Artemisinin inhibits monocyte adhesion to HUVECs through the NF-κB and MAPK pathways in vitro

Artemisinin and Its Derivatives: Promising Therapeutic Agents for Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in older adults. Its pathogenesis involves multiple factors, including aging, environmental influences, genetic predisposition, oxidative stress, metabolic dysfunction, and immune dysregulation. Currently, AMD treatment focuses primarily on wet AMD, managed through repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) therapies. While anti-VEGF agents represent a major breakthrough in wet AMD care, repeated injections may lead to incomplete responses or resistance in some patients, and carry a risk of progressive fibrosis. Artemisinin (ART) and its derivatives, originally developed as antimalarial drugs, exhibit a broad spectrum of pleiotropic activities beyond their established use, including anti-inflammatory, anti-angiogenic, antioxidant, anti-fibrotic, mitochondrial regulatory, lipid metabolic, and immunosuppressive effects. These properties position ART as a promising therapeutic candidate for AMD. A growing interest in ART-based therapies for AMD has emerged in recent years, with numerous studies demonstrating their potential benefits. However, no comprehensive review has systematically summarized the specific roles of ART and its derivatives in AMD pathogenesis and treatment. This paper aims to fill the knowledge gap by synthesizing the therapeutic efficacy and molecular mechanisms of ART and its derivatives in AMD, thereby providing a foundation for future investigations.

New Roles of Artemisinins in Atherosclerosis Progression

Artemisinin is a natural compound derived from the Chinese plant Artemisia annua , which was officially approved by the FDA for its antimalarial effects. In recent years, a growing body of studies has shown the novel function of artemisinin in atherosclerosis therapy. In vivo studies have shown that artemisinin can inhibit the progression of atherosclerosis plaque. In the present review, the evidence showing the inhibitory effects of artemisinin on the progression of atherosclerosis plaque and its underlying mechanisms is discussed. Mechanistically, artemisinin and its derivatives act by modulating various atherosclerosis-mediating risk factors, including hyperlipidemia, inflammation, oxidative stress, and malfunctioning vascular smooth muscle cells (VSMCs). Notably, artesunate, but not artemisinin, can attenuate the plasma levels of TG, TC, VLDL-C, and LDL-c, along with a substantial decline in arterial lipid deposition through enhancing the LDPL activity via inducing the KFL2/NRF2/TCF7L2 axis. Artemisinin was found to ameliorate the atherosclerosis plaque inflammation by reducing monocyte adhesion and subsequent transmigration to the intima, via inhibiting the expression of ICAM-1 and VCAM-1, diminishing NLRP3 inflammasome activation, and reducing the expression of inflammatory factors such as IL-1β, IL-18, TNF-α, MCP-1, and TGF-β1 mechanistically and mainly via suppressing the by NF-κB activity. Artemisinin could exert antioxidant effects through activating the PI3K/Akt/eNOS signaling pathway and suppressing the ROS-mediated NF-κB signal pathway. Artemisinin could also improve the VSMC function in the atherosclerosis plaque. These findings can suggest artemisinin as a new therapeutic agent for treating atherosclerosis; however, future clinical trials are warranted to validate its therapeutic efficiency in patients with atherosclerosis.

Adenohypophysis-Inducible Sex Hormones Correlate with Interleukin-6, -8, and Tumor Necrosis Factor-α in Patients with Systemic Lupus Erythematosus

Adenohypophysis-inducible sex hormones include prolactin (PRL), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). These hormones influence the occurrence of lupus erythematosus by affecting the endocrine and immune systems. The present study analyzed the relationship between serum sex hormones and several cytokines in patients with systemic lupus erythematosus (SLE). Compared with the healthy controls, early-onset SLE female patients with menopause had higher PRL levels than the healthy controls and cutaneous lupus erythematosus (CLE) group. FSH levels were higher in male patients with SLE than in the healthy controls or CLE group. In SLE patients, the estradiol levels correlated negatively with interleukin (IL)-8. The levels of FSH versus IL-8, PRL versus IL-6, PRL versus tumor necrosis factor (TNF)-α, and LH versus IL-8 levels were moderately positively correlated. In conclusion, PRL, FSH, and LH are positively associated with IL-6, IL-8, and TNF-α in the sera from SLE patients, which indicates that sex hormone levels can serve as an indicator of disease activity during SLE diagnosis.

Recruitment of neutrophils in glomeruli in early mouse sepsis is associated with E-selectin expression and activation of endothelial nuclear factor kappa-light-chain-enhancer of activated B cells and mitogen-activated protein kinase pathways

Sepsis is a dysregulated systemic inflammatory response to an infection, which can lead to multiple organ dysfunction syndrome that includes the kidney. Leukocyte recruitment is an important process of the host immune defense in response to sepsis. Endothelial cells (EC) actively regulate leukocyte recruitment by expressing adhesion molecules following the activation of dedicated intracellular signal transduction pathways. Previous studies reported that the expression of adhesion molecules was associated with the activation of endothelial nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 and mitogen-activated protein kinase (MAPK) c-Jun pathways in vitro in response to conditions that mimic processes that occur in inflammation. This study aimed to investigate the spatiotemporal patterns of leukocyte recruitment, expression of adhesion molecules, and endothelial nuclear p65 and c-Jun localization in renal microvascular beds of septic mice. Here, we used a cecal ligation and puncture (CLP) sepsis mouse model and RT-qPCR and immunohistochemical staining. We showed that neutrophils, macrophages, and T lymphocytes were all present in the kidney, yet only neutrophils accumulated in a spatiotemporally discernible pattern, mainly in glomeruli at 4 h after CLP sepsis initiation. E-selectin, not vascular cell adhesion molecule-1 (VCAM-1), was expressed in glomeruli at the same time point. In a subset of mice at 72 h after CLP sepsis started, VCAM-1 expression was prominent in glomerular EC, which was not related to changes in mmu-microRNA(miR)-126a-3p levels, a short noncoding microRNA previously shown to inhibit the translation of VCAM-1 mRNA into protein. Nuclear localization of p65 and c-Jun occurred in EC of all microvascular segments at 4 and 7 h after CLP sepsis initiation. In summary, sepsis-induced recruitment of neutrophils, E-selectin expression, and NF-κB p65 and MAPK c-Jun pathway activation coincided in glomeruli at the early stage of the disease. In the other microvascular beds, sepsis led to NF-κB p65 and MAPK c-Jun pathway activation with limited expression of E-selectin and no association with VCAM-1 expression or leukocyte recruitment.

