Astragalin and Isoquercitrin Isolated from Aster scaber Suppress LPS-Induced Neuroinflammatory Responses in Microglia and Mice

UHPLC-MS/MS analysis and protective effects on neurodegenerative diseases of phenolic compounds in different parts of Diospyros kaki L. cv. Mopan

Persimmon (Diospyros kaki L. cv. Mopan.), an important commercial crop belonging to the genus of Diospyros in the Ebenaceae family, is rich in bioactive phenolic compounds. In this study, the phenolic compounds from fruits, leaves, and calyces of persimmon were qualitatively and quantitatively determined by UPLC-Q-Exactive-Orbitrap/MS and UPLC-QqQ-MS/MS, respectively. Furthermore, the role of phenolic extract from different parts of persimmon on neuroprotective activity in vitro, through against oxidative stress and anti-neuroinflammation effect was firstly evaluated. The results showed that 75 phenolic compounds, and 3 other kinds of compounds were identified, among which 44 of phenolic compounds were quantified from different parts of persimmon. It is the first time that epicatechin-epigallocatechin, catechin-epigallocatechin, catechin-epigallocatechin (A-type), and glycoside derivatives of laricitrin were identified in persimmon extract. The dominated phenolic compounds in three parts of persimmon were significantly different. All phenolic extracts from each part of persimmon showed strong neuroprotective activities against H2O2-induced oxidative stress in PC-12 cells and LPS-induced BV2 cells. The fruit extract presented the strongest activity, followed by calyx and leaf extract. The systematic knowledge on the phytochemical composition along with activity evaluation of different parts of persimmon could contribute to their targeted selection and development.

Research Progress on Anti-Inflammatory Effects and Related Mechanisms of Astragalin

Chronic inflammation is a significant contributor to the development of cancer, cardiovascular disease, diabetes, obesity, autoimmune disease, inflammatory bowel disease, and other illnesses. In the academic field, there is a constant demand for effective methods to alleviate inflammation. Astragalin (AST), a type of flavonoid glycoside that is the primary component in several widely used traditional Chinese anti-inflammatory medications in clinical practice, has garnered attention from numerous experts and scholars. This article focuses on the anti-inflammatory effects of AST and conducts research on relevant literature from 2003 to 2023. The findings indicate that AST demonstrates promising anti-inflammatory potential in various models of inflammatory diseases. Specifically, AST is believed to possess inhibitory effects on inflammation-related factors and protein levels in various in vitro cell models, such as macrophages, microglia, and epithelial cells. In vivo studies have shown that AST effectively alleviates neuroinflammation and brain damage while also exhibiting potential for treating moderate diseases such as depression and stroke; it also demonstrates significant anti-inflammatory effects on both large and small intestinal epithelial cells. Animal experiments have further demonstrated that AST exerts therapeutic effects on colitis mice. Molecular biology studies have revealed that AST regulates complex signaling networks, including NF-κB, MAPK, JAK/STAT pathways, etc. In conclusion, this review will provide insights and references for the development of AST as an anti-inflammatory agent as well as for related drug development.

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Involvement of estrogen receptor activation in kaempferol-3-O-glucoside's protection against aging-related cognition impairment and microglial inflammation

Estrogens have been demonstrated to inhibit age-related cognitive decline via binding to estrogen receptors (ERs). As a natural flavonoid component of Cuscuta Chinensis Lam., Kaempferol-3-O-glucoside (K-3-G) not only possesses anti-neuroinflammatory potential but also functions as an agonist for ERα and ERβ. This study aimed to determine whether K-3-G improved cognition during the aging process, with an emphasis on its effect on microglial inflammation. In vivo, K-3-G (5 or 10 mg/kg/day) was orally given to the senescence-accelerated mouse prone 8 (SAMP8) mice from six to eight-month old. In addition to mitigating the memory and learning deficits of SAMP8 mice, K-3-G upregulated the expression of ERα and ERβ in their hippocampal CA1 region, with the higher dose being more effective. Less Iba-1+ microglial cells presented in SAMP8 mice treated with K-3-G. The formation of NLR Family Pyrin Domain Containing 3 (NLRP3) complex, production of pro-inflammatory cytokines and oxidative stress-related markers, as well as expression of pro-apoptotic proteins were reduced by K-3-G. In vitro, BV2 microglial cells exposed to oligomeric amyloid beta (Aβ)1-42 were treated with 100 μM K-3-G. K-3-G showed similar anti-inflammatory effects on BV2 cells as in vivo. K-3-G-induced alterations were partly diminished by fulvestrant, an ER antagonist. Moreover, dual-luciferase reporter system demonstrated that K-3-G induced ER expression by activating the transcription of estrogen-response elements (EREs). Collectively, these findings demonstrate that K-3-G may be a novel therapeutic agent for senescence-related cognitive impairment by inhibiting microglial inflammation through its action on ERs.

