Ampelopsin attenuates lipopolysaccharide-induced inflammatory response through the inhibition of the NF-κB and JAK2/STAT3 signaling pathways in microglia

S32, a Novel 3-Acetylaminocoumarin Compound, Exerts Neuroprotective Effects through the Inhibition of Neuroinflammation and Oxidative Stress In Vitro and In Vivo

Neuroinflammation and oxidative stress are key factors leading to neuronal injury. In this study, we investigated the role of S32, a novel 3-acetylaminocoumarin compound, in ameliorating neuronal injury induced by neuroinflammation and oxidative stress in vitro and in vivo. First, we found that S32 reduced the expression levels of p-P65 and p-P38, inhibited the nuclear translocation of P65, and lowered the levels of pro-inflammatory factors in LPS-induced BV2 cells, which indicated that S32 had an antineuroinflammatory effect. Second, BV2 cell culture medium was used as the conditioned medium to establish a model of oxidative damage in PC12 cells. It was found that S32 reduced the level of ROS and increased mitochondrial membrane potential of PC12 cells, which indicated that S32 can protect PC12 cells against conditioned medium-induced injury. Next, we found that S32 inhibited the decrease of cell viability of PC12 cells caused by H2O2, inhibited nuclear damage, decreased the level of ROS, increased MMP, activated the AKT and ERK pathways, increased Bcl-2 levels, and decreased Bax and Cleaved-Caspase3 expression levels, indicating that S32 ameliorated the damaging effects of H2O2-induced PC12 cells. Finally, we found that S32 exerted the antineuroinflammatory and apoptosis-inhibiting effects in LPS-induced mice. In conclusion, this study first demonstrated that S32, a novel 3-acetylaminocoumarin compound, can reduce neuroinflammation and neuroinflammation-induced neuronal injury, exerting an indirect protective effect on neurons, and also exert a direct protective effect on neurons by reducing oxidative stress.

Isolation and characterization of a hepatoprotective polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit against APAP-induced acute liver injury mice

The structure and bioactivities of a novel polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit (THP-3) were investigated. The crude polysaccharides of Turcz. ex Herd. (THP) were extracted by hot water extraction. After purification, the chemical structure of polysaccharides was identified. Then, a mouse model of acute drug-induced liver injury was constructed using 4-acetamidophenol (APAP) and pretreated with THP. The number-average molecular weight of THP-3 was 48.89 kDa and the mass average molar mass was 97.87 kDa. THP-3 was mainly composed of arabinose (42.54 %), glucose (27.62 %), galacturonic acid and galactose (29.84 %). The main linkage types of THP-3 were 1-linked Araf, 1,4-linked Glcp, and 1,3,6-linked Galp. In addition, after THP treatment, serum Alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and γ-glutamyl transpeptidase (γGT) in AILI mice were successfully down-regulated. The results showed that THP could prevent the characteristic morphological changes of hepatic lobular injury and lipid depletion caused by APAP, reduced the level of oxidative damage in mice, increased the expression of APAP-induced hypolipidemia and related inflammatory indicators, and improved the detoxification function of liver. In general, the newly extracted THP polysaccharide has a good liver protection effect and is an ideal natural medicine for the treatment of liver diseases.

Design and Synthesis of Marine Polybrominated Diphenyl Ether Derivatives as Potential Anti-Inflammatory Agents

Natural polybrominated diphenyl ethers are generally isolated from sponges and possess a broad range of biological activities. Through screening of our marine natural product library, we discovered that polybrominated diphenyl ethers 5 and 6 exhibit considerable anti-inflammatory activity. In order to expand our repertoire of derivatives for further biological activity studies, we designed and synthesized a series of 5-related polybrominated diphenyl ethers. Importantly, compound 5a showed comparable anti-inflammatory activity while much lower cytotoxicity on lipopolysaccharide (LPS)-induced RAW264.7 cells. Additionally, western blotting analysis showed that 5a reduced the expression of phosphorylated extracellular signal-regulated kinase (p-ERK). Besides, molecular docking experiments were conducted to predict and elucidate the potential mechanisms underlying the varying anti-inflammatory activities exhibited by compounds 5a, 5, and 6.

A comprehensive review of vine tea: Origin, research on Materia Medica, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Vine tea is a popular folk tea that has been consumed in China for more than 1200 years. It is often used in ethnic medicine by ethnic groups in southwest China with at least 35 aliases in 10 provinces. In coastal areas, vine tea is mostly used to treat heatstroke, aphtha, aphonia, toothache, etc. In contrast, in the southwest inland regions, vine tea is mostly used to clear away heat and toxic materials, antiphlogosis and relieving sore-throat, lowering blood pressure and lipid levels, and alleviating fatigue. Three main species have been used as the source of vine tea, Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla. Among them, the leaves of Nekemias grossedentata were considered as new food resource in complicance with regulations, according to the Food Safety Standards published by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China.

AIM OF THE STUDY

At present, the comprehensively summary of Materia Medica on the history and source of vine tea is currently unavailable. The current article summed up the Materia Medica, species origin and pharmacological effects of all 3 major species used in vine tea to fill the knowledge gaps. We also aim to provide a reference for future research on historical textual, resource development and medicinal utilization of vine tea.

MATERIALS AND METHODS

Adhering to the literature screening methodology outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this review encompasses 148 scholarly research papers from three database, paper ancient books, local chronicles and folklore through field investigations. We then comprehensively summarized and discussed research progresses in scientific and application studies of vine tea.

RESULTS

The historical records indicated that vine tea could have been used as early as Southern and Northern Dynasties (AC 420-589). Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla, were used to considered as vine tea in the ethnic medicine. The main phytochemicals found in three plants are flavonoids, polyphenols and terpenoids, among which dihydromyricetin (DHM) is the most important and most studied active substance. The key words "Ampelopsis grossedentata" (Synonym of Nekemias grossedentata) and "dihydromyricetin/DHM" showed the highest frequency over the last 27 year based on the research trend analysis. And the ethnopharmacology studies drawn the main activities of vine tea are antioxidant, antibacterial, hepatoprotective, neuroprotective and anti-atherosclerosis activities.

CONCLUSIONS

This review systematically summarized and discussed vine tea from the following five aspects, history, genetic relationship, phytochemistry, research trend and ethnopharmacology. Vine tea has a long historical usage in Chinese ethnic medicine. Its outstanding therapeutic efficacies have attracted extensive attention in other places in the world at present. Nekemias cantonensis and Nekemias megalophylla are quite similar to Nekemias grossedentata in terms of many aspects. However, the current research has a narrow focus on mainly Nekemias grossedentata and DHM. We propose that future studies could be carried out to determine the synergistic effect of multi-components and multi-targets of vine tea including all 3 species to provide valuable knowledge.

