Quercetin alleviates atherosclerosis by suppressing oxidized LDL-induced senescence in plaque macrophage via inhibiting the p38MAPK/p16 pathway

Exploring the molecular mechanism of Epimedium for the treatment of ankylosing spondylitis based on network pharmacology, molecular docking, and molecular dynamics simulations

Ankylosing spondylitis (AS) is a rheumatic disease that causes inflammation and bone formation in the spine. Despite significant advances in treatment, adverse side effects have triggered research into natural compounds. Epimedium (EP) is a traditional Chinese herb with a variety of pharmacological activities, including antirheumatic, anti-inflammatory, and immunomodulatory activities; however, its direct effects on AS treatment and the underlying molecular mechanisms have not been systematically studied. Thus, here, we used network pharmacology, molecular docking, and molecular dynamics simulations to explore the targets of EP for treating AS. We constructed an interaction network to elucidate the complex relationship between EP and AS. Sixteen active ingredients in EP were screened; 80 potential targets were identified. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone, anhydroicaritin, and luteolin were the core components and TNF, IL-6, IL-1β, MMP9, and PTGS2 were the core targets. The GO and KEGG analyses indicated that EP may modulate multiple biological processes and pathways, including the AGE-RAGE, TNF, NF-κB/MAPK, and TLR signaling pathways, for AS treatment. Molecular docking and molecular dynamics simulations showed good affinity between the active components and core targets of EP, with stable binding within 100 nanoseconds. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone possessed the highest free energy of binding to PTGS2 and TNF (-115.575 and - 87.676 kcal/mol, respectively). Thus, EP may affect AS through multiple pathways, including the alleviation of inflammation, oxidative stress, and immune responses. In summary, we identified the active components and potential targets of EP, highlighting new strategies for the further experimental validation and exploration of lead compounds for treating AS.

An ethanolic extract of Arctium lappa L. leaves ameliorates experimental atherosclerosis by modulating lipid metabolism and inflammatory responses through PI3K/Akt and NF-κB singnaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS), a lipid-induced inflammatory condition of the arteries, is a primary contributor to atherosclerotic cardiovascular diseases including stroke. Arctium lappa L. leaf (ALL), an edible and medicinal herb in China, has been documented and commonly used for treating stroke since the ancient times. However, the elucidations on its anti-AS effects and molecular mechanism remain insufficient.

AIM OF THE STUDY

To investigate the AS-ameliorating effects and the underlying mechanism of action of an ethanolic extract of leaves of Arctium lappa L. (ALLE).

MATERIALS AND METHODS

ALLE was reflux extracted using with 70% ethanol. An HPLC method was established to monitor the quality of ALLE. High fat diet (HFD) and vitamin D3-induced experimental AS in rats were used to determine the in vivo effects; and oxidized low-density lipoprotein-induced RAW264.7 macrophage foam cells were used for in vitro assays. Simvatatin was used as positive control. Biochemical assays were implemented to ascertain the secretions of lipids and pro-inflammatory mediators. Haematoxylin-eosin (H&E) and Oil red O stains were employed to assess histopathological alterations and lipid accumulation conditions, respectively. CCK-8 assays were used to measure cytotoxicity. Immunoblotting assay was conducted to measure protein levels.

RESULTS

ALLE treatment significantly ameliorated lipid deposition and histological abnormalities of aortas and livers in AS rats; improved the imbalances of serum lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C); notably attenuated serum concentrations of inflammation-associated cytokines/molecules including TNF-α, IL-6, IL-1β, VCAM-1, ICAM-1and MMP-9. Mechanistic studies demonstrated that ALLE suppressed the phosphorylation/activation of PI3K, Akt and NF-κB in AS rat aortas and in cultured foam cells. Additionally, the PI3K agonist 740Y-P notably reversed the in vitro inhibitory effects of ALLE on lipid deposition, productions of TC, TNF-α and IL-6, and protein levels of molecules of PI3K/Akt and NF-κB singnaling pathways.

CONCLUSIONS

ALLE ameliorates HFD- and vitamin D3-induced experimental AS by modulating lipid metabolism and inflammatory responses, and underlying mechanisms involves inhibition of the PI3K/Akt and NF-κB singnaling pathways. The findings of this study provide scientific justifications for the traditional application of ALL in managing atherosclerotic diseases.

