Oridonin inhibits vascular inflammation by blocking NF-κB and MAPK activation

Oridonin Attenuates Diabetes‑induced Renal Fibrosis via the Inhibition of TXNIP/NLRP3 and NF‑κB Pathways by Activating PPARγ in Rats

INTRODUCTION

Oridonin possesses remarkable anti-inflammatory, immunoregulatory properties. However, the renoprotective effects of oridonin and the underlying molecular mechanisms in diabetic nephropathy (DN). We hypothesized that oridonin could ameliorate diabetes‑induced renal fibrosis.

METHODS

Streptozocin (STZ)-induced diabetic rats were provided with a high-fat diet to establish a type 2 diabetes mellitus (T2DM) animal model, and then treated with Oridonin (10, 20 mg/kg/day) for two weeks. Kidney function and renal fibrosis were assessed. High glucose-induced human renal proximal tubule epithelial cells (HK-2) were also treated with oridonin. The expression of inflammatory factors and fibrotic markers were analyzed.

RESULTS

Oridonin treatment preserved kidney function and markedly limited the renal fibrosis size in diabetic rats. The renal fibrotic markers were inhibited in the oridonin 10 mg/kg/day and 20 mg/kg/day groups compared to the T2DM group. The expression of thioredoxin-interacting proteins/ nod-like receptor protein-3 (TXNIP/NLRP3) and nuclear factor (NF)‑κB pathway decreased, while that of peroxisome proliferator-activated receptor-gamma (PPARγ) increased in the oridonin treatment group compared to the non-treated group. In vitro, PPARγ intervention could significantly regulate the effect of oridonin on the high glucose-induced inflammatory changes in HK-2 cells.

CONCLUSION

Oridonin reduces renal fibrosis and preserves kidney function via the inhibition of TXNIP/NLRP3 and NF‑κB pathways by activating PPARγ in rat T2DM model, which indicates potential effect of oridonin in the treatment of DN.

Plant-Derived Terpenoids: A Plethora of Bioactive Compounds with Several Health Functions and Industrial Applications-A Comprehensive Overview

Terpenoids are a large class of natural secondary plant metabolites which are highly diverse in structure, formed from isoprene units (C-5), associated with a wide range of biological properties, including antioxidant, antimicrobial, anti-inflammatory, antiallergic, anticancer, antimetastatic, antiangiogenesis, and apoptosis induction, and are considered for potential application in the food, cosmetics, pharmaceutical, and medical industries. In plants, terpenoids exert a variety of basic functions in growth and development. This review gives an overview, highlighting the current knowledge of terpenoids and recent advances in our understanding of the organization, regulation, and diversification of core and specialized terpenoid metabolic pathways and addressing the most important functions of volatile and non-volatile specialized terpenoid metabolites in plants. A comprehensive description of different aspects of plant-derived terpenoids as a sustainable source of bioactive compounds, their biosynthetic pathway, the several biological properties attributed to these secondary metabolites associated with health-promoting effects, and their potential industrial applications in several fields will be provided, and emerging and green extraction methods will also be discussed. In addition, future research perspectives within this framework will be highlighted. Literature selection was carried out using the National Library of Medicine, PubMed, and international reference data for the period from 2010 to 2024 using the keyword "terpenoids". A total of 177,633 published papers were found, of which 196 original and review papers were included in this review according to the criteria of their scientific reliability, their completeness, and their relevance to the theme considered.

Role of inflammasomes in endothelial dysfunction

The vascular endothelium dynamically responds to environmental cues and plays a pivotal role in maintaining vascular homeostasis by regulating vasomotor tone, blood cell trafficking, permeability and immune responses. However, endothelial dysfunction results in various pathological conditions. Inflammasomes are large intracellular multimeric complexes activated by pathogens or cellular damage. Inflammasomes in vascular endothelial cells (ECs) initiate innate immune responses, which have emerged as significant mediators in endothelial dysfunction, contributing to the pathophysiology of an array of diseases. This review summarizes the mechanisms and ramifications of inflammasomes in ECs and related vascular diseases such as atherosclerosis, abdominal aortic aneurysm, stroke, and lung and kidney diseases. We also discuss potential drugs targeting EC inflammasomes and their applications in treating vascular diseases.

Toll-like receptor signaling pathway involved in pathogenesis of thromboangiitis obliterans through activating of NF-κB

OBJECTIVES

The pathogenic mechanisms of Thromboangiitis Obliterans (TAO) are not entirely known and autoimmune inflammation plays a vital role in the initiation and continuance of TAO activity. The authors investigated in this study the role of the TLR signaling pathway in the pathogenesis of TAO.

METHODS

First, the authors detected the expressions of MyD88, TRIF and NF-κB in vascular walls of 46 patients with TAO and 32 patients with trauma and osteosarcoma by western blot assay. Second, the authors detected the cellular localization of MyD88, TRIF and NF-κB in vascular walls of patients with TAO by immunofluorescent assay.

RESULTS

The protein expressions of MyD88, TRIF and NF-κB were much higher in vascular walls of TAO patients (p < 0.05). Higher expressions of MyD88 and NF-κB were detected both on vascular endothelial and vascular smooth muscle cells of TAO patients. However, higher expression of TRIF was just detected on vascular smooth muscle cells of TAO patients.

CONCLUSIONS

These dates suggest that the TLR signaling pathway might play an important role in the pathogenesis of TAO, it might induce vasospasm, vasculitis and thrombogenesis to lead to the pathogenesis and progression of TAO.

Betulinic acid attenuates T-2 toxin-induced lung injury by activating Nrf2 signaling pathway and inhibiting MAPK/NF-κB signaling pathway

T-2 toxin, a type-A trichothecene mycotoxin, exists ubiquitously in mildewed foods and feeds. Betulinic acid (BA), a pentacyclic triterpenoid derived from plants, has the effect of relieving inflammation and oxidative stress. The purpose of this study was to investigate whether BA mitigates lung impairment caused by T-2 toxin and elucidate the underlying mechanism. The results indicated that T-2 toxin triggered the inflammatory cell infiltration, morphological alterations and cell apoptosis in the lungs. It is gratifying that BA ameliorated T-2 toxin-caused lung injury. The protein expression of nuclear factor erythrocyte 2-related factor 2 (Nrf2) pathway and the markers of antioxidative capability were improved in T-2 toxin induced lung injury by BA mediated protection. Simultaneously, BA supplementation could suppress T-2 toxin-induced mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB)-dependent inflammatory response and mitochondrial apoptotic pathway. Therefore, T-2 toxin gave rise to pulmonary toxicity, but these changes were moderated by BA administration through regulation of the Nrf2/MAPK/NF-κB pathway, which maybe offer a viable alternative for mitigating the lung impairments caused by the mycotoxin.

Diterpenoid WT-29 isolated from Wedelia exerted anti-inflammatory and anti-allergic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Wedelia (Sphagneticola trilobata) is a traditional anti-inflammatory herb native to tropical America. It is commonly used to treat some inflammatory related diseases clinically, such as pertussis, pharyngitis, etc. However, its specific anti-inflammatory mechanism is still unclear.

AIM OF THE STUDY

WT-29 (3α-angeloyloxy-9β-hydroxyent-kaura-16-en-19-oic acid) is a main bioactive diterpenoid isolated and purified from Wedelia. This study aims to explore the potential anti-inflammatory and anti-allergic properties of WT-29 on RAW264.7 cells stimulated with LPS and P815 cells induced by C48/80, as well as investigating their underlying molecular mechanisms.

METHODS

The anti-inflammatory mechanism of WT-29 was analyzed and predicted using network pharmacology, and then verified through experiments. The Griess reagent assay was employed to evaluate the impact of WT-29 on the generation of nitric oxide (NO) in RAW264.7 cells induced by LPS, the expression of various inflammatory cytokines and the release of histamine in cells were measured through qRT-PCR and ELISA techniques. The impact of WT-29 on the translocation of the NF-κB p65 protein to the nucleus was assessed through immunofluorescence staining. Western blot technique was utilized to investigate protein expression in inflammation, allergy, and autophagy pathways.

