Kurarinone alleviated Parkinson's disease via stabilization of epoxyeicosatrienoic acids in animal model

Acovenosigenin A β-glucoside mediates JAK2-STAT3 signaling pathway by targeting GP130 in A549 and H460 cells based on integrative analysis of transcriptome and proteome and biological verification

Acovenosigenin A β-glucoside (AAG) is a cardiac glycoside derived from Streptocaulon juventas (Lour.) Merr, which exhibited the potential in treating lung cancer in our previous research. However, the action mechanism remains unclear. In this research, JAK2-STAT3 signaling pathway was predicted to be the critical regulation pathway based on the integrative analysis of transcriptome and proteome. Western blotting and qPCR assays were performed to identify that AAG can regulate JAK2-STAT3 signaling pathway and its downstream genes, such as c-Myc, Survivin, Cyclin B1, CDK1, Bcl-2. And this action of AAG depended on the suppression of STAT3 phosphorylation and its nuclear translocation through the experiments of Immunofluorescence, transient transfection and cryptotanshinone treatment. Additionally, AAG was discovered to mediate the JAK2-STAT3 pathway in IL-6-driven A549 and H460 cells, which in turn inhibited cell proliferation, promoted mitochondria-related apoptosis, and arrested the cell cycle progression. By molecular docking analysis, CETSA and SIP experiments, the protein of GP130 was identified as the specific target of AAG in A549 and H460 cells. Further studies suggested that AAG inhibited JAK2-STAT3 pathway and its downstream genes by targeting GP130 in nude mice xenograft model in vivo. This research presented that AAG exhibits the promising potential in the treatment of NSCLC.

Myricetin mitigates motor disturbance and decreases neuronal ferroptosis in a rat model of Parkinson's disease

Ferroptosis is an iron-dependent cell death form characterized by reactive oxygen species (ROS) overgeneration and lipid peroxidation. Myricetin, a flavonoid that exists in numerous plants, exhibits potent antioxidant capacity. Given that iron accumulation and ROS-provoked dopaminergic neuron death are the two main pathological hallmarks of Parkinson's disease (PD), we aimed to investigate whether myricetin decreases neuronal death through suppressing ferroptosis. The PD models were established by intraperitoneally injecting 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into rats and by treating SH-SY5Y cells with 1-methyl-4-phenylpyridinium (MPP+), respectively. Ferroptosis was identified by assessing the levels of Fe2+, ROS, malondialdehyde (MDA), and glutathione (GSH). The results demonstrated that myricetin treatment effectively mitigated MPTP-triggered motor impairment, dopamine neuronal death, and α-synuclein (α-Syn) accumulation in PD models. Myricetin also alleviated MPTP-induced ferroptosis, as evidenced by decreased levels of Fe2+, ROS, and MDA and increased levels of GSH in the substantia nigra (SN) and serum in PD models. All these changes were reversed by erastin, a ferroptosis activator. In vitro, myricetin treatment restored SH-SY5Y cell viability and alleviated MPP+-induced SH-SY5Y cell ferroptosis. Mechanistically, myricetin accelerated nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and subsequent glutathione peroxidase 4 (Gpx4) expression in MPP+-treated SH-SY5Y cells, two critical inhibitors of ferroptosis. Collectively, these data demonstrate that myricetin may be a potential agent for decreasing dopaminergic neuron death by inhibiting ferroptosis in PD.

Dynamin-related protein 1 mediates the therapeutic effect of isoliquiritigenin in diabetic intimal hyperplasia via regulation of mitochondrial fission

Phenotypic shift of vascular smooth muscle cells (VSMCs) plays a key role in intimal hyperplasia, especially in patients with diabetes mellitus (DM). This study aimed to investigate the role of dynamin-related protein 1 (DRP1) in mitochondrial fission-mediated VSMC phenotypic shift and to clarify whether DRP1 is the therapeutic target of isoliquiritigenin (ISL). Wire injury of carotid artery or platelet-derived growth factor treatment was performed in DM mice or high-glucose cultured human aortic smooth muscle cells (HASMCs), respectively. The effects of DRP1 silencing on DM-induced intimal hyperplasia were investigated both in vivo and in vitro. Phenotypic shift of HASMCs was evaluated by detection of reactive oxygen species (ROS) generation, cell viability, and related protein expressions. The effects of ISL on DM-induced intimal hyperplasia were evaluated both in vivo and in vitro. DRP1 silencing and ISL treatment attenuated DM-induced intimal hyperplasia with reduced ROS generation, cell viability, and VSMC dedifferentiation. The GTPase domain of DRP1 protein played a critical role in mitochondrial fission in DM-induced VSMC phenotypic shift. Cellular experiments showed that ISL inhibited mitochondrial fission and reduced the GTPase activity of DRP1, which was achieved by the directly binding to K216 of the DRP1 GTPase domain. ISL attenuated mouse intimal hyperplasia by reducing GTPase activity of DRP1 and inhibiting mitochondrial fission in vivo. In conclusion, increased GTPase activity of DRP1 aggregated DM-induced intimal hyperplasia by increasing mitochondrial fission-mediated VSMC phenotypic shift. ISL attenuated mouse intimal hyperplasia by reducing DRP1 GTPase activity and inhibiting mitochondrial fission of VSMCs.

Asiaticoside exerts neuroprotection through targeting NLRP3 inflammasome activation

BACKGROUND

Parkinson's disease (PD), a neurodegenerative disorder, is characterized by motor symptoms due to the progressive loss of dopaminergic neurons in the substantia nigra (SN) and striatum (STR), alongside neuroinflammation. Asiaticoside (AS), a primary active component with anti-inflammatory and neuroprotective properties, is derived from Centella asiatica. However, the precise mechanisms through which AS influences PD associated with inflammation are not yet fully understood.

PURPOSE

This study aimed to explore the protective mechanism of AS in PD.

METHODS

Targets associated with AS and PD were identified from the Swiss Target Prediction, Similarity Ensemble Approach, PharmMapper, and GeneCards database. A protein-protein interaction (PPI) network was constructed to identify potential therapeutic targets. Concurrently, GO and KEGG analyses were performed to predict potential signaling pathways. To validate these mechanisms, the effects of AS on 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in mice were investigated. Furthermore, neuroinflammation and the activation of the NLRP3 inflammasome were assessed to confirm the anti-inflammatory properties of AS. In vitro experiments in BV2 cells were then performed to investigate the mechanisms of AS in PD. Moreover, CETSA, molecular docking, and molecular dynamics simulations (MDs) were performed for further validation.

RESULTS

Network pharmacology analysis identified 17 potential targets affected by AS in PD. GO and KEGG analyses suggested the biological roles of these targets, demonstrating that AS interacts with 149 pathways in PD. Notably, the NOD-like receptor signaling pathway was identified as a key pathway mediating AS's effect on PD. In vivo studies demonstrated that AS alleviated motor dysfunction and reduced the loss of dopaminergic neurons in MPTP-induced PD mice. In vitro experiments demonstrated that AS substantially decreased IL-1β release in BV2 cells, attributing this to the modulation of the NLRP3 signaling pathway. CETSA and molecular docking studies indicated that AS forms a stable complex with NLRP3. MDs suggested that ARG578 played an important role in the formation of the complex.