Acer tegmentosum Maxim and Bacillus subtilis-fermented products inhibit TNF-α-induced endothelial inflammation and vascular dysfunction of the retina: the role of tyrosol moiety in active compounds targeting Glu230 in SIRT1

Acer tegmentosum Maxim (AT) is a medicinal plant used to treat hepatic, neurological diseases, and cancer. However, the beneficial effects of AT on endothelial dysfunction have not been reported yet. In this study, we evaluated the effects of AT and the main compounds against TNF-α-mediated inflammatory responses and their possible mechanism of action. The anti-inflammatory effect and its molecular mechanism were analyzed by adhesion assay, immunoblotting, promoter-luciferase assay, ELISA, RT-PCR, immunocytochemistry, immunoprecipitation, siRNA gene knockdown, docking, and molecular dynamics simulation. AT and its compounds salidroside and tyrosol reduced TNF-α-induced adhesion between monocytes and endothelial cells. Fermentation of AT with Bacillus subtilis converted salidroside to tyrosol, which is salidroside's aglycone. The fermented AT product (ATF) potently inhibited TNF-α-mediated monocyte adhesion with higher potency than AT. AT or ATF abrogated TNF-α-induced expression of adhesion molecules (VCAM-1 and ICAM-1) and production of MCP-1 with the inhibition of phosphorylated MAP kinases. TNF-α-mediated NF-κB transactivation and RelA/p65 acetylation were suppressed by AT and ATF through the interaction of NF-κB with sirtuin-1 (SIRT1), an NAD+-dependent histone deacetylase. Sirt1 gene knockdown diminished the protective effects of AT and ATF against TNF-α-mediated signaling and inflammatory response. Interestingly, SIRT1 protein expression was significantly increased by ATF and tyrosol rather than by AT and salidroside, respectively. Molecular docking showed that the tyrosol moiety is critical for the interaction with Glu230 of SIRT1 (PDB ID: 4ZZH and 4ZZJ) for the deacetylase activity. Molecular dynamics revealed that tyrosol can induce the movement of the N-terminal domain toward the catalytic domain of SIRT1. This study demonstrates the potential of AT and ATF to prevent endothelial inflammation and vascular dysfunction of the retina by the MAPK/NF-κB/SIRT1 signaling pathways and targeting of the tyrosol moiety to Glu230 in SIRT1.

Curcumin potentiates the anti-inflammatory effects of Tehranolide by modulating the STAT3/NF-κB signaling pathway in breast and ovarian cancer cell lines

BACKGROUND

Studies have demonstrated that natural products, such as curcumin and artemisinin, possess anti-inflammatory effects, which can be beneficial for cancer treatment. Tehranolide, as a novel natural product, has a wide range of biological activities, including anti-cancer effects. However, many properties of Tehranolide, like its anti-inflammatory activity and its combination with curcumin, have not been investigated yet. This investigation examined the anti-inflammatory activity of Tehranolide, either alone or in combination with curcumin, via modulating the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and STAT3 (signal transducer and activator of transcription 3) signaling pathways in MDA-MB-231 and SKOV3, breast and ovarian cancer cell lines.

METHODS

ELISA-based methods were employed to measure the pro-inflammatory cytokine levels and the NF-κB activity in lipopolysaccharide (LPS)-induced cells. The real-time PCR experiment and Griess test were performed to evaluate inducible nitric oxide synthase (iNOS) gene expression and nitrite levels, respectively. The STAT3 and NF-κB signaling pathways were investigated by Western blotting analysis. Tehranolide's anti-cancer activity was also assessed in a mouse model of breast cancer using the TUNEL (terminal deoxynucleotidyl transferase nick-end labeling) assay.

RESULTS

Tehranolide diminished levels of pro-inflammatory cytokines in cancer cells. Additionally, it suppressed NF-κB DNA binding and STAT3 phosphorylation, reducing iNOS gene expression and nitrite production. Moreover, Western blotting showed that Tehranolide enhanced the inhibitory κB (IκBα) and Bcl-2 (B-cell lymphoma 2)-associated X (BAX) expression, and downregulated the expression of Bcl-2 proteins. Furthermore, the TUNEL assay demonstrated that Tehranolide induced apoptosis in a breast cancer mouse model. Curcumin potentiated all the anti-inflammatory effects of Tehranolide.

CONCLUSION

This investigation indicated for the first time that Tehranolide, either alone or in combination with curcumin, exerted its anti-inflammatory effects by suppressing NF-κB and STAT3 signaling pathways in SKOV3 and MDA-MB-231 cells.

Medicinal and mechanistic overview of artemisinin in the treatment of human diseases

Artemisinin (ART) is a bioactive compound isolated from the plant Artemisia annua and has been traditionally used to treat conditions such as malaria, cancer, viral infections, bacterial infections, and some cardiovascular diseases, especially in Asia, North America, Europe and other parts of the world. This comprehensive review aims to update the biomedical potential of ART and its derivatives for treating human diseases highlighting its pharmacokinetic and pharmacological properties based on the results of experimental pharmacological studies in vitro and in vivo. Cellular and molecular mechanisms of action, tested doses and toxic effects of artemisinin were also described. The analysis of data based on an up-to-date literature search showed that ART and its derivatives display anticancer effects along with a wide range of pharmacological activities such as antibacterial, antiviral, antimalarial, antioxidant and cardioprotective effects. These compounds have great potential for discovering new drugs used as adjunctive therapies in cancer and various other diseases. Detailed translational and experimental studies are however needed to fully understand the pharmacological effects of these compounds.