The role of natural flavonoids on neuroinflammation as a therapeutic target for Alzheimer's disease: a narrative review

Alzheimer's disease is a neurodegenerative disease that affects a large proportion of older adult people and is characterized by memory loss, progressive cognitive impairment, and various behavioral disturbances. Although the pathological mechanisms underlying Alzheimer's disease are complex and remain unclear, previous research has identified two widely accepted pathological characteristics: extracellular neuritic plaques containing amyloid beta peptide, and intracellular neurofibrillary tangles containing tau. Furthermore, research has revealed the significant role played by neuroinflammation over recent years. The inflammatory microenvironment mainly consists of microglia, astrocytes, the complement system, chemokines, cytokines, and reactive oxygen intermediates; collectively, these factors can promote the pathological process and aggravate the severity of Alzheimer's disease. Therefore, the development of new drugs that can target neuroinflammation will be a significant step forward for the treatment of Alzheimer's disease. Flavonoids are plant-derived secondary metabolites that possess various bioactivities. Previous research found that multiple natural flavonoids could exert satisfactory treatment effects on the neuroinflammation associated with Alzheimer's disease. In this review, we describe the pathogenesis and neuroinflammatory processes of Alzheimer's disease, and summarize the effects and mechanisms of 13 natural flavonoids (apigenin, luteolin, naringenin, quercetin, morin, kaempferol, fisetin, isoquercitrin, astragalin, rutin, icariin, mangiferin, and anthocyanin) derived from plants or medicinal herbs on neuroinflammation in Alzheimer's disease. As an important resource for the development of novel compounds for the treatment of critical diseases, it is essential that we focus on the exploitation of natural products. In particular, it is vital that we investigate the effects of flavonoids on the neuroinflammation associated with Alzheimer's disease in greater detail.

Flavonoids: the use in mental health and related diseases

Given the current increase in mental and neurological disorders, there is an urgent need to develop alternative treatments for patients. Flavonoids exhibit diverse biological activities, including antioxidant, anti-inflammatory and neuroprotective, and has been considered potential therapies for central nervous system diseases, such as Alzheimer's disease, Parkinson's disease, drug addiction, and stroke. Studies have shown that flavonoids protect neurons from oxidative stress, reduce inflammation, improve brain blood flow and enhance cognitive function. Moreover, its modulation of neurotransmission, such as GABAergic, dopaminergic, serotoninergic, and noradrenergic, has been studied for the treatment of mental disorders that require sedative effects, antidepressants, sleep inducers and anxiety reduction. Although more research is needed to fully understand the mechanisms and potential benefits of these compounds, the use of flavonoids for neurological diseases is a promising avenue for future research and development. This review focuses on major flavonoid subclasses and their applications in central nervous system disorders.

Astragalin: a food-origin flavonoid with therapeutic effect for multiple diseases

Naturally occurring flavonoids have long been utilized as essential templates for the development of novel drugs and as critical ingredients for functional foods. Astragalin (AG) is a natural flavonoid that can be isolated from a variety of familiar edible plants, such as the seeds of green tea, Morus alba L., and Cuscuta chinensis. It is noteworthy that AG has a wide range of pharmacological activities and possesses therapeutic effects against a variety of diseases, covering cancers, osteoarthritis, osteoporosis, ulcerative colitis, mastitis, obesity, diabetes mellitus, diabetic complications, ischemia/reperfusion injury, neuropathy, respiratory diseases, and reproductive system diseases. This article reviewed the natural source and pharmacokinetics of AG and systematically summarized the pharmacological activities and potential mechanisms of AG in treating diverse diseases in order to promote the development of AG as a functional food, in doing so providing references for its clinical application in disease therapy.

