in SH-SY5Y-MOCK cells. ALA treatment showed significant differences in respiration chain complex activities in SH-SY5Y-MOCK cells. Citrate synthase activity was unaffected. ROS levels were significantly lower in both cell lines treated with ALA. Conclusions: ALA increased the activity of the different complexes of the respiratory chain, and consequently enhanced the MMP, leading to increased ATP levels indicating improved mitochondrial function. ALA only marginally protects from additional rotenone-induced mitochondrial stress.

Effects of Combining Biofactors on Bioenergetic Parameters, Aβ Levels and Survival in Alzheimer Model Organisms

Increased amyloid beta (Aβ) levels and mitochondrial dysfunction (MD) in the human brain characterize Alzheimer disease (AD). Folic acid, magnesium and vitamin B6 are essential micro-nutrients that may provide neuroprotection. Bioenergetic parameters and amyloid precursor protein (APP) processing products were investigated in vitro in human neuroblastoma SH-SY5Y-APP695 cells, expressing neuronal APP, and in vivo, in the invertebrate Caenorhabditis elegans (CL2006 & GMC101) expressing muscular APP. Model organisms were incubated with either folic acid and magnesium-orotate (ID63) or folic acid, magnesium-orotate and vitamin B6 (ID64) in different concentrations. ID63 and ID64 reduced Aβ, soluble alpha APP (sAPPα), and lactate levels in SH-SY5Y-APP695 cells. The latter might be explained by enhanced expression of lactate dehydrogenase (LDHA). Micronutrient combinations had no effects on mitochondrial parameters in SH-SY5Y-APP695 cells. ID64 showed a significant life-prolonging effect in C. elegans CL2006. Incubation of GMC101 with ID63 significantly lowered Aβ aggregation. Both combinations significantly reduced paralysis and thus improved the phenotype in GMC101. Thus, the combinations of the tested biofactors are effective in pre-clinical models of AD by interfering with Aβ related pathways and glycolysis.

Walnut Oil Reduces Aβ Levels and Increases Neurite Length in a Cellular Model of Early Alzheimer Disease

(1) Background: Mitochondria are the cells' main source of energy. Mitochondrial dysfunction represents a key hallmark of aging and is linked to the development of Alzheimer's disease (AD). Maintaining mitochondrial function might contribute to healthy aging and the prevention of AD. The Mediterranean diet, including walnuts, seems to prevent age-related neurodegeneration. Walnuts are a rich source of α-linolenic acid (ALA), an essential n3-fatty acid and the precursor for n3-long-chain polyunsaturated fatty acids (n3-PUFA), which might potentially improve mitochondrial function. (2) Methods: We tested whether a lipophilic walnut extract (WE) affects mitochondrial function and other parameters in human SH-SY5Y cells transfected with the neuronal amyloid precursor protein (APP695). Walnut lipids were extracted using a Soxhlet Extraction System and analyzed using GC/MS and HPLC/FD. Adenosine triphosphate (ATP) concentrations were quantified under basal conditions in cell culture, as well as after rotenone-induced stress. Neurite outgrowth was investigated, as well as membrane integrity, cellular reactive oxygen species, cellular peroxidase activity, and citrate synthase activity. Beta-amyloid (Aβ) was quantified using homogenous time-resolved fluorescence. (3) Results: The main constituents of WE are linoleic acid, oleic acid, α-linolenic acid, and γ- and δ-tocopherol. Basal ATP levels following rotenone treatment, as well as citrate synthase activity, were increased after WE treatment. WE significantly increased cellular reactive oxygen species but lowered peroxidase activity. Membrane integrity was not affected. Furthermore, WE treatment reduced Aβ_1-40 and stimulated neurite growth. (4) Conclusions: WE might increase ATP production after induction of mitochondrial biogenesis. Decreased Aβ_1-40 formation and enhanced ATP levels might enhance neurite growth, making WE a potential agent to enhance neuronal function and to prevent the development of AD. In this sense, WE could be a promising agent for the prevention of AD.

Crystal Structure, Solubility, and Pharmacokinetic Study on a Hesperetin Cocrystal with Piperine as Coformer

Hesperetin (HES) is a key biological active ingredient in citrus peels, and is one of the natural flavonoids that attract the attention of researchers due to its numerous therapeutic bioactivities that have been identified in vitro. As a bioenhancer, piperine (PIP) can effectively improve the absorption of insoluble drugs in vivo. In the present study, a cocrystal of HES and PIP was successfully obtained through solution crystallization. The single-crystal structure was illustrated and comprehensive characterization of the cocrystal was conducted. The cocrystal was formed by two drug molecules at a molar ratio of 1:1, which contained O–H–O hydrogen bonds between the carbonyl and ether oxygen of PIP and the phenolic hydroxyl group of HES. In addition, a solubility experiment was performed on powder cocrystal in simulated gastrointestinal fluid, and the result revealed that the cocrystal improves the dissolution behavior of HES compared with that of the pure substance. Furthermore, HES’s bioavailability in the cocrystal was six times higher than that of pristine drugs. These results may provide an efficient oral formulation for HES.

Natural Product-based Nanomedicine: Recent Advances and Issues for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) affects the elderly and is characterized by progressive neurodegeneration caused by different pathologies. The most significant challenges in treating AD include the inability of medications to reach the brain because of its poor solubility, low bioavailability, and the presence of the blood-brain barrier (BBB). Additionally, current evidence suggests the disruption of BBB plays an important role in the pathogenesis of AD. One of the critical challenges in treating AD is the ineffective treatments and their severe adverse effects. Nanotechnology offers an alternative approach to facilitate the treatment of AD by overcoming the challenges in drug transport across the BBB. Various nanoparticles (NP) loaded with natural products were reported to aid in drug delivery for the treatment of AD. The nano-sized entities of NP are great platforms for incorporating active materials from natural products into formulations that can be delivered effectively to the intended action site without compromising the material's bioactivity. The review highlights the applications of medicinal plants, their derived components, and various nanomedicinebased approaches for the treatment of AD. The combination of medicinal plants and nanotechnology may lead to new theragnostic solutions for the treatment of AD in the future.

Nanotechnology-Based Drug Delivery Strategies to Repair the Mitochondrial Function in Neuroinflammatory and Neurodegenerative Diseases

Mitochondria are vital organelles in eukaryotic cells that control diverse physiological processes related to energy production, calcium homeostasis, the generation of reactive oxygen species, and cell death. Several studies have demonstrated that structural and functional mitochondrial disturbances are involved in the development of different neuroinflammatory (NI) and neurodegenerative (ND) diseases (NI&NDDs) such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Remarkably, counteracting mitochondrial impairment by genetic or pharmacologic treatment ameliorates neurodegeneration and clinical disability in animal models of these diseases. Therefore, the development of nanosystems enabling the sustained and selective delivery of mitochondria-targeted drugs is a novel and effective strategy to tackle NI&NDDs. In this review, we outline the impact of mitochondrial dysfunction associated with unbalanced mitochondrial dynamics, altered mitophagy, oxidative stress, energy deficit, and proteinopathies in NI&NDDs. In addition, we review different strategies for selective mitochondria-specific ligand targeting and discuss novel nanomaterials, nanozymes, and drug-loaded nanosystems developed to repair mitochondrial function and their therapeutic benefits protecting against oxidative stress, restoring cell energy production, preventing cell death, inhibiting protein aggregates, and improving motor and cognitive disability in cellular and animal models of different NI&NDDs.