Involvement of TLR2 and TLR9 in the anti-inflammatory effects of chlorogenic acid in HSV-1-infected microglia

Exploring anti-inflammatory and antioxidant-related quality markers of Artemisia absinthium L. based on spectrum-effect relationship

INTRODUCTION

Artemisia absinthium L. is a well-known medicinal, aromatic, and edible plant with important medicinal and economic properties and a long history of use in treating liver inflammation and other diseases; however, there has been insufficient progress in quality control.

OBJECTIVE

This study aimed to investigate the quality markers for the anti-inflammatory and antioxidant activities of A. absinthium based on spectrum-effect relationship analysis.

MATERIALS AND METHODS

Eighteen batches of A. absinthium from different origins were used. Chemical fingerprints were obtained by ultra-performance liquid chromatography (UPLC). The chemical compositions were identified by quadrupole-Orbitrap high-resolution mass spectrometry. Anti-inflammatory activity was assessed by inhibition of cyclooxygenase-2 and 15-lipoxygenase in vitro and inhibition of nitric oxide release in lipopolysaccharide-induced BV-2 cells. Antioxidant activity was assessed by DPPH and ABTS radical scavenging assays. The relationship between bioactivity and chemical fingerprints was then analyzed using chemometrics including gray relational analysis, bivariate correlation analysis, and orthogonal partial least squares analysis.

RESULTS

Different batches of A. absinthium extracts possessed significant anti-inflammatory and antioxidant activities to varying degrees. Eighty compounds were identified from A. absinthium, and 12 main common peaks were obtained from the UPLC fingerprints. P3 (chlorogenic acid), P5 (isochlorogenic acid A), and P6 (isochlorogenic acid C) were screened as the most promising active compounds by correlation analysis and further validated for their remarkable anti-inflammatory effects.

CONCLUSION

This is the first study to screen the quality markers of A. absinthium by establishing the spectrum-effect relationship, which can provide a reference for the development of quality standards and further research on A. absinthium.

Phenolic acids from medicinal and edible homologous plants: a potential anti-inflammatory agent for inflammatory diseases

Inflammation has been shown to trigger a wide range of chronic diseases, particularly inflammatory diseases. As a result, the focus of research has been on anti-inflammatory drugs and foods. In recent years, the field of medicinal and edible homology (MEH) has developed rapidly in both medical and food sciences, with 95% of MEH being associated with plants. Phenolic acids are a crucial group of natural bioactive substances found in medicinal and edible homologous plants (MEHPs). Their anti-inflammatory activity is significant as they play a vital role in treating several inflammatory diseases. These compounds possess enormous potential for developing anti-inflammatory drugs and functional foods. However, their development is far from satisfactory due to their diverse structure and intricate anti-inflammatory mechanisms. In this review, we summarize the various types, structures, and distribution of MEHP phenolic acids that have been identified as of 2023. We also analyze their anti-inflammatory activity and molecular mechanisms in inflammatory diseases through NF-κB, MAPK, NLRP3, Nrf2, TLRs, and IL-17 pathways. Additionally, we investigate their impact on regulating the composition of the gut microbiota and immune responses. This analysis lays the groundwork for further exploration of the anti-inflammatory structure-activity relationship of MEHP phenolic acids, aiming to inspire structural optimization and deepen our understanding of their mechanism, and provides valuable insights for future research and development in this field.

Neuroprotective Effect of Chlorogenic Acid in an Animal Model of Sporadic Alzheimer's Disease Induced by Streptozotocin