Discovery of acylated isoquercitrin derivatives as potent anti-neuroinflammatory agents in vitro and in vivo

Neuroinflammation is considered as an important pathological mechanism in neurodegenerative diseases. The natural isoquercitrin (IQ) was reported to have potential anti-neuroinflammatory activity. The acylation of glycoside in IQ enhanced its hydrophobicity, which was expected to enhance the protective effect against inflammation. In this study, three carboxylic acids with anti-neuroinflammatory effects including cinnamic acid, ibuprofen (IBU) and acetylsalicylic acid were introduced into the 6''-OH of IQ through the corresponding vinyl esters intermediates (8a-8c). Ultimately, the acylated IQ derivatives (Compound 9a-9c) were obtained with 35-42% yields using immobilized lipase Novozym 435 as catalyst. Subsequently, their anti-neuroinflammatory activities were evaluated in lipopolysaccharide (LPS)-induced BV2 cells. Compound 9b improved cell viability in the range of ≤50 μM and significantly decreased NO, PGE2 production and TNF-α, IL-1β release and oxidative stress level with a concentration-dependent manner. Also, it could downregulate iNOS, COX-2, TNF-α and IL-1β expression levels, approximately 40% reduction were achieved when 15μM compound 9b was employed. In addition, compound 9b resisted phosphorylation and degradation of IkBαs, suppressing the activation of NF-κB signaling pathway, exhibiting excellent neuroinflammatory inhibition. Moreover, the administration of compound 9b (30, 60 mg/kg) alleviated behavioral disorders and neuronal damages in LPS-induced neuroinflammatory mice. Meanwhile, the decreased TNF-α, IL-1β release, expression and the inhibited glial cells activation were obtained in compound 9b-treated group, which was superior to that of IQ or IBU. Overall, these findings demonstrated that compound 9b, formed by the introduction of ibuprofen into IQ, can serve as a novel promising therapeutic agent for anti-neuroinflammation.

Analysis of Floral Scent and Volatile Profiles of Different Aster Species by E-nose and HS-SPME-GC-MS

Plants from the Aster species are known to be a rich source of bioactive chemical compositions and are popularly known for their medicinal properties. To investigate the relationship between the nine species of Aster, the floral fragrance and volatile profile patterns were characterized using E-nose and HS-SPME-GC-MS. Initial optimization for fragrance analysis was performed with Aster yomena using E-nose by evaluating the scent patterns in different flowering stages. Aster yomena exhibited varied scent patterns in each flowering stage, with the highest relative aroma intensity (RAI) in the full flowering stage. PCA analysis to compare and analyze the scent characteristics of nine Aster species, showed a species-specific classification. HS-SPME-GC-MS analysis of flowers from nine Aster species revealed 52 volatile compounds including β-myrcene, α-phellandrene, D-limonene, trans-β-ocimene, caryophyllene, and β-cadinene. The terpenoid compounds accounted for the largest proportion. Among the nine Aster species flowers, Aster koraiensis had sesquiterpenes as the major component, and the remaining eight varieties had monoterpenes in abundance. These results could distinguish the species according to the scent patterns and volatile components of the nine Aster species. Additionally, flower extracts from the Aster species’ plants exhibited radical scavenging antioxidant activity. Among them, it was confirmed that Aster pseudoglehnii, Aster maackii, and Aster arenarius had high antioxidant activity. In conclusion, the results of this study provide fundamental data of the volatile compound properties and antioxidant activity of Aster species, offering basic information of valuable natural sources that can be utilized in the pharmaceutical, perfume, and cosmetic industries.

