Luteolin suppresses inflammation through inhibiting cAMP-phosphodiesterases activity and expression of adhesion molecules in microvascular endothelial cells

Investigating the Effects and Mechanisms of Cyclomorusin on Osteoclasts in a High Glucose Environment

Diabetes mellitus is an endocrine disease characterized by prolonged hyperglycemia. Prolonged high blood sugar levels interfere with the differentiation and maturation process of OBs and OCs, leading to the onset of osteoporosis. However, OCs differentiation and maturation is a complex regulatory process. In this study, we used a co-culture system of RAW264.7 and MC3T3-E1 cells under HG concentration to explore the effect of CYM on OCs in a HG environment. The effects of CYM on the formation and function of OCs were observed using TRAP-positive cell counts and bone resorption pits. Then, mRNA and protein expression levels of OCs-related genes were detected by real-time qPCR and western blotting. The results showed that CYM had an inhibitory effect on OCs differentiation and bone resorption, reduced mRNAs expression of OCs-associated genes, and downregulated RANKL/RANK/TRAF6 pathway that mediates OCs differentiation. CYM could be a promising natural compound against diabetic osteoporosis.

Highly pathogenic porcine reproductive and respiratory syndrome virus-induced inflammatory response in porcine pulmonary microvascular endothelial cells and effects of herbal ingredients on main inflammatory molecules

The role of microvascular endothelial cells (MVECs) in viral infection has received increasing attention. Our previous study demonstrated the susceptibility of porcine pulmonary MVECs to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV), while their responses to the viral infection remain unclear. This study aimed to understand effects of the HP-PRRSV infection on functions of porcine pulmonary MVECs and the intervention effects of Chinese herbal ingredients on them. Highly purified porcine pulmonary MVECs were separated using CD31-immunomagnetic beads and infected with HP-PRRSV JXA1 and HN strain. The virus particles in cells and the ultrastructural pathological changes of cells were revealed by transmission electron microscopy. High-throughput transcriptome sequencing indicated that 104 and 228 genes were differentially expressed at 36 h post-infection, respectively, including many inflammatory molecules such as interleukins, chemokines, and adhesion molecules. The expression kinetics of HP-PRRSV-induced IL-1α, IL-6, IL-8, and VCAM-1 were characterized at the mRNA and protein levels. Luteolin significantly down-regulated HP-PRRSV-induced increase of the four molecules at both levels, and glycyrrhetinic acid and baicalin reduced that of IL-6 and VCAM-1. Our results suggest that porcine pulmonary MVECs play important roles in the inflammatory lung injury caused by HP-PRRSV infection and that herbal ingredients have potential regulatory effects on the HP-PRRSV-induced dysfunction of MVECs.

Phytochemicals as potential target on thioredoxin-interacting protein (TXNIP) for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are currently the major cause of death and morbidity on a global scale. Thioredoxin-interacting protein (TXNIP) is a marker related to metabolism, oxidation, and inflammation induced in CVDs. The overexpression of TXNIP is closely related to the occurrence and development of CVDs. Hence, TXNIP inhibition is critical for reducing the overactivation of its downstream signaling pathway and, as a result, myocardial cell damage. Due to the chemical variety of dietary phytochemicals, they have garnered increased interest for CVDs prevention and therapy. Phytochemicals are a source of medicinal compounds for a variety of conditions, which aids in the development of effective and safe TXNIP-targeting medications. The objective of this article is to find and virtual screen novel safe, effective, and economically viable TXNIP inhibitors from flavonoids, phenols, and alkaloids derived from foods and plants. The results of the docking study revealed that silibinin, rutin, luteolin, baicalin, procyanidin B2, hesperetin, icariin, and tilianin in flavonoids, polydatin, resveratrol, and salidroside in phenols, and neferine in alkaloids had the highest Vina scores, indicating that these compounds are the active chemicals on TXNIP. In particular, silibinin can be utilized as a lead chemical in the process of structural alteration. These dietary phytochemicals may aid in the discovery of lead compounds for the development of innovative TXNIP agents for the treatment of cardiovascular disease.