Alzheimer's Disease is a degenerative neurological condition which leads to a decline in memory and cognitive function. Chlorogenic Acid (CGA) presents properties including neuroprotective, antioxidant and anti-inflammatory. The aim of this study was to examine the impact of CGA on cognitive impairments, neuroinflammation and neuronal damage in mice submitted to an experimental model of Sporadic Alzheimer Disease (SAD) induced by intracerebroventricular administration of streptozotocin (ICV-STZ). Male Swiss mice received bilateral ICV-STZ injections (3 mg/Kg) on days 1 and 3. The treatment with CGA (5 mg/Kg, orally) or vehicle (water, orally), was initiated and continued for 26 days, starting 2 h after the second induction procedure. At first, there was no change in serum glucose levels after SAD induction. ICV-STZ induces impairments in aversive, recognition, and spatial memory, while CGA treatment significantly alleviated these memory deficits. Furthermore, locomotor activity, working memory, and anxiety-related activities remained unaffected by the treatments. CGA treatment protects against ICV-STZ-induced increase in the nitrite/nitrate and TBARS levels. ICV-STZ induced a reduction in viable cells, depletion of BDNF, and triggered astrogliosis and microgliosis in the cortex and hippocampus. Treatment with CGA preserves viable cell count in the prefrontal cortex, CA1, and CA3 regions of the hippocampus. Additionally, it prevented BDNF depletion in the prefrontal cortex and hippocampus (CA1, CA3, and DG regions), and mitigated astrogliosis and microgliosis in the prefrontal cortex and hippocampus (CA1, CA3, and DG regions). These findings indicate the neuroprotective effects of CGA, underscoring their potential as therapeutic agents or adjuncts in the treatment of SAD.

Chlorogenic acid inhibits porcine deltacoronavirus release by targeting apoptosis

Porcine deltacoronavirus (PDCoV), belonging to family Coronaviridae, genus Deltacoronavirus, can cause acute diarrhea in piglets, and also possesses cross-species transmission potential, leading to severe economic losses and threatening public health. However, no approved drug against PDCoV infection is available. Here, we investigated the antiviral effect of chlorogenic acid (CGA), the main active component of Lonicerae Japonicae Flos, against PDCoV infection. The results showed that CGA inhibited the replication of PDCoV significantly both in LLC-PK1 and ST cells, with a selectivity index greater than 80. CGA decreased the synthesis of PDCoV viral RNA and protein, and viral titers in a dose-dependent manner. The results of the time-of-addition assay indicated that CGA mainly affected the early stage of virus replication and viral release. Moreover, CGA significantly reduced apoptosis caused by PDCoV infection, and the application of apoptosis agonist and inhibitor revealed that apoptosis could promote progeny virus release. Further study demonstrated that CGA can inhibit virus release by directly targeting apoptosis caused by PDCoV infection. In conclusion, CGA is an effective agent against PDCoV, which provides a foundation for drug development for the treatment of PDCoV and other coronavirus infections.

Scratching the Surface Takes a Toll: Immune Recognition of Viral Proteins by Surface Toll-like Receptors

Early innate viral recognition by the host is critical for the rapid response and subsequent clearance of an infection. Innate immune cells patrol sites of infection to detect and respond to invading microorganisms including viruses. Surface Toll-like receptors (TLRs) are a group of pattern recognition receptors (PRRs) that can be activated by viruses even before the host cell becomes infected. However, the early activation of surface TLRs by viruses can lead to viral clearance by the host or promote pathogenesis. Thus, a plethora of research has attempted to identify specific viral ligands that bind to surface TLRs and mediate progression of viral infection. Herein, we will discuss the past two decades of research that have identified specific viral proteins recognized by cell surface-associated TLRs, how these viral proteins and host surface TLR interactions affect the host inflammatory response and outcome of infection, and address why controversy remains regarding host surface TLR recognition of viral proteins.

Nicotinamide n-Oxide Attenuates HSV-1-Induced Microglial Inflammation through Sirtuin-1/NF-κB Signaling

HSV-1 is a typical neurotropic virus that infects the brain and causes keratitis, cold sores, and occasionally, acute herpes simplex encephalitis (HSE). The large amount of proinflammatory cytokines induced by HSV-1 infection is an important cause of neurotoxicity in the central nervous system (CNS). Microglia, as resident macrophages in CNS, are the first line of defense against neurotropic virus infection. Inhibiting the excessive production of inflammatory cytokines in overactivated microglia is a crucial strategy for the treatment of HSE. In the present study, we investigated the effect of nicotinamide n-oxide (NAMO), a metabolite mainly produced by gut microbe, on HSV-1-induced microglial inflammation and HSE. We found that NAMO significantly inhibits the production of cytokines induced by HSV-1 infection of microglia, such as IL-1β, IL-6, and TNF-α. In addition, NAMO promotes the transition of microglia from the pro-inflammatory M1 type to the anti-inflammatory M2 type. More detailed studies revealed that NAMO enhances the expression of Sirtuin-1 and its deacetylase enzymatic activity, which in turn deacetylates the p65 subunit to inhibit NF-κB signaling, resulting in reduced inflammatory response and ameliorated HSE pathology. Therefore, Sirtuin-1/NF-κB axis may be promising therapeutic targets against HSV-1 infection-related diseases including HSE.