Molecular insights into artemisinin resistance in Plasmodium falciparum: An updated review

Malaria still poses a major burden on human health around the world, especially in endemic areas. Plasmodium resistance to several antimalarial drugs has been one of the major hindrances in control of malaria. Thus, the World Health Organization recommended artemisinin-based combination therapy (ACT) as a front-line treatment for malaria. The emergence of parasites resistant to artemisinin, along with resistant to ACT partner drugs, has led to ACT treatment failure. The artemisinin resistance is mostly related to the mutations in the propeller domain of the kelch13 (k13) gene that encodes protein Kelch13 (K13). The K13 protein has an important role in parasite reaction to oxidative stress. The most widely spread mutation in K13, with the highest degree of resistance, is a C580Y mutation. Other mutations, which are already identified as markers of artemisinin resistance, are R539T, I543T, and Y493H. The objective of this review is to provide current molecular insights into artemisinin resistance in Plasmodium falciparum. The trending use of artemisinin beyond its antimalarial effect is described. Immediate challenges and future research directions are discussed. Better understanding of the molecular mechanisms underlying artemisinin resistance will accelerate implementation of scientific findings to solve problems with malarial infection.

Human IL-32θA94V mutant attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 via binding to cell surface receptor integrin αVβ3 and αVβ6 in TNF-α-stimulated HUVECs

Interleukin-32 (IL-32), first reported in 2005, and its isoforms have been the subject of numerous studies investigating their functions in virus infection, cancer, and inflammation. IL-32θ, one of the IL-32 isoforms, has been shown to modulate cancer development and inflammatory responses. A recent study identified an IL-32θ mutant with a cytosine to thymine replacement at position 281 in breast cancer tissues. It means that alanine was also replaced to valine at position 94 in amino acid sequence (A94V). In this study, we investigated the cell surface receptors of IL-32θA94V and evaluated their effect on human umbilical vein endothelial cells (HUVECs). Recombinant human IL-32θA94V was expressed, isolated, and purified using Ni-NTA and IL-32 mAb (KU32-52)-coupled agarose columns. We observed that IL-32θA94V could bind to the integrins αVβ3 and αVβ6, suggesting that integrins act as cell surface receptors for IL-32θA94V. IL-32θA94V significantly attenuated monocyte-endothelial adhesion by inhibiting the expression of Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor (TNF)-α-stimulated HUVECs. IL-32θA94V also reduced the TNF-α-induced phosphorylation of protein kinase B (AKT) and c-jun N-terminal kinases (JNK) by inhibiting phosphorylation of focal adhesion kinase (FAK). Additionally, IL-32θA94V regulated the nuclear translocation of nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which are involved in ICAM-1 and VCAM-1 expression. Monocyte-endothelial adhesion mediated by ICAM-1 and VCAM-1 is an important early step in atherosclerosis, which is a major cause of cardiovascular disease. Our findings suggest that IL-32θA94V binds to the cell surface receptors, integrins αVβ3 and αVβ6, and attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 in TNF-α-stimulated HUVECs. These results demonstrate that IL-32θA94V can act as an anti-inflammatory cytokine in a chronic inflammatory disease such as atherosclerosis.

Establishment and application of a high-throughput screening model for cell adhesion inhibitors

The cell adhesion between leukocytes and endothelial cells plays an important balanced role in the pathophysiological function, while excessive adhesion caused by etiological agents is associated with the occurrence and development of many acute and chronic diseases. Cell adhesion inhibitors have been shown to have a potential therapeutic effect on these diseases, therefore, efficient and specific inhibitors against cell adhesion are highly desirable. Here, using lipopolysaccharide-induced human umbilical vein endothelial cells (HUVECs) and calcein-AM-labeled human monocytic cell THP-1, we established a high-throughput screening model for cell adhesion inhibitors with excellent model evaluation parameters. Using the drug repurposing strategy, we screened out lifitegrast, a potent cell adhesion inhibitor, which inhibited cell adhesion between HUVEC and THP-1 cells by directly interrupting the adhesion interaction between HUVEC and THP-1 cells and showed a strong therapeutic effect on the mouse acute liver injury induced by poly (I:C)/D-GalN. Therefore, the screening model is suitable for screening and validating cell adhesion inhibitors, which will promote the research and development of inhibitors for the treatment of diseases caused by excessive cell adhesion.

Protective effects of rivaroxaban against cisplatin-induced testicular damage in rats: Impact on oxidative stress, coagulation, and p-NF-κB/VCAM-1 signaling

Coagulation is a main pathway in various diseases pathogenesis including testicular damage. This study evaluated rivaroxaban (RVX) protective effects in testicular impairment by cisplatin (CP). Rats were randomly allocated into five groups: Control, RVX (7 mg/kg/day), CP (10 mg/kg), RVX 5 mg + CP and RVX 7 mg + CP. Serum testosterone and testicular ALT, AST, and ALP were assessed. Testicular oxidative stress and antioxidant parameters and inflammatory indicators including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were assessed. qRT-PCR was used to determine mRNA expression of 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and steroidogenic acute regulatory protein (stAR). Protein expressions of p-Nuclear factor kappa B (p- NF-κB) and vascular cell adhesion protein-1 (VCAM-1) were analyzed by Western blot analysis. Tissue factor (TF) expression was immunohistochemically analyzed. Results revealed that RVX significantly increased serum testosterone and sperm count while significantly reduced IL-1β and TNF-α. It significantly decreased tissue MDA and NO contents while increased SOD and GPx. In addition, RVX attenuated CP-induced histopathological aberrations and normalized TF. It also decreased the VCAM-1 and p-NF-κB expression and showed strong expression of 3β-HSD, 17β-HSD, and stAR, indicating improvement of steroidogenesis. In conclusion, RVX counteracted testicular damage by CP via suppressing oxidative stress, inflammation, and coagulation and downregulating p-NF-κB/VCAM-1 signaling.