RESULTS

The study found that WT-29 can reduce the secretion of inflammatory factors (NO, iNOS, COX-2, IL-6, IL-1β and TNF-α), inhibit NF-κB activation and MAPK family phosphorylation, and induce autophagy in RAW264.7 cells stimulated with LPS. In addition, it demonstrated that WT-29 could inhibit histamine release and degranulation, as well as inhibit the MAPK family in C48/80-induced P815 cells.

CONCLUSION

WT-29 isolated from Wedelia exerts anti-inflammatory and anti-allergic effects mainly through NF-κB, Nrf2/Keap-1, MAPK pathways and regulating of autophagy, suggesting that it might be a potential anti-inflammatory and anti-allergic agent and could be used as medicine or health benefit product.

Serum IgA augments adhesiveness of cultured lung microvascular endothelial cells and suppresses angiogenesis

Immunoglobulin A (IgA) is important in local immunity and is also abundant in the blood. This study aimed to evaluate the effects of serum IgA on cultured lung microvascular endothelial cells (HMVEC-Ls), which are involved in the pathogenesis of inflammatory lung diseases. Serum IgA induced adhesion molecules and inflammatory cytokine production from HMVEC-Ls, and enhanced adhesion of peripheral blood mononuclear cells to HMVEC-Ls. In contrast, migration, proliferation, and tube formation of HMVEC-Ls were significantly suppressed by serum IgA. Experiments with siRNAs and western blotting revealed that two known IgA receptors, β1,4-galactosyltransferase 1 (b4GALT1) and asialoglycoprotein receptor 1 (ASGR1), and mitogen-activated protein kinase and nuclear factor-kappa B pathways were partly involved in serum IgA-induced cytokine production by HMVEC-Ls. Collectively, serum IgA enhanced cytokine production and adhesiveness of HMVEC-L, with b4GALT1 and ASGR1 partially being involved, and suppressed angiogenesis. Thus, serum IgA may be targeted to treat inflammatory lung diseases.

Diverse diterpenoids from Callicarpa rubella Lindl. As natural inhibitors of macrophage foam cell formation

Ten undescribed diterpenoids namely rubellawus E-N of structural types pimarane (1, 3-4), nor-abietane (2), nor-pimarane (5-6), isopimarane (7-9), and nor-isopimarane (10), along with eleven known compounds, were isolated and identified from the aerial parts of Callicarpa rubella Lindl. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analyses and quantum chemical computations. Pharmacologically, almost all the compounds exhibited a potential inhibitory effect on oxidized low-density lipoprotein-induced macrophage foam cell formation, which suggests that these compounds may be promising candidates in the treatment of atherosclerosis.

Protective effects of oridonin against osteoporosis by regulating immunity and activating the Wnt3a/β-catenin/VEGF pathway in ovariectomized mice

This study was performed with the aim of investigating the effect of oridonin (ORI) on estrogen deprivation-induced osteoporosis in mice and its mechanism. Animal experiments were used in this work to validate the anti-osteoporotic efficacy of ORI. Morphometric analysis was performed by micro-CT. A special protein meter was used to detect the content of immunoglobulin lgM, immunoglobulin lgG, complement C3 and C4 in the serum of mice. The expression of CD4⁺CD25⁺Foxp3⁺ Treg cell and CD4⁺/CD8⁺ lymphocyte subsets in mice was detected by flow cytometry. ELISA was used to detect the content of insulin-like growth factor (IGF-1), tumor necrosis factor (TNF-α), interleukin-1 (IL-1) and interleukin-6 (IL-6). In addition, key signaling molecules in the Wnt3a/β-catenin signaling pathway were detected by Western blotting. The results showed that compared with the model group, the contents of calcium and phosphorus in the femurs of mice in the ORI groups were increased, and the spleen coefficient was decreased. The ALP activity in the serum of mice in the high and medium dose ORI groups was decreased, and the uterine coefficient was increased. ORI significantly increased the maximum bending load and the maximum bending stress of the femurs of mice, increased the number of trabeculae, and repaired the bone microstructure. At the same time, ORI could significantly increase the levels of immunoglobulin (lgG and lgM) and complement (C3 and C4), increase the activity of peritoneal macrophages in mice, increase the expression of CD4⁺CD25⁺Foxp3⁺ Tregs and CD4⁺/CD8⁺ in the spleen, increase the content of IGF-1, reduce the content of TNF-α, IL-1 and IL-6 and increase the expression levels of VEGF, Wnt3a, p-GSK3β/GSK3β and β-catenin/Lamin in the femoral tissue. These results indicated that ORI might regulate the expression of VEGF through the Wnt3a/β-catenin signaling pathway, improve the immunity of mice, maintain the balance of the immune system, and promote angiogenesis, thereby improving the bone mineral density and bone tissue morphology of mice and playing an anti-osteoporotic role.

Research Progress on Anti-Inflammatory Mechanisms of Black Ginseng

In recent years, black ginseng, a new type of processed ginseng product, has attracted the attention of scholars globally. Ginsenoside and ginseng polysaccharide, the main active substances of black ginseng, have been shown to carry curative effects for many diseases. This article focuses on the mechanism of their action in anti-inflammatory response, which is mainly divided into three aspects: activation of immune cells to exert immune regulatory response; participation in inflammatory response-related pathways and regulation of the expression level of inflammatory factors; effect on the metabolic activity of intestinal flora. This study identifies active anti-inflammatory components and an action mechanism of black ginseng showing multi-component, multi-target, and multi-channel characteristics, providing ideas and a basis for a follow-up in-depth study of its specific mechanism.

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.

miRNA let-7 family regulated by NEAT1 and ARID3A/NF-κB inhibits PRRSV-2 replication in vitro and in vivo

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating diseases affecting the swine industry worldwide. To investigate the role of miRNAs in the infection and susceptibility of PRRS virus (PRRSV), twenty-four miRNA libraries were constructed and sequenced from PRRSV-infected and mock-infected Porcine alveolar macrophages (PAMs) of Meishan, Landrace, Pietrain and Qingping pigs at 9 hours post infection (hpi), 36 hpi, and 60 hpi. The let-7 family miRNAs were significantly differentially expressed between PRRSV-infected and mock-infected PAMs from 4 pig breeds. The let-7 family miRNAs could significantly inhibit PRRSV-2 replication by directly targeting the 3’UTR of the PRRSV-2 genome and porcine IL6, which plays an important role in PRRSV replication and lung injury. NEAT1 acts as a competing endogenous lncRNA (ceRNA) to upregulate IL6 by attaching let-7 in PAMs. EMSA and ChIP results confirmed that ARID3A could bind to the promoter region of pri-let-7a/let-7f/let-7d gene cluster and inhibit the expression of the let-7 family. Moreover, the NF-κB signaling pathway inhibits the expression of the let-7 family by affecting the nuclear import of ARID3A. The pEGFP-N1-let-7 significantly reduced viral infections and pathological changes in PRRSV-infected piglets. Taken together, NEAT1/ARID3A/let-7/IL6 play significant roles in PRRSV-2 infection and may be promising therapeutic targets for PRRS.

There are significant differences in susceptibility/resistance to PRRSV among different pig breeds. Especially the local pig breeds in China had strong resistance to PRRSV. However, due to the complexity of the interaction mechanism between pigs and PRRSV, the genetic mechanism leading to PRRSV susceptibility/resistance in different pig breeds is still unclear. MiRNAs play a vital regulatory role in immune response and development of PRRS. In this study, we found that the expression of miRNA let-7 family members were significantly different in PRRSV-infected/mock-infected PAMs from Pietrain, Qingping, Meishan, and Landrace pigs. Our findings illustrated that NEAT1/ARID3A/let-7/IL6 had a significant role in PRRSV-2 infection. What’s more, let-7 family could significantly reduce PRRSV infection and pathological changes in vitro and in vivo. This discovery provided a new idea for breeding PRRSV resistant pigs by revealing the molecular mechanism of PRRSV susceptibility in different pig breeds. Altogether, let-7 family have significant roles in PRRSV infection and may be promising therapeutic targets for PRRS.

Poldip2 knockdown protects against lipopolysaccharide-induced acute lung injury via Nox4/Nrf2/NF-κB signaling pathway

Polymerase δ-interacting protein 2 (Poldip2) has been reported to mediate acute lung injury (ALI); however, the underlying mechanism is not fully explored. Male C57BL/6 mice and A549 cells were used to establish the lipopolysaccharide (LPS)-induced ALI model, then the expression of Poldip2 and its effect on oxidative stress and the resulting inflammation were detected. Adeno-associated virus serotype 6 (AAV6) mediated Poldip2 knockdown was transfected into mice via intratracheal atomization. And A549 cells stimulated with LPS was used to further confirm our hypothesis in vitro. ML385, specifically inhibited the activation of the Nrf2 signaling pathway. Our data suggested that LPS stimulation remarkably increased protein levels of Nox4 and p-P65, activities of NADPH and MPO, and generation of ROS, TNF-α, and IL-1β while decreased protein levels of Nrf2 and HO-1 compared with those in NC shRNA + Saline group, which were obviously reversed by Poldip2 knockdown. Concomitantly, Poldip2 knockdown dramatically reduced contents of MDA and enhanced activities of SOD and GSH-Px compared to NC shRNA + LPS group. In vitro, we found that knockdown of Poldip2 significantly reversed LPS-induced increase protein levels of Nox4 and p-P65, activity of NADPH, and generation of ROS, TNF-α, and IL-1β, and decrease protein levels of Nrf2 and HO-1, ML385 pretreatment reversed the effects of Poldip2 knockdown mentioned above. Our study indicated that Poldip2 knockdown alleviates LPS-induced ALI via inhibiting Nox4/Nrf2/NF-κB signaling pathway.

Clostridium difficile Induced Inflammasome Activation and Coagulation Derangements

C. difficile enterocolitis (CDAC) is the most common hospital infection, burdened by an increased incidence of coagulation-related complications such as deep vein thrombosis (DVT) and disseminated intravascular coagulation (DIC) as well as a significant sepsis-related mortality. In this review, we analyzed the available data concerning the correlation between coagulation complications related to C. difficile infection (CDI) and inflammasome activation, in particular the pyrin-dependent one. The little but solid available preclinical and clinical evidence shows that inflammasome activation increases the risk of venous thromboembolism (VTE). As proof of this, it has been observed that in vitro inhibition of the molecules (e.g., tissue factor) mainly involved in coagulation activation could block the process. In vivo studies show that it could be possible to reduce the incidence of complications associated with C. difficile infection (CDI) and mortality due to a state of hypercoagulability. A personalized therapeutic approach to reduce the inflammatory activity and prevent thromboembolic complications could be preliminarily defined to reduce mortality.

Oridonin Attenuates Burkholderia cenocepacia Virulence by Suppressing Quorum-Sensing Signaling

Burkholderia cenocepacia is a human opportunistic pathogen that mostly employs two types of quorum-sensing (QS) systems to regulate its various biological functions and pathogenicity: the cis-2-dodecenoic acid (BDSF) system and the N-acyl homoserine lactone (AHL) system. In this study, we reported that oridonin, which was screened from a collection of natural products, disrupted important B. cenocepacia phenotypes, including motility, biofilm formation, protease production, and virulence. Genetic and biochemical analyses showed that oridonin inhibited the production of BDSF and AHL signals by decreasing the expression of their synthase-encoding genes. Furthermore, we revealed that oridonin directly binds to the regulator RqpR of the two-component system RqpSR that dominates the above-mentioned QS systems to inhibit the expression of the BDSF and AHL signal synthase-encoding genes. Oridonin also binds to the transcriptional regulator CepR of the cep AHL system to inhibit its binding to the promoter of bclACB. These findings suggest that oridonin could potentially be developed as a new QS inhibitor against pathogenic B. cenocepacia. IMPORTANCE Burkholderia cenocepacia is an important human opportunistic pathogen that can cause life-threatening infections in susceptible individuals. It employs quorum-sensing (QS) systems to regulate biological functions and virulence. In this study, we have identified a lead compound, oridonin, that is capable of interfering with B. cenocepacia QS signaling and physiology. We demonstrate that oridonin suppressed cis-2-dodecenoic acid (BDSF) and N-acyl homoserine lactone (AHL) signal production and attenuated virulence in B. cenocepacia. Oridonin also impaired QS-regulated phenotypes in various Burkholderia species. These results suggest that oridonin could interfere with QS signaling in many Burkholderia species and might be developed as a new antibacterial agent.

Lactococcus lactis‑fermented spinach juice suppresses LPS‑induced expression of adhesion molecules and inflammatory cytokines through the NF‑κB pathway in HUVECs

Spinach (Spinacia oleracea L.), a green leafy vegetable, is widely regarded as a functional food due to its biological activities; however, to the best of our knowledge, there are no previous studies that have investigated the protective effects of fermented spinach against endothelial dysfunction and its underlying mechanisms. Therefore, this study investigated the effects and possible mechanisms of action of fresh spinach juice (S.juice) and fermented S.juice on lipopolysaccharide (LPS)-induced inflammatory responses in human umbilical vein endothelial cells (HUVECs). The HUVECs were treated with S.juice and fermented S.juice for 18 h before LPS exposure, and the levels of cytokines and chemokines, such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6), were detected using enzyme-linked immunosorbent assays (ELISA). Furthermore, to examine the changes in inflammatory responses to the two treatments, immunofluorescence analysis was used to visualize the nuclear translocation of nuclear factor-κB (NF-κB). Western blot analysis was also performed to detect the differences in the expression of endothelial cell adhesion molecules, specifically vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Both S.juice and fermented S.juice inhibited the LPS-induced expression of MCP-1 and IL-6, and suppressed VCAM-1 and ICAM-1. Additionally, fermented S.juice inhibited the LPS-induced activation of NF-κB and degradation of the inhibitor of NF-κB (IκBα) in an LPS dose-dependent manner. These results suggest that the anti-inflammatory effect of vitamin K₂-enriched fermented S.juice is mediated by the suppression of the NF-κB pathway, suggesting its potential as a novel therapeutic candidate for inflammatory cardiovascular disease.

Oridonin Relieves Angiotensin II-Induced Cardiac Remodeling via Inhibiting GSDMD-Mediated Inflammation

Myocardial remodeling is one of the main lesions in the late stage of chronic heart failure and seriously affects the prognosis of patients. Continuous activation of the renin-angiotensin-aldosterone system (RAAS) contributes to the development of myocardial remodeling greatly, and angiotensin II (Ang II), its main constituent, can directly lead to cardiac remodeling through an inflammatory response and oxidative stress. Since Ang II-induced myocardial remodeling is closely related to inflammation, we tried to explore whether the anti-inflammatory drug oridonin (Ori) can reverse this process and its possible mechanism. Our study investigated that hypertrophy and fibrosis can be induced after being treated with Ang II in cardiomyocytes (H9c2 cells and primary rat cardiomyocytes) and C57BL/6J mice. The anti-inflammatory drug oridonin could effectively attenuate the degree of cardiac remodeling both in vivo and vitro by inhibiting GSDMD, a key protein of intracellular inflammation which can further activate kinds of inflammation factors such as IL-1β and IL-18. We illustrated that oridonin reversed cardiac remodeling by inhibiting the process of inflammatory signaling through GSDMD. After inhibiting the expression of GSDMD in cardiomyocytes by siRNA, it was found that Ang II-induced hypertrophy was attenuated. These results suggest that oridonin is proved to be a potential protective drug against GSDMD-mediated inflammation and myocardial remodeling.

Phenols and terpenoids: natural products as inhibitors of NLRP3 inflammasome in cardiovascular diseases

Inflammatory infiltration has been implicated in the pathogenesis of cardiovascular diseases (CVDs). The NLRP3 inflammasome is involved in the development of several types of CVDs, including myocardial infarction, myocardial ischemia-reperfusion damage, heart failure, atrial fibrillation, and hypertension. Inhibiting the activity of NLRP3 inflammasome can inhibit the progress of CVDs. However, there is no NLRP3 inflammasome inhibitor in clinic, and it is very important to find a safe and effective NLRP3 inhibitor. Phenols and terpenoids are naturally natural products that have many anti-inflammatory effects in CVDs by modulating the NLRP3 inflammatory pathway. Thus, 20 natural products from phenols and terpenoids for the treatment of cardiovascular disease based on the inhibition of NLRP3 inflammasome were summarized and screened. Docking results showed salvianolic acid B and ellagic acid in phenols, and oridonin and triptolide in terpenoids had a better binding activity with NLRP3, which can provide theoretical support for finding novel NLRP3 inflammasome inhibitors or lead compounds in the future.

Effect of oridonin on oxylipins in the livers of mice with acute liver injury induced by D-galactosamine and lipopolysaccharide

BACKGROUND AND PURPOSE

Oridonin (Ori) has been shown to protect against acute liver injury (ALI) induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS). Oxylipins are oxidation products of polyunsaturated fatty acids (PUFAs) and are key proinflammatory mediators. This study aimed to investigate the changes in oxylipins in the livers of mice with D-GalN/LPS-induced ALI and the effects of Ori on these changes.

RESULTS

54 oxylipins in liver tissues were identified and qualitatively and quantitatively analyzed by ultra-performance liquid chromatography-electrospray ionization triple quadrupole mass spectrometry (UPLC-QTRAP/MS/MS). The levels of 12-HETE, 12-HEPE, 14(S)-HDHA, PGE2, dihomo-γ-linolenic acid and 13-HOTrE in the liver were significantly increased in the D-GalN/LPS-induced ALI group compared with the control group, and the levels of EPA and 7-HDHA were significantly decreased. However, pretreatment with Ori dramatically decreased the levels of 12-HETE, 12-HEPE, 14(S)-HDHA, PGE2 and 13-HOTrE compared with those of the ALI group and induced 7-HDHA and 15-oxoETE. Moreover, Ori reduced the protein levels of COX-1, COX-2, ALOX5, ALOX12 and ALOX15 induced by D-GalN/LPS, indicating that Ori altered oxylipins through the COX and LOX pathways.

CONCLUSIONS

These results suggest that the protective effect of Ori on ALI is partly mediated by affecting the oxylipin pathway.

Biophysical and biochemical properties of PHGDH revealed by studies on PHGDH inhibitors

The rate-limiting serine biogenesis enzyme PHGDH is overexpressed in cancers. Both serine withdrawal and genetic/pharmacological inhibition of PHGDH have demonstrated promising tumor-suppressing activities. However, the enzyme properties of PHGDH are not well understood and the discovery of PHGDH inhibitors is still in its infancy. Here, oridonin was identified from a natural product library as a new PHGDH inhibitor. The crystal structure of PHGDH in complex with oridonin revealed a new allosteric site. The binding of oridonin to this site reduced the activity of the enzyme by relocating R54, a residue involved in substrate binding. Mutagenesis studies showed that PHGDH activity was very sensitive to cysteine mutations, especially those in the substrate binding domain. Conjugation of oridonin and other reported covalent PHGDH inhibitors to these sites will therefore inhibit PHGDH. In addition to being inhibited enzymatically, PHGDH can also be inhibited by protein aggregation and proteasome-mediated degradation. Several tested PHGDH cancer mutants showed altered enzymatic activity, which can be explained by protein structure and stability. Overall, the above studies present new biophysical and biochemical insights into PHGDH and may facilitate the future design of PHGDH inhibitors.

Oridonin inhibits SASP by blocking p38 and NF-κB pathways in senescent cells

Cellular senescence is a state of irreversible cell growth arrest that functions as a biological defense mechanism against severe DNA damage. Senescent cells with DNA damage produce pro-inflammatory cytokines, such as IL-6 and IL-8, and this phenomenon is called the senescence-associated secretory phenotype (SASP). SASP factors have been implicated in various disorders, including cancer. We performed a screening assay and identified oridonin as a candidate SASP inhibitor. Oridonin is an active diterpenoid that is isolated from Isodon plants and has been reported to exhibit anti-inflammatory, antibacterial, antioxidant, and antitumor activities. It reduced the secretion of IL-6 and IL-8 in senescent cells at the protein and mRNA levels. Oridonin also inhibited p65 subunit of NF-κB activity. However, oridonin did not affect SA β-gal activity and enhanced the expression of p21. The expression and phosphorylation of p38 were down-regulated by oridonin. The p38 inhibitor SB203580 inhibited the secretion of IL-8, slightly inhibited the secretion of IL-6, and did not affect NF-κB activity. Therefore, the NF-κB and p38 pathways may contribute to the inhibition of SASP by oridonin. Oridonin has potential as a therapeutic agent for SASP-related diseases.

Nicaraven inhibits TNFα-induced endothelial activation and inflammation through suppression of NF-κB signaling pathway

Inflammation-induced activation and dysfunction of endothelial cells play an important role in the pathology of multiple vascular diseases. Nicaraven, a potent hydroxyl radical scavenger, has recently been found to have anti-inflammatory roles; however, the mechanism of its action is not fully understood. Here we investigated the effects of Nicaraven on tumor necrosis factor α (TNFα) - induced inflammatory response in human umbilical vein endothelial cells and we explore the underlying mechanisms related to the nuclear factor-κB (NF-κB) signaling pathway. Our results showed that Nicaraven significantly reduced the reactive oxygen species production after TNFα stimulation. Nicaraven suppressed TNFα-induced mRNA expression of multiple adhesion molecules and pro-inflammatory cytokines, including vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), E-selectin, MCP-1, TNFα, interleukin-1β (IL-1β), IL-6, and IL-8. In addition, Nicaraven inhibited monocyte adhesion and reduced the protein levels of VCAM-1 and ICAM-1. Mechanistically, Nicaraven prevented TNFα-induced activation of NF-κB signaling pathway by suppressing the phosphorylation of NF-κB p65, IκBα, and IκB kinase (IKK)α/β, stabilizing IκBα, and inhibiting the translocation of p65 from cytosol to nucleus. Finally, we showed that Nicaraven improved the functions of endothelial cells, seen as the upregulation of endothelial nitric oxide synthase and increased nitric oxide levels. Our findings indicated that Nicaraven effectively inhibits TNFα-induced endothelial activation and inflammatory response at least partly through inhibiting NF-κB signaling pathway.

Oridonin: A Review of Its Pharmacology, Pharmacokinetics and Toxicity

Oridonin, as a natural terpenoids found in traditional Chinese herbal medicine Isodon rubescens (Hemsl.) H.Hara, is widely present in numerous Chinese medicine preparations. The purpose of this review focuses on providing the latest and comprehensive information on the pharmacology, pharmacokinetics and toxicity of oridonin, to excavate the therapeutic potential and explore promising ways to balance toxicity and efficacy of this natural compound. Information concerning oridonin was systematically collected from the authoritative internet database of PubMed, Elsevier, Web of Science, Wiley Online Library and Europe PMC applying a combination of keywords involving "pharmacology," "pharmacokinetics," and "toxicology". New evidence shows that oridonin possesses a wide range of pharmacological properties, including anticancer, anti-inflammatory, hepatorenal activities as well as cardioprotective protective activities and so on. Although significant advancement has been witnessed in this field, some basic and intricate issues still exist such as the specific mechanism of oridonin against related diseases not being clear. Moreover, several lines of evidence indicated that oridonin may exhibit adverse effects, even toxicity under specific circumstances, which sparked intense debate and concern about security of oridonin. Based on the current progress, future research directions should emphasize on 1) investigating the interrelationship between concentration and pharmacological effects as well as toxicity, 2) reducing pharmacological toxicity, and 3) modifying the structure of oridonin-one of the pivotal approaches to strengthen pharmacological activity and bioavailability. We hope that this review can provide some inspiration for the research of oridonin in the future.

Oridonin Attenuates the Effects of Chronic Alcohol Consumption Inducing Oxidative, Glycative and Inflammatory Injury in the Mouse Liver

BACKGROUND/AIM

Oridonin (Ori) is a diterpenoid naturally present in medicinal plants with a potential as an antioxidant agent. This study aimed to evaluate the hepatic anti-oxidative, anti-glycative and anti-inflammatory properties of Ori at 0.125 and 0.25% against chronic ethanol intake in mice.

MATERIALS AND METHODS

Mice were divided into five groups: i) normal diet group, ii) Ori group, iii) ethanol diet (Lieber-DeCarli liquid diet with ethanol) group, iv) ethanol diet plus 0.125% Ori and v) ethanol diet plus 0.25% Ori. After 8 weeks of Ori supplementation, blood and liver tissue were used for analyses.

RESULTS

Ethanol increased the production of reactive oxygen species and nitric oxide, decreased glutathione content, and lowered the activity of glutathione peroxide, glutathione reductase and catalase. Ethanol suppressed the hepatic mRNA expression of nuclear factor E2-related factor 2. Ori supplements reversed these changes. Ethanol increased hepatic N^e-(carboxyethymethyl)-lysine (CML) and pentosidine levels, and enhanced aldose reductase (AR) activity and mRNA expression. Ori supplements at only 0.25% decreased CML and pentosidine levels, and lowered the AR activity as well as its mRNA expression. Ethanol increased the hepatic release of tumor necrosis factor-alpha, transforming growth factor-beta1, interleukin (IL)-1beta and IL-6. Histological data showed that ethanol induced necrosis and inflammatory cell infiltration, while Ori supplements alleviated these inflammatory responses. Ethanol up-regulated the hepatic mRNA expression of nuclear factor kappa B, myeloperoxidase and p38. Ori supplements reversed these changes.

CONCLUSIONS

These novel findings suggest that Ori could be used as a potent agent against alcohol-induced hepatotoxicity.

Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases

The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition to NLRP3-mediated diseases. For this purpose, we performed a systematic literature search by screening PubMed, Scopus, and Google Scholar databases. By compiling the data of phytochemical inhibitors targeting NLRP3 inflammasome activation, a complex balance between inflammasome activation or inhibition with NLRP3 as central player was pointed out in NLRP3-driven pathological conditions. Phytochemicals represent potential therapeutic leads, enabling the generation of chemical derivatives with improved pharmacological features to treat NLRP3-mediated inflammatory diseases.

Vascular Stress Signaling in Hypertension

Cells respond to stress by activating a variety of defense signaling pathways, including cell survival and cell death pathways. Although cell survival signaling helps the cell to recover from acute insults, cell death or senescence pathways induced by chronic insults can lead to unresolved pathologies. Arterial hypertension results from chronic physiological maladaptation against various stressors represented by abnormal circulating or local neurohormonal factors, mechanical stress, intracellular accumulation of toxic molecules, and dysfunctional organelles. Hypertension and aging share common mechanisms that mediate or prolong chronic cell stress, such as endoplasmic reticulum stress and accumulation of protein aggregates, oxidative stress, metabolic mitochondrial stress, DNA damage, stress-induced senescence, and proinflammatory processes. This review discusses common adaptive signaling mechanisms against these stresses including unfolded protein responses, antioxidant response element signaling, autophagy, mitophagy, and mitochondrial fission/fusion, STING (signaling effector stimulator of interferon genes)-mediated responses, and activation of pattern recognition receptors. The main molecular mechanisms by which the vasculature copes with hypertensive and aging stressors are presented and recent advancements in stress-adaptive signaling mechanisms as well as potential therapeutic targets are discussed.

Cinnamaldehyde Could Reduce the Accumulation of Diarrhetic Shellfish Toxins in the Digestive Gland of the Mussel Perna viridis under Laboratory Conditions

Diarrhetic shellfish toxins (DSTs), some of the most important phycotoxins, are distributed almost all over the world, posing a great threat to human health through the food chain. Therefore, it is of great significance to find effective methods to reduce toxin accumulation in shellfish. In this paper, we observed the effects of four phytochemicals including cinnamaldehyde (CA), quercetin, oridonin and allicin on the accumulation of DSTs in the digestive gland of Perna viridis after exposure to the DSTs-producing Prorocentrum lima. We found that, among the four phytochemicals, CA could effectively decrease the accumulation of DSTs (okadaic acid-eq) in the digestive gland of P. viridis. Further evidence demonstrated that CA could reduce the histological alterations of the digestive gland of a mussel caused by DSTs. RT-qPCR showed that CA could suppress the CYP3A4 induction by DSTs, suggesting that the DSTs’ decrease induced by CA might be related to the inhibition of CYP3A4 transcription induction. However, further studies on the underlying mechanism, optimal treatment time, ecological safety and cost should be addressed before cinnamaldehyde is used to decrease the accumulation of DSTs in field.

Oridonin alleviates d-GalN/LPS-induced acute liver injury by inhibiting NLRP3 inflammasome

Acute liver injury (ALI) is a serious syndrome that is associated with high mortality, but there are few effective treatments. The activation of NLRP3 inflammasome is associated with ALI. Oridonin is a natural substance with an anti-inflammatory effect and has been reported to be an inhibitor of NLRP3. The aim of this study was to investigate the protective effect of oridonin on d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced ALI and whether the effect is mediated by NLRP3. Mice were pretreated with oridonin (5 or 10 mg/kg) for 3 days. Then, they were injected with d-GalN (400 mg/kg) and LPS (40 μg/kg). The levels of inflammatory factors were measured by RT-PCR, Western blot, and enzyme-linked immunosorbent assay. We confirmed that oridonin significantly alleviated ALI induced by d-GalN/LPS in mice. Oridonin markedly decreased the inflammatory response by reducing the levels of inflammatory cytokines. More importantly, oridonin markedly reduced the expression of NLRP3, caspase-1, IL-18, and IL-1β. This study showed that oridonin has a protective effect on d-GalN/LPS-induced ALI, and the underlying mechanisms may be associated with the inhibition of the NLRP3 inflammatory pathways.

Recent Progress of Oridonin and Its Derivatives for the Treatment of Acute Myelogenous Leukemia

First stage human clinical trial (CTR20150246) for HAO472, the L-alanine-(14-oridonin) ester trifluoroacetate, was conducted by a Chinese company, Hengrui Medicine Co. Ltd, to develop a new treatment for acute myelogenous leukemia. Two patents, WO2015180549A1 and CN201410047904.X, covered the development of the I-type crystal, stability experiment, conversion rate research, bioavailability experiment, safety assessment, and solubility study. HAO472 hewed out new avenues to explore the therapeutic properties of oridonin derivatives and develop promising treatment of cancer originated from naturally derived drug candidates. Herein, we sought to overview recent progress of the synthetic, physiological, and pharmacological investigations of oridonin and its derivatives, aiming to disclose the therapeutic potentials and broaden the platform for the discovery of new anticancer drugs.

Neferine suppresses vascular endothelial inflammation by inhibiting the NF-κB signaling pathway

The vascular endothelium, as the interface between the blood and the surrounding tissues, plays a pivotal role in inflammation. Neferine, which was isolated from Lotus Plumule, has many biological roles, such as antifibrotic, antioxidative, anti-inflammatory, and antineoplastic activities. We demonstrated the role of neferine in the inhibition of pro-adhesion and pro-inflammatory responses of endothelial cells in vitro. We found that neferine could significantly inhibit the adhesion of Tohoku Hospital Pediatrics-1 (THP-1) cells to primary human umbilical vein endothelial cells (HUVECs). At the molecular level, neferine could significantly alleviate the interleukin 1β (IL-1β)-induced mRNA and protein expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1). Our data showed that neferine suppressed nuclear factor-κB (NF-κB) nuclear translocation and inhibited the NF-κB-p65-induced transcriptional activity of ICAM1 and VCAM1. Therefore, we concluded that neferine suppressed the inflammatory response in endothelial cells in vitro, which could be mainly due to inhibition of NF-κB signaling activation. Moreover, we found that neferine alleviated LPS-induced acute inflammation injury in vivo. Thus, neferine may serve as an effective regulator during the pathogenesis of vascular inflammatory diseases.

Diagnostic and prognostic potential of circulating miRNAs for intracranial aneurysms

Intracranial aneurysm (IA) is an abnormal focal dilation of an artery in the brain that results from a weakening of the inner muscular layer of a blood vessel wall. IAs represent the most common etiology of nontraumatic subarachnoid hemorrhage (SAH). Despite technological advances in the treatment and use of new diagnostic methods for IAs, they continue to pose a significant risk of mortality and disability. Thus, early recognition of IA with a high risk of rupture is crucial for the stratification of patients with such a formidable disease. MicroRNAs (miRNA) are endogenous noncoding RNAs of 18-22 nucleotides that regulate gene expression at the post-transcriptional level through interaction with 3'-untranslated regions (3'UTRs) of the target mRNAs. MiRNAs are involved in the pathogenesis of IAs, including in the mechanisms of formation, growth, and rupture. It is known that in many biological fluids of the human body, such as blood or cerebrospinal fluid (CSF), numerous miRNAs, called circulating miRNAs, have been detected. The expression profile of circulating miRNAs represents a certain part of the cells in which they are modified and secreted in accordance with the physiological or pathological conditions of these cells. Circulating miRNAs can be secreted from cells into human biological fluids in extracellular vesicles or can be bound to Ago2 protein, which makes them resistant to the effects of RNAse. Therefore, circulating miRNAs are considered as new potential biomarkers of interest in many diseases, including IA.

Promote anti-inflammatory and angiogenesis using a hyaluronic acid-based hydrogel with miRNA-laden nanoparticles for chronic diabetic wound treatment

Chronic diabetic wound causes serious threat to human health due to its long inflammatory phase and the reduced vascularization. Herein, we develop a hydrogel system for the treatment of diabetic wound, which can short the inflammatory stage (through the use of ori) and promote the angiogenesis (through the addition of siRNA-29a gene). Based on the Schiff base bonds, the Gel/Alg@ori/HA-PEI@siRNA-29a hydrogel was prepared by mixing oxidized hydroxymethyl propyl cellulose (OHMPC), adipic dihydrazide-modified hyaluronic acid (HA-ADH), oridonin (ori) loaded alginate microspheres (Alg@ori) and siRNA-29a gene-loading hyaluronic acid-polyethyleneimine complex HA-PEI@siRNA-29a (HA-PEI@siRNA-29a) under physiological conditions, which had moderate mechanical strength, appropriate swelling property, impressive stability, and slow release ability of ori and siRNA-29a. Excellent biocompatibility of the prepared hydrogel was also confirmed by in vitro mouse fibroblasts L929 cells culture study. Moreover, in vivo experiments further demonstrated that the prepared Gel/Alg@ori/HA-PEI@siRNA-29a hydrogel not only significantly accelerated the diabetic wound healing, angiogenesis factors (α-SMA and CD31) production, but also inhibited pro-inflammatory factors (IL-6 and TNF-α). In summary, we believe that the prepared hydrogels exhibit great potential for the treatment of chronic diabetic wound.

Mir-331-3p Inhibits PRRSV-2 Replication and Lung Injury by Targeting PRRSV-2 ORF1b and Porcine TNF-α

Porcine reproductive and respiratory syndrome (PRRS) caused by a single-stranded RNA virus (PRRSV) is a highly infectious respiratory disease and leads to huge economic losses to the swine industry worldwide. To investigate the role of miRNAs in the infection and lung injury induced by PRRSV, the differentially expressed miRNAs (DE-miRs) were isolated from PRRSV-2 infected/mock-infected PAMs of Meishan, Landrace, Pietrain, and Qingping pigs at 9, 36, and 60 hpi. Mir-331-3p was the only common DE-miR in each set of miRNA expression profile at 36 hpi. Mir-210 was one of 7 common DE-miRs between PRRSV infected and mock-infected PAMs of Meishan, Pietrain, and Qingping pigs at 60 hpi. Mir-331-3p/mir-210 could target PRRSV-2 ORF1b, bind and downregulate porcine TNF-α/STAT1 expression, and inhibit PRRSV-2 replication, respectively. Furthermore, STAT1 and TNF-α could mediate the transcriptional activation of MCP-1, VCAM-1, and ICAM-1. STAT1 could also upregulate the expression of TNF-α by binding to its promoter region. In vivo, pEGFP-N1-mir-331-3p could significantly reduce viral replication and pathological changes in PRRSV-2 infected piglets. Taken together, Mir-331-3p/mir-210 have significant roles in the infection and lung injury caused by PRRSV-2, and they may be promising therapeutic targets for PRRS and lung injury/inflammation.

NLRP3 inflammasome in endothelial dysfunction

Inflammasomes are a class of cytosolic protein complexes. They act as cytosolic innate immune signal receptors to sense pathogens and initiate inflammatory responses under physiological and pathological conditions. The NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex. Its activation triggers the cleavage of pro-interleukin (IL)-1β and pro-IL-18, which are mediated by caspase-1, and secretes mature forms of these mediators from cells to promote the further inflammatory process and oxidative stress. Simultaneously, cells undergo pro-inflammatory programmed cell death, termed pyroptosis. The danger signals for activating NLRP3 inflammasome are very extensive, especially reactive oxygen species (ROS), which act as an intermediate trigger to activate NLRP3 inflammasome, exacerbating subsequent inflammatory cascades and cell damage. Vascular endothelium at the site of inflammation is actively involved in the regulation of inflammation progression with important implications for cardiovascular homeostasis as a dynamically adaptable interface. Endothelial dysfunction is a hallmark and predictor for cardiovascular ailments or adverse cardiovascular events, such as coronary artery disease, diabetes mellitus, hypertension, and hypercholesterolemia. The loss of proper endothelial function may lead to tissue swelling, chronic inflammation, and the formation of thrombi. As such, elimination of endothelial cell inflammation or activation is of clinical relevance. In this review, we provided a comprehensive perspective on the pivotal role of NLRP3 inflammasome activation in aggravating oxidative stress and endothelial dysfunction and the possible underlying mechanisms. Furthermore, we highlighted the contribution of noncoding RNAs to NLRP3 inflammasome activation-associated endothelial dysfunction, and outlined potential clinical drugs targeting NLRP3 inflammasome involved in endothelial dysfunction. Collectively, this summary provides recent developments and perspectives on how NLRP3 inflammasome interferes with endothelial dysfunction and the potential research value of NLRP3 inflammasome as a potential mediator of endothelial dysfunction.

Chicoric acid attenuates hyperglycemia-induced endothelial dysfunction through AMPK-dependent inhibition of oxidative/nitrative stresses

BACKGROUND

Endothelial dysfunction is a driving force during the development and progression of cardiovascular complications in diabetes. Targeting endothelial injury may be an attractive avenue for the management of diabetic vascular disorders. Chicoric acid is reported to confer antioxidant and anti-inflammatory properties in various diseases including diabetes. However, the role and mechanism of chicoric acid in hyperglycemia-induced endothelial damage are not well understood.

METHODS

In the present study, human umbilical vein endothelial cells (HUVECs) were incubated with high glucose/high fat (HG + HF) to induce endothelial cell injury.

RESULTS

We found that exposure of HUVECs to HG + HF medium promoted the release of cytochrome c (cytc) from mitochondrion into the cytoplasm, stimulated the cleavage of caspase-3 and poly ADP-ribose-polymerase (PARP), then inducing cell apoptosis, the effects that were prevented by administration of chicoric acid. Besides, we found that chicoric acid diminished HG + HF-induced phosphorylation and degradation of IκBα, and subsequent p65 NFκB nuclear translocation, thereby contributing to its anti-inflammatory effects in HUVECs. We also confirmed that chicoric acid mitigated oxidative/nitrative stresses under HG + HF conditions. Studies aimed at exploring the underlying mechanisms found that chicoric acid activated the AMP-activated protein kinase (AMPK) signaling pathway to attenuate HG + HF-triggered injury in HUVECs as AMPK inhibitor Compound C or silencing of AMPKα1 abolished the beneficial effects of chicoric acid in HUVECs.

CONCLUSION

Collectively, chicoric acid is likely protected against diabetes-induced endothelial dysfunction by activation of the AMPK signaling pathway. Chicoric acid could be a novel candidate for the treatment of the diabetes-associated vascular endothelial injury.

Oridonin and its derivatives for cancer treatment and overcoming therapeutic resistance

Cancer is one of the diseases with high morbidity and mortality on a global scale. Chemotherapy remains the primary treatment option for most cancer patients, including patients with progressive, metastatic, and recurrent diseases. To date, hundreds of chemotherapy drugs are used to treat various cancers, however, the anti-cancer efficacy and outcomes are largely hampered by chemotherapy-associated toxicity and acquired therapeutic resistance. The natural product (NP) oridonin has been extensively studied for its anti-cancer efficacy. More recently, oridonin has been shown to overcome drug resistance through multiple mechanisms, with yet-to-be-defined bona fide targets. Hundreds of oridonin derivative analogs (oridonalogs) have been synthesized and screened for improved potency, bioavailability, and other drug properties. Particularly, many of these oridonalogs have been tested against oridonin for tumor growth inhibition, potential for overcoming therapeutic resistance, and immunity modulation. This concise review seeks to summarize the advances in this field in light of identifying clinical-trial level drug candidates with the promise for treating progressive cancers and reversing chemoresistance.

Oridonin Attenuates Myocardial Ischemia/Reperfusion Injury via Downregulating Oxidative Stress and NLRP3 Inflammasome Pathway in Mice

Oridonin (ORI), the major pharmacological component extracted from a traditional Chinese medicine, possesses a beneficial effect on myocardial ischemia/reperfusion (I/R) injury. However, the underlying molecular mechanism by which ORI effects take place is not completely known. Thus, whether ORI works via downregulating oxidative stress and nod-like receptor protein-3 (NLRP3) inflammasome pathway was investigated in this study. Mice underwent surgery to induce myocardial I/R injury, and some were administered ORI (10 mg/kg/day) pretreatment, while others were not. The myocardial enzymes' levels, infarct area, and inflammatory injury were measured. The activation situation of oxidative stress and NLRP3 inflammasome was also detected. We found that ORI pretreatment significantly alleviated CK-MB and cTnI levels and infarct size induced by I/R. ORI mitigated the inflammatory injury by decreasing the pathological damage and lowering TNF-α, IL-1β, and IL-18 levels. Moreover, the SOD1 and eNOS levels were significantly increased by ORI, while MDA and iNOS levels were relatively decreased. The oxidative stress was reversed using ORI pretreatment. Importantly, NLRP3 inflammasome pathway was also inhibited by ORI, as reflected by the lower protein levels of NLRP3, caspase-1, and IL-1β. In conclusion, ORI alleviates myocardial injury induced by I/R via inhibiting the oxidative stress and NLRP3 inflammasome pathway.

Mn-TAT PTD-Ngb ameliorates inflammation through the elimination of damaged mitochondria and the activation of Nrf2-antioxidant signaling pathway

Inflammation, mitochondrial dysfunction and oxidative stress are closely associated with neurological diseases. In this study, Mn-TAT PTD-Ngb, a novel artificial recombinant protein, exerted inhibitory effects on the inflammatory response and inflammasome activation. During the lipopolysaccharide (LPS)-induced inflammatory response, Mn-TAT PTD-Ngb suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and the release of proinflammatory cytokines and attenuated the phosphorylation of mitogen-activated protein kinase (MAPK). Furthermore, the recombinant protein blocked reactive oxygen species (ROS) production, abated mitochondrial dysfunction and significantly suppressed the assembly of the inflammasome, which led to the overproduction of proinflammatory cytokines IL-1β and IL-18. Mn-TAT PTD-Ngb increased the level of nuclear factor-erythroid 2 -related factor 2 (Nrf2), which protected against oxidative stress and improved pyroptosis. Mn-TAT PTD-Ngb might be a promising drug for curing neurological diseases.

Diterpenoids from Isodon rubescens and their nitric oxide production inhibitory activity

Six new ent-kaurane diterpenoids, isodonrubescins A-F (1-6), together with twenty-five known ent-kaurane diterpenoids (7-31), a known ent-atisane diterpenoid (32), and two known ent-abietane diterpenoids (33-34), were isolated from Isodon rubescens. Their structures were established by means of extensive MS and NMR data analysis. Among the all isolates, compound 7 was found in a natural product for the first time, and ent-atisane diterpenoid was discovered from I. rubescens in Hubei Province, P. R. China for the first time. Furthermore, all the isolated compounds were tested for their NO production inhibitory activity in LPS stimulated RAW264.7 cells. Compounds 7-9, 12, 13, 16, and 17 displayed NO production inhibitory activities with IC50 values ranging from 1.36 to 18.25 μM, respectively.

Salidroside prevents tumor necrosis factor-α-induced vascular inflammation by blocking mitogen-activated protein kinase and NF-κB signaling activation

Vascular inflammation is a key factor in the pathogenesis of atherosclerosis. Salidroside is an important active ingredient extracted from the root of the Rhodiola rosea plant, which has been reported to have antioxidative, anti-cancer, neuroprotective and cardioprotective effects. However, the effects of salidroside on vascular inflammation have not been clarified. The purpose of the present study was to investigate the protective effects of salidroside against tumor necrosis factor (TNF)-α-induced vascular inflammation in cardiac microvascular endothelial cells (CMECs), a specific cell type derived from coronary micro-vessels. Over a 24-h period, salidroside did not exert any significant cytotoxicity up to a dose of 100 µM. Additionally, salidroside decreased the expression levels of the cell adhesion molecule vascular cell adhesion molecule-1 (VCAM-1) in TNF-α-stimulated CMECs, thus suppressing monocyte-to-CMEC adhesion. Salidroside also decreased the production of inflammatory cytokines such as interleukin (IL)-1β, IL-6 and monocyte chemotactic protein 1 (MCP-1) in TNF-α-induced CMECs, as well as suppressing TNF-α-activated mitogen-activated protein kinase (MAPK) and NF-κB activation. Since MAPKs and NF-κB both serve notable roles in regulating the expression of VCAM-1, IL-1β, IL-6 and MCP-1, the present study provided a preliminary understanding of the mechanism underlying the protective effects of salidroside. Overall, salidroside alleviated vascular inflammation by mediating MAPK and NF-κB activation in TNF-α-induced CMECs. These results indicated that salidroside may have potential applications as a therapeutic agent against vascular inflammation and atherosclerosis.

Oridonin enhances TRAIL-induced apoptosis through GALNT14-mediated DR5 glycosylation

Oridonin is a diterpenoid isolated from the Rabdosia rubescens and has multiple biological effects, such as anti-inflammation and anti-tumor activities. In present study, we revealed that the sensitizing effect of oridonin on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in several cancer cells, but not in normal cells. Oridonin enhanced death-signaling inducing complexes (DISC) formation and DR5 glycosylation without affecting expression of downstream intracellular apoptosis-related proteins. Oridonin upregulated peptidyl O-glycosyltransferase GALNT14 in a dose- and time-dependent manner. Knockdown of GALNT14 by siRNA and Endo H treatment reduced oridonin-induced DR5 glycosylation. Furthermore, treatment with inhibitor of glycosylation (benzyl-α-GalNAc) blocked oridonin plus TRAIL-induced apoptosis. Collectively, our results suggest that oridonin-induced DR5 glycosylation contributes to TRAIL-induced apoptotic cell death in cancer cells.

Naringenin attenuates carotid restenosis in rats after balloon injury through its anti-inflammation and anti-oxidative effects via the RIP1-RIP3-MLKL signaling pathway

Vascular restenosis has been proved as the major drawback of percutaneous coronary interventions, which is characterized by neointimal hyperplasia. Naringenin is a kind of natural dihydroflavonoid with a variety of beneficial effects, including anti-oxidative, anti-microbial, anti-cancer and anti-inflammatory properties. However, the effects of naringenin on vascular restenosis remain unclear. This study aimed at investigating the effect and the mechanisms of naringenin on balloon injury (BI)-induced neointimal hyperplasia in the common carotid artery (CCA). BI model of CCA was induced by a 2F Forgarty catheter balloon, and the pathological process of neointimal hyperplasia was noted at 1, 3, 7 and 14 days. Neointimal hyperplasia in CCA increased significantly, especially on day 14 after BI. Subsequently, naringenin (25, 50, 100 mg/kg/d) or volume-matched vehicle were administered to the rats by gavage daily for 14 days. Ultrasound detection and histopathological examination showed that naringenin dose-dependently inhibited BI-induced intimal hyperplasia, as evidenced by reducing imima-media thickness (IMT), neointimal area (NIA), neointimal area/media area (NIA/MA) and neointimal area/internal elastic area (NIA/IELA). Immunohistochemistry revealed that naringenin decreased the expression of proliferating cell nuclear antigen (PCNA) and the cluster of differentiation 163 (CD163). ELISA indicated naringenin significantly reduced the overproduction of IL-1β and TNF-α. By detecting the activity of superoxide dismutase and the level of malondialdehyde and glutathione, we found that naringenin attenuated BI-induced oxidative stress. Additionally, RT-qPCR demonstrated that receptor-interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain-like (MLKL) mRNA expression were further down-regulated by naringenin treatment. These results suggested that naringenin can suppress BI-induced vascular neointimal hyperplasia through anti-inflammation and anti-oxidative stress, which may be related to the regulation of RIP1-RIP3-MLKL signaling pathway.

Oridonin protects LPS-induced acute lung injury by modulating Nrf2-mediated oxidative stress and Nrf2-independent NLRP3 and NF-κB pathways

Background

Oxidative stress and the resulting inflammation are essential pathological processes in acute lung injury (ALI). Nuclear factor erythroid 2-related factor 2 (Nrf2), a vital transcriptional factor, possesses antioxidative potential and has become a primary target to treat many diseases. Oridonin (Ori), isolated from the plant Rabdosia Rrubescens, is a natural substance that possesses antioxidative and anti-inflammatory effects. Our aim was to study whether the anti-inflammatory and antioxidant effects of Ori on LPS-induced ALI were mediated by Nrf2.

Methods

MTT assays, Western blotting analysis, a mouse model, and hematoxylin-eosin (H & E) staining were employed to explore the mechanisms by which Ori exerts a protective effect on LPS-induced lung injury in RAW264.7 cells and in a mouse model.

Results

Our results indicated that Ori increased the expression of Nrf2 and its downstream genes (HO-1, GCLM), which was mediated by the activation of Akt and MAPK. Additionally, Ori inhibited LPS-induced activation of the pro-inflammatory pathways NLRP3 inflammasome and NF-κB pathways. These two pathways were also proven to be Nrf2-independent by the use of a Nrf2 inhibitor. In keeping with these findings, Ori alleviated LPS-induced histopathological changes, the enhanced production of myeloperoxidase and malondialdehyde, and the depleted expression of GSH and superoxide dismutase in the lung tissue of mice. Furthermore, the expression of LPS-induced NLRP3 inflammasome and NF-κB pathways was more evident in Nrf2-deficient mice but could still be reversed by Ori.

Conclusions

Our results demonstrated that Ori exerted protective effects on LPS-induced ALI via Nrf2-independent anti-inflammatory and Nrf2-dependent antioxidative activities.

Oridonin inhibits LPS-induced inflammation in human gingival fibroblasts by activating PPARγ

Oridonin, the major terpene isolated from Rabdosia rubescens, has been used as dietary supplement. Recently, it has been known to exhibit anti-inflammatory effect. This study we employed an in vitro model of LPS-stimulated human gingival fibroblasts to investigate the anti-inflammatory effects and mechanism of oridonin. Oridonin (10-30 μg/mL) was administrated 1 h before LPS treatment. The results showed that oridonin significantly inhibited inflammatory mediators PGE₂, NO, IL-6, and IL-8 production. Immunoblotting experiments revealed that oridonin reduced the expression of phosphorylation levels of NF-κB p65 and IκBα. Furthermore, the expression of PPARγ was up-regulated by the treatment of oridonin. Further studies showed that PPARγ inhibitor GW9662 could reverse the inhibition of oridonin on PGE₂, NO, IL-6, and IL-8 production. In conclusion, oridonin inhibited LPS-induced microglia activation through activating PPARγ.

Oridonin inhibits IL-1β-induced inflammation in human osteoarthritis chondrocytes by activating PPAR-γ

Osteoarthritis (OA), a progressive disease of the joints, affects millions of people worldwide. In the present study, we investigated the effects of oridonin, a diterpenoid isolated from Rabdosia rubescens, on IL-1β-induced inflammation using human osteoarthritis chondrocytes. The results showed that oridonin significantly suppressed IL-1β-induced MMP1, MMP3, and MMP13 production. IL-1β-induced NO and PGE₂ production, as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were also attenuated by oridonin. Western blot analysis demonstrated IL-1β-induced NF-κB activation was reduced by oridonin. Furthermore, the expression of PPAR-γ was increased by oridonin in a concentration-dependent manner. PPAR-γ antagonist could reverse the anti-inflammatory activity of oridonin. The results suggested that oridonin could be a candidate agent for the treatment of OA.

Senkyunolide H protects against MPP+-induced apoptosis via the ROS-mediated mitogen-activated protein kinase pathway in PC12 cells

Senkyunolide H (SNH) is a phthalide isolated from the rhizome of Ligusticum chuanxiong Hort. that has been reported to have several pharmacological activities, including anti-atherosclerotic, antiproliferative, and cytoprotective effects. In this study, we investigated the neuroprotective effects and potential mechanisms of SNH against 1-methyl-4-phenylpyridinium (MPP⁺)-induced oxidative stress. We demonstrated that SNH pretreatment significantly attenuated MPP⁺-induced neurotoxicity and apoptosis in PC12 cells. In addition, SNH attenuated the effect of MPP⁺ on the expression of the pro-apoptotic factors Bax and caspase-3. Meanwhile, SNH prevented oxidative stress by reducing reactive oxygen species generation, mitochondrial membrane potential loss, cytochrome C release, and malondialdehyde levels while increasing antioxidant enzyme activity (e.g., superoxide dismutase, catalase, and glutathione peroxidase). In addition, SNH inhibited nuclear accumulation of nuclear factor-κB and c-Jun N-terminal kinase and phosphorylation p38 mitogen-activated protein kinases (MAPKs). Overall, this investigation provides novel evidence that SNH exerts neuroprotective effects via the ROS-mediated MAPK pathway and represents a potential preventive or therapeutic agent for neuronal disorders.