Untargeted metabolomics reveals the regulatory effect of geniposidic acid on lipid accumulation in HepG2 cells and Caenorhabditis elegans and validation in hyperlipidemic hamsters

BACKGROUND

Geniposidic acid (GPA) alleviates oxidative stress and inflammation in mice However, whether it can effectively regulate lipid accumulation and prevent hyperlipidemia requires further investigation.

PURPOSE

This study combined the untargeted metabolomics of cells and a Caenorhabditis elegans model to evaluate the anti-hyperlipidemic potential of GPA by modulating oxidative stress and regulating lipid metabolism. A golden hamster model of hyperlipidemia was used to further validate the lipid-lowering effect and mechanism of action of GPA.

METHODS

Chemical staining, immunofluorescence, and flow cytometry were performed to examine the effects of GPA on lipid accumulation and oxidative stress. Untargeted metabolomic analysis of cells and C. elegans was performed using ultra-performance liquid chromatography coupled with quadrupole electrostatic field Orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap MS) to identify biomarkers altered by GPA action, analyze the affected metabolic pathways, and validate the mechanisms by which GPA regulates lipid metabolism and oxidative stress. A golden hamster model of hyperlipidemia was established to test the lipid-lowering effects of GPA. Body weight, biochemical markers, rate-limiting enzymes, and key proteins were assessed. Hematoxylin and eosin (H&E) and Oil Red O staining were performed.

RESULTS

Phenotypic data showed that GPA decreased free fatty acid (FFA)-induced lipid buildup and high reactive oxygen species (ROS) levels, reversed the decrease in mitochondrial membrane potential (MMP), and increased the cellular reduced glutathione/oxidized glutathione disulfide (GSH/GSSG) ratio. GPA also reduces high glucose-induced lipid build-up and ROS production in C. elegans. Metabolomic analysis showed that GPA affected purine, lipid, and amino acid metabolism. Moreover, GPA inhibited xanthine oxidase (XOD), glutamate dehydrogenase (GLDH), fatty acid synthase (FAS), phosphorylation of P38 MAPK, and upregulated the expression of SIRT3 and CPT1A protein production to control lipid metabolism and produce antioxidant benefits in cells and golden hamsters.

CONCLUSION

Current evidence suggests that GPA can effectively regulate lipid metabolism and the oxidative stress response, and has the potential to prevent hyperlipidemia. This study also provided an effective method for evaluating the mechanism of action of GPA.

Quercetin Attenuates Atherosclerosis via Modulating Apelin Signaling Pathway Based on Plasma Metabolomics

OBJECTIVE

To interpret the pharmacology of quercetin in treatment of atherosclerosis (AS).

METHODS

Fourteen apolipoprotein E-deficient (ApoE-/-) mice were divided into 2 groups by a random number table: an AS model (ApoE-/-) group and a quercetin treatment group (7 in each). Seven age-matched C57 mice were used as controls (n=7). Quercetin [20 mg/(kg·d)] was administered to the quercetin group intragastrically for 8 weeks for pharmacodynamic evaluation. Besides morphological observation, the distribution of CD11b, F4/80, sirtuin 1 (Sirt1) and P21 was assayed by immunohistochemistry and immunofluorescence to evaluate macrophage infiltration and tissue senescence. Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MSC/MS) was performed to study the pharmacology of quercetin against AS. Then, simultaneous administration of an apelin receptor antagonist (ML221) with quercetin was conducted to verify the possible targets of quercetin. Key proteins in apelin signaling pathway, such as angiotensin domain type 1 receptor-associated proteins (APJ), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), tissue plasminogen activator (TPA), uncoupling protein 1 (UCP1) and angiotensin II receptor 1 (AT1R), were assayed by Western blot.

RESULTS

Quercetin administration decreased lipid deposition in arterial lumen and improved the morphology of ApoE-/- aortas in vivo. Quercetin decreased the densities of CD11b, F4/80 and P21 in the aorta and increased the level of serum apelin and the densities of APJ and Sirt1 in the aorta in ApoE-/- mice (all P<0.05). Plasma metabolite profiling identified 118 differential metabolites and showed that quercetin affected mainly glycerophospholipids and fatty acyls. Bioinformatics analysis suggested that the apelin signaling pathway was one of the main pathways. Quercetin treatment increased the protein expressions of APJ, AMPK, PGC-1α, TPA and UCP1, while decreased the AT1R level (all P<0.05). After the apelin pathway was blocked by ML221, the effect of quercetin was abated significantly, confirming that quercetin attenuated AS by modulating the apelin signaling pathway (all P<0.05).