CONCLUSION

In this study, we first predicted that the potential target and pathway of AS's effect on PD could be NLRP3 protein and NOD-like receptor signaling pathway by network pharmacology analysis. Further, we demonstrated that AS could alleviate symptoms of PD induced by MPTP through its interaction with the NLRP3 protein for the first time by in vivo and in vitro experiments. By binding to NLRP3, AS effectively inhibits the assembly and activation of the inflammasome. These findings suggest that AS is a promising inhibitor for PD driven by NLRP3 overactivation.

Kurarinone, a flavonoid from Radix Sophorae Flavescentis, inhibits RANKL-induced osteoclastogenesis in mouse bone marrow-derived monocyte/macrophages

Inflammation-induced osteoclast proliferation is a crucial contributor to impaired bone metabolism. Kurarinone (KR), a flavonoid extracted from the Radix Sophorae Flavescentis, exhibits notable anti-inflammatory properties. Nevertheless, the precise influence of KR on osteoclast formation remains unclear. This study's objective was to assess the impact of KR on osteoclast activity in vitro and unravel its underlying mechanism. Initially, a target network for KR-osteoclastogenesis-osteoporosis was constructed using network pharmacology. Subsequently, the intersecting targets were identified through the Venny platform and a PPI network was created using Cytoscape 3.9.1. Key targets within the network were identified employing topological algorithms. GO enrichment and KEGG pathway analysis were then performed on these targets to explore their specific functions and pathways. Additionally, molecular docking of potential core targets of KR was conducted, and the results were validated through cell experiments. A total of 83 target genes overlapped between KR and osteoclastogenesis-osteoporosis targets. Enrichment analysis revealed their role in inflammatory response, protein tyrosine kinase activity, osteoclast differentiation, and MAPK and NF-κB signaling pathways. PPI analysis and molecular docking demonstrate that key targets MAPK14 and MAPK8 exhibit more stable binding with KR compared to other proteins. In vitro experiments demonstrate that KR effectively inhibits osteoclast differentiation and bone resorption without cellular toxicity. It suppresses key osteoclast genes (NFATc1, c-Fos, TRAP, MMP9, Ctsk, Atp6v2), hinders IκB-α degradation, and inhibits ERK and JNK phosphorylation, while not affecting p38 phosphorylation. The results indicate that KR may inhibit osteoclast maturation and bone resorption by blocking NF-κB and MAPK signaling pathways, suggesting its potential as a natural therapeutic agent for osteoporosis.

Kurarinone regulates Th17/Treg balance and ameliorates autoimmune uveitis via Rac1 inhibition

INTRODUCTION

Autoimmune uveitis (AU) is a severe intraocular autoimmune disorder with a chronic disease course and a high rate of blindness. Kurarinone (KU), a major component of the traditional Chinese medicine Sophorae Flavescentis Radix, possesses a wide spectrum of activities and has been used to treat several inflammation-related diseases.

OBJECTIVE

We aimed to investigate the effects of KU on AU and its modulatory mechanisms.

METHODS

We used an experimental autoimmune uveitis (EAU) animal model and characterized the comprehensive immune landscape of KU-treated EAU mice using single-cell RNA sequencing (scRNA-seq). The retina and lymph nodes were analyzed. The siRNAs and selective inhibitors were used to study the signaling pathway. The effect of KU on peripheral blood mononuclear cells (PBMCs) from uveitis patients was also examined.

RESULTS

We found that KU relieved chorioretinal lesions and immune cell infiltration in EAU model mice. Subsequent single-cell analysis revealed that KU downregulated the EAU-upregulated expression of inflammatory and autoimmune-related genes and suppressed pathways associated with immune cell differentiation, activation, and migration in a cell-specific manner. KU was implicated in restoring T helper 17 (Th17)/regulatory T (Treg) cell balance by alleviating inflammatory injury and elevating the expression of modulatory mediators in Tregs, while simultaneously ameliorating excessive inflammation by Th17 cells. Furthermore, Rac1 and the Id2/Pim1 axis potentiated the pathogenicity of Th17 cells during EAU, which was inhibited by KU treatment, contributing to the amelioration of EAU-induced inflammation and treatment of AU. In addition, KU suppressed inflammatory cytokine production in activated human PBMCs by inhibiting Rac1. Integration of the glucocorticoid-treated transcriptome suggests that KU has immunomodulatory effects on lymphocytes.

CONCLUSION

Our study constructed a high-resolution atlas of the immunoregulatory effects of KU treatment on EAU and identified its potential therapeutic mechanisms, which hold great promise in treating autoimmune disorders.

Role of HCN channels in the functions of basal ganglia and Parkinson's disease

Parkinson's disease (PD) is a motor disorder resulting from dopaminergic neuron degeneration in the substantia nigra caused by age, genetics, and environment. The disease severely impacts a patient's quality of life and can even be life-threatening. The hyperpolarization-activated cyclic nucleotide-gated (HCN) channel is a member of the HCN1-4 gene family and is widely expressed in basal ganglia nuclei. The hyperpolarization-activated current mediated by the HCN channel has a distinct impact on neuronal excitability and rhythmic activity associated with PD pathogenesis, as it affects the firing activity, including both firing rate and firing pattern, of neurons in the basal ganglia nuclei. This review aims to comprehensively understand the characteristics of HCN channels by summarizing their regulatory role in neuronal firing activity of the basal ganglia nuclei. Furthermore, the distribution and characteristics of HCN channels in each nucleus of the basal ganglia group and their effect on PD symptoms through modulating neuronal electrical activity are discussed. Since the roles of the substantia nigra pars compacta and reticulata, as well as globus pallidus externus and internus, are distinct in the basal ganglia circuit, they are individually described. Lastly, this investigation briefly highlights that the HCN channel expressed on microglia plays a role in the pathological process of PD by affecting the neuroinflammatory response.

Targeting Keap1 with Inulae Herba activated the Nrf2 receptor to alleviate LPS-mediated acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Inulae Herba (IH) is known as Jinfeicao recorded in Chinese Pharmacopoeia with effects of lowering qi and eliminating phlegm, and used for the treatment of pulmonary diseases. However, its protective mechanism on pulmonary diseases, especially acute lung injury (ALI), is still undefined.

AIM OF THE STUDY

This study aimed to explore anti-inflammatory and anti-oxidation effects of IH and its underlying mechanism for treating ALI.

MATERIALS AND METHODS

We constructed a lipopolysaccharide (LPS)-ALI mouse model to reveal the therapeutical effect of IH. Western blot, real-time quantitative PCR, flow cytometry, small RNA interference, immunohistochemical staining, and the dual-luciferase experiment were performed to study the mechanism of IH for treating ALI.

RESULTS

IH attenuated LPS-mediated pathological changes (e.g. pneumonedema and pulmonary congestion) through inactivation of macrophages in an ALI mouse model. The result of flow cytometry demonstrated that IH regulated the homeostasis of M1 (CD80+CD206-) and M2 (CD80+CD206+) phenotype macrophages. Furthermore, IH suppressed mRNA expressions of M1 phenotype markers, such as iNOS and IL-6, whereas promoted mRNA expressions of M2 phenotype markers, such as ARG1 and RETNLA in LPS-mediated mice. Notably, IH targeted Keap1 to activate the Nrf2 receptor, exerting its anti-inflammatory and anti-oxidation effects proved by using immunohistochemical staining, dual-luciferase, and Keap1 knockdown technologies.