Epac: A Promising Therapeutic Target for Vascular Diseases: A Review

Vascular diseases affect the circulatory system and comprise most human diseases. They cause severe symptoms and affect the quality of life of patients. Recently, since their identification, exchange proteins directly activated by cAMP (Epac) have attracted increasing scientific interest, because of their role in cyclic adenosine monophosphate (cAMP) signaling, a well-known signal transduction pathway. The role of Epac in cardiovascular disease and cancer is extensively studied, whereas their role in kidney disease has not been comprehensively explored yet. In this study, we aimed to review recent studies on the regulatory effects of Epac on various vascular diseases, such as cardiovascular disease, cerebrovascular disease, and cancer. Accumulating evidence has shown that both Epac1 and Epac2 play important roles in vascular diseases under both physiological and pathological conditions. Additionally, there has been an increasing focus on Epac pharmacological modulators. Therefore, we speculated that Epac could serve as a novel therapeutic target for the treatment of vascular diseases.

The Effect of Dietary Polyphenols on Vascular Health and Hypertension: Current Evidence and Mechanisms of Action

The aim of this review was to explore existing evidence from studies conducted on humans and summarize the mechanisms of action of dietary polyphenols on vascular health, blood pressure and hypertension. There is evidence that some polyphenol-rich foods, including berry fruits rich in anthocyanins, cocoa and green tea rich in flavan-3-ols, almonds and pistachios rich in hydroxycinnamic acids, and soy products rich in isoflavones, are able to improve blood pressure levels. A variety of mechanisms can elucidate the observed effects. Some limitations of the evidence, including variability of polyphenol content in plant-derived foods and human absorption, difficulty disentangling the effects of polyphenols from other dietary compounds, and discrepancy of doses between animal and human studies should be taken into account. While no single food counteracts hypertension, adopting a plant-based dietary pattern including a variety of polyphenol-rich foods is an advisable practice to improve blood pressure.

A Combination Extract of Gardeniae Fructus and Perillae Folium Exerts Anti-Inflammatory Effects on LPS-Activated RAW 264.7 Mouse Macrophages via an ER Stress-Induced CHOP Pathway

The aim of this study is to investigate the effects of a combination extract of Gardeniae Fructus and Perillae Folium (GP) on inflammatory reactions in lipopolysaccharide (LPS)-activated mouse macrophages RAW 264.7 cells. Multiplex cytokine assay, Fluo-4 calcium assay, Flow cytometry assay for phospho-P38 MAPK, and quantitative PCR were carried out. GP significantly reduced LPS-induced productions of macrophage inflammatory protein (MIP)-1α and monokine induced by gamma interferon (MIG) and release of intracellular calcium in LPS-activated RAW 264.7 cells. GP also significantly inhibited P38 MAPK phosphorylation and mRNA levels of Chop, Camk2a, Stat1, Stat3, Jak2, Fas, Nos2, and Ptgs2 in LPS-activated RAW 264.7 cells. Taken together, this study represents that GP exerts anti-inflammatory effects on LPS-activated RAW 264.7 cells via ER stress-induced CHOP pathway.

Anticoronavirus and Immunomodulatory Phenolic Compounds: Opportunities and Pharmacotherapeutic Perspectives

In 2019, COVID-19 emerged as a severe respiratory disease that is caused by the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The disease has been associated with high mortality rate, especially in patients with comorbidities such as diabetes, cardiovascular and kidney diseases. This could be attributed to dysregulated immune responses and severe systemic inflammation in COVID-19 patients. The use of effective antiviral drugs against SARS-CoV-2 and modulation of the immune responses could be a potential therapeutic strategy for COVID-19. Studies have shown that natural phenolic compounds have several pharmacological properties, including anticoronavirus and immunomodulatory activities. Therefore, this review discusses the dual action of these natural products from the perspective of applicability at COVID-19.