Tetramethylpyrazine promotes axonal remodeling and modulates microglial polarization via JAK2-STAT1/3 and GSK3-NFκB pathways in ischemic stroke

Ischemic stroke results in demyelination that underlies neurological disfunction. Promoting oligodendrogenesis will rescue the injured axons and accelerate remyelination after stroke. Microglia react to ischemia/hypoxia and polarize to M1/M2 phenotypes influencing myelin injury and repair. Tetramethylpyrazine (TMP) has neuroprotective effects in treating cerebrovascular disorders. This study aims to evaluate whether TMP promotes the renovation of damaged brain tissues especially on remyelination and modulates microglia phenotypes following ischemic stroke. Here magnetic resonance imaging (MRI)-diffusion tensor imaging (DTI) and histopathological evaluation are performed to characterize the process of demyelination and remyelination. Immunofluorescence staining is used to prove oligodendrogenesis and microglial polarization. Western blotting is conducted to examine interleukin (IL)-6, IL-10, transforming growth factor β (TGF-β) and Janus protein tyrosine kinase (JAK) 2-signal transducer and activator of transcription (STAT) 1/3-glycogen synthase kinase (GSK) 3-nuclear transcription factor κB (NFκB) signals. Results show TMP alleviates the injury of axons and myelin sheath, increases NG2+, Ki67+/NG2+, CNPase+, Ki67+/CNPase+, Iba1+/Arg-1+ cells and decreases Iba1+ and Iba1+/CD16+ cells in periinfarctions of rats. Particularly, TMP downregulates IL-6 and upregulates IL-10 and TGF-β expressions, besides, enhances JAK2-STAT3 and suppresses STAT1-GSK3-NFκB activation in middle cerebral artery occlusion (MCAo) rats. Then we demonstrate that TMP reverses M1/M2 phenotype via JAK2-STAT1/3 and GSK3-NFκB pathways in lipopolysaccharide (LPS) plus interferon-γ (IFN-γ)-stimulated BV2 microglia. Blocking JAK2 with AG490 counteracts TMP's facilitation on M2 polarization of microglia. This study warrants the promising therapy for stroke with TMP treatment.

Preparation of Dihydromyricetin-Loaded Self-Emulsifying Drug Delivery System and Its Anti-Alcoholism Effect

Intraperitoneal injection of dihydromyricetin (DMY) has shown promising potential in the treatment of alcoholism. However, its therapeutic effect is limited due to its low solubility, poor stability, and high gut-liver first-pass metabolism, resulting in very low oral bioavailability. In this study, we developed a DMY-loaded self-emulsifying drug delivery system (DMY-SEDDS) to enhance the oral bioavailability and anti-alcoholism effect of DMY. DMY-SEDDS improved the oral absorption of DMY by facilitating lymphatic transport. The area under the concentration-time curve (AUC) of DMY in the DMY-SEDDS group was 4.13-fold higher than in the DMY suspension group. Furthermore, treatment with DMY-SEDDS significantly enhanced the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the liver of mice (p < 0.05). Interestingly, DMY-SEDDS also increased ADH activity in the stomach of mice with alcoholism (p < 0.01), thereby enhancing ethanol metabolism in the gastrointestinal tract and reducing ethanol absorption into the bloodstream. As a result, the blood alcohol concentration of mice with alcoholism was significantly decreased after DMY-SEDDS treatment (p < 0.01). In the acute alcoholism mice model, compared to saline treatment, DMY-SEDDS prolonged the onset of LORR (loss of righting reflex) (p < 0.05) and significantly shortened the duration of LORR (p < 0.01). Additionally, DMY-SEDDS treatment significantly reduced gastric injury in acute alcoholism mice. Collectively, these findings demonstrate the potential of DMY-SEDDS as a treatment in the treatment of alcoholism.

Network pharmacology to explore the mechanism of scutellarin in the treatment of brain ischaemia and experimental verification of JAK2/STAT3 signalling pathway

Scutellarin is used to treat brain ischaemia. However, its underlying mechanism of action remains unclear. This study aimed to elucidate the potential mechanism of action of scutellarin in brain ischaemia through network pharmacology and experimental verification. The JAK2/STAT3 signalling pathway was identified and experimentally verified. Expression of JAK2/STAT3 signalling related proteins in TNC-1 astrocytes with BV-2 microglia-conditioned medium (CM), CM + lipopolysaccharide (LPS) (CM + L), and CM pretreated with scutellarin + LPS (CM + SL) was analysed by Western Blot and immunofluorescence staining. Expression levels of JAK2, p-JAK2, STAT3, and p-STAT3 were evaluated in astrocytes pre-treated with AG490. Middle cerebral artery occlusion (MCAO) in rats was performed in different experimental groups to detect expression of the above biomarkers. Network pharmacology suggested that the JAK2/STAT3 signalling pathway is one of the mechanisms by which scutellarin mitigates cerebral ischaemic damage. In TNC-1 astrocytes, p-JAK2 and p-STAT3 expression were significantly up-regulated in the CM + L group. Scutellarin promoted the up-regulation of various markers and AG490 neutralised the effect of scutellarin. In vivo, up-regulation of p-JAK2 and p-STAT3 after ischaemia is known. These results are consistent with previous reports. Scutellarin further enhanced this upregulation at 1, 3, and 7 d after MCAO. Scutellarin exerts its therapeutic effects on cerebral ischaemia by activating the astrocyte JAK2/STAT3 signalling, which provides a firm experimental basis for its clinical application.

Stilbenes, a Versatile Class of Natural Metabolites for Inflammation-An Overview

Stilbenes are polyphenolic allelochemicals synthesized by plants, especially grapes, peanuts, rhubarb, berries, etc., to defend themselves under stressful conditions. They are now exploited in medicine for their antioxidant, anti-proliferative and anti-inflammatory properties. Inflammation is the immune system's response to invading bacteria, toxic chemicals or even nutrient-deprived conditions. It is characterized by the release of cytokines which can wreak havoc on healthy tissues, worsening the disease condition. Stilbenes modulate NF-κB, MAPK and JAK/STAT pathways, and reduce the transcription of inflammatory factors which result in maintenance of homeostatic conditions. Resveratrol, the most studied stilbene, lowers the Michaelis constant of SIRT1, and occupies the substrate binding pocket. Gigantol interferes with the complement system. Besides these, oxyresveratrol, pterostilbene, polydatin, viniferins, etc., are front runners as drug candidates due to their diverse effects from different functional groups that affect bioavailability and molecular interactions. However, they each have different thresholds for toxicity to various cells of the human body, and thus a careful review of their properties must be conducted. In animal models of autoinflammatory diseases, the mode of application of stilbenes is important to their absorption and curative effects, as seen with topical and microemulsion gel methods. This review covers the diversity seen among stilbenes in the plant kingdom and their mechanism of action on the different inflammatory pathways. In detail, macrophages' contribution to inflamed conditions in the liver, the cardiac, connective and neural tissues, in the nephrons, intestine, lungs and in myriad other body cells is explored, along with detailed explanation on how stilbenes alleviate the symptoms specific to body site. A section on the bioavailability of stilbenes is included for understanding the limitations of the natural compounds as directly used drugs due to their rapid metabolism. Current delivery mechanisms include sulphonamides, or using specially designed synthetic drugs. It is hoped that further research may be fueled by this comprehensive work that makes a compelling argument for the exploitation of these compounds in medicine.

Therapy-resistant breast cancer in focus: Clinically relevant mitigation by flavonoids targeting cancer stem cells

Significant limitations of the reactive medical approach in breast cancer management are clearly reflected by alarming statistics recorded worldwide. According to the WHO updates, breast malignancies become the leading cancer type. Further, the portion of premenopausal breast cancer cases is permanently increasing and demonstrates particularly aggressive patterns and poor outcomes exemplified by young patients with triple-negative breast cancer that lacks targeted therapy. Accumulating studies suggest the crucial role of stem cells in tumour biology, high metastatic activity, and therapy resistance of aggressive breast cancer. Therefore, targeting breast cancer stem cells is a promising treatment approach in secondary and tertiary breast cancer care. To this end, naturally occurring substances demonstrate high potential to target cancer stem cells which, however, require in-depth analysis to identify effective anti-cancer agents for cost-effective breast cancer management. The current article highlights the properties of flavonoids particularly relevant for targeting breast cancer stem cells to mitigate therapy resistance. The proposed approach is conformed with the principles of 3P medicine by applying predictive diagnostics, patient stratification and treatments tailored to the individualised patient profile. Expected impacts are very high, namely, to overcome limitations of reactive medical services improving individual outcomes and the healthcare economy in breast cancer management. Relevant clinical applications are exemplified in the paper.