CONCLUSION

These findings suggested that targeting Keap1 with IH alleviated LPS-mediated ALI, and it could serve as a herbal agent for developing anti-ALI drugs.

Degradation profile of environmental pollutant 17β-estradiol by human intestinal fungus Aspergillus niger RG13B1 and characterization of genes involved in its degradation

Environmental hormones have attracted more attention because of their adverse impact on the health and ecological security of human. Biodegradation is still an efficient tactics to remove environmental hormones, but human intestinal microbes remain to be elucidated in the role of their degradation. In the present work, we intended to perform the in vitro experiment for investigating the degradation of 17β-estradiol, the main environmental estrogen, by human intestinal microflora Aspergillus niger RG13B1. Its degradation led to the production of eighteen metabolites characterized by 1H, 13C, and 2D NMR, and HRMS spectra, including nine new (1-9) and nine known metabolites (10-18). Based on their structures, the degradation pathway of 17β-estradiol mediated by A. niger RG13B1 involved hydroxylation, oxidation, methylation, acetylation, and dehydrogenation, especially infrequent lactylation, and the key degradation enzymes were found in the gene cluster of A. niger. In addition, we found that metabolite 12 interacted with amino acid residues Lys37, Gln39, Lys93, and Asn115 of NF-κB p65 to suppress expressions of inflammatory genes or proteins, exerting its anti-inflammatory effect. This study first illustrated the role of human gut microbe in 17β-estradiol degradation and provided new insights into its degradation mechanism by A. niger RG13B1.

Soluble epoxide hydrolase deficiency attenuates airway inflammation in COPD via IRE1α/JNK/AP-1 signaling pathway

BACKGROUND

Soluble Epoxide Hydrolase (sEH) metabolizes anti-inflammatory epoxyeicosatrienoic acids and critically affects airway inflammation in chronic obstructive pulmonary disease (COPD). Considering the excessive endoplasmic reticulum stress is associated with the earlier onset of COPD. The role of sEH and endoplasmic reticulum stress in the pathogenesis of COPD remains unknown.

METHOD

16 weeks of cigarette-exposed mice were used to detect the relationship between sEH and endoplasmic reticulum stress in COPD. Human epithelial cells were used in vitro to determine the regulation mechanism of sEH in endoplasmic reticulum stress induced by cigarette smoke.

RESULTS

sEH deficiency helps reduce emphysema formation after smoke exposure by alleviating endoplasmic reticulum stress response. sEH deficiency effectively reverses the upregulation of phosphorylation IRE1α and JNK and the nuclear expression of AP-1, alleviating the secretion of inflammatory factors induced by cigarette smoke extract. Furthermore, the treatment with endoplasmic reticulum stress and IRE1α inhibitor downregulated cigarette smoke extract-induced sEH expression and the secretion of inflammatory factors.

CONCLUSION

sEH probably alleviates airway inflammatory response and endoplasmic reticulum stress via the IRE1α/JNK/AP-1 pathway, which might attenuate lung injury caused by long-term smoking and provide a new pharmacological target for preventing and treating COPD.

Neuroprotective effect of Kurarinone against corticosterone-induced cytotoxicity on rat hippocampal neurons by targeting BACE1 to activate P13K-AKT signaling - A potential treatment in insomnia disorder

The hippocampus has been implicated in the pathogenesis of insomnia disorder (ID) and the purpose of this study was to investigate the neuroprotective mechanism of the natural flavone Kurarinone (Kur) on hippocampal neurotoxicity as a potential treatment of ID. The effect of Kur on hippocampal neuronal cell (HNC) viability and apoptosis were assessed by Cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Then, the effect of Kur on β-site amyloid precursor protein-cleaving enzyme 1 (BACE1), brain-derived neurotrophic factor (BDNF), and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) phosphorylation level were measured by Western blot. Further, SwissTargetPrediction analysis and molecular docking experiments were used to detect a potential target of Kur. Then, the p-chlorophenylalanine (PCPA) model was established in vivo to further study the effect of BACE1 expression on Kur and HNC. As a result, HNC viability was only significantly decreased by 2 μM of Kur. Kur reversed the impacts of corticosterone upon inhibiting viability (0.25-1 μM), PI3K (0.5-1 μM)/AKT phosphorylation, and BDNF (1 μM) level, and enhancing the apoptosis (0.25-1 μM) and BACE1 expression (1 μM) in HNCs. BACE1 was a potential target of Kur. Notably, Kur (150 mg/kg) attenuated PCPA-induced upregulation of BACE1 expression in rat hippocampal tissues as ZRAS (0.8 g/kg). The effects of Kur (1 μM) on corticosterone-treated HNCs were reversed by BACE1 overexpression. Collectively, Kur downregulates BACE1 level to activate PI3K/AKT, thereby attenuating corticosterone-induced toxicity in HNCs, indicating that Kur possibly exerted a neuroprotective effect, which providing a new perspective for the treatment of insomnia disorders.

Astaxanthin ameliorates dopaminergic neuron damage in paraquat-induced SH-SY5Y cells and mouse models of Parkinson's disease

Parkinson's disease (PD) is the second largest neurodegenerative disorder caused by the decreased number of dopaminergic (DAc) neurons in the substantia nigra pars compacta (SNpc). There is evidence that oxidative stress can contribute degeneration of DAc neurons in SNpc which is mainly caused by apoptotic cell death. Thus, suppressing oxidative stress and apoptosis of DAc neurons is an effective strategy to mitigate the progress of PD. Astaxanthin (AST) is a carotenoid, which mainly exists in marine organisms and is a powerful biological antioxidant. In this study, we aimed to determine the neuroprotective effect of AST on paraquat (PQ) -induced models of PD in vitro and in vivo. Here, we showed that AST significantly enhanced cell survival of SH-SY5Y cells against PQ toxicity by suppressing apoptotic cell death and oxidative stress. Moreover, we found that AST significantly ameliorated PQ-induced behavioral disorders associated with PD in C57BL/6 J mice and the damage to DAc neurons in the SNpc of mice. Lastly, we found that the neuroprotective effects of AST were conducted through inhibiting PQ-induced activation of MAPK signaling. In conclusion, our study indicates that AST had a strong protective effect on PQ-induced oxidative stress and antagonized apoptotic cell death in SH-SY5Y cells and PQ-induced mice PD model, which might provide new insights of AST for PD treatment.