7-Methoxyisoflavone suppresses vascular endothelial inflammation by inhibiting the expression of endothelial adhesion molecules

Endothelial cells (ECs) are vital regulators of inflammatory processes, there is the potential for inhibition of EC inflammation to be a therapeutic target in chronic inflammatory diseases. This study aimed to investigate the effect of 7-methoxyisoflavone (7-Mif) on endothelial inflammation. Our results showed that 7-Mif have no cytotoxicity on HUVECs. Pretreatment with 5 μM, 10 μM and 50 μM 7-Mif significantly reduced IL-1β-induced ICAM-1 (28.1% ± 4.1%, 25.9 ± 2.5% and 32.0% ± 3.2%, respectively) and VCAM-1 (48.0% ± 5.6%, 40.1 ± 3.1% and 39.6% ± 3.1%, respectively) mRNA expression. And pretreatment with 10 μM and 50 μM 7-Mif significantly reduced IL-1β-induced ICAM-1 (45.1% ± 4.4% and 33.6 ± 4.4%, respectively) and VCAM-1 (53.0% ± 3.7% and 53.7 ± 5.1%, respectively) protein levels. Furthermore, pretreatment with 50 μM 7-Mif inhibited monocyte-endothelial cell adhesion (50.2% ± 4.2%). Mechanistically, our results showed that 7-Mif reversed IL-1β-induced NF-κB activation and p65 translocation to the nucleus, therefore inhibiting endothelial cell inflammation. In addition, we confirmed that 7-Mif 10 mg/kg and 20 mg/kg reduced LPS-induced ICAM-1 (47.3% ± 1.3% and 39.0% ± 3.2%, respectively) and VCAM-1 (56.5 ± 2.8% and 47.8 ± 4.3%, respectively) expression and attenuated inflammatory injury in mice. In conclusion, we showed the inhibitory effect of 7-Mif on endothelial inflammation by suppressing the expression of endothelial adhesion molecules and monocyte adhesion. Our data illustrated that 7-Mif could positively regulate the process of endothelial inflammation.

Artemisinin and Procyanidins loaded multifunctional nanocomplexes alleviate atherosclerosis via simultaneously modulating lipid influx and cholesterol efflux

The development of new reagents combining with nanotechnology has become an efficient strategy for improving the immune escaping ability and increasing local drug concentration for natural compounds with low therapy efficiency. In this study, we prepared biomimetic membrane-coated Prussian blue nanoparticles (PB NPs) for the treatment of atherosclerosis, using the function of Artemisinin (ART) and Procyanidins (PC) on the lipid influx and cholesterol efflux of macrophages, two logical steps involved in the plaque progression. In vitro results indicated that the prepared nanocomplexes have significant scavenging effect on ROS and NO, followed by inhibiting NF-κB/NLRP3 pathway, leading to the suppression of lipid influx. Meanwhile, they can notably reduce the uptake and internalization of oxLDL through significantly enhancing AMPK/mTOR/autophagy pathway, accompanied by promoting cholesterol efflux. In vivo study showed that the improved biocompatibility and immune-escape ability of nanocomplexes allowed less drug clearance during the circulation and high drug accumulation in the atherosclerotic plaque of ApoE^-/- mice model. More importantly, the ART and PC co-loaded nanocomplexes showed the high efficacy against atherosclerosis of ApoE^-/- mice model with both 8-week low dosage treatment or 1-week high dosage treatment. These findings indicated that ART and PC co-loaded nanocomplexes was promising for the targeted treatment of atherosclerosis.

Acute Glucose Shift Induces the Activation of the NLRP3 Inflammasome in THP-1 Cells

We aimed to investigate the effect of acute glucose shift on the activation of the NLRP3 inflammasome, IL-1β secretion, and underlying signaling pathways in THP-1 cells. THP-1 cells were divided into four groups and exposed to the following glucose concentrations for 24 h: constant normal glucose (NG, 5.5 mM), constant high glucose (HG, 25 mM), normal to high glucose shift (NG-to-HG, 5.5 to 25 mM), and high to normal glucose shift (HG-to-NG, 25 to 5.5 mM). Cell viability, oxidative stress, and the levels of NLRP3 inflammasome components were assessed. Both directions of the acute glucose shift increased the activation of the NLRP3 inflammasome, generation of reactive oxygen species (ROS), and expression of phosphorylated p38 MAPK, JNK, and NF-κB compared with either constant NG or HG. Treatment with N-acetylcysteine, a pharmacological antioxidant, inhibited the acute glucose shift-induced generation of ROS, activation of NLRP3 inflammasome, and upregulation of MAPK-NF-κB. Further analysis using inhibitors of p38 MAPK, JNK, and NF-κB indicated that acute glucose shifts promoted IL-1β secretion by activating the signaling pathway in a ROS-MAPK-NF-κB-NLRP3 inflammasome in THP-1 cells. These findings suggested that acute changes in glucose concentration might cause monocyte inflammation, which is associated with diabetic complications.

Artesunate Attenuated the Progression of Abdominal Aortic Aneurysm in a Mouse Model

BACKGROUND

The inflammatory reaction is an important mechanism of pathogenesis of abdominal aortic aneurysm (AAA). Artesunate (AS) has been found to have anti-inflammatory effects in cardiovascular disease. The purpose of this study was to investigate whether AS could inhibit the development of AAA.

MATERIALS AND METHODS

AngII infused ApoE (-/-) male mice were selected as AAA model. Mice were spilt into three groups, the experimental control group (AngII), the AS treatment group (AngII + AS) and the negative control group (Vehicle) with 14 in each group. Daily administration of AS (100 mg/kg/d) or vehicle performed 3 day before the perfusion. At the end of the 28-day experiment, animal ultrasound and electronic digital caliper were used to measure the diameter of abdominal aorta. Histologic assays were performed to observe the microstructure of the aorta wall. Immunofluorescence staining was performed to detect inflammatory cells, as well as the levels of matrix metalloproteinases (MMPs). The transcription of cytokines and adhesion molecules were investigated by real-time fluorescence quantitative PCR (qPCR). Western blotting was performed to determine whether the NF-κB pathway is involved in the mechanism.