The pivotal role of JAK/STAT and IRS/PI3K signaling pathways in neurodegenerative diseases: Mechanistic approaches to polyphenols and alkaloids

BACKGROUND

Neurodegenerative diseases (NDDs) are characterized by progressive neuronal dysfunctionality which results in disability and human life-threatening events. In recent decades, NDDs are on the rise. Besides, conventional drugs have not shown potential effectiveness to attenuate the complications of NDDs. So, exploring novel therapeutic agents is an urgent need to combat such disorders. Accordingly, growing evidence indicates that polyphenols and alkaloids are promising natural candidates, possessing several beneficial pharmacological effects against diseases. Considering the complex pathophysiological mechanisms behind NDDs, Janus kinase (JAK), insulin receptor substrate (IRS), phosphoinositide 3-kinase (PI3K), and signal transducer and activator of transcription (STAT) seem to play critical roles during neurodegeneration/neuroregeneration. In this line, modulation of the JAK/STAT and IRS/PI3K signaling pathways and their interconnected mediators by polyphenols/alkaloids could play pivotal roles in combating NDDs, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), stroke, aging, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), depression and other neurological disorders.

PURPOSE

Thus, the present study aimed to investigate the neuroprotective roles of polyphenols/alkaloids as multi-target natural products against NDDs which are critically passing through the modulation of the JAK/STAT and IRS/PI3K signaling pathways.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was performed to highlight the modulatory roles of polyphenols and alkaloids on the JAK/STAT and IRS/PI3K signaling pathways in NDDs, according to the PRISMA guideline, using scholarly electronic databases, including Scopus, PubMed, ScienceDirect, and associated reference lists.

RESULTS

In the present study 141 articles were included from a total of 1267 results. The results showed that phenolic compounds such as curcumin, epigallocatechin-3-gallate, and quercetin, and alkaloids such as berberine could be introduced as new strategies in combating NDDs through JAK/STAT and IRS/PI3K signaling pathways. This is the first systematic review that reveals the correlation between the JAK/STAT and IRS/PI3K axis which is targeted by phytochemicals in NDDs. Hence, this review highlighted promising insights into the neuroprotective potential of polyphenols and alkaloids through the JAK/STAT and IRS/PI3K signaling pathway and interconnected mediators toward neuroprotection.

CONCLUSION

Amongst natural products, phenolic compounds and alkaloids are multi-targeting agents with the most antioxidants and anti-inflammatory effects possessing the potential of combating NDDs with high efficacy and lower toxicity. However, additional reports are needed to prove the efficacy and possible side effects of natural products.

Anti-inflammatory effects and molecular mechanisms of bioactive small molecule garlic polysaccharide

Although garlic polysaccharides have been found to possess anti-inflammatory activities, anti-inflammatory study on small molecule water-soluble garlic polysaccharide (WSGP) is few. In this study, a novel WSGP with a molecular weight of 1853 Da was isolated by DEAE-52 and Sephadex G-100 column and the chemical composition was identified by monosaccharide composition and methylation analysis. Furthermore, the antioxidant effects of WSGP and the potential molecular mechanisms on LPS-induced inflammatory responses in RAW264.7 macrophage cells were investigated. The results showed that WSGP has strong antioxidant activity, such as DPPH, hydroxyl, superoxide anion, ABTS radical scavenging capacity, Fe²⁺ chelating ability and reducing power. Meanwhile, WSGP could considerably suppress the manufacturing of NO and the mRNA and protein expression degrees of IL-6, TNF-α, and IL-1β in LPS inspired RAW264.7 macrophages WSGP could significantly suppress the production of NO and the mRNA and protein expression levels of IL-1β, IL-6, and TNF-α in LPS stimulated RAW264.7 macrophage cells (p < 0.05). In addition, the phosphorylated IκB-α, p65, and STAT3 proteins were significantly increased in LPS-induced macrophages, while this trend was significantly reversed by WSGP treatment in a concentration-dependent manner (p < 0.05). Consequently, WSGP supplementation might reduce LPS-induced inflammatory responses by suppressing proinflammatory cytokines and NF-κB and STAT3 pathway activation. The finding of this research would give scientific guidelines for the judicious use of small molecular garlic polysaccharide in anti-inflammatory treatments.

Microbiological Properties and Cytotoxicity of PNVCL Hydrogels Containing Flavonoids as Intracanal Medication for Endodontic Therapy

This study aimed to evaluate the cytotoxicity and microbiological properties of poly (N-vinylcaprolactam)-PNVCL hydrogels containing flavonoids as intracanal medication for endodontic therapy. Antimicrobial activity of ampelopsin (AMP), isoquercitrin and rutin was determined against Enterococcus faecalis, Actinomyces israelii, Lactobacillus casei, Streptococcus mutans, and Fusobacterium nucleatum by the microdilution method. After synthesis and characterization by rheology, PNVCL hydrogels were loaded with AMP and controls calcium hydroxide (CH) and chlorhexidine (CHX), and determined the compounds release profile. PNVCL+AMP, PNVCL+CH, PNVCL+CHX were evaluated on multi-species biofilms and analyzed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Cytotoxicity was determined after fibroblasts exposure to serial dilutions of AMP and PNVCL hydrogel extracts. AMP was effective against all of the bacteria tested, especially against S. mutans, A. israelli and F. nucleatum. SEM and CLSM analysis showed that PNVCL + AMP caused a significant decrease and disorganization of multi-species biofilms and reduction of intracanal viable cells, superior to the other groups. AMP affected fibroblast viability at concentrations above 0.125 mg/mL, and extracts of PNVCL+AMP showed low cytotoxicity. In conclusion, PNVCL containing AMP demonstrated cytocompatibility and potent effect against multi-species biofilms and could be potential intracanal medication for endodontic purposes.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Ampelopsin targets in cellular processes of cancer: Recent trends and advances

Cancer is being considered as a serious threat to human health globally due to limited availability and efficacy of therapeutics. In addition, existing chemotherapeutic drugs possess a diverse range of toxic side effects. Therefore, more research is welcomed to investigate the chemo-preventive action of plant-based metabolites. Ampelopsin (dihydromyricetin) is one among the biologically active plant-based chemicals with promising anti-cancer actions. It modulates the expression of various cellular molecules that are involved in cancer progressions. For instance, ampelopsin enhances the expression of apoptosis inducing proteins. It regulates the expression of angiogenic and metastatic proteins to inhibit tumor growth. Expression of inflammatory markers has also been found to be suppressed by ampelopsin in cancer cells. The present review article describes various anti-tumor cellular targets of ampelopsin at a single podium which will help the researchers to understand mechanistic insight of this phytochemical.

Therapeutic benefits of flavonoids against neuroinflammation: a systematic review

Flavonoids are an important class of natural polyphenolic compounds reported to exert beneficial effects in cardiovascular and metabolic diseases, cancer, autoimmune and neurological disorders. Flavonoids possess potential antioxidant, anti-inflammatory, antiapoptotic and immuno-modulation properties. Intriguingly, the importance of flavonoids in different neurological disorders is gaining more attention due to the safety, better pharmacokinetic profile and blood-brain barrier penetration, cost-effectiveness and readiness for clinical uses/trials. Many in vitro and in vivo research studies have established the neuroprotective mechanism of flavonoids in the central nervous system (CNS) diseases. The present review summarizes the benefits of various classes of flavonoids (flavones, flavonols, flavanones, anthocyanidins, isoflavones, flavanols), chemical nature, classification, their occurrence and distribution, pharmacokinetics and bioavailability. The manuscript also presents available evidences relating to the role of flavonoids in regulating key signaling pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, mitogen-activated protein kinase (MAPK) pathway, Janus kinase and signal transducer and activator of transcription proteins (JAK/STAT) pathway, Toll-like receptors (TLR) pathway, nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and cAMP response element-binding protein (CREB) pathway involved in neuroinflammation associated with major neurological disorders. Literature search was conducted using electronic databases like Google Scholar, Scopus, PubMed central, Springer search and Web of science. Chemical structures used in the present analysis were drawn using Chemdraw Professional 15.0 software. This collective information provides comprehensive knowledge on disease pathways and therapeutic benefits of flavonoids in neurological disorders, druggability and future scope for research.