By-Product Extracts from Castanea sativa Counteract Hallmarks of Neuroinflammation in a Microglial Model

Castanea sativa is very common in Italy, and the large amount of waste material generated during chestnut processing has a high environmental impact. Several studies demonstrated that chestnut by-products are a good source of bioactive compounds, mainly endowed with antioxidant properties. This study further investigates the anti-neuroinflammatory effect of chestnut leaf and spiny bur extracts, together with the deepest phytochemical characterisation (by NMR and MS) of active biomolecules contained in leaf extracts, which resulted in being more effective than spiny bur ones. BV-2 microglial cells stimulated with lipopolysaccharide (LPS) were used as a model of neuroinflammation. In BV-2 cells pre-treated with chestnut extracts, LPS signalling is partially blocked via the reduced expression of TLR4 and CD14 as well as the expression of LPS-induced inflammatory markers. Leaf extract fractions revealed the presence of specific flavonoids, such as isorhamnetin glucoside, astragalin, myricitrin, kaempferol 3-rhamnosyl (1-6)(2″-trans-p-coumaroyl)hexoside, tiliroside and unsaturated fatty acids, all of which could be responsible for the observed anti-neuroinflammatory effects. Interestingly, the kaempferol derivative has been identified in chestnut for the first time. In conclusion, the exploitation of chestnut by-products is suitable for the achievement of two goals: satisfaction of consumers’ demand for new, natural bio-active compounds and valorisation of by-products.

Effect of Isoquercitrin on Free Fatty Acid-Induced Lipid Accumulation in HepG2 Cells

Liver metabolic disorders and oxidative stress are crucial factors in the development of nonalcoholic fatty liver disease (NAFLD); however, treatment strategies to combat NAFLD remain poorly established, presenting an important challenge that needs to be addressed. Herein, we aimed to examine the effect of isoquercitrin on lipid accumulation induced by exogenous free fatty acids (FFA) using HepG2 cells and elucidate the underlying molecular mechanism. The cells were exposed to 0.5 mM FFA to induce intracellular lipid accumulation, followed by co-treatment with isoquercitrin to confirm the potential inhibitory effect on FFA-induced lipid production. HepG2 cells exposed to FFA alone exhibited intracellular lipid accumulation, compromised endoplasmic reticulum (ER) stress, and enhanced expression of proteins and genes involved in lipid synthesis; however, co-treatment with isoquercitrin decreased the expression of these molecules in a dose-dependent manner. Furthermore, isoquercitrin could activate AMP-activated protein kinase (AMPK), a key regulatory protein of hepatic fatty acid oxidation, suppressing new lipid production by phosphorylating acetyl-CoA carboxylase (ACC) and inhibiting sterol regulatory element-binding transcription factor 1 (SREBP-1)/fatty acid synthase (FAS) signals. Overall, these findings suggest that isoquercitrin can be employed as a therapeutic agent to improve NAFLD via the regulation of lipid metabolism by targeting the AMPK/ACC and SREBP1/FAS pathways.

An insight into the neuroprotective and anti-neuroinflammatory effects and mechanisms of Moringa oleifera

Neurodegenerative diseases (NDs) are sporadic maladies that affect patients' lives with progressive neurological disabilities and reduced quality of life. Neuroinflammation and oxidative reaction are among the pivotal factors for neurodegenerative conditions, contributing to the progression of NDs, such as Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS) and Huntington's disease (HD). Management of NDs is still less than optimum due to its wide range of causative factors and influences, such as lifestyle, genetic variants, and environmental aspects. The neuroprotective and anti-neuroinflammatory activities of Moringa oleifera have been documented in numerous studies due to its richness of phytochemicals with antioxidant and anti-inflammatory properties. This review highlights up-to-date research findings on the anti-neuroinflammatory and neuroprotective effects of M. oleifera, including mechanisms against NDs. The information was gathered from databases, which include Scopus, Science Direct, Ovid-MEDLINE, Springer, and Elsevier. Neuroprotective effects of M. oleifera were mainly assessed by using the crude extracts in vitro and in vivo experiments. Isolated compounds from M. oleifera such as moringin, astragalin, and isoquercitrin, and identified compounds of M. oleifera such as phenolic acids and flavonoids (chlorogenic acid, gallic acid, ferulic acid, caffeic acid, kaempferol, quercetin, myricetin, (-)-epicatechin, and isoquercitrin) have been reported to have neuropharmacological activities. Therefore, these compounds may potentially contribute to the neuroprotective and anti-neuroinflammatory effects. More in-depth studies using in vivo animal models of neurological-related disorders and extensive preclinical investigations, such as pharmacokinetics, toxicity, and bioavailability studies are necessary before clinical trials can be carried out to develop M. oleifera constituents into neuroprotective agents.