RESULTS

While AS failed to reduce the incidence of AAA, AS effectively reduced the diameter of AAA independently of blood pressure effects. Immunofluorescence detection showed that AS effectively reduced the levels of CD45+ cells and MAC3+ macrophages as well as MMP-2 and MMP-9. qPCR revealed that AS reduced mRNA transcription levels of MMP-2, MMP-9, the cytokine IL-1β, TNF-α, adhesion molecules ICAM-1, VCAM-1. AS decreased the levels of NF-κB signaling pathway in aorta.

CONCLUSIONS

AS can attenuate the development of AAA in mice. The possible mechanism is anti-inflammation.

Sesquiterpene Lactones: Promising Natural Compounds to Fight Inflammation

Inflammation is a crucial and complex process that reestablishes the physiological state after a noxious stimulus. In pathological conditions the inflammatory state may persist, leading to chronic inflammation and causing tissue damage. Sesquiterpene lactones (SLs) are composed of a large and diverse group of highly bioactive plant secondary metabolites, characterized by a 15-carbon backbone structure. In recent years, the interest in SLs has risen due to their vast array of biological activities beneficial for human health. The anti-inflammatory potential of these compounds results from their ability to target and inhibit various key pro-inflammatory molecules enrolled in diverse inflammatory pathways, and prevent or reduce the inflammatory damage on tissues. Research on the anti-inflammatory mechanisms of SLs has thrived over the last years, and numerous compounds from diverse plants have been studied, using in silico, in vitro, and in vivo assays. Besides their anti-inflammatory potential, their cytotoxicity, structure–activity relationships, and pharmacokinetics have been investigated. This review aims to gather the most relevant results and insights concerning the anti-inflammatory potential of SL-rich extracts and pure SLs, focusing on their effects in different inflammatory pathways and on different molecular players.

Artemisinin Attenuates Transplant Rejection by Inhibiting Multiple Lymphocytes and Prolongs Cardiac Allograft Survival

Immunological rejection is an important factor resulting in allograft dysfunction, and more valid therapeutic methods need to be explored to improve allograft outcomes. Many researches have indicated that artemisinin and its derivative exhibits immunosuppressive functions, apart from serving as a traditional anti-malarial drug. In this assay, we further explored the therapeutic effects of artemisinin for transplant rejection in a rat cardiac transplantation model. We found that it markedly attenuated allograft rejection and histological injury and significantly prolonged the survival of allograft. Upon further exploring the mechanism, we demonstrated that artemisinin not only attenuated T cell-mediated rejection (TCMR) by reducing effector T cell infiltration and inflammatory cytokine secretion and increasing regulatory T cell infiltration and immunoregulatory cytokine levels, but also attenuated antibody-mediated rejection (ABMR) through inhibition of B cells activation and antibody production. Furthermore, artemisinin also reduced macrophage infiltration in allografts, which was determined to be important for TCMR and ABMR. Moreover, we demonstrated that artemisinin significantly inhibited the function of pure T cells, B cells, and macrophages in vitro. All in all, this study provide evidence that artemisinin significantly attenuates TCMR and ABMR by targeting multiple effectors. Therefore, this agent might have potential for use in clinical settings to protect against transplant rejection.

Artemisinin protects endothelial function and vasodilation from oxidative damage via activation of PI3K/Akt/eNOS pathway

INTRODUCTION

Previous studies showed that artemisinin (ART) may be useful in the protection against the early development of atherosclerosis, but the effects of ART on vasodilation and eNOS remained unclear.

OBJECTIVES AND METHODS

In the current study, we investigated the protective effect of ART on endothelial cell injury induced by oxidative stress and its underlying mechanism via MTT assay, Flow Cytometry Assay, Vasodilation study, Western blotting and vivo assay.

RESULTS

We found that pretreatment of human umbilical vein endothelial cells (HUVECs) with ART significantly suppressed H2O2-induced cell death by decreasing the extent of oxidation and MDA activity, activating SOD, increasing NO production and inhibiting caspase 3/7 activity. Meanwhile, we also found that ART was able to activate PI3K/Akt/eNOS pathway. PI3K inhibitor LY294002 or Akt kinase specific inhibitor Akt inhibitor VIII blocked the protective effect of ART. To explore the effect of ART in the damage of vasodilation induced by H2O2 in mice, we treated the aortic ring from C57BL/6 mice with H2O2 with or without ART, the results demonstrated that ART ameliorated endothelium-dependent vasodilation damage induced by H2O2.

CONCLUSION

Taken together, these data suggest that ART is able to protect endothelial function and vasodilation from oxidative damage, at least in part through activation of PI3K/Akt/eNOS pathway. Our findings indicate that artemisinin maybe as a potential therapeutic agent for patients with atherosclerosis.

FGF9 induces neurite outgrowth upon ERK signaling in knock-in striatal Huntington's disease cells

AIMS

Huntington's disease (HD) is a neurodegenerative disease that causes deficits in neurite outgrowth, which suggests that enhancement of neurite outgrowth is a potential direction by which to improve HD. Our previous publications showed that fibroblast growth factor 9 (FGF9) provides anti-apoptosis and anti-oxidative functions in striatal cell models of HD through the extracellular signal-regulated kinases (ERK) pathway, and FGF9 also stimulates cytoskeletons to enhance neurite outgrowth via nuclear factor kappa B (NF-kB) signaling. In this study, we further demonstrate the importance of the ERK pathway for the neurite outgrowth induced by FGF9 in HD striatal models.

MATERIALS AND METHODS

FGF9 was treated with ERK (U0126) or NF-kB (BAY11-7082) inhibitors in STHdh^Q7/Q7 and STHdh^Q111/Q111 striatal knock-in cell lines to examine neurite outgrowth, cytoskeletal markers, and synaptic proteins via immunofluorescence staining and Western blotting. NF-kB activity was analyzed by NF-kB promoter reporter assay.

KEY FINDINGS

Here, we show that suppression of ERK signaling significantly inhibits FGF9-induced neurite outgrowth, cytoskeletal markers, and synaptic proteins in HD striatal cells. In addition, we also show suppression of ERK signaling significantly decreases FGF9-induced NF-kB activation, whereas suppression of NF-kB does not decrease FGF9-induced ERK signaling. These results suggest that FGF9 activates ERK signaling first, stimulates NF-kB upregulation, and then enhances neurite outgrowth in HD striatal cells.