Genetic deletion or pharmacological inhibition of soluble epoxide hydrolase attenuated particulate matter 2.5 exposure mediated lung injury

Air pollution represented by particulate matter 2.5 (PM2.5) is closely related to diseases of the respiratory system. Although the understanding of its mechanism is limited, pulmonary inflammation is closely correlated with PM2.5-mediated lung injury. Soluble epoxide hydrolase (sEH) and epoxy fatty acids play a vital role in the inflammation. Herein, we attempted to use the metabolomics of oxidized lipids for analyzing the relationship of oxylipins with lung injury in a PM2.5-mediated mouse model, and found that the cytochrome P450 oxidases/sEH mediated metabolic pathway was involved in lung injury. Furthermore, the sEH overexpression was revealed in lung injury mice. Interestingly, sEH genetic deletion or the selective sEH inhibitor TPPU increased levels of epoxyeicosatrienoic acids (EETs) in lung injury mice, and inactivated pulmonary macrophages based on the MAPK/NF-κB pathway, resulting in protection against PM2.5-mediated lung injury. Additionally, a natural sEH inhibitor luteolin from Inula japonica displayed a pulmonary protective effect towards lung injury mediated by PM2.5 as well. Our results are consistent with the sEH message and protein being both a marker and mechanism for PM2.5-induced inflammation, which suggest its potential as a pharmaceutical target for treating diseases of the respiratory system.

The dual face of microglia (M1/M2) as a potential target in the protective effect of nutraceuticals against neurodegenerative diseases

The pathophysiology of different neurodegenerative illnesses is significantly influenced by the polarization regulation of microglia and macrophages. Traditional classifications of macrophage phenotypes include the pro-inflammatory M1 and the anti-inflammatory M2 phenotypes. Numerous studies demonstrated dynamic non-coding RNA modifications, which are catalyzed by microglia-induced neuroinflammation. Different nutraceuticals focus on the polarization of M1/M2 phenotypes of microglia and macrophages, offering a potent defense against neurodegeneration. Caeminaxin A, curcumin, aromatic-turmerone, myricetin, aurantiamide, 3,6'-disinapoylsucrose, and resveratrol reduced M1 microglial inflammatory markers while increased M2 indicators in Alzheimer's disease. Amyloid beta-induced microglial M1 activation was suppressed by andrographolide, sulforaphane, triptolide, xanthoceraside, piperlongumine, and novel plant extracts which also prevented microglia-mediated necroptosis and apoptosis. Asarone, galangin, baicalein, and a-mangostin reduced oxidative stress and pro-inflammatory cytokines, such as interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha in M1-activated microglia in Parkinson's disease. Additionally, myrcene, icariin, and tenuigenin prevented the nod-like receptor family pyrin domain-containing 3 inflammasome and microglial neurotoxicity, while a-cyperone, citronellol, nobiletin, and taurine prevented NADPH oxidase 2 and nuclear factor kappa B activation. Furthermore, other nutraceuticals like plantamajoside, swertiamarin, urolithin A, kurarinone, Daphne genkwa flower, and Boswellia serrata extracts showed promising neuroprotection in treating Parkinson's disease. In Huntington's disease, elderberry, curcumin, iresine celosia, Schisandra chinensis, gintonin, and pomiferin showed promising results against microglial activation and improved patient symptoms. Meanwhile, linolenic acid, resveratrol, Huperzia serrata, icariin, and baicalein protected against activated macrophages and microglia in experimental autoimmune encephalomyelitis and multiple sclerosis. Additionally, emodin, esters of gallic and rosmarinic acids, Agathisflavone, and sinomenine offered promising multiple sclerosis treatments. This review highlights the therapeutic potential of using nutraceuticals to treat neurodegenerative diseases involving microglial-related pathways.

Parkinson's disease model in zebrafish using intraperitoneal MPTP injection

Introduction

Parkinson's disease (PD) is the second most common neurodegenerative disease that severely affects the quality of life of patients and their family members. Exposure to 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to reflect behavioral, molecular, and proteomic features of PD. This study aimed to assess the protocol for inducing PD following MPTP injection in adult zebrafish.

Methods

Fish were injected with 100 μg/g of MPTP intraperitoneally once or twice and then assessed on days 1 to 30 post-injection.

Results

Between one-time and two-time injections, there was no significant difference in most locomotor parameters, expressions of tyrosine hydroxylase-2 (th2) and dopamine transporter (dat) genes, and dopaminergic neurons (tyrosine hydroxylase positive, TH+ cells) counts. However, caspase-3 levels significantly differed between one- and two-time injections on the day 1 assessment.

Discussion

Over a 30-day period, the parameters showed significant differences in swimming speed, total distance traveled, tyrosine hydroxylase-1 (th1) and dat gene expressions, caspase-3 and glutathione protein levels, and TH+ cell counts. Days 3 and 5 showed the most changes compared to the control. In conclusion, a one-time injection of MPTP with delayed assessment on days 3 to 5 is a good PD model for animal studies.

IκB kinase β (IKKβ): Structure, transduction mechanism, biological function, and discovery of its inhibitors

The effective approach to discover innovative drugs will ask natural products for answers because of their complex and changeable structures and multiple biological activities. Inhibitory kappa B kinase beta (IKKβ), known as IKK2, is a key regulatory kinase responsible for the activation of NF-κB through its phosphorylation at Ser177 and Ser181 to promote the phosphorylation of inhibitors of kappa B (IκBs), triggering their ubiquitination and degradation to active the nuclear factor kappa-B (NF-κB) cascade. Chemical inhibition of IKKβ or its genetic knockout has become an effective method to block NF-κB-mediated proliferation and migration of tumor cells and inflammatory response. In this review, we summarized the structural feature and transduction mechanism of IKKβ and the discovery of inhibitors from natural resources (e.g. sesquiterpenoids, diterpenoids, triterpenoids, flavonoids, and alkaloids) and chemical synthesis (e.g. pyrimidines, pyridines, pyrazines, quinoxalines, thiophenes, and thiazolidines). In addition, the biosynthetic pathway of novel natural IKKβ inhibitors and their biological potentials were discussed. This review will provide inspiration for the structural modification of IKKβ inhibitors based on the skeleton of natural products or chemical synthesis and further phytochemistry investigations.

MAT as a promising therapeutic strategy against triple-negative breast cancer via inhibiting PI3K/AKT pathway

Triple-negative breast cancer (TNBC), a highly aggressive and heterogeneous subtype of breast cancer, lacks effective treatment options. Sophora flavescens Aiton, a Chinese medicinal plant, is often used in traditional Chinese medicine to treat cancer. Matrine (MAT) is an alkaloid extracted from Sophora flavescens. It has good anticancer effects, and thus can be explored as a new therapeutic agent in TNBC research. We performed bioinformatics analysis to analyze the differentially expressed genes between normal breast tissues and TNBC tissues, and comprehensive network pharmacology analyses. The activity and invasion ability of TNBC cells treated with MAT were analyzed. Apoptosis and cell cycle progression were determined using cytometry. We used Monodansylcadaverine (MDC) staining to determine the condition of autophagosomes. Finally, the expression levels of the key target proteins of the PI3K/AKT pathway were determined using western blotting. The proliferation and invasion ability of MDA-MB-231 and MDA-MB-468 can be effectively inhibited by MAT. The results of flow cytometry indicated that MAT arrested the TNBC cell cycle and induced apoptosis. In addition, we confirmed that MAT inhibited the expression of BCL-2 while up-regulating the expression of cleaved caspase-3. Moreover, enhanced intensity of MDC staining and high LC3-II expression were observed, which confirmed that MAT induced autophagy in TNBC cells. Western blotting showed that MAT inhibited the PI3K/AKT pathway and downregulated the expressions of PI3K, AKT, p-AKT, and PGK1. This study provides feasible methods, which include bioinformatics analysis and in vitro experiments, for the identification of compounds with anti-TNBC properties. MAT inhibited the PI3K/AKT signaling pathway, arrested cell cycle, as well as promoted cell apoptosis and autophagy. These experiments provide evidence for the anti-TNBC effect of MAT and identified potential targets against TNBC.