Dissipation Kinetics and Risk Assessment of Spirodiclofen and Tebufenpyrad in Aster scaber Thunb

The dissipation kinetics of spirodiclofen and tebufenpyrad after their application on Aster scaber Thunb were studied for 10 days, including the pre-harvest intervals. Spirodiclofen and tebufenpyrad were used in two greenhouses in Taean-gun, Chungcheongnam province (Field 1) and Gwangyang-si, Jeollanam province (Field 2), Republic of Korea. Samples were taken at 0, 1, 3, 5, 7, and 10 days after pesticide application. The method validations were performed utilizing liquid chromatography (LC)-tandem mass spectrometry (MS/MS). The recoveries of the studied pesticides ranged from 82.0-115.9%. The biological half-lives of spirodiclofen and tebufenpyrad were 4.4 and 3.8 days in Field 1, and 4.5 and 4.2 days in Field 2, respectively. The pre-harvest residue limits (PHRLs; 10 days before harvesting) of Aster scaber were 37.6 mg/kg (Field 1) and 41.2 mg/kg (Field 2) for spirodiclofen, whereas the PHRLs were 7.2 (Field 1) and 3.6 (Field 2) for tebufenpyrad. The hazard quotient for both pesticides at pre-harvest intervals was less than 100% except in the case of spirodiclofen (0 day).

Potential of natural flavonols and flavanones in the treatment of ulcerative colitis

Ulcerative colitis (UC) is an inflammatory bowel disease generally characterized by chronic, persistent, recurrent, and non-specific ulcers of the intestine. Its main clinical manifestations include abdominal pain, diarrhea, and bloody stools. This disease is difficult to cure and even carries the risk of canceration. It has been listed as a modern refractory disease by the World Health Organization. Though a large amount of drugs are available for the inhibition of UC, the conventional treatment such as aminosalicylic acids, glucocorticoids, immunosuppressors, and biological agents possess certain limitations and serious side effects. Therefore, it is urgently needed for safe and effective drugs of UC, and natural-derived flavonols and flavanones showed tremendous potential. The present study concentrated on the progress of natural-derived flavonols and flavanones from edible and pharmaceutical plants for the remedy of UC over the last two decades. The potential pharmaceutical of natural-derived flavonols and flavanones against UC were closely connected with the modulation of gut microflora, gut barrier function, inflammatory reactions, oxidative stress, and apoptosis. The excellent efficacy and safety of natural flavonols and flavanones make them prospective drug candidates for UC suppression.

Mixed computational-experimental study to reveal the anti-metastasis and anti-angiogenesis effects of Astragalin in human breast cancer

BACKGROUND

Breast cancer is the most aggressive malignant tumor with high morbidity and mortality. Astragalin, a flavonoid widely found in a variety of edible and medicinal plants, is recorded to possess multiple biological and pharmacological activities. However, its effect of anti-breast cancer has been unknown.

METHODS

Computational pharmacology was employed to explore the potential mechanism of anti-metastasis and anti-angiogenesis effects of Astragalin on breast cancer. The targets of Astragalin were obtained from TCMSP, Swiss Target Prediction, SEA, BATMAN-TCM, ChemMapper and STITCH databases, and targets of breast cancer were got from OMIM, GeneCards, and DisGeNET databases. Protein-protein interaction network (PPI), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate the interactions of these two groups of targets. Moreover, the anti-metastasis and anti-angiogenesis effects of Astragalin were validated by in vitro and in vivo experiments using wound healing assay, transwell migration and invasion assay, gelatin zymography assay, tube formation assay, and chick embryo chorioallantoic membrane model.

RESULTS

Computational pharmacology analysis indicated that the effects of Astragalin against breast cancer were mainly related to the regulation of the cell movement, migration, and angiogenesis, and taking AKT, ZEB1, VEGF, and MMP9 as the promising targets. Further experimental pharmacology indicated that Astragalin exerted anti-metastasis and anti-angiogenesis activities on breast cancer, and verified AKT, ZEB1, VEGF, and MMP9 as the key targets.

CONCLUSION

Astragalin suppresses the metastasis and angiogenesis of breast cancer, and AKT, ZEB1, VEGF, and MMP9 are the promising targets for Astragalin against breast cancer. Thus, Astragalin is a potential therapeutic agent for breast cancer.