Genistein-3'-sodium sulfonate ameliorates cerebral ischemia injuries by blocking neuroinflammation through the α7nAChR-JAK2/STAT3 signaling pathway in rats

BACKGROUND

Neuroinflammation plays a pivotal role in the acute progression of cerebral ischemia/reperfusion injury (I/RI). We previously reported that genistein-3'-sodium sulfonate (GSS), a derivative from the extract of the phytoestrogen genistein (Gen), protects cortical neurons against focal cerebral ischemia. However, the molecular mechanism underlying the neuroprotective effects exerted by GSS remains unclear.

PURPOSE

The present study focused on the anti-inflammatory effects of GSS following I/RI in rats.

STUDY DESIGN

Randomized controlled trial.

METHODS

The tMCAO rat model and LPS-stimulated BV2 in vitro model were used. Longa's scare was used to observe neurological function. TTC staining and Nissl staining were used to evaluate brain injury. ELISA, qRT-PCR, Western blotting and immunofluorescent staining methods were used to detect cytokine concentration, mRNA level, protein expression and location.

RESULTS

GSS treatment improves neurological function, reduces the volume of cerebral infarction, attenuates proinflammatory cytokines and inactivates the phosphorylation of JAK2 and STAT3 in I/RI rats. Furthermore, GSS increased the expression of α7nAChR. More importantly, the neuroprotective, anti-inflammatory and inhibiting JAK2/STAT3 signaling pathway effects of GSS were counteracted in the presence of alpha-bungarotoxin (α-BTX), an α7nAChR inhibitor, suggesting that α7nAChR is a potential target associated with the anti-inflammatory effects of GSS in the I/RI rats. GSS also inhibited BV2 cells from releasing IL-1β via the α7nAChR pathway after LPS stimulation.

CONCLUSION

GSS protects against cerebral I/RI through the expression of α7nAChR and inhibition of the JAK2/STAT3 pathway. Our findings provide evidence for the role of the cholinergic anti-inflammatory pathway in neuroinflammation and uncover a potential novel mechanism for GSS treatment in ischemic stroke. The downstream signals of GSS, α7nAChR- JAK2/STAT3 could also be potential targets for the treatment of I/RI.

Ampelopsin Inhibits Cell Viability and Metastasis in Renal Cell Carcinoma by Negatively Regulating the PI3K/AKT Signaling Pathway

Background

Previous studies have shown that Ampelopsin has an inhibitory effect on human tumors. However, the effect of Ampelopsin on renal cell carcinoma (RCC) is rarely reported. Therefore, this study aims to explain the role of Ampelopsin in RCC.

Methods

Different concentrations of Ampelopsin (0, 10, 25, 50, and 100 μM) were used to treat 786-O cells. Cell viability was detected by MTT assay, colony formation assay, and flow cytometry assay. Transwell assay and Wound healing assay were used to detect cell migration and invasion. Western blot analysis was applied to detect protein expression.

Results

Ampelopsin inhibited cell proliferation and induced apoptosis in RCC. And Ampelopsin can inhibit cell migration and invasion in RCC. All these results changed in a dose-dependent manner. Ampelopsin (100 uM) had the strongest inhibitory effect on cell viability and metastasis. In addition, Ampelopsin negatively regulated the PI3K/AKT signaling pathway in RCC cells. Moreover, Ampelopsin was only cytotoxic to RCC cells.

Conclusion

Ampelopsin inhibits cell viability and metastasis in RCC by negatively regulating the PI3K/AKT signaling pathway.

Pantoprazole Attenuates MAPK (ERK1/2, JNK, p38)-NF-κB and Apoptosis Signaling Pathways after Renal Ischemia/Reperfusion Injury in Rats

Ischemia/reperfusion injury (IRI) in the kidney is the most common cause of acute renal dysfunction through different cell damage mechanisms. This study aimed to investigate, on molecular basics for the first time, the effect of pantoprazole on renal IRI in rats. Different biochemical parameters and oxidative stress markers were assessed. ELISA was used to estimate proinflammatory cytokines. qRT-PCR and western blot were used to investigate the gene and protein expression. Renal histopathological examination was also performed. IRI resulted in tissue damage, elevation of serum levels of creatinine, urea nitrogen, malondialdehyde, TNF-α, IL-6, IL-1β, up-regulation of NF-κB, JNK1/2, ERK1/2, p38, and cleaved caspase-3 proteins. Furthermore, it up-regulated the expression of the Bax gene and down-regulated the expression of the Bcl-2 gene. Treatment of the injured rats with pantoprazole, either single dose or multiple doses, significantly alleviated IRI-induced biochemical and histopathological changes, attenuated the levels of proinflammatory cytokines, down-regulated the expression of NF-κB, JNK1/2, ERK1/2, p38, and cleaved caspase-3 proteins, and the Bax gene, and up-regulated Bcl-2 gene expression. Moreover, treatment with pantoprazole multiple doses has an ameliorative effect that is greater than pantoprazole single-dose. In conclusion, pantoprazole diminished renal IRI via suppression of apoptosis, attenuation of the pro-inflammatory cytokines’ levels, and inhibition of the intracellular signaling pathway MAPK (ERK1/2, JNK, p38)–NF-κB.

Recent advances in research on vine tea, a potential and functional herbal tea with dihydromyricetin and myricetin as major bioactive compounds

Vine tea has been used as an herbal tea by several ethnic minorities for hundreds of years in China. Flavonoids, a kind of indispensable component in a variety of nutraceutical, pharmaceutical and cosmetic applications, are identified to be the major metabolites and bioactive ingredients in vine tea. Interestingly, vine tea exhibits a wide range of significant bioactivities including anti-oxidant, anti-inflammatory, anti-tumor, antidiabetic, neuroprotective and other activities, but no toxicity. These bioactivities, to some extent, enrich the understanding about the role of vine tea in disease prevention and therapy. The health benefits of vine tea, particularly dihydromyricetin and myricetin, are widely investigated. However, there is currently no comprehensive review available on vine tea. Therefore, this report summarizes the most recent studies investigating bioactive constituents, pharmacological effects and possible mechanisms of vine tea, which will provide a better understanding about the health benefits and preclinical assessment of novel application of vine tea.

FPS-ZM1 inhibits LPS-induced microglial inflammation by suppressing JAK/STAT signaling pathway

FPS-ZM1 is an inhibitor of the receptor for advanced glycation end products (RAGE). Nevertheless, there are few reports about its direct effects on microglial inflammation, and the underlying molecular mechanisms remain to be clarified. The present study investigated the potential effects of FPS-ZM1 on lipopolysaccharide (LPS)-mediated microglial inflammation both in vivo and in vitro, and further elucidated the possible molecular mechanisms of action. FPS-ZM1 decreased LPS-induced overproduction of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and cyclooxygenase 2 (COX-2), in both BV-2 cells and primary microglial cells. FPS-ZM1 (10 mg/kg, i.p.) ameliorated proliferation and activation of microglia in the hippocampus of C57BL/6J mice subjected to LPS challenge (5 mg/kg, i.p.). Meanwhile, overproduction of pro-inflammatory cytokines IL-1β and TNF-α in the hippocampus was alleviated after treatment with FPS-ZM1. RNA-Sequencing (RNA-Seq) analysis showed involvement of Janus kinase (JAK)-signal transducers and activators of transcription (STAT) signaling pathway in the regulation of FPS-ZM1 on LPS-induced microglial inflammation. Further investigations demonstrated that FPS-ZM1 downregulated LPS-mediated increases in the phosphorylation levels of JAK/STAT both in vivo and in vitro. FPS-ZM1 also suppressed the nuclear translocation of transcription factor STAT1/3/5 in BV-2 cells. In addition, inhibition of JAK/STAT signaling pathway had an anti-inflammatory effect similar to FPS-ZM1 treatment. Taken together, our results verified the inhibitory effects of FPS-ZM1 against LPS-stimulated microglial inflammation, and for the first time demonstrated such anti-inflammatory activities on microglia are associated with regulation of JAK/STAT signaling pathway both in vivo and in vitro, which may shed new light on the pharmacological mechanisms of FPS-ZM1 against microglial inflammation.