Chlorogenic Acid Alleviates the Inflammatory Stress of LPS-Induced BV2 Cell via Interacting with TLR4-Mediated Downstream Pathway

Background

Neuroinflammation is related with the inflammatory stress of brain tissue induced by the activation of microglial in the central nervous system (CNS), which is still an intractable disease for modern clinical system. Chlorogenic acid has multiple biological activities such as antivirus and anti-inflammation, while few researches have revealed its therapeutic functions in neuroinflammation.

Methods

BV2 cells were treated with lipopolysaccharide (LPS) to establish neuroinflammation cell models, and the effects and mechanism of chlorogenic acid in improving the inflammatory progression were investigated. In brief, the toxicity of chlorogenic acid on BV2 cells was detected with MTT assay. The levels of the inflammatory factors including TNF-α, IL-6, IL-1β, and IFN-α were measured with ELISA, and the abundances of TLR4, MyD88, TRIF, and NF-κB were observed by qRT-PCR and western blot.

Results

Chlorogenic acid did not exhibit obvious toxic and side effects on BV2 cells. The levels of TNF-α, IL-6, IL-1β, and IFN-α were observably upregulated in BV2 cells after treating with LPS. Chlorogenic acid significantly reduced the levels of TNF-α, IL-6, IL-1β, and IFN-α. Moreover, the abundances of TLR4, MyD88, TRIF, and NF-κB were increased in LPS-induced BV2 cells, while chlorogenic acid could obviously reduce their expressions.

Conclusion

This study suggests that chlorogenic acid can improve the inflammatory stress of LPS-induced BV2 cell via interacting with the TLR4-mediated downstream pathway, which is a potential drug for neuroinflammation treatment.

Phenolic Acids and Prevention of Cognitive Decline: Polyphenols with a Neuroprotective Role in Cognitive Disorders and Alzheimer's Disease

Cognitive impairment, also known as cognitive decline, can occur gradually or suddenly and can be temporary or more permanent. It represents an increasingly important public health problem and can depend on normal aging or be linked to different neurodegenerative disorders, including Alzheimer's disease (AD). It is now well-established that lifestyle factors including dietary patterns play an important role in healthy aging as well as in the prevention of cognitive decline in later life. Among the natural compounds, dietary polyphenols including phenolic acids have been recently the focus of major attention, with their supplementation being associated with better cognitive status and prevention of cognitive decline. Despite their therapeutic potential, human studies investigating the relation between phenolic acids intake and cognitive outcomes are rather scarce. In this review, we provide preclinical evidence that different dietary polyphenols such as rosmarinic acid, ellagic acid, and cinnamic aldehyde can exert neuroprotective and pro-cognitive activities through different molecular mechanisms including the modulation of pro-oxidant and antioxidant machinery as well as inflammatory status. Future and more numerous in vivo studies are needed to strengthen the promising results obtained at the preclinical level. Despite the excellent pharmacokinetic properties of phenolic acids, which are able to be accumulated in the brain at pharmacologically relevant levels, future studies should also identify which among the different metabolites produced as a consequence of phenolic acids' consumption may be responsible for the potential neuroprotective effects of this subgroup of polyphenols.

Phenolic Acids and Prevention of Cognitive Decline: Polyphenols with a Neuroprotective Role in Cognitive Disorders and Alzheimer's Disease

Cognitive impairment, also known as cognitive decline, can occur gradually or suddenly and can be temporary or more permanent. It represents an increasingly important public health problem and can depend on normal aging or be linked to different neurodegenerative disorders, including Alzheimer's disease (AD). It is now well-established that lifestyle factors including dietary patterns play an important role in healthy aging as well as in the prevention of cognitive decline in later life. Among the natural compounds, dietary polyphenols including phenolic acids have been recently the focus of major attention, with their supplementation being associated with better cognitive status and prevention of cognitive decline. Despite their therapeutic potential, human studies investigating the relation between phenolic acids intake and cognitive outcomes are rather scarce. In this review, we provide preclinical evidence that different dietary polyphenols such as rosmarinic acid, ellagic acid, and cinnamic aldehyde can exert neuroprotective and pro-cognitive activities through different molecular mechanisms including the modulation of pro-oxidant and antioxidant machinery as well as inflammatory status. Future and more numerous in vivo studies are needed to strengthen the promising results obtained at the preclinical level. Despite the excellent pharmacokinetic properties of phenolic acids, which are able to be accumulated in the brain at pharmacologically relevant levels, future studies should also identify which among the different metabolites produced as a consequence of phenolic acids' consumption may be responsible for the potential neuroprotective effects of this subgroup of polyphenols.