SIGNIFICANCE

We elucidate the more detailed mechanisms of neurite outgrowth enhanced by FGF9 in these HD striatal cells. This study may provide insights into targeting neurite outgrowth for HD therapy.

The Potential Roles of Artemisinin and Its Derivatives in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic disease that has become a global public health problem. Studies on T2DM prevention and treatment mostly focus on discovering therapeutic drugs. Artemisinin and its derivatives were originally used as antimalarial treatments. In recent years, the roles of artemisinins in T2DM have attracted much attention. Artemisinin treatments not only attenuate insulin resistance and restore islet ß-cell function in T2DM but also have potential therapeutic effects on diabetic complications, including diabetic kidney disease, cognitive impairment, diabetic retinopathy, and diabetic cardiovascular disease. Many in vitro and in vivo experiments have confirmed the therapeutic utility of artemisinin and its derivatives on T2DM, but no article has systematically demonstrated the specific role artemisinin plays in the treatment of T2DM. This review summarizes the potential therapeutic effects and mechanism of artemisinin and its derivatives in T2DM and associated complications, providing a reference for subsequent related research.

Artemisinin inhibits glycosaminoglycan chain synthesizing gene expression but not proliferation of human vascular smooth muscle cells

Pleotropic growth factor, transforming growth factor (TGF)-β drives the modification and elongation of glycosaminoglycan (GAG) chains on proteoglycans. Hyperelongated GAG chains bind and trap lipoproteins in the intima leading to the formation of atherosclerotic plaques. We have identified that phosphorylation of Smad2 linker region drives GAG chain modification. The identification of an inhibitor of Smad2 linker region phosphorylation and GAG chain modification signifies a potential therapeutic for cardiovascular diseases. Artemisinin renowned for its potent anti-malarial effects possesses a broad range of biological effects. Our aim was to characterise the anti-atherogenic role of artemisinin in vascular smooth muscle cells (VSMCs). We demonstrate that TGF-β mediated Smad2 linker region phosphorylation and GAG chain elongation was attenuated by artemisinin; however, we observed no effect on VSMC proliferation. Our data demonstrates the potential for artemisinin to be developed as a therapy to inhibit the development of atherosclerosis by prevention of lipid deposition in the vessel wall without affecting the proliferation of VSMCs.

Prothrombotic effects of high uric acid in mice via activation of MEF2C-dependent NF-κB pathway by upregulating let-7c

Serum uric acid is reportedly associated with thrombosis development. However, still unclear is the mechanism of high uric acid in thrombosis with the involvement of let-7c. In an aim to fill this void, we conducted this study by treating mice and human umbilical vein endothelial cells with high uric acid. Analysis indicated that let-7c was upregulated in hyperuricemia patients as well as in mice and human umbilical vein endothelial cells treated with high uric acid. Furthermore, high uric acid inhibited myocyte enhancer factor-2C, but activated nuclear factor-kappa B pathway in human umbilical vein endothelial cells. Then the targeting relationship between let-7c and myocyte enhancer factor-2C was verified. On the one hand, high uric acid shortened activated partial thromboplastin time and prothrombin time of mice and declined tissue plasminogen activator level. Additionally, the treatment prolonged thrombin time and elevated the levels of thrombosis related molecules or proteins such as Fibrinogen and D-dimer. Nevertheless, these alternations could be reversed by inhibition of let-7c and nuclear factor-kappa B pathway or overexpressing myocyte enhancer factor-2C. To sum up, our results uncovered the pro-thrombotic effect of high uric acid in mice by activating myocyte enhancer factor-2C-dependent nuclear factor-kappa B pathway via let-7c upregulation.

Telmisartan Inhibits TNFα-Induced Leukocyte Adhesion by Blocking ICAM-1 Expression in Astroglial Cells but Not in Endothelial Cells

Telmisartan is an angiotensin-II receptor blocker and acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPARγ). Several studies have demonstrated that telmisartan ameliorates depression and memory dysfunction and reduces brain inflammation. We hypothesized that the beneficial effects of telmisartan on brain could be due to modulation of the blood-brain barrier (BBB) function. Here, we examined the effect of telmisartan on tumor necrosis factor alpha (TNF-α)-induced expression of intercellular adhesion molecule 1 (ICAM-1) which plays an important role in leukocyte transcytosis through the BBB. Telmisartan blocked TNF-α-induced ICAM-1 expression and leukocyte adhesion in U87MG human glioma cells but showed no effect on human brain microvascular endothelial cells. In U87MG cells, a PPAR antagonist, GW9662 did not block the effect of telmisartan on ICAM1 expression but rather potentiated. Moreover, GW9662 caused no change in TNF-α-induced ICAM-1 expression, suggesting no implication of PPARγ in the telmisartan effect. Further studies showed that telmisartan blocked TNF-α- induced activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factorkappa B (NF-κB). In contrast, inhibitors of JNK, ERK1/2 and NF-κB but not p38, blocked ICAM-1 expression induced by TNF-α. Thus, our findings suggest that the beneficial effect of telmisartan is likely due to the reduction of astrocytic ICAM1 expression and leukocytes adhesion to astrocytes, and that this response was mediated by the inhibition of JNK/ERK1/2/NF-κB activation and in the PPAR-independent manner. In conclusion, this study enhances our understanding of the mechanism by which telmisartan exerts the beneficial brain function.

Cellular mechanisms and molecular signaling pathways in stress-induced anxiety, depression, and blood-brain barrier inflammation and leakage

Depression and anxiety are comorbid conditions in many neurological or psychopathological disorders. Stress is an underlying event that triggers development of anxiety and depressive-like behaviors. Recent experimental data indicate that anxiety and depressive-like behaviors occurring as a result of stressful situations can cause blood-brain barrier (BBB) dysfunction, which is characterized by inflammation and leakage. However, the underlying mechanisms are not completely understood. This paper sought to review recent experimental preclinical and clinical data that suggest possible molecular mechanisms involved in development of stress-induced anxiety and depression with associated BBB inflammation and leakage. Critical therapeutic targets and potential pharmacological candidates for treatment of stress-induced anxiety and depression with associated BBB dysfunctions are also discussed.