Exploring the treatment of COVID-19 with Yinqiao powder based on network pharmacology

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In China, Yinqiao powder is widely used to prevent and treat COVID-19 patients with Weifen syndrome. In this study, the screening and verification of active ingredients, target selection and DisGeNET scoring, drug-ingredient-gene network construction, protein-protein interaction network construction, molecular docking and surface plasmon resonance (SPR) analysis, gene ontology (GO) functional analysis, gene tissue analysis, and kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were used to explore the active ingredients, targets, and potential mechanisms of Yinqiao powder in the treatment of COVID-19. We also predicted the therapeutic effect of Yinqiao powder using TCM anti-COVID-19 (TCMATCOV). Yinqiao powder has a certain therapeutic effect on COVID-19, with an intervention score of 20.16. Hesperetin, eriodictyol, luteolin, quercetin, and naringenin were the potentially effective active ingredients against COVID-19. The hub-proteins were interleukin-6 (IL-6), mitogen-activated protein kinase 3 (MAPK3), tumor necrosis factor (TNF), and tumor protein P53 (TP53). The potential mechanisms of Yinqiao powder in the treatment of COVID-19 are the TNF signaling pathway, T-cell receptor signaling pathway, Toll-like receptor signaling pathway, and MAPK signaling pathway. This study provides a new perspective for discovering potential drugs and mechanisms of COVID-19.

Role of luteolin in overcoming Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting elderly people (>60 years old) worldwide. There is no permanent cure for the disease but the symptomatic relief can be obtained by using dopamine agonists besides L-dopa therapy. The longer use of the drugs is associated with several side effects. Hence, the researchers have made a considerable attention toward the development of neuroprotective agents from plants. A number of phytochemicals have been demonstrated for their protective effects in various in vitro, in vivo, and clinical studies. In this context, luteolin, a flavone which is present in fruits and vegetables has been attributed to a number of pharmacological properties including neuroprotective. The present review demonstrates the bioavailability, oral absorption, and mechanism of action against PD.

Role of sphingosine-1-phosphate receptors in vascular injury of inflammatory bowel disease

Sphingosine‐1‐phosphate receptors (S1PRs) have an impact on the intestinal inflammation of inflammatory bowel disease (IBD) by regulating lymphocyte migration and differentiation. S1PR modulators as an emerging therapeutic approach are being investigated for the treatment of IBD. However, the role of S1PRs in intestinal vessels has not drawn much attention. Intestinal vascular damage is one of the major pathophysiological features of IBD, characterized by increased vascular density and impaired barrier function. S1PRs have pleiotropic effects on vascular endothelial cells, including proliferation, migration, angiogenesis and barrier homeostasis. Mounting evidence shows that S1PRs are abnormally expressed on intestinal vascular endothelial cells in IBD. Unexpectedly, S1PR modulators may damage intestinal vasculature, for example increase intestinal bleeding; therefore, S1PRs are thought to be involved in the regulation of intestinal vascular function in IBD. However, little is understood about how S1PRs regulate intestinal vascular function and participate in the initiation and progression of IBD. In this review, we summarize the pathogenic role of S1PRs in and the underlying mechanisms behind the intestinal vascular injury in IBD in order for improving IBD practice including S1PR‐targeted therapies.

Luteolin ameliorates lipopolysaccharide-induced microcirculatory disturbance through inhibiting leukocyte adhesion in rat mesenteric venules

Background

Microcirculatory disturbance is closely associated with multiple diseases such as ischemic and septic stroke. Luteolin (3,4,5,7-tetrahydroxyflavone) is a vascular protective flavonoid present in several dietary foods. However, how luteolin plays a role in microcirculatory disturbance is still unknown. The purpose of this study was to find out the influence of luteolin on the lipopolysaccharide (LPS)-induced microcirculatory disturbance, focusing on its effect on leukocyte adhesion and the underlying mechanism of this effect.

Methods

After injecting LPS into rats, we used an inverted intravital microscope to observe the velocity of red blood cells in venules, numbers of leukocytes adherent to and emigrated across the venular wall, hydrogen peroxide production in venular walls and mast cell degranulation. Intestinal microcirculation blood flow was measured by High-resolution Laser Doppler Perfusion Imaging. Histological changes of small intestine and mesenteric arteries were evaluated. Additionally, cell adhesion stimulated by LPS was tested on EA.hy926 and THP-1 cells. The production of pro-inflammatory cytokines, adhesion molecules and the activation of TLR4/Myd88/NF-κB signaling pathway were determined.