Antiinflammatory phytochemicals against virus-induced hyperinflammatory responses: Scope, rationale, application, and limitations

Uncontrolled inflammatory responses or cytokine storm associated with viral infections results in deleterious consequences such as vascular leakage, severe hemorrhage, shock, immune paralysis, multi-organ failure, and even death. With the emerging new viral infections and lack of effective prophylactic vaccines, evidence-based complementary strategies that limit viral infection-mediated hyperinflammatory responses could be a promising approach to limit host tissue injury. The present review emphasizes the potentials of antiinflammatory phytochemicals in limiting hyperinflammatory injury caused by viral infections. The predominant phytochemicals along with their mechanism in limiting hyperimmune and pro-inflammatory responses under viral infection have been reviewed comprehensively. How certain phytochemicals can be effective in limiting hyper-inflammatory response indirectly by favorably modulating gut microbiota and maintaining a functional intestinal barrier has also been presented. Finally, we have discussed improved systemic bioavailability of phytochemicals, efficient delivery strategies, and safety measures for effective antiinflammatory phytotherapies, in addition to emphasizing the requirement of tightly controlled clinical studies to establish the antiinflammatory efficacy of the phytochemicals. Collectively, the review provides a scooping overview on the potentials of bioactive phytochemicals to mitigate pro-inflammatory injury associated with viral infections.

Innate Immune Signaling and Role of Glial Cells in Herpes Simplex Virus- and Rabies Virus-Induced Encephalitis

The environment of the central nervous system (CNS) represents a double-edged sword in the context of viral infections. On the one hand, the infectious route for viral pathogens is restricted via neuroprotective barriers; on the other hand, viruses benefit from the immunologically quiescent neural environment after CNS entry. Both the herpes simplex virus (HSV) and the rabies virus (RABV) bypass the neuroprotective blood-brain barrier (BBB) and successfully enter the CNS parenchyma via nerve endings. Despite the differences in the molecular nature of both viruses, each virus uses retrograde transport along peripheral nerves to reach the human CNS. Once inside the CNS parenchyma, HSV infection results in severe acute inflammation, necrosis, and hemorrhaging, while RABV preserves the intact neuronal network by inhibiting apoptosis and limiting inflammation. During RABV neuroinvasion, surveilling glial cells fail to generate a sufficient type I interferon (IFN) response, enabling RABV to replicate undetected, ultimately leading to its fatal outcome. To date, we do not fully understand the molecular mechanisms underlying the activation or suppression of the host inflammatory responses of surveilling glial cells, which present important pathways shaping viral pathogenesis and clinical outcome in viral encephalitis. Here, we compare the innate immune responses of glial cells in RABV- and HSV-infected CNS, highlighting different viral strategies of neuroprotection or Neuroinflamm. in the context of viral encephalitis.

Beneficial effects of chlorogenic acid treatment on neuroinflammation after deep hypothermic circulatory arrest may be mediated through CYLD/NF-κB signaling

Deep hypothermic circulatory arrest (DHCA) during heart surgery may induce neuroinflammation leading to neurocognitive dysfunction. Chlorogenic acid (CA) is a common phytochemical, which can attenuate neuroinflammation. Nevertheless, the underlying mechanism involved in the anti-inflammatory effect of CA after DHCA is unknown. The present study therefore characterized the anti-inflammatory functions of CA after DHCA using in vivo and in vitro DHCA models. The activation of microglia, inflammatory cytokine levels, and the NF-κB pathway were measured. The results showed that CA treatment ameliorated neurocognitive function and reduced the inflammatory cytokine levels in the brain and circulation. Furthermore, the microglial and NF-κB activations were suppressed after DHCA. CA exerted the same anti-inflammatory effect in hypothermia OGD microglial cells as the in vivo study. Additional studies indicated that the regulation of ubiquitin ligase activity of TRAF6 and RIP1 by CYLD was related to the mechanism involving inhibition of CA in the NF-κB pathway. Together, the results showed that CA may attenuate neuroinflammation after DHCA by modulating the signaling of CYLD/NF-κB.