Dihydroartemisinin derivative DC32 inhibits inflammatory response in osteoarthritic synovium through regulating Nrf2/NF-κB pathway

Synovitis is an aseptic inflammation that leads to joint effusion, pain and swelling. As one of the main drivers of pathogenesis in osteoarthritis (OA), the presence of synovitis contributes to pain, incidence and progression of OA. In our previous study, DC32 [(9α,12α-dihydroartemisinyl) bis(2'-chlorocinnmate)], a dihydroartemisinin derivative, was found to have an antirheumatic ability via immunosuppression, but the effect of DC32 on synovitis has not been fully illuminated. In this study, we chose to evaluate the effect and mechanism of DC32 on attenuating synovial inflammation. Fibroblast-like synoviocytes (FLSs) of papain-induced OA rats were isolated and cultured. And DC32 significantly inhibited the invasion and migration of cultured OA-FLSs, as well as the transcription of IL-6, IL-1β, CXCL12 and CX3CL1 in cultured OA-FLSs measured by qPCR. DC32 remarkably inhibited the activation of ERK and NF-κB pathway, increased the expression of Nrf2 and HO-1 in cultured OA-FLSs detected by western blot. DC32 inhibited the degradation and phosphorylation of IκBα which further prevented the phosphorylation of NF-κB p65 and the effect of DC32 could be relieved by siRNA for Nrf2. In papain-induced OA mice, DC32 significantly alleviated papain-induced mechanical allodynia, knee joint swelling and infiltration of inflammatory cell in synovium. DC32 upregulated the mRNA expression of Type II collagen and aggrecan, and downregulated the mRNA expression of MMP2, MMP3, MMP13 and ADAMTS-5 in the knee joints of papain-induced OA mice measured by qPCR. The level of TNF-α in the serum and secretion of TNF-α in the knee joints were also reduced by DC32 in papain-induced OA mice. In conclusion, DC32 inhibited the inflammatory response in osteoarthritic synovium through regulating Nrf2/NF-κB pathway and attenuated OA. In this way, DC32 may be a potential agent in the treatment of OA.

Insulin Promotes Wound Healing by Inactivating NFkβP50/P65 and Activating Protein and Lipid Biosynthesis and alternating Pro/Anti-inflammatory Cytokines Dynamics

Four hundred and twenty-two million people have diabetes due to excess free body glucose in their body fluids. Diabetes leads to various problems including retinopathy, neuropathy, arthritis, damage blood vessels etc; it also causes a delay in wound healing. Insufficiency of insulin is the main reason for diabetes-I and systemic insulin treatment is a remedy. The perspective of the potential use of insulin/insulin based drugs to treat chronic wounds in diabetic conditions is focused on in this review. At the site of the wound, TNF-ɑ, IFN-ϒ, IL-1β and IL-6 pro-inflammatory cytokines cause the generation of free radicals, leading to inflammation which becomes persistent in diabetes. Insulin induces expression of IL-4/IL-13, IL-10 anti-inflammatory cytokines etc which further down-regulates NFkβP50/P65 assembly. Insulin shifts the equilibrium towards NFkβP50/P50 which leads to down-regulation of inflammatory cytokines such as IL-6, IL-10 etc through STAT6, STAT3 and c-Maf activation causing nullification of an inflammatory condition. Insulin also promotes protein and lipid biosynthesis which indeed promotes wound recovery. Here, in this article, the contributions of insulin in controlling wound tissue microenvironments and remodulation of tissue have been summarised, which may be helpful to develop novel insulin-based formulation(s) for effective treatment of wounds in diabetic conditions.

Calreticulin induced endothelial ICAM-1 up-regulation associated with tristetraprolin expression alteration through PI3K/Akt/eNOS/p38 MAPK signaling pathway in rheumatoid arthritis

The present study was undertaken to determine whether extracellular calreticulin (CRT) participates in the regulation of ICAM-1in rheumatoid arthritis (RA) and further explore the potential mechanism. Our results showed that ICAM-1 and VCAM-1 levels were positively correlated with CRT levels in RA serum and synovial fluid, respectively. In RA synovial tissue, increased co-expressions of CRT and ICAM-1 in vascular endothelium and perivascular areas and elevated co-location of CRT and VCAM-1 localized predominantly to lining layer were observed compared to those in OA. In in vitro HUVECs model, enhanced ICAM-1expression and increased phosphorylation levels of Akt and eNOS were detected in the presence of CRT. Increased phosphorylated eNOS was significantly inhibited by a PI3K inhibitor LY294002 and elevated ICAM-1expression was partially blocked by the inhibitors of both PI3K and eNOS (L-NAME). It has been certified that the RNA-binding protein TTP targets AU-rich elements in the ICAM-1 3'-UTR and suppresses ICAM-1 expression. Knocking down TTP in HUVECs led to an increased induction of ICAM-1 by CRT. We have currently known that activation of p38 downstream kinase MK-2 leads to phosphorylation and inactivation of human TTP. The block of p38 MAPK/MK-2 signaling led to decreased protein expression and mRNA stability of TTP and ICAM-1. Furthermore, L-NAME and/or LY294002 pre-treated HUVECs manifested decreased p38 and MK-2 phosphorylation, which was accompanied by reduced TTP and ICAM-1 protein expression as well as decreased mRNA stability. Our results suggested that CRT could promote ICAM-1 expression in endothelial cells through PI3K/Akt/eNOS/p38 MAPK signaling mediated TTP accumulation, probably in an inactive form, which may provide a possible proinflammatory mechanism of CRT in RA.