Matcha green tea prevents obesity-induced hypothalamic inflammation via suppressing the JAK2/STAT3 signaling pathway

Obesity is an increasingly severe global health problem, leading to chronic inflammation and metabolic disorders in both peripheral tissues and the central nervous system. Matcha is a powdered green tea, and it is very popular in recent years as a beverage and food additive. Matcha green tea has been reported to have outstanding potential in regulating obesity-related metabolic syndrome. However, there are few studies on the regulation mechanism of matcha green tea on the central nervous system. In this study, we established a high-fat diet-induced obese mouse model. The results showed that dietary supplementation with matcha could effectively inhibit the weight gain, fat accumulation, glycemia and lipidemia increase, and excessive activation of microglia in the arcuate nucleus of the hypothalamus. Furthermore, we used different concentrations (100%, 80%, 60%, 40%, and 20%, v/v) of ethanol solution to prepare matcha ethanol extracts, and investigated their effects on palmitic acid-induced inflammation of microglial BV-2 cells. The results showed that matcha ethanol extracts could significantly reduce the release of inflammatory cytokines and the expression and phosphorylation of JAK2 and STAT3.

Ampelopsin Improves Cognitive Impairment in Alzheimer's Disease and Effects of Inflammatory Cytokines and Oxidative Stress in the Hippocampus

BACKGROUND

Neuroinflammation and oxidative stress have significant effects on cognitive deficiency in the pathophysiological development of Alzheimer's disease (AD). In the present study, we studied the influences of Ampelopsin (AMP) on proinflammatory cytokines (PICs, IL-1β, IL-6 and TNF-α), and products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α, a product of oxidative stress); and 8-hydroxy-2'-deoxyguanosine (8-OHdG, a key biomarker of protein oxidation) in the hippocampus using a rat model of AD.

METHODS

ELISA was used to examine PICs and oxidative stress production; and western blotting to examine NADPH oxidase (NOXs). The Spatial working memory tests and Morris water maze were utilized to assess cognitive functions.

RESULTS

We observed amplification of IL-1β, IL-6 and TNF-α as well as 8-iso PGF2α and 8-OHdG in the hippocampus of AD rats. AMP attenuated upregulation of PICs and oxidative stress production. AMP also inhibited NOX4 in the AD rat hippocampus. Notably, AMP mostly improved learning performance in AD rat and this was linked to signal pathways of PIC and oxidative stress.

CONCLUSION

AMP plays a significant role in improving the memory deficiency in AD rats via inhibition of signal pathways of neuroinflammation and oxidative stress, suggesting that AMP is likely to prospect in preventing and relieving development of the cognitive dysfunctions in AD as a complementary alternative intervention.

Ampelopsin Inhibits Cell Proliferation and Induces Apoptosis in HL60 and K562 Leukemia Cells by Downregulating AKT and NF-κB Signaling Pathways

Leukemia is a type of blood cancer caused by the rapid proliferation of abnormal white blood cells. Currently, several treatment options, including chemotherapy, radiation therapy, and bone marrow transplantation, are used to treat leukemia, but the morbidity and mortality rates of patients with leukemia are still high. Therefore, there is still a need to develop more selective and less toxic drugs for the effective treatment of leukemia. Ampelopsin, also known as dihydromyricetin, is a plant-derived flavonoid that possesses multiple pharmacological functions, including antibacterial, anti-inflammatory, antioxidative, antiangiogenic, and anticancer activities. However, the anticancer effect and mechanism of action of ampelopsin in leukemia remain unclear. In this study, we evaluated the antileukemic effect of ampelopsin against acute promyelocytic HL60 and chronic myelogenous K562 leukemia cells. Ampelopsin significantly inhibited the proliferation of both leukemia cell lines at concentrations that did not affect normal cell viability. Ampelopsin induced cell cycle arrest at the sub-G1 phase in HL60 cells but the S phase in K562 cells. In addition, ampelopsin regulated the expression of cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors differently in each leukemia cell. Ampelopsin also induced apoptosis in both leukemia cell lines through nuclear condensation, loss of mitochondrial membrane potential, increase in reactive oxygen species (ROS) generation, activation of caspase-9, caspase-3, and poly ADP-ribose polymerase (PARP), and regulation of Bcl-2 family members. Furthermore, the antileukemic effect of ampelopsin was associated with the downregulation of AKT and NF-κB signaling pathways. Moreover, ampelopsin suppressed the expression levels of leukemia stemness markers, such as Oct4, Sox2, CD44, and CD133. Taken together, our findings suggest that ampelopsin may be an attractive chemotherapeutic agent against leukemia.

Columbianadin Dampens In Vitro Inflammatory Actions and Inhibits Liver Injury via Inhibition of NF-κB/MAPKs: Impacts on ∙OH Radicals and HO-1 Expression

Columbianadin (CBN), a natural coumarin isolated from Angelica decursiva, is reported to have numerous biological activities, including anticancer and platelet aggregation inhibiting properties. Here, we investigated CBN’s anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell activation and deciphered the signaling process, which could be targeted by CBN as part of the mechanisms. Using a mouse model of LPS-induced acute liver inflammation, the CBN effects were examined by distinct histologic methods using trichrome, reticulin, and Weigert’s resorcin fuchsin staining. The result showed that CBN decreased LPS-induced expressions of TNF-α, IL-1β, and iNOS and NO production in RAW 264.7 cells and mouse liver. CBN inhibited LPS-induced ERK and JNK phosphorylation, increased IκBα levels, and inhibited NF-κB p65 phosphorylation and its nuclear translocation. Application of inhibitors for ERK (PD98059) and JNK (SP600125) abolished the LPS-induced effect on NF-κB p65 phosphorylation, which indicated that ERK and JNK signaling pathways were involved in CBN-mediated inhibition of NF-κB activation. Treatment with CBN decreased hydroxyl radical (^•OH) generation and increased HO-1 expression in RAW 264.7 cells. Furthermore, LPS-induced liver injury, as indicated by elevated serum levels of liver marker enzymes (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) and histopathological alterations, were reversed by CBN. This work demonstrates the utility of CBN against LPS-induced inflammation, liver injury, and oxidative stress by targeting JNK/ERK and NF-κB signaling pathways.

Dihydromyricetin Acts as a Potential Redox Balance Mediator in Cancer Chemoprevention

Dihydromyricetin (DHM) is a flavonoid extracted from the leaves and stems of the edible plant Ampelopsis grossedentata that has been used for Chinese Traditional Medicine. It has attracted considerable attention from consumers due to its beneficial properties including anticancer, antioxidative, and anti-inflammatory activities. Continuous oxidative stress caused by intracellular redox imbalance can lead to chronic inflammation, which is intimately associated with the initiation, promotion, and progression of cancer. DHM is considered a potential redox regulator for chronic disease prevention, and its biological activities are abundantly evaluated by using diverse cell and animal models. However, clinical investigations are still scanty. This review summarizes the current potential chemopreventive effects of DHM, including its properties such as anticancer, antioxidative, and anti-inflammatory activities, and further discusses the underlying molecular mechanisms of DHM in cancer chemoprevention by targeting redox balance and influencing the gut microbiota.