CETSA and thermal proteome profiling strategies for target identification and drug discovery of natural products

BACKGROUND

Monitoring target engagement at various stages of drug development is essential for natural product (NP)-based drug discovery and development. The cellular thermal shift assay (CETSA) developed in 2013 is a novel, broadly applicable, label-free biophysical assay based on the principle of ligand-induced thermal stabilization of target proteins, which enables direct assessment of drug-target engagement in physiologically relevant contexts, including intact cells, cell lysates and tissues. This review aims to provide an overview of the work principles of CETSA and its derivative strategies and their recent progress in protein target validation, target identification and drug lead discovery of NPs.

METHODS

A literature-based survey was conducted using the Web of Science and PubMed databases. The required information was reviewed and discussed to highlight the important role of CETSA-derived strategies in NP studies.

RESULTS

After nearly ten years of upgrading and evolution, CETSA has been mainly developed into three formats: classic Western blotting (WB)-CETSA for target validation, thermal proteome profiling (TPP, also known as MS-CETSA) for unbiased proteome-wide target identification, and high-throughput (HT)-CETSA for drug hit discovery and lead optimization. Importantly, the application possibilities of a variety of TPP approaches for the target discovery of bioactive NPs are highlighted and discussed, including TPP-temperature range (TPP-TR), TPP-compound concentration range (TPP-CCR), two-dimensional TPP (2D-TPP), cell surface-TPP (CS-TPP), simplified TPP (STPP), thermal stability shift-based fluorescence difference in 2D gel electrophoresis (TS-FITGE) and precipitate supported TPP (PSTPP). In addition, the key advantages, limitations and future outlook of CETSA strategies for NP studies are discussed.

CONCLUSION

The accumulation of CETSA-based data can significantly accelerate the elucidation of the mechanism of action and drug lead discovery of NPs, and provide strong evidence for NP treatment against certain diseases. The CETSA strategy will certainly bring a great return far beyond the initial investment and open up more possibilities for future NP-based drug research and development.

A Shift in Thinking: Cellular Thermal Shift Assay-Enabled Drug Discovery

A decade has passed since the cellular thermal shift assay (CETSA) was introduced to the drug discovery community. Over the years, the method has guided numerous projects by providing insights about, for example, target engagement, lead generation, target identification, lead optimization, and preclinical profiling. With this Microperspective, we intend to highlight recently published applications of CETSA and how the data generated can enable efficient decision-making and prioritization throughout the drug discovery and development value chain.

Macrophage Inactivation by Small Molecule Wedelolactone via Targeting sEH for the Treatment of LPS-Induced Acute Lung Injury

Soluble epoxide hydrolase (sEH) plays a critical role in inflammation by modulating levels of epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs). Here, we investigate the possible role of sEH in lipopolysaccharide (LPS)-mediated macrophage activation and acute lung injury (ALI). In this study, we found that a small molecule, wedelolactone (WED), targeted sEH and led to macrophage inactivation. Through the molecular interaction with amino acids Phe362 and Gln384, WED suppressed sEH activity to enhance levels of EETs, thus attenuating inflammation and oxidative stress by regulating glycogen synthase kinase 3beta (GSK3β)-mediated nuclear factor-kappa B (NF-κB) and nuclear factor E2-related factor 2 (Nrf2) pathways in vitro. In an LPS-stimulated ALI animal model, pharmacological sEH inhibition by WED or sEH knockout (KO) alleviated pulmonary damage, such as the increase in the alveolar wall thickness and collapse. Additionally, WED or sEH genetic KO both suppressed macrophage activation and attenuated inflammation and oxidative stress in vivo. These findings provided the broader prospects for ALI treatment by targeting sEH to alleviate inflammation and oxidative stress and suggested WED as a natural lead candidate for the development of novel synthetic sEH inhibitors.

Natural products targeting cellular processes common in Parkinson's disease and multiple sclerosis

The hallmarks of Parkinson's disease (PD) include the loss of dopaminergic neurons and formation of Lewy bodies, whereas multiple sclerosis (MS) is an autoimmune disorder with damaged myelin sheaths and axonal loss. Despite their distinct etiologies, mounting evidence in recent years suggests that neuroinflammation, oxidative stress, and infiltration of the blood-brain barrier (BBB) all play crucial roles in both diseases. It is also recognized that therapeutic advances against one neurodegenerative disorder are likely useful in targeting the other. As current drugs in clinical settings exhibit low efficacy and toxic side effects with long-term usages, the use of natural products (NPs) as treatment modalities has attracted growing attention. This mini-review summarizes the applications of natural compounds to targeting diverse cellular processes inherent in PD and MS, with the emphasis placed on their neuroprotective and immune-regulating potentials in cellular and animal models. By reviewing the many similarities between PD and MS and NPs according to their functions, it becomes evident that some NPs studied for one disease are likely repurposable for the other. A review from this perspective can provide insights into the search for and utilization of NPs in treating the similar cellular processes common in major neurodegenerative diseases.

Inhibition effect of 1-acetoxy-6α-(2-methylbutyryl)eriolanolide toward soluble epoxide hydrolase: Multispectral analysis, molecular dynamics simulation, biochemical, and in vitro cell-based studies

Soluble epoxide hydrolase (sEH) serves as a potential target in inflammation-related diseases. Based on the bioactivity-guided separation, a new sesquiterpenoid inulajaponoid A (1) was isolated from Inula japonica with a sEH inhibitory effect, together with five known compounds, such as 1-O-acetyl-6-O-isobutyrylbritannilactone (2), 6β-hydroxytomentosin (3), 1β,8β-dihydroxyeudesma-4(15),11(13)-dien-12,6α-olide (4), (4S,6S,7S,8R)-1-O-acetyl-6-O-(3-methylvaleryloxy)-britannilactone (5), and 1-acetoxy-6α-(2-methylbutyryl)eriolanolide (6). Among them, compounds 1 and 6 were assigned as mixed and uncompetitive inhibitors, respectively. The result of immunoprecipitation (IP)-MS demonstrated the specific binding of compound 6 to sEH in the complex system, which was further confirmed by the fluorescence-based binding assay showing its equilibrium dissociation constant (K_d = 2.43 μM). The detail molecular stimulation revealed the mechanism of action of compound 6 with sEH through the hydrogen bond of amino acid residue Gln384. Furthermore, this natural sEH inhibitor (6) could suppress the MAPK/NF-κB activation to regulate inflammatory mediators, such as NO, TNF-α, and IL-6, which confirmed the anti-inflammatory effect of inhibition of sEH by 6. These findings provided a useful insight to develop sEH inhibitors upon the sesquiterpenoids.

The antimicrobial peptide LK2(6)A(L) exhibits anti-inflammatory activity by binding to the myeloid differentiation 2 domain and protects against LPS-induced acute lung injury in mice

Acute lung injury (ALI) is a life-threatening disease that is generally attributable to an uncontrolled inflammatory response in the lung, but there is a lack of effective treatments. At present, regulating the inflammatory response has become an important strategy for treating ALI. In the present study, LK2(6)A(L), a peptide derived from the natural antimicrobial peptide temporin-1CEa, inhibited lipopolysaccharide (LPS)-induced expression of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and NO in RAW264.7 cells. Herein, the anti-inflammatory mechanism of LK2(6)A(L) was investigated. The RNA-sequencing (RNA-seq) results showed that LK2(6)A(L) significantly inhibited the TLR4-mediated NF-κB and MAPK signaling pathways in LPS-induced RAW264.7 cells. The results of co-immunoprecipitation (Co-IP), pull-down experiment, confocal laser scanning microscopy, and surface plasmon resonance (SPR) suggested that MD2 was the direct target of LK2(6)A(L). Chemical inhibition of MD2 and its knockdown abolished the anti-inflammatory effect of LK2(6)A(L). Molecular dynamic simulation indicated that LK2(6)A(L) could bind to the active domain of the MD2 hydrophobic pocket via six hydrogen bonds. The truncated peptides were designed based on analysis of the molecular docking of LK2(6)A(L) to MD2. The truncated peptide IS-7 showed strong affinity to MD2 and a remarkable inhibitory effect on pro-inflammatory factors that was comparable to the effect of LK2(6)A(L). Finally, LK2(6)A(L) and IS-7 relieved inflammatory symptoms and lung tissue destruction in the ALI mouse model. Overall, our study suggested that LK2(6)A(L) showed promising anti-inflammatory activity by targeting MD2, and the amino acid domain 7-13 was an important area that binds with MD2 and also an anti-inflammatory active region. LK2(6)A(L) and IS-7 may be potential new treatments for ALI and other acute inflammatory diseases.

Bacteroid Development, Transcriptome, and Symbiotic Nitrogen-Fixing Comparison of Bradyrhizobium arachidis in Nodules of Peanut (Arachis hypogaea) and Medicinal Legume Sophora flavescens

Bradyrhizobium arachidis strain CCBAU 051107 could differentiate into swollen and nonswollen bacteroids in determinate root nodules of peanut (Arachis hypogaea) and indeterminate nodules of Sophora flavescens, respectively, with different N2 fixation efficiencies. To reveal the mechanism of bacteroid differentiation and symbiosis efficiency in association with different hosts, morphologies, transcriptomes, and nitrogen fixation efficiencies of the root nodules induced by strain CCBAU 051107 on these two plants were compared. Our results indicated that the nitrogenase activity of peanut nodules was 3 times higher than that of S. flavescens nodules, demonstrating the effects of rhizobium-host interaction on symbiotic effectiveness. With transcriptome comparisons, genes involved in biological nitrogen fixation (BNF) and energy metabolism were upregulated, while those involved in DNA replication, bacterial chemotaxis, and flagellar assembly were significantly downregulated in both types of bacteroids compared with those in free-living cells. However, expression levels of genes involved in BNF, the tricarboxylic acid (TCA) cycle, the pentose phosphate pathway, hydrogenase synthesis, poly-β-hydroxybutyrate (PHB) degradation, and peptidoglycan biosynthesis were significantly greater in the swollen bacteroids of peanut than those in the nonswollen bacteroids of S. flavescens, while contrasting situations were found in expression of genes involved in urea degradation, PHB synthesis, and nitrogen assimilation. Especially higher expression of ureABEF and aspB genes in bacteroids of S. flavescens might imply that the BNF product and nitrogen transport pathway were different from those in peanut. Our study revealed the first differences in bacteroid differentiation and metabolism of these two hosts and will be helpful for us to explore higher-efficiency symbiosis between rhizobia and legumes. IMPORTANCE Rhizobial differentiation into bacteroids in leguminous nodules attracts scientists to investigate its different aspects. The development of bacteroids in the nodule of the important oil crop peanut was first investigated and compared to the status in the nodule of the extremely promiscuous medicinal legume Sophora flavescens by using just a single rhizobial strain of Bradyrhizobium arachidis, CCBAU 051107. This strain differentiates into swollen bacteroids in peanut nodules and nonswollen bacteroids in S. flavescens nodules. The N2-fixing efficiency of the peanut nodules is three times higher than that of S. flavescens. By comparing the transcriptomes of their bacteroids, we found that they have similar gene expression spectra, such as nitrogen fixation and motivity, but different spectra in terms of urease activity and peptidoglycan biosynthesis. Those altered levels of gene expression might be related to their functions and differentiation in respective nodules. Our studies provided novel insight into the rhizobial differentiation and metabolic alteration in different hosts.

Inula japonica ameliorated the inflammation and oxidative stress in LPS-induced acute lung injury through the MAPK/NF-κB and Keap1/Nrf2 signalling pathways

OBJECTIVES

To investigate the protective effect and underlying mechanism of Inula japonica (TEIJ) in the treatment of acute lung injury (ALI).

METHODS

Protective effects of TEIJ in the inflammation and oxidative stress were studied in lipopolysaccharide (LPS)-induced ALI mice. Meanwhile, Western blot and real-time qPCR were carried out to investigate the underlying mechanism of TEIJ for ALI as well as immunohistochemistry.

KEY FINDINGS

TEIJ significantly alleviated the course of ALI via suppressing the interstitial infiltrated inflammatory cells, the increase of inflammatory factors and the decrease of anti-oxidative factors. TEIJ inactivated the MAPK/NF-κB signalling pathway to suppress the transcription of its downstream target genes, such as TNF-α, IL-6, etc. Meanwhile, TEIJ activated the Keap1/Nrf2 signalling pathway to regulate expression levels of Nrf2 and its target proteins. The results of LC-QTOF-MS/MS indicated potential active constituents of I. japonica, terpenoids and flavonoids. Additionally, terpenoids and flavonoids synergistically alleviated LPS-induced ALI depending on MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

CONCLUSION

I. japonica could be considered a potential agent to treat ALI via regulating the MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

Aflatoxin B1 exposure disrupts the intestinal immune function via a soluble epoxide hydrolase-mediated manner

Aflatoxin B1 (AFB1) contamination in food and feed leads to severe global health problems. Acting as the frontier immunological barrier, the intestinal mucosa is constantly challenged by exposure to foodborne toxins such as AFB1 via contaminated diets, but the detailed toxic mechanism and endogenous regulators of AFB1 toxicity are still unclear. Here, we showed that AFB1 disrupted intestinal immune function by suppressing macrophages, especially M2 macrophages, and antimicrobial peptide-secreting Paneth cells. Using an oxylipinomics approach, we identified that AFB1 immunotoxicity is associated with decreased epoxy fatty acids, notably epoxyeicosatrienoic acids, and increased soluble epoxide hydrolase (sEH) levels in the intestine. Furthermore, sEH deficiency or inhibition rescued the AFB1-compromised intestinal immunity by restoring M2 macrophages as well as Paneth cells and their-derived lysozyme and α-defensin-3 in mice. Altogether, our study demonstrates that AFB1 exposure impairs intestinal immunity, at least in part, in a sEH-mediated way. Moreover, the present study supports the potential application of pharmacological intervention by inhibiting the sEH enzyme in alleviating intestinal immunotoxicity and associated complications caused by AFB1 global contamination.

Direct targeting of sEH with alisol B alleviated the apoptosis, inflammation, and oxidative stress in cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is a pathological condition characterized by a rapid decrease in glomerular filtration rate and nitrogenous waste accumulation during hemodynamic regulation. Alisol B, from Alisma orientale, displays anti-tumor, anti-complement, and anti-inflammatory effects. However, its effect and action mechanism on AKI is still unclear. Herein, alisol B significantly attenuated cisplatin (Cis)-induced renal tubular apoptosis through decreasing expressions levels of cleaved-caspase 3 and cleaved-PARP and the ratio of Bax/Bcl-2 depended on the p53 pathway. Alisol B also alleviated Cis-induced inflammatory response (e.g. the increase of ICAM-1, MCP-1, COX-2, iNOS, IL-6, and TNF-α) and oxidative stress (e.g. the decrease of SOD and GSH, the decrease of HO-1, GCLC, GCLM, and NQO-1) through the NF-κB and Nrf2 pathways. In a target fishing experiment, alisol B bound to soluble epoxide hydrolase (sEH) as a direct cellular target through the hydrogen bond with Gln384, which was further supported by inhibition kinetics and surface plasmon resonance (equilibrium dissociation constant, K _D = 1.32 μM). Notably, alisol B enhanced levels of epoxyeicosatrienoic acids and decreased levels of dihydroxyeicosatrienoic acids, indicating that alisol B reduced the sEH activity in vivo. In addition, sEH genetic deletion alleviated Cis-induced AKI and abolished the protective effect of alisol B in Cis-induced AKI as well. These findings indicated that alisol B targeted sEH to alleviate Cis-induced AKI via GSK3β-mediated p53, NF-κB, and Nrf2 signaling pathways and could be used as a potential therapeutic agent in the treatment of AKI.

Biotransformation of 18β-Glycyrrhetinic Acid by Human Intestinal Fungus Aspergillus niger RG13B1 and the Potential Anti-Inflammatory Mechanism of Its Metabolites

18β-Glycyrrhetinic acid (GA) is a triterpenoid possessing an anti-inflammatory activity in vivo, while the low bioavailability limits its application due to its intestinal accumulation. In order to investigate the metabolism of GA in intestinal microbes, it was incubated with human intestinal fungus Aspergillus niger RG13B1, finally leading to the isolation and identification of three new metabolites (1-3) and three known metabolites (4-6) based on 1D and 2D NMR and high-resolution electrospray ionization mass spectroscopy spectra. Metabolite 6 could target myeloid differentiation protein 2 (MD2) to suppress the activation of nuclear factor-kappa B (NF-κB) signaling pathway via inhibiting the nuclear translocation of p65 to downregulate its target proteins and genes in lipopolysaccharide (LPS)-mediated RAW264.7 cells. Molecular dynamics suggested that metabolite 6 interacted with MD2 through the hydrogen bond of amino acid residue Arg90. These findings demonstrated that metabolite 6 could serve as a potential candidate to develop the new inhibitors of MD2.

Total terpenoids of Inula japonica activated the Nrf2 receptor to alleviate the inflammation and oxidative stress in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening lung disease and characterized by pulmonary edema and atelectasis. Inula japonica Thunb. is a commonly used traditional Chinese medicine for the treatment of lung diseases. However, the potential effect and mechanism of total terpenoids of I. japonica (TTIJ) on ALI remain obscure.

PURPOSE

This study focused on the protective effect of TTIJ on lipopolysaccharide (LPS)-induced ALI in mice and its potential mechanism.

STUDY DESIGN AND METHODS

A mouse model of ALI was established by intratracheal instillation of LPS to investigate the protective effect of TTIJ. RNA-seq and bioinformatics were then performed to reveal the underlying mechanism. Finally, western blot and real-time qPCR were used to verify the effects of TTIJ on the inflammation and oxidative stress.

RESULTS

TTIJ notably attenuated LPS-induced histopathological changes of lung. The RNA-seq result suggested that the protective effect of TTIJ on LPS-induced ALI were associated with the Toll-like receptor 4 (TLR4) and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathways. Pretreatment with TTIJ significantly reduced the inflammation and oxidative stress via regulating levels of pro-inflammatory and anti-oxidative cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), superoxide dismutase (SOD), and glutathione (GSH), in LPS-induced ALI mice. TTIJ treatment could suppress the cyclooxygenase-2 (COX-2) expression level and the phosphorylation of p65, p38, ERK, and JNK through the inactivation of the MAPK/NF-κB signaling pathway in a TLR4-independent manner. Meanwhile, TTIJ treatment upregulated expression levels of proteins involved in the Nrf2 signaling pathway, such as heme oxygenase-1 (HO-1), NAD(P)H: quinoneoxidoreductase-1 (NQO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM), via activating the Nrf2 receptor, which was confirmed by the luciferase assay.

CONCLUSION

TTIJ could activate the Nrf2 receptor to alleviate the inflammatory response and oxidative stress in LPS-induced ALI mice, which suggested that TTIJ could serve as the potential agent in the treatment of ALI.

Total flavonoids of Inula japonica alleviated the inflammatory response and oxidative stress in LPS-induced acute lung injury via inhibiting the sEH activity: Insights from lipid metabolomics

BACKGROUND

Acute lung injury (ALI) is a severe respiratory disease characterized by diffuse lung interstitial and respiratory distress and pulmonary edema with a mortality rate of 35%-40%. Inula japonica Thunb., known as "Xuan Fu Hua" in Chinese, is a traditional Chinese medicine Inulae Flos to use for relieving cough, eliminating expectorant, and preventing bacterial infections in the clinic, and possesses an anti-pulmonary fibrosis effect. However, the effect and action mechanism of I. japonica on ALI is still unclear.

PURPOSE

This study aimed to investigate the protective effect and underlying mechanism of total flavonoids of I. japonica (TFIJ) in the treatment of ALI.

STUDY DESIGN AND METHODS

A mouse ALI model was established through administration of LPS by the intratracheal instillation. Protective effects of TFIJ in the inflammation and oxidative stress were studied in LPS-induced ALI mice based on inflammatory and oxidative stress factors, including MDA, MPO, SOD, and TNF-α. Lipid metabolomics, bioinformatics, Western blot, quantitative real-time PCR, and immunohistochemistry were performed to reveal the potential mechanism of TFIJ in the treatment of ALI.

RESULTS

TFIJ significantly alleviated the interstitial infiltration of inflammatory cells and the collapse of the alveoli in LPS-induced ALI mice. Lipid metabolomics demonstrated that TFIJ could significantly affect the CYP2J/sEH-mediated arachidonic acid metabolism, such as 11,12-EET, 14,15-EET, 8,9-DHET, 11,12-DHET, and 14,15-DHET, revealing that sEH was the potential target of TFIJ, which was further supported by the recombinant sEH-mediated the substrate hydrolysis in vitro (IC₅₀ = 1.18 μg/ml). Inhibition of sEH by TFIJ alleviated the inflammatory response and oxidative stress via the MAPK, NF-κB, and Nrf2 signaling pathways.

CONCLUSION

These results demonstrated that TFIJ could suppress the sEH activity to stabilize the level of EETs, allowing the alleviation of the pathological course of lung injury in LPS-treated mice, which suggested that TFIJ could serve as the potential agents in the treatment of ALI.

Kurarinone alleviates hemin-induced neuroinflammation and microglia-mediated neurotoxicity by shifting microglial M1/M2 polarization via regulating the IGF1/PI3K/Akt signaling

Cerebral hemorrhage is a fatal disease that causes severe damage to local nerve function. The purpose of this research is to analyze the effect of kurarinone on hemin-induced neuroinflammation and neurotoxicity. In our study, according to the results of bioinformatics analysis, we hypothesized that kurarinone might modulate cerebral hemorrhage advancement via the insulin-like growth factor 1/phosphoinositide 3-kinase/protein kinase B (IGF1/PI3K/Akt) signaling. Kurarinone promoted M2 microglia polarization, and curbed M1 polarization and inflammation in human microglial cells (HMC3) cells with hemin treatment. Besides, kurarinone upregulated IGF1 expression and activated the PI3K/Akt signaling pathway in hemin-treated HMC3 cells. In addition, downregulation of IGF1 or inhibition of the PI3K/Akt signaling weakened the effects of kurarinone on microglia polarization and inflammation in HMC3 cells with hemin treatment. Kurarinone alleviated apoptosis and oxidative damage of SH-SY5Y cells co-cultured with hemin-treated HMC3 cells. In conclusion, kurarinone lessened hemin-induced neuroinflammation and microglia-mediated neurotoxicity by regulating microglial polarization through modulating the IGF1/PI3K/Akt signaling. These results delivered a new prospective therapeutic drug for the treatment of cerebral hemorrhage.

Quercetin Protects against MPP+/MPTP-Induced Dopaminergic Neuron Death in Parkinson’s Disease by Inhibiting Ferroptosis

Ferroptosis, a novel form of regulated cell death, is caused by accumulation of lipid peroxides and excessive iron deposition. This process has been linked to the death of dopaminergic neurons in substantia nigra compacta (SNc) of Parkinson's disease (PD) patients. Quercetin (QCT), a natural flavonoid, has multiple pharmacological activities. However, it has not been established whether QCT can protect against dopaminergic neuron death by inhibiting ferroptosis. In this study, we investigated the potential antiferroptotic effects of QCT in cellular models established using specific ferroptosis inducers (Erastin and RSL-3) and MPP⁺. The effects were also explored using MPTP-induced PD mouse models. The cell counting kit-8 (CCK-8) assay was performed to assess cell viability. Variations in mitochondrial morphology were evaluated by transmission electron microscopy (TEM) while the mitochondrial membrane potential, mass, and ROS were measured by fluorescent probes. Lipid peroxidation levels were assayed through measurement of lipid ROS, MDA, GSH, and SOD levels. The effects of QCT on MPTP-induced behavioral disorders were examined by rotarod and open field tests. In vitro and in vivo, QCT significantly inhibited ferroptosis by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) protein. Additionally, QCT ameliorated motor behavioral impairments and protected against the loss of dopaminergic neurons in MPTP-induced PD models. Interestingly, Nrf2 knockdown alleviated the protective effects of QCT against ferroptosis. In conclusion, these results demonstrate that ferroptosis is involved in MPP⁺/MPTP-induced PD, and QCT inhibits ferroptosis by activating the Nrf2 protein. Therefore, QCT is a potential agent for preventing the loss of dopaminergic neurons by targeting ferroptosis.

Evidence for Oxidative Pathways in the Pathogenesis of PD: Are Antioxidants Candidate Drugs to Ameliorate Disease Progression?

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that arises due to a complex and variable interplay between elements including age, genetic, and environmental risk factors that manifest as the loss of dopaminergic neurons. Contemporary treatments for PD do not prevent or reverse the extent of neurodegeneration that is characteristic of this disorder and accordingly, there is a strong need to develop new approaches which address the underlying disease process and provide benefit to patients with this debilitating disorder. Mitochondrial dysfunction, oxidative damage, and inflammation have been implicated as pathophysiological mechanisms underlying the selective loss of dopaminergic neurons seen in PD. However, results of studies aiming to inhibit these pathways have shown variable success, and outcomes from large-scale clinical trials are not available or report varying success for the interventions studied. Overall, the available data suggest that further development and testing of novel therapies are required to identify new potential therapies for combating PD. Herein, this review reports on the most recent development of antioxidant and anti-inflammatory approaches that have shown positive benefit in cell and animal models of disease with a focus on supplementation with natural product therapies and selected synthetic drugs.

Soluble Epoxide Hydrolase as a Therapeutic Target for Neuropsychiatric Disorders

It has been found that soluble epoxide hydrolase (sEH; encoded by the EPHX2 gene) in the metabolism of polyunsaturated fatty acids (PUFAs) plays a key role in inflammation, which, in turn, plays a part in the pathogenesis of neuropsychiatric disorders. Meanwhile, epoxy fatty acids such as epoxyeicosatrienoic acids (EETs), epoxyeicosatetraenoic acids (EEQs), and epoxyeicosapentaenoic acids (EDPs) have been found to exert neuroprotective effects in animal models of neuropsychiatric disorders through potent anti-inflammatory actions. Soluble expoxide hydrolase, an enzyme present in all living organisms, metabolizes epoxy fatty acids into the corresponding dihydroxy fatty acids, which are less active than the precursors. In this regard, preclinical findings using sEH inhibitors or Ephx2 knock-out (KO) mice have indicated that the inhibition or deficiency of sEH can have beneficial effects in several models of neuropsychiatric disorders. Thus, this review discusses the current findings of the role of sEH in neuropsychiatric disorders, including depression, autism spectrum disorder (ASD), schizophrenia, Parkinson’s disease (PD), and stroke, as well as the potential mechanisms underlying the therapeutic effects of sEH inhibitors.

Unprecedented diterpenoid dimers with soluble epoxide hydrolase inhibitory effect from Euphorbia fischeriana

Biseuphoids A (1) and B (2), two unprecedented ent-abietane-type diterpenoid dimers linked by monomeric blocks through C-17-C-12' and C-17-C-11', respectively, were isolated from Euphorbia fischeriana, along with their biogenesis related diterpenoid monomers, 17-hydroxyjolkinolide B (3), caudicifolin (4), and fischeriabietane C (5). Their structures were elucidated by extensive spectroscopy assisted by quantum chemical NMR and ECD calculations. The unusual dimeric skeletons are possibly derived from the adduct of diterpenoid monomers through Michael-like reactions. The novel dimers 1 and 2 exhibited inhibitory activities on soluble epoxide hydrolase (sEH) with IC₅₀ values of 8.17 and 5.61 μM, respectively. Molecular dynamics studies illustrated that both 1 and 2 can occupy the catalytic pocket of sEH by forming stable hydrogen bonds with the key amino acid residues including Gln384, Asn378, Pro361, Ala365, Asn366, and Asn472.