Natural products and their derivatives as cyclooxygenase-2 inhibitors

From ancient times, natural products have been continuously used as therapeutic agents in the treatment of various ailments. Many drugs from the natural origin are available in the market as potent medicines. Over expression of cyclooxygenase-2 (COX-2) enzyme is associated with various physical disorders like various types of inflammations associated with cardiovascular diseases or malignancies. The COX-2 inhibitory activity of many active constituents derived from plants is well established in the literature. These include coumarins, alkaloids, flavonoids, cinnamates, stilbenes and xanthines. In the present review, an attempt has been made to summarize applications of compounds since 2000 obtained from natural sources as COX-2 inhibitors. A brief synthetic methodology to access these natural product derivatives has been highlighted along with the Structure Activity Relationship (SAR).

Resveratrol-based cinnamic ester hybrids: synthesis, characterization, and anti-inflammatory activity

Twenty-three novel resveratrol-based cinnamic ester hybrids were designed and synthesized. All the compounds were evaluated for their anti-inflammatory activity using RAW264.7 cells. Among them, compound D15 was found to be the most potent one in inhibiting NO production in LPS-stimulated RAW264.7 cells. The further study indicated that compound D15 could suppress expression of proteins iNOS, COX-2, p-p65, and p-IκB LPS-induced. Immunofluorescence further revealed compound D15 could reduce activation p65 in nuclei. All the results indicated that the anti-inflammatory activity of title compound may partly due to its inhibitory effect on the NF-κB signaling pathway.

Anti-inflammatory evaluation of the methanolic extract of Taraxacum officinale in LPS-stimulated human umbilical vein endothelial cells

Background

Atherosclerosis is a chronic vascular inflammatory disease. Since even low-level endotoxemia constitutes a powerful and independent risk factor for the development of atherosclerosis, it is important to find therapies directed against the vascular effects of endotoxin to prevent atherosclerosis. Taraxacum officinale (TO) is used for medicinal purposes because of its choleretic, diuretic, antioxidative, anti-inflammatory, and anti-carcinogenic properties, but its anti-inflammatory effect on endothelial cells has not been established.

Methods

We evaluated the anti-inflammatory activity of TO filtered methanol extracts in LPS-stimulated human umbilical vein endothelial cells (HUVECs) by monocyte adhesion and western blot assays. HUVECs were pretreated with 100 μg/ml TO for 1 h and then incubated with 1 μg/ml LPS for 24 h. The mRNA and protein expression levels of the targets (pro-inflammatory cytokines and adhesion molecules) were analyzed by real-time PCR and western blot assays. We also preformed HPLC analysis to identify the components of the TO methanol extract.

Results

The TO filtered methanol extracts dramatically inhibited LPS-induced endothelial cell–monocyte interactions by reducing vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, and pro-inflammatory cytokine expression. TO suppressed the LPS-induced nuclear translocation of NF-κB, whereas it did not affect MAPK activation.

Conclusions

Our findings demonstrated that methanol extracts of TO could attenuate LPS-induced endothelial cell activation by inhibiting the NF-κB pathway. These results indicate the potential clinical benefits and applications of TO for the prevention of vascular inflammation and atherosclerosis.

Electronic supplementary material

The online version of this article (10.1186/s12906-017-2022-7) contains supplementary material, which is available to authorized users.

Quinic acid inhibits vascular inflammation in TNF-α-stimulated vascular smooth muscle cells

Atherosclerosis is a chronic inflammatory disease, and the increased expression of adhesion molecules on vascular smooth muscle cells contributes to the progression of vascular disease. Quinic acid (QA) has been shown to possess radioprotection, anti-neuroinflammatory, and anti-oxidant activities; however, an anti-vascular inflammatory effect has not been reported. This study investigated the effect of QA on the expression of vascular cell adhesion molecule-1 (VCAM-1) stimulated by TNF-α in MOVAS cells. Pre-incubation of MOVAS cells, the mouse vascular smooth muscle cell line for 2h with QA (0.1, 1 and 10 μg/mL) dose-dependently inhibits TNF-α-induced mRNA and protein expression of VCAM-1 and monocyte adhesion. QA inhibits TNF-α-stimulated phosphorylation of MAP kinase and NK-κB activation. Our results indicate that QA inhibits the TNF-α-stimulated induction of VCAM-1 in VSMC by inhibiting the MAP kinase and NF-κB signaling pathways and the adhesion capacity of VSMC, which may explain the ability of QA to inhibit vascular inflammation such as atherosclerosis.

Resveratrol attenuates ICAM-1 expression and monocyte adhesiveness to TNF-α-treated endothelial cells: evidence for an anti-inflammatory cascade mediated by the miR-221/222/AMPK/p38/NF-κB pathway

Resveratrol, an edible polyphenolic phytoalexin, improves endothelial dysfunction and attenuates inflammation. However, the mechanisms have not been thoroughly elucidated. Therefore, we investigated the molecular basis of the effects of resveratrol on TNF-α-induced ICAM-1 expression in HUVECs. The resveratrol treatment significantly attenuated the TNF-α-induced ICAM-1 expression. The inhibition of p38 phosphorylation mediated the reduction in ICAM-1 expression caused by resveratrol. Resveratrol also decreased TNF-α-induced IκB phosphorylation and the phosphorylation, acetylation, and translocation of NF-κB p65. Moreover, resveratrol induced the AMPK phosphorylation and the SIRT1 expression in TNF-α-treated HUVECs. Furthermore, TNF-α significantly suppressed miR-221/-222 expression, which was reversed by resveratrol. miR-221/-222 overexpression decreased p38/NF-κB and ICAM-1 expression, which resulted in reduced monocyte adhesion to TNF-α-treated ECs. In a mouse model of acute TNF-α-induced inflammation, resveratrol effectively attenuated ICAM-1 expression in the aortic ECs of TNF-α-treated wild-type mice. These beneficial effects of resveratrol were lost in miR-221/222 knockout mice. Our data showed that resveratrol counteracted the TNF-α-mediated reduction in miR-221/222 expression and decreased the TNF-α-induced activation of p38 MAPK and NF-κB, thereby suppressing ICAM-1 expression and monocyte adhesion. Collectively, our results show that resveratrol attenuates endothelial inflammation by reducing ICAM-1 expression and that the protective effect was mediated partly through the miR-221/222/AMPK/p38/NF-κB pathway.