Results

The results showed luteolin significantly inhibited LPS-induced leukocyte adhesion, hydrogen peroxide production and mast cell degranulation, and increased intestinal microcirculation blood flow and ameliorated pathological changes in the mesenteric artery and the small intestine. Furthermore, luteolin inhibited the release of pro-inflammatory cytokines, the expression of TLR4, Myd88, ICAM-1, and VCAM-1, the phosphorylation of IκB-α and NF-κB/p65 in LPS stimulated EA.hy926.

Conclusions

Our findings revealed that it is likely that luteolin can ameliorate microcirculatory disturbance. The inhibitory effects of luteolin on the leukocyte adhesion stimulated by LPS, which participates in the development of microcirculatory disturbance, are mediated through the regulation of the TLR4/Myd88/NF-κB signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03196-9.

Chemical Constituents from Physalis Calyx seu Fructus and Their Inhibitory Effects against Oxidative Stress and Inflammatory Response

Physalis Calyx seu Fructus, a traditional Chinese medicine consisting of the calyxes and fruits of Physalis alkekengi var. franchetii, has been used as therapy for inflammation-related respiratory diseases such as excessive phlegm, cough, sore throat, and pharyngitis for a long history in China. The aim of the present study was to investigate the chemical constituents of Physalis Calyx seu Fructus and identify the bioactive constituents responsible for its traditional application as therapy for inflammation-related diseases. In the present study, one new phenylpropanoid (1: ), two new steroids (17: and 18: ), together with 55 known constituents have been purified from the EtOH extract of Physalis Calyx seu Fructus. Among them, seven and twelve known constituents were isolated for the first time from Physalis Calyx seu Fructus and the genus Physalis, respectively. Fourteen constituents, including steroids [physalins (5:  - 9, 12:  - 14: , and 15: ) and ergostane (21: )], a sesquiterpenoid (35: ), alkaloids (36: and 37: ), and a flavonoid (44: ), showed inhibitory effects against oxidative stress. Ten constituents, including steroids (5, 6, 8, 13: , and 15: ), sesquiterpenoids (34: and 35: ), alkaloids (37: and 41: ), and a flavonoid (43: ), were found be potential anti-inflammatory constituents of this medicinal plant. The inhibition of oxidative stress and inflammatory response may be related to the regulation of Nrf2 and nuclear factor-κB pathways. The ethnomedical use of Physalis Calyx seu Fructus as a treatment for respiratory diseases might be attributed to the combined inhibitory effects of steroids, alkaloids, sesquiterpenoids, and flavonoids against oxidative stress and inflammatory response.

"Fei Yan No. 1" as a Combined Treatment for COVID-19: An Efficacy and Potential Mechanistic Study

There has been a large global outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), representing a major public health issue. In China, combination therapy, including traditional Chinese medicine (TCM) as a treatment for COVID-19 has been used widely. “Fei Yan No. 1” (QFDYG) is a formula recommended by the Hubei Government to treat COVID-19. A retrospective study of 84 COVID-19 patients from Hubei Provincial Hospital of TCM and Renmin Hospital of Hanchuan was conducted to explore the clinical efficacy of QFDYG combination therapy. TCMSP and YaTCM databases were used to determine the components of all Chinese herbs in QFDYG. Oral bioavailability (OB) ≥ 30% and drug-like (DL) quality ≥ 0.18 were selected as criteria for screening the active compounds identified within the TCMSP database. The targets of active components in QFDYG were determined using the Swiss TargetPrediction (SIB) and Targetnet databases. The STRING database and the Network Analyzer plugin in Cytoscape were used to obtain protein-protein interaction (PPI) network topology parameters and to identify hub targets. Gene Ontology (GO) enrichment was conducted using FunRich version 3.1.3, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment using ClueGO version 2.5.6 software. PPI and compound-pathway (C-T) networks were constructed using Cytoscape 3.6.0. Compared with the control group, combined treatment with QFDYG resulted in a significantly higher rate of patients recovering from symptoms and shorter the time. After 14 days of treatment, QFDYG combined treatment increased the proportion of patients testing negative for SARS-CoV-2 nucleic acid by RT-PCR. Compared with the control group, promoting focal absorption and inflammation as viewed on CT images. GO and KEGG pathway enrichment indicated that QFDYG principally regulated biological processes, such as inflammation, an immune response, and apoptosis. The present study revealed that QFDYG combination therapy offered particular therapeutic advantages, indicating that the theoretical basis for the treatment of COVID-19 by QFDYG may play an antiviral and immune response regulation through multiple components, targets, and pathways, providing reference for the clinical treatment of COVID-19.

Blame the signaling: Role of cAMP for the resolution of inflammation

A complex intracellular signaling governs different cellular responses in inflammation. Extracellular stimuli are sensed, amplified, and transduced through a dynamic cellular network of messengers converting the first signal into a proper response: production of specific mediators, cell activation, survival, or death. Several overlapping pathways are coordinated to ensure specific and timely induction of inflammation to neutralize potential harms to the tissue. Ideally, the inflammatory response must be controlled and self-limited. Resolution of inflammation is an active process that culminates with termination of inflammation and restoration of tissue homeostasis. Comparably to the onset of inflammation, resolution responses are triggered by coordinated intracellular signaling pathways that transduce the message to the nucleus. However, the key messengers and pathways involved in signaling transduction for resolution are still poorly understood in comparison to the inflammatory network. cAMP has long been recognized as an inducer of anti-inflammatory responses and cAMP-dependent pathways have been extensively exploited pharmacologically to treat inflammatory diseases. Recently, cAMP has been pointed out as coordinator of key steps of resolution of inflammation. Here, we summarize the evidence for the role of cAMP at inducing important features of resolution of inflammation.

Luteolin alleviates neuroinflammation via downregulating the TLR4/TRAF6/NF-κB pathway after intracerebral hemorrhage

The activation of microglia and inflammatory responses is essential for the process of intracerebral hemorrhage (ICH)-induced secondary brain injury (SBI). In this study, we investigated the effects of luteolin on ICH-induced SBI and the potential mechanisms. Autologous blood was injected to establish the ICH model in vivo, and oxyhemoglobin (OxyHb) was used to mimic the ICH model in vitro. We found that the administration of luteolin significantly improved motor and sensory impairments and inhibited neuronal cell degeneration in vivo. In the in vitro study, the decrease of the neuronal cell viability induced by activated microglia was alleviated by luteolin treatment. Furthermore, by antagonizing the activation of the Toll-like receptor 4 (TLR4)/TNF receptor-associated factor 6 (TRAF6)/nuclear transcription factor-κB (NF-κB) signaling pathway, the ICH-induced elevation of cytokine release was decreased after treatment with luteolin, which was confirmed both in vivo and in vitro. Additionally, we found that luteolin engaged with TRAF6 and inhibited the ubiquitination of TRAF6. Taken together, our findings demonstrate the neuroprotective effects of luteolin after ICH and the potential mechanisms, which suggest that luteolin is a potential therapeutic candidate for ICH treatment.

Rosmarinus officinalis L. (rosemary) as therapeutic and prophylactic agent

Rosmarinus officinalis L. (rosemary) is a medicinal plant native to the Mediterranean region and cultivated around the world. Besides the therapeutic purpose, it is commonly used as a condiment and food preservative. R. officinalis L. is constituted by bioactive molecules, the phytocompounds, responsible for implement several pharmacological activities, such as anti-inflammatory, antioxidant, antimicrobial, antiproliferative, antitumor and protective, inhibitory and attenuating activities. Thus, in vivo and in vitro studies were presented in this Review, approaching the therapeutic and prophylactic effects of R. officinalis L. on some physiological disorders caused by biochemical, chemical or biological agents. In this way, methodology, mechanisms, results, and conclusions were described. The main objective of this study was showing that plant products could be equivalent to the available medicines.