[Dihydromyricetin inhibits proliferation and migration of gastric cancer cells through regulating Akt/STAT3 signaling pathways and HMGB1 expression]

OBJECTIVE

To investigate the inhibitory effects of dihydromyricetin on the proliferation and migration of gastric cancer BGC-823 cells and explore the molecular mechanisms.

METHODS

BGC-823 cells in routine culture were treated with different concentrations of dihydromyricetin (0, 40, 60, 80, 100, and 120 μg/mL) for 24 h, and the changes in cell viability were detected using CCK-8 assay; colony forming assay and Transwell assay were performed to assess the changes in colonyforming and migration abilities of the cells, respectively. The levels of MMP-2 and MMP-9 in the treated cells were determined using ELISA, and Western blotting was used to detect the expressions of E-cadherin, N-cadherin, cyclin D1, cyclin E1, HSP70 and HMGB1 and the phosphorylation levels of Akt and Stat3.

RESULTS

CCK-8 assay showed that dihydromyricetin treatment dose-dependently inhibited the viability of BGC-823 cells (P < 0.05). Treatment with dihydromyricetin obviously suppressed the proliferation and migration of BGC-823 cells, significantly reduced the expression levels of cyclin D1, cyclin E1 and Ncadherin, enhanced E-cadherin expression, inhibited the phosphorylation of Akt and stat3, and downregulated HMGB1 expression in the cells. The results of ELISA demonstrated significantly lowered levels of MMP-2 and MMP-9 in dihydromyricetin-treated cells.

CONCLUSIONS

Dihydromyricetin inhibits the proliferation and migration of BGC-823 cells through suppressing the activation of Akt/stat3 signaling pathways and HMGB1 expression.

Poncirin suppresses lipopolysaccharide (LPS)-induced microglial inflammation and ameliorates brain ischemic injury in experimental stroke in mice

Background

Based on accumulating evidence, excessive activation of microglia-mediated inflammatory responses plays an essential role in ischemic stroke. Poncirin (Pon) exerts anti-hyperalgesic, anti-osteoporotic and anti-tumor effects on various diseases. However, the roles of Pon in microglial activation and the underlying mechanism have not been elucidated. This study aimed to explore whether Pon inhibits lipopolysaccharide (LPS)-induced microglial neuroinflammation and protects against brain ischemic injury in experimental stroke in mice.

Methods

Primary microglia cells were prepared from the cerebral cortices of 1- to 2-day-old C57BL/6J mice. Murine BV2 cells and primary microglia were stimulated with LPS and the effects of a non-cytotoxic concentration of Pon on LPS-stimulated pro-inflammatory factors were measured using real-time PCR and enzyme-linked immunosorbent assays (ELISAs). Western blot analyses were used for mechanistic studies. In an in vivo study, 8-week-old male C57BL/6J mice were subjected to focal cerebral ischemia through middle cerebral artery occlusion (MCAO). Pon (30 mg/kg, i.p.) or the same volume of saline was administered after the MCAO model was established, and the infarct volume was evaluated using 2,3,5-triphenyltetrazolium chloride (TTC) staining. We also evaluated animal behaviours, the expression of pro-inflammatory cytokines and microglial activation in the ischemic hemisphere.

Results

Pon prevented the release of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β, IL-6 and tumor necrosis factor-alpha (TNF-α) in both BV2 cells and primary microglia stimulated with LPS. The inhibitory effects of Pon were associated with the regulation of the ERK1/2, JNK and nuclear factor kappa B (NF-κB) signaling pathways. In mice that underwent MCAO, Pon administration decreased the lesion size and improved neurological deficits. Furthermore, Pon attenuated the production of inflammatory cytokines mainly by restraining microglial activation after ischemic stroke.

Conclusions

Based on the findings from the present study, Pon provides neuroprotection through its anti-inflammatory effects on microglia and it may be a useful treatment for ischemic stroke.

Targeting connexin 43 provides anti-inflammatory effects after intracerebral hemorrhage injury by regulating YAP signaling

Background

In the central nervous system (CNS), connexin 43 (Cx43) is mainly expressed in astrocytes and regulates astrocytic network homeostasis. Similar to Cx43 overexpression, abnormal excessive opening of Cx43 hemichannels (Cx43Hcs) on reactive astrocytes aggravates the inflammatory response and cell death in CNS pathologies. However, the role of excessive Cx43Hc opening in intracerebral hemorrhage (ICH) injury is not clear.

Methods

Hemin stimulation in primary cells and collagenase IV injection in C57BL/6J (B6) mice were used as ICH models in vitro and in vivo. After ICH injury, the Cx43 mimetic peptide Gap19 was used for treatment. Ethidium bromide (EtBr) uptake assays were used to measure the opening of Cx43Hcs. Western blotting and immunofluorescence were used to measure protein expression. qRT-PCR and ELISA were used to determine the levels of cytokines. Coimmunoprecipitation (Co-IP) and the Duolink in situ proximity ligation assay (PLA) were applied to measure the association between proteins.

Results

In this study, Cx43 expression upregulation and excessive Cx43Hc opening was observed in mice after ICH injury. Delayed treatment with Gap19 significantly alleviated hematoma volume and neurological deficits after ICH injury. In addition, Gap19 decreased inflammatory cytokine levels in the tissue surrounding the hematoma and decreased reactive astrogliosis after ICH injury in vitro and in vivo. Intriguingly, Cx43 transcriptional activity and expression in astrocytes were significantly increased after hemin stimulation in culture. However, Gap19 treatment downregulated astrocytic Cx43 expression through the ubiquitin-proteasome pathway without affecting Cx43 transcription. Additionally, our data showed that Gap19 increased Yes-associated protein (YAP) nuclear translocation. This subsequently upregulated SOCS1 and SOCS3 expression and then inhibited the TLR4-NFκB and JAK2-STAT3 pathways in hemin-stimulated astrocytes. Finally, the YAP inhibitor, verteporfin (VP), reversed the anti-inflammatory effect of Gap19 in vitro and almost completely blocked its protective effects in vivo after ICH injury.

Conclusions

This study provides new insight into potential treatment strategies for ICH injury involving astroglial Cx43 and Cx43Hcs. Suppression of abnormal astroglial Cx43 expression and Cx43Hc opening by Gap19 has anti-inflammatory and neuroprotective effects after ICH injury.

Molecular Level Insight Into the Benefit of Myricetin and Dihydromyricetin Uptake in Patients With Alzheimer's Diseases

Alzheimer's disease (AD) is a neurodegenerative disease with a high incidence rate and complicated pathogenesis. Currently, all anti-AD drugs treat the symptoms of the disease, and with currently no cure for AD. Flavonoid containing natural products, Myricetin (MYR) and Dihydromyricetin (DMY), are abundant in fruits and vegetables, and have been approved as food supplements in some countries. Interestingly, MYR and DMY have been reported to have anti-AD effects. However, the underlying anti-AD mechanism of action of MYR and DMY is complex with many facets being identified. In this review, we explore the benefit of MYR and DMY in AD patients from a molecular level. Their mechanism of action are discussed from various aspects including amyloid β-protein (Aβ) imbalance, neuroinflammation, dyshomeostasis of metal ions, autophagy disorder, and oxidative stress.

6-Gingerol attenuates microglia-mediated neuroinflammation and ischemic brain injuries through Akt-mTOR-STAT3 signaling pathway

Neuroinflammation is critical for the pathogenesis of ischemia brain damage. Over-activated microglia-mediated inflammation plays a very important role in ischemia cerebral injuries. 6-Gingerol, obtained from edible ginger (Zingiber Officinale) exhibits protective effects against inflammation. In this study, we found that 6-Gingerol could reduce the size of infarction (P = 0.0184) and improve neurological functions (P = 0.04) at the third day after ischemic brain injury in vivo. Since 6-Gingerol has the anti-inflammatory effects, we further investigated its impacts on neuroinflammation mediated by microglia both in vivo and in vitro. We found that the levels of pro-inflammatory cytokines Interleukin-1 beta (IL-1β, P = 0.0213), Interleukin-6 (IL-6, P = 0.0316), and inducible NO synthase (iNOS, P = 0.0229) in the infarct penumbra were lower in 6-Gingerol treated groups. Furthermore, microglia induced pro-inflammatory cytokines, such as IL-6, IL-1β, incremental intercellular nitric oxide (NO), as well as iNOS were blocked by the treatment of 6-Gingerol in lipopolysaccharide (LPS) stimulated microglia. In terms of mechanism, 6-Gingerol potently suppressed phosphorylation of serine-threonine protein kinase (Akt) - mammalian target of rapamycin (mTOR) - signal transducer and activator of transcription 3 (STAT3) in LPS-treated microglia. Taken together, the present study suggested that 6-Gingerol improved cerebral ischemia injury by suppressing microglia-mediated neuroinflammation by down-regulating Akt-mTOR-STAT3 pathway.

Ganoderic acid A alleviates myocardial ischemia-reperfusion injury in rats by regulating JAK2/STAT3/NF-κB pathway

This study aimed to investigate the protective effect of GanodericacidA (GA) on myocardial ischemia-reperfusion (MIR) injury. The myocardial injury model in rats was established by ligating left anterior descending coronary artery. We measured cardiac hemodynamic, antioxidant enzyme activity, and various biochemical indexes of myocardial tissue, and evaluated myocardial infarction and damage. Further, the expression of JAK2/STAT3/NF-κB signaling pathway-related proteins in myocardial tissue was measured by western blot. The results showed that the myocardial infarction extention was obviously reduced upon GA treatment. Compared with the control group, ischemia-reperfusion rats showed significant increase in lactate dehydrogenase (LDH) and creatine Kinase (CK), which were significantly decreased in GA group. Besides, GA pretreatment effectively decreased the levels of inflammatory cytokines in serum. The phosphorylation of Janus Kinase 2 (JAK2), signal transducer and activator of transcription (STAT3)and Nuclear factor-κB (NF-κB) in reperfusion group were significantly higher than that in control group, which were reversed upon GA treatment. In conclusion, GA may reduce myocardial injury by regulating JAK2/STAT3/NF-κB pathway.

Ampelopsin inhibits high glucose-induced extracellular matrix accumulation and oxidative stress in mesangial cells through activating the Nrf2/HO-1 pathway

Oxidative stress plays an important role in diabetic nephropathy (DN), which is a diabetic complication. Ampelopsin (AMP) is a natural flavonoid that has been found to possess antidiabetic and antioxidative activities. However, the effect of AMP on DN remains unclear. In this study, we aimed to evaluate the protective effect of AMP on glomerular mesangial cells (MCs) exposed to high glucose (HG). We found that AMP improved HG-caused cell viability reduction in MCs. AMP significantly suppressed the intracellular ROS production and expression levels of ROS producing enzymes NADPH oxidase 2 (NOX2) and NOX4. Increased of NOX activity in HG-stimulated MCs was suppressed by AMP. Pretreatment with AMP inhibited extracellular matrix (ECM) accumulation in HG-stimulated MCs with decreased expression levels of fibronectin (FN) and collagen type IV (Col IV). Furthermore, AMP elevated the expression levels of nuclear Nrf2 and heme oxygenase-1 (HO-1), as well as increased the mRNA levels of Nrf2-driven genes NAD(P)H dehydrogenase quinone-1 (NQO-1) and HO-1 in HG-treated MCs. Knockdown of Nrf2 reversed the protective effects of AMP against HG-induced oxidative stress and EMC accumulation in MCs. In conclusion, these findings indicated that AMP protected MCs from HG-induced oxidative damage and ECM accumulation, which might be mediated by Nrf2/HO-1 pathway.

Ampelopsin alleviates sevoflurane-induced cognitive dysfunction by mediating NF-κB pathway in aged rats

BACKGROUND

Cancer-induced bone pain (CIBP) is the pain caused by bone metastasis from malignant tumors, and the largest source of pain for cancer patients. miR-300 is an important miRNA in cancer. It has been shown that miR-300 regulates tumorigenesis of various tumors.

PURPOSE

This study aims to investigate the role of miR-300 in CIBP and its underlying molecular mechanisms in vitro and in vivo.

METHODS

We constructed CIBP model in rats and investigated the mechanism through which miR-300 affects CIBP. We first examined expression level of miR-300 in CIBP rats and then tested the effect of its overexpression. Next, we identified the target of miR-300 using TargetScan analysis and double luciferase assay. Finally, we studied genetic interactions between miR-300 and its target and their roles in CIBP.

RESULTS

We found that miR-300 was downregulated in CIBP rats. Overexpression of miR-300 significantly attenuated cancer-induced neuropathic pain (p < 0.01). Furthermore, TargetScan analysis and double luciferase assay show High Mobility Group Box 1 (HMGB1) is a target of miR-300. Notably, HMGB1 is overexpressed in CIBP rats, while up-regulation of miR-300 significantly suppresses expression of HMGB1 (p < 0.01). Moreover, knockdown of HMGB1 by siRNA significantly relieves cancer-induced neuropathic pain in rats (p < 0.01). On the other hand, HMGB1 overexpression partially blocked the effect of miR-300 on cancer-induced nerve pain.

CONCLUSION

miR-300 relieves cancer-induced neuropathic pain by inhibiting HMGB1 expression. These results may be beneficial for the treatment of CIBP in clinical practice.

Hoveniae Semen Seu Fructus Ethanol Extract Exhibits Anti-Inflammatory Activity via MAPK, AP-1, and STAT Signaling Pathways in LPS-Stimulated RAW 264.7 and Mouse Peritoneal Macrophages

Hoveniae semen seu fructus (HSF, fruit and seed of Hovenia dulcis Thunb) is an important traditional herbal medicine and food supplement in East Asia for the treatment of liver diseases, alcohol poisoning, obesity, allergy, and cancer. HSF has also been reported to have anti-inflammatory activity, but the cellular mechanism of action is not fully understood. We assessed the anti-inflammatory properties of an HSF ethanol (HSFE) extract and explored its precise mechanism. The ability of HSFE to suppress inflammatory responses was investigated in a murine macrophage cell line, RAW 264.7, and mouse primary macrophages. Secretions of NO, proinflammatory cytokines, inflammatory factors, and related proteins were measured using the Griess assay, ELISA, Western blot analysis, and real-time PCR, respectively. In addition, the main components of HSFE were analyzed by HPLC, and their anti-inflammatory activity was confirmed. Our results showed that pretreatment of HSFE markedly reduced the expression of NO and iNOS without causing cytotoxicity and significantly attenuated secretion of proinflammatory cytokines, including TNF-α, IL-6, and IL-1β. In addition, HSFE strongly suppressed phosphorylation of MAPK and decreased the activation of AP-1, JAK2/STAT, and NF-κB in LPS-stimulated RAW 264.7 cells in a concentration-dependent manner. Furthermore, HSFE strongly suppressed the inflammatory cytokine levels in mouse peritoneal macrophages. Also, as a result of HPLC analysis, three main components, ampelopsin, taxifolin, and myricetin, were identified in the HSFE extract, and each compound effectively inhibited the secretion of inflammatory mediators induced by LPS. These findings show that HSFE exerts anti-inflammatory effects by suppressing the activation of MAPK, AP-1, JAK2/STAT, and NF-κB signaling pathways in LPS-stimulated macrophages. In addition, the anti-inflammatory efficacy of HSFE appears to be closely related to the action of the three main components. Therefore, HSFE appears to be a promising candidate for the treatment of inflammatory diseases.

TMEM16A Inhibition Preserves Blood-Brain Barrier Integrity After Ischemic Stroke

The inflammatory response plays a pivotal role in Blood–Brain Barrier (BBB) destruction following ischemic brain injury. Enhanced leukocyte adhesion to vascular endothelial cells is an essential event in the inflammatory process. TMEM16A, a newly discovered protein regulating calcium-activated chloride channels, is widely expressed in eukaryotes. Recent studies have suggested that upregulated expression of TMEM16A is associated with the occurrence and development of many diseases. However, the role of TMEM16A in regulating BBB integrity after ischemic stroke has not been fully investigated. In this study, we found that TMEM16A is mainly expressed in brain endothelial cells and upregulated after ischemic stroke in the mouse brain. Caccinh-A01, an TMEM16A inhibitor that reduced its upregulation, attenuated brain infarct size and neurological deficits after ischemic stroke. ICAM-1 and MPO expression and BBB permeability were decreased after TMEM16A inhibitor administration. In addition, TMEM16A silencing rescued oxygen-glucose deprivation/reoxygenation (OGD/R)-induced transendothelial permeability in vitro accompanied by decreased ICAM-1 expression and leukocyte adhesion. Furthermore, our mechanistic study showed that TMEM16A knockdown alleviated NF-κB activation and nuclear translocation, indicating that TMEM16A knockdown downregulated OGD/R-induced ICAM-1 expression in an NF-κB-dependent manner. Finally, NF-κB inhibitor treatment also alleviated OGD/ R-induced BBB permeability, confirming that activated NF-κB and increased ICAM-1 are essential factors involved in ischemia-induced BBB damage. Thus, our research provides a promising treatment strategy against BBB destruction after ischemic stroke, and TMEM16A may become a potential target for the treatment of ischemic stroke.

Natural products as a potential modulator of microglial polarization in neurodegenerative diseases

Neurodegenerative diseases (NDs) are characterized by the progressive loss of structure and function of neurons most common in elderly population, mainly including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). Neuroinflammation caused by microglia as the resident macrophages of the central nervous system (CNS) plays a contributory role in the onset and progression of NDs. Activated microglia, as in macrophages, to be heterogeneous, can polarize into M1 (pro-inflammatory) and M2 (anti-inflammatory) functional phenotypes. The former elaborate pro-inflammatory mediators promoting neuroinflammation and neuronal damage. In contrast, the latter generate anti-inflammatory mediators and neurotrophins that inhibit neuroinflammation and promote neuronal healing. Consistently, the regulation of microglial polarization from M1 to M2 phenotype appears as an outstanding therapeutic and preventive approach for NDs treatment. Although non-steroidal anti-inflammatory drugs (NSAIDs) currently used to alleviate M1 microglia-associated neuroinflammation responsible for the development of NDs, these drugs have different degrees of adverse effects and limited efficacy. As the advantages of novel structure, multi-target, high efficiency and low toxicity, natural products as the modulators of microglial polarization have attracted considerable concerns in the therapeutic areas of NDs. In this review, we mainly summarized the therapeutic potential of natural products and their various molecular mechanisms for NDs treatment through modulating microglial polarization. The aim of the current review is expected to be useful to develop innovative modulators of microglial polarization from natural products for the amelioration and treatment of NDs.

Astaxanthin Ameliorates Lipopolysaccharide-Induced Neuroinflammation, Oxidative Stress and Memory Dysfunction through Inactivation of the Signal Transducer and Activator of Transcription 3 Pathway

Astaxanthin (AXT), a xanthophyll carotenoid compound, has potent antioxidant, anti-inflammatory and neuroprotective properties. Neuroinflammation and oxidative stress are significant in the pathogenesis and development of Alzheimer's disease (AD). Here, we studied whether AXT could alleviate neuroinflammation, oxidative stress and memory loss in lipopolysaccharide (LPS) administered mice model. Additionally, we investigated the anti-oxidant activity and the anti-neuroinflammatory response of AXT in LPS-treated BV-2 microglial cells. The AXT administration ameliorated LPS-induced memory loss. This effect was associated with the reduction of LPS-induced expression of inflammatory proteins, as well as the production of reactive oxygen species (ROS), nitric oxide (NO), cytokines and chemokines both in vivo and in vitro. AXT also reduced LPS-induced β-secretase and Aβ_1⁻42 generation through the down-regulation of amyloidogenic proteins both in vivo and in vitro. Furthermore, AXT suppressed the DNA binding activities of the signal transducer and activator of transcription 3 (STAT3). We found that AXT directly bound to the DNA- binding domain (DBD) and linker domain (LD) domains of STAT3 using docking studies. The oxidative stress and inflammatory responses were not downregulated in BV-2 cells transfected with DBD-null STAT3 and LD-null STAT3. These results indicated AXT inhibits LPS-induced oxidant activity, neuroinflammatory response and amyloidogenesis via the blocking of STAT3 activity through direct binding.

Protective role of Dihydromyricetin in Alzheimer's disease rat model associated with activating AMPK/SIRT1 signaling pathway

The aim of the present study was to understand the possible role of the Dihydromyricetin (DHM) in Alzheimer's disease (AD) rat model through regulation of the AMPK/SIRT1 signaling pathway. Rats were divided into Sham group, AD group, AD + DHM (100 mg/kg) group and AD + DHM (200 mg/kg) group. The spatial learning and memory abilities of rats were assessed by Morris Water Maze. Then, the inflammatory cytokines expressions were determined by radioimmunoassay while expressions of AMPK/SIRT1 pathway-related proteins by Western blot; and the apoptosis of hippocampal cells was detected by TdT-mediated dUTP nick end labeling assay. AD rats had an extended escape latency with decreases in the number of platform crossings, the target quadrant residence time, as well as swimming speed, and the inflammatory cytokines in serum and hippocampus were significantly elevated but AMPK/SIRT1 pathway-related proteins were reduced. Meanwhile, the apoptosis of hippocampal cells was significantly up-regulated with decreased Bcl-2 and increased Bax, as compared with Sham rats (all P<0.05). After AD rats treated with 100 or 200 mg/kg of DHM, the above effects were significantly reversed, resulting in a completely opposite tendency, and especially with 200 mg/kg DHM treatment, the improvement of AD rats was more obvious. DHM exerts protective role in AD via up-regulation of AMPK/SIRT1 pathway to inhibit inflammatory responses and hippocampal cell apoptosis and ameliorate cognitive function.

Neuroinflammation Signaling Modulated by ASS234, a Multitarget Small Molecule for Alzheimer's Disease Therapy

There is clear evidence that neuroinflammation plays a crucial role in the pathogenesis of Alzheimer's disease. Consequently, modulating the inflammatory environment in brain has become a powerful and attractive strategy to deal with Alzheimer's disease physiopathology. In spite of the neuroprotective capacity shown by ASS234, a multitarget propargylamine targeted for Alzheimer's disease, its regulation of inflammation in the brain still remains unexplored. Therefore, we aimed to characterize possible anti-inflammatory effects of ASS234, counteracting induced inflammatory effects in RAW 264.7 cells and evaluating seven neuroinflammation related genes expression profiling (IL-6, IL-10, IL1β, NF-κB, TNF-α, TNFR1, and TGF-β), after ASS234 (5 μM) treatment in SH-SY5Y cells. The analysis of the obtained fold changes lead us to conclude that ASS234 may play an important role facing the neuroinflammatory environment in Alzheimer's disease pathology.