CONCLUSION

Quercetin alleviated AS lesions by up-regulation the apelin signaling pathway.

High-Throughput Phytochemical Unscrambling of Flowers Originating from Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) P. K. Hsiao and Astragalus membranaceus (Fisch.) Bug. by Applying the Intagretive Plant Metabolomics Method Using UHPLC-Q-TOF-MS/MS

Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) P. K. Hsiao (MO) and Astragalus membranaceus (Fisch.) Bug. (ME) are two primary sources of the Astragalus herb, also known as "Huangqi" in China, which is widely applied to treat hypertension, glomerulonephritis, ischemic heart disease, and diabetes mellitus. As two different sources of the Astragalus herb, the chemical profiles of MO and ME may be different. Previous studies showed abundant differences in chemical composition between MO and ME. Therefore, the by-products of MO and ME, such as Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) P. K. Hsiao flower (MOF) and Astragalus membranaceus (Fisch.) Bug. flower (MEF), may have different phytochemical profiles. In this paper, a metabolomics method combined with ultra-high-performance liquid chromatography and electrospray ionization/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was employed to analyze the components of MOF and MEF. Consequently, the results of principal component analysis (PCA) showed that MOF and MEF could be separated clearly. In total, 31 chemical markers differentiating MOF and MEF were successfully identified, including 22 flavonoids, 8 isoflavones and 1 benzopyran. Among them, the contents of 18 components, including Calycosin, Cyanidin-3-O-glucoside, Quercetin, Rutin, Kaempferol, Formononetin, Isomucronulatol and Prim-O-glucosylcimifugin in MEF, were significantly higher than in MOF. In turn, the contents of another 13 components, covering Biochanin A, Tectoridin, Isomucronulatol-7-O-glucoside, Liquiritin, Rhamnetin, etc., were lower in the MEF group than that in the MOF group. It is worth noting that flavonoids, especially flavonoid glycosides, were the primary active chemical ingredients in MOF and MEF. The 18 ingredients in MEF with a higher level carried out diverse activities, like anti-oxidant, anti-inflammatory, anti-bacterial and anti-tumor activities, which led us to speculate that MEF may have greater pharmacological effects and potential development prospects than MOF. The present results displayed that the contents of ingredients in the two different species of plants were radically different, and there was significant uniqueness to the components of MOF and MEF. Our study not only provides helpful chemical information for further quality assessment and active mechanism research of MOF and MEF but also offers scientific support for the resource utilization of MOF and MEF.

Regulation of Acetylation States by Nutrients in the Inhibition of Vascular Inflammation and Atherosclerosis

Atherosclerosis (AS) is a chronic metabolic disorder and primary cause of cardiovascular diseases, resulting in substantial morbidity and mortality worldwide. Initiated by endothelial cell stimulation, AS is characterized by arterial inflammation, lipid deposition, foam cell formation, and plaque development. Nutrients such as carotenoids, polyphenols, and vitamins can prevent the atherosclerotic process by modulating inflammation and metabolic disorders through the regulation of gene acetylation states mediated with histone deacetylases (HDACs). Nutrients can regulate AS-related epigenetic states via sirtuins (SIRTs) activation, specifically SIRT1 and SIRT3. Nutrient-driven alterations in the redox state and gene modulation in AS progression are linked to their protein deacetylating, anti-inflammatory, and antioxidant properties. Nutrients can also inhibit advanced oxidation protein product formation, reducing arterial intima-media thickness epigenetically. Nonetheless, knowledge gaps remain when it comes to understanding effective AS prevention through epigenetic regulation by nutrients. This work reviews and confirms the underlying mechanisms by which nutrients prevent arterial inflammation and AS, focusing on the epigenetic pathways that modify histones and non-histone proteins by regulating redox and acetylation states through HDACs such as SIRTs. These findings may serve as a foundation for developing potential therapeutic agents to prevent AS and cardiovascular diseases by employing nutrients based on epigenetic regulation.