Chlorogenic acid is a positive regulator of MDA5, TLR7 and NF-κB signaling pathways mediated antiviral responses against Gammacoronavirus infection

Chlorogenic acid (CGA) is a phenolic compound that has been well studied for its antiviral, anti-inflammatory and immune stimulating properties. This research was aimed to focus on the antiviral properties of CGA on infectious bronchitis virus (IBV) in vivo and in vitro for the very first time. The outcome of in vitro experiments validated that, out of five previously reported antiviral components, CGA significantly reduced the relative mRNA expression of IBV-N in CEK cells. At high concentration (400 mg/kg), CGA supplementation reduced IBV-N mRNA expression levels and ameliorated the injury in trachea and lungs. The mRNA expression levels of IL-6, IL-1β, IL-12, and NF-κB were considerably turned down, but IL-22 and IL-10 were enhanced in trachea. However, CGA-H treatment had considerably increased the expression levels of MDA5, MAVS, TLR7, MyD88, IRF7, IFN-β and IFN-α both in trachea and lungs. Moreover, CGA-H notably induced the CD3+, CD3+ CD4+ and CD4+/CD8+ proliferation and significantly increased the IgA, IgG, and IgM levels in the serum. In conclusion, these results showed that at high concentration CGA is a strong anti-IBV compound that can effectively regulate the innate immunity through MDA5, TLR7 and NF-κB signaling pathways and have the potential to induce the cell mediated and humoral immune response in IBV infected chickens.

Brain-derived neurotrophic factor is down regulated after bovine alpha-herpesvirus 5 infection in both wild-type and TLR3/7/9 deficient mice

Neurotrophic factors have been implicated in the control of neuronal survival and plasticity in different brain diseases. Meningoencephalitis caused by bovine alpha-herpesvirus 5 (BoHV-5) infection is a frequent neurological disease of young cattle, being the involvement of apoptosis in the development of neuropathological changes frequently discussed in the literature. It's well known that Toll-like receptors (TLRs) can activate neuroinflammatory response and consequently lead to neuronal loss. However, there are no studies evaluating the expression of neurotrophic factors and their association with brain pathology and TLRs during the infection by BoHV-5. The current study aimed to analyze brain levels of neurotrophic factors along with neuropathological changes during acute infection by BoHV-5 in wild-type (WT) and TLR3/7/9 (TLR3/7/9-/-) deficiency mice. The infection was induced by intracranial inoculation of 1 × 104 TCID50 of BoHV-5. Infected animals presented similar degrees of clinical signs and neuropathological changes. Both infected groups had meningoencephalitis and neuronal damage in CA regions from hippocampus. BoHV-5 infection promoted the proliferation of Iba-1 positive cells throughout the neuropil, mainly located in the frontal cortex. Moreover, significant lower levels of brain-derived neurotrophic factor (BDNF) were detected in both BoHV-5 infected WT and TLR3/7/9 deficient mice, compared with non-infected animals. Our study showed that BDNF down regulation was associated with brain inflammation, reactive microgliosis and neuronal loss after bovine alpha-herpesvirus 5 infection in mice. Moreover, we demonstrated that combined TLR3/7/9 deficiency does not alter those parameters.

Compounds with Antiviral, Anti-Inflammatory and Anticancer Activity Identified in Wine from Hungary's Tokaj Region via High Resolution Mass Spectrometry and Bioinformatics Analyses

(1) Background: Wine contains a variety of molecules with potential beneficial effects on human health. Our aim was to examine the wine components with high-resolution mass spectrometry including high-resolution tandem mass spectrometry in two wine types made from grapes with or without the fungus Botrytis cinerea, or "noble rot". (2) For LC-MS/MS analysis, 12 wine samples (7 without and 5 with noble rotting) from 4 different wineries were used and wine components were identified and quantified. (3) Results: 288 molecules were identified in the wines and the amount of 169 molecules was statistically significantly different between the two wine types. A database search was carried out to find the molecules, which were examined in functional studies so far, with high emphasis on molecules with antiviral, anti-inflammatory and anticancer activities. (4) Conclusions: A comprehensive functional dataset related to identified wine components is also provided highlighting the importance of components with potential health benefits.

Toll-like receptor-mediated innate immunity against herpesviridae infection: a current perspective on viral infection signaling pathways

Background

In the past decades, researchers have demonstrated the critical role of Toll-like receptors (TLRs) in the innate immune system. They recognize viral components and trigger immune signal cascades to subsequently promote the activation of the immune system.

Main body

Herpesviridae family members trigger TLRs to elicit cytokines in the process of infection to activate antiviral innate immune responses in host cells. This review aims to clarify the role of TLRs in the innate immunity defense against herpesviridae, and systematically describes the processes of TLR actions and herpesviridae recognition as well as the signal transduction pathways involved.

Conclusions

Future studies of the interactions between TLRs and herpesviridae infections, especially the subsequent signaling pathways, will not only contribute to the planning of effective antiviral therapies but also provide new molecular targets for the development of antiviral drugs.

Detection of Viral Infections by Innate Immunity

Pattern recognition receptors (PRRs) and inflammasomes are a key part of the anti-viral innate immune system as they detect conserved viral pathogen-associated molecular patterns (PAMPs). A successful host response to viral infections critically depend on the initial activation of PRRs by viruses, mainly by viral DNA and RNA. The signalling pathways activated by PRRs leads to the expression of pro-inflammatory cytokines, to recruit immune cells, and type I and type III interferons which leads to the induction of interferon stimulated genes (ISG), powerful virus restriction factors that establish the "antiviral state". Inflammasomes contribute to anti-viral responses through the maturation of interleukin (IL)-1 and IL-18 and through triggering pyroptotic cell death. The activity of the innate immune system along with the adaptive immune response normally leads to successful virus elimination, although disproportionate innate responses contribute to viral pathology. In this review we will discuss recent insights into the influence of PRR activation and inflammasomes on viral infections and what this means for the mammalian host. We will also comment on how specific PRRs and inflammasomes may be relevant to how SARS-CoV-2, the virus responsible for the current COVID-19 pandemic, interacts with host innate immunity.

Herpes Simplex Virus Type 1 Interactions with the Interferon System

The interferon (IFN) system is one of the first lines of defense activated against invading viral pathogens. Upon secretion, IFNs activate a signaling cascade resulting in the production of several interferon stimulated genes (ISGs), which work to limit viral replication and establish an overall anti-viral state. Herpes simplex virus type 1 is a ubiquitous human pathogen that has evolved to downregulate the IFN response and establish lifelong latent infection in sensory neurons of the host. This review will focus on the mechanisms by which the host innate immune system detects invading HSV-1 virions, the subsequent IFN response generated to limit viral infection, and the evasion strategies developed by HSV-1 to evade the immune system and establish latency in the host.

Inhibitory Effect of Corilagin on miR-21-Regulated Hepatic Fibrosis Signaling Pathway

Corilagin is a polyphenol that can be extracted from many medicinal plants and shows multiple pharmacological effects. We aimed to investigate the role of corilagin on miR-21-regulated hepatic fibrosis, especially miR-21-regulated TGF-β1/Smad signaling pathway, in hepatic stellate LX2 cell line and Sprague-Dawley rats. The mRNA or protein levels of miR-21, Smad7, connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), collagen type I alpha 1 (COL1A1), Smad2, Smad3, Smad2/3, p-Smad2, p-Smad3, p-Smad2/3, and transforming growth factor-β1 (TGF-β1) in LX2 cells and liver tissues were determined. Furthermore, gain-of and loss-of function of miR-21 in miR-21-regulated TGF-β1/Smad signaling pathway were analyzed in LX2 cells. Liver tissues and serum were collected for pathological analysis, immunohistochemical staining, and enzyme-linked immunosorbent assay (ELISA). Corilagin treatment reduced mRNA or protein levels of miR-21, CTGF, α-SMA, TIMP-1, TGF-β1, COL1A1, p-Smad2, p-Smad3, and p-Smad2/3 both in vitro and in vivo. While corilagin increased mRNA and protein levels of Smad7 and MMP-9. After gain-of and loss-of function of miR-21, the downstream effectors of miR-21-regulated TGF-β1/Smad signaling pathway in LX2 cells changed accordingly, and the changes were inhibited by corilagin. Simultaneously, administration of corilagin not only ameliorated pathological manifestation of liver fibrosis but also reduced levels of α-SMA and COL1A1 in liver tissues and TGF-β1, ALT levels in serum. Corilagin is able to potentially prevent liver fibrosis by blocking the miR-21-regulated TGF-β1/Smad signaling pathway in LX2 cells and CCl₄-induced liver fibrosis rats, which may provide a novel therapeutic strategy for liver fibrosis.

Chlorogenic Acid Attenuates Kidney Ischemic/Reperfusion Injury via Reducing Inflammation, Tubular Injury, and Myofibroblast Formation

Kidney ischemic/reperfusion (I/R) injury is the main cause of acute kidney injury (AKI) involving renal function deterioration, renal architecture damage, and inflammation. This condition may lead to kidney fibrosis with epithelial to mesenchymal transition (EMT) and myofibroblast formation. Inhibition of chronic effects of kidney I/R injury may provide effective strategies for treating AKI and chronic kidney diseases (CKDs). Chlorogenic acid (CGA) is recognized as a powerful antioxidant, with anti-inflammatory and antifibrotic properties in many conditions. However, the effect of CGA on kidney I/R injury has not been elucidated yet. Kidney I/R injury was performed on male Swiss background mice (I/R group, n = 5, 3-4 months, 30–40 g) which underwent bilateral renal pedicles clamping for 30 minutes and then were euthanized on day three after operation. Three groups of I/R were treated with 3 different doses of CGA intraperitoneally for 2 days: 3.5 (I/R + CGA1 group), 7 (I/R + CGA2 group), and 14 (I/R + CGA3 group) mg/kg of body weight. Tubular injury was quantified based on Periodic Acid-Schiff staining, while reverse transcriptase PCR (RT-PCR) was performed to quantify mRNA expression of TGF-β1, vimentin, SOD-1, TLR-4, TNF-α, NF-κB and MCP-1. Immunohistochemical staining was done to quantify proliferating cell nuclear antigen (PCNA), myofibroblast (α-SMA), SOD-1 and macrophage (CD68) number. Kidney I/R demonstrated tubular injury and increased inflammatory mediator expression, macrophage number, and myofibroblast expansion. Meanwhile, histological analysis showed lower tubular injury with higher epithelial cell proliferation in CGA-treated groups compared to the I/R group. RT-PCR also revealed significantly lower TGF-β1 and vimentin mRNA expressions with higher SOD-1 mRNA expression. CGA-treated groups also demonstrated a significantly lower macrophage and myofibroblast number compared to the I/R group. These findings associated with lower mRNA expression of TLR-4, TNF-α, NF-κB, and MCP-1 as inflammatory mediators in CGA groups. I/R + CGA3 represented the highest amelioration effect among other CGA-treated groups. CGA treatment attenuates kidney I/R injury through reducing inflammation, decreasing myofibroblast expansion, and inducing epithelial cells proliferation.

Roles of HSV-1 infection-induced microglial immune responses in CNS diseases: friends or foes?

Microglia, as brain-resident macrophages, are the first line of defense against brain invading pathogens. Further, their dysfunction has been recognized to be closely associated with mounting CNS diseases. Of note, chronic HSV-1 infection leads to the persistent activation of microglia, which elicit a comprehensive response by generating certain factors with neurotoxic and neuroprotective effects. CNS infection with HSV-1 results in herpes simplex encephalitis and herpes simplex keratitis. Microglial immune response plays a crucial role in the development of these diseases. Moreover, HSV-1 infection is strongly associated with several CNS diseases, especially Alzheimer's disease and schizophrenia. These CNS diseases can be effectively ameliorated by eliciting an appropriate immune response, such as inhibition of microglial proliferation and activation. Therefore, it is crucial to reassess the positive and negative roles of microglia in HSV-1 CNS infection for a more comprehensive and detailed understanding of the relationship between microglia and CNS diseases. Hence, the present review focuses on the dual roles of microglia in mediating HSV-1 CNS infection, as well as on the strategy of targeting microglia to ameliorate CNS diseases. Further research in this field can help comprehensively elucidate the dual role of the microglial immune response in HSV-1 CNS infection, providing a theoretical basis for identifying therapeutic targets against overactive microglia in CNS diseases and HSV-1 infection.

Emodin Rescues Intrahepatic Cholestasis via Stimulating FXR/BSEP Pathway in Promoting the Canalicular Export of Accumulated Bile

Aim

Bile salt export pump (BSEP) have been confirmed to play an important role for bile acid canalicular export in the treatment of cholestasis. In this study, we investigated the stimulatory effect of emodin on BSEP signaling pathway in cholestasis.

Methods

Cell and animal experiments were given different concentrations of emodin. The BSEP upstream molecule farnesoid X receptor was down-regulated by small interfering RNA (siRNA) technology or guggulsterones and up-regulated by lentivirus or GW4064. Real-time PCR and Western blotting was employed to detect the mRNA and protein levels of BSEP in LO2 cell, rat primary hepatocytes and liver tissue. Immunohistochemistry (IHC) was used to examine the expression of BSEP in liver tissues. Rat liver function and pathological changes of liver tissue were performed by biochemical test and hematoxylin and eosin (HE) staining.

Results

Emodin could increase the mRNA and protein expression of BSEP and FXR. When down-regulating farnesoid X receptor expression with the siRNA or inhibitor guggulsterones, and up-regulating farnesoid X receptor expression with the lentivirus or agonist GW4064, emodin could increase the mRNA level of BSEP and FXR and the protein level of BSEP, FXR1, and FXR2. Emodin also had a notable effect on rat primary hepatocytes experiment, rat pathological manifestation, BSEP, FXR1, and FXR2 positive staining in liver tissues and the test of liver function.

Conclusion

Emodin has a protective effect and a rescue activity on cholestasis via stimulating FXR/BSEP pathways in promoting the canalicular export of accumulated bile.

AT-533, a Hsp90 inhibitor, attenuates HSV-1-induced inflammation

Inflammatory events are tightly associated with the death caused by Herpes simplex virus 1 (HSV-1) infection of the brain. Heat shock protein 90 (Hsp90) is a molecular chaperone that is stimulated in response to many stressful conditions (e.g., inflammation and hypoxia) and Hsp90 inhibitors are suggested to be potent inhibitors of the inflammatory response. The aim of this study was to investigate the effect of Hsp90 inhibitor AT-533 on HSV-1-induced inflammation. AT-533 at a non-antiviral concentration was found to show a prominent inhibitory effect on the production of cytokines induced by HSV-1 infection, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β). Mechanically, HSV-1 early infection induced inflammation through NF-κB signaling and NLRP3 inflammasome activation, as illustrated by the nuclear translocation of NF-κB and the enhanced cleavage of caspase-1. Besides, HSV-1 enhanced the interaction between NLRP3 and Hsp90. Moreover, AT-533 reduced the nuclear translocation of NF-κB and inflammasome activation via inhibiting the chaperone function of Hsp90. Furthermore, AT-533 inhibited the cleavage of pro-IL-1β to mature IL-1β in a NLRP3-independent manner. In summary, AT-533 may be a promising therapeutic strategy in HSV-1-infected inflammation management.

Corilagin Interferes With Toll-Like Receptor 3-Mediated Immune Response in Herpes Simplex Encephalitis

Herpes simplex encephalitis (HSE) is the most common infectious disease of the central nervous system worldwide. However, the pathogenesis of HSE is not clear. Research has shown that the immune response mediated by the toll-like receptor 3 (TLR3) signaling pathway is essential to protect the central nervous system against herpes simplex virus (HSV) infection. However, an excessive immune response may cause tissue damage accompanied by pathological changes. The aim of this study was to explore the molecular mechanism via which corilagin controls HSE through the TLR3 signaling pathway in vitro and in vivo. Cells and mice were pre-treated with polyriboinosinic polyribocytidylic acid [poly(I:C)] or HSV type 1, and then treated with corilagin. After treatment, the mRNA and protein levels of TLR3, TLR-like receptor-associated interferon factor (TRIF), tumor necrosis factor (TNF) receptor type 1-associated DEATH domain protein (TRADD), TNF receptor-associated factor (TRAF) 3 and 6, nuclear factor-kappa-B (NF-κB) essential modulator (NEMO), P38, and interferon regulatory factor 3 (IRF3) were decreased. Interleukin-6 (IL-6), TNF-α, and type 1 interferon-β were also decreased. When TLR3 expression was silenced or increased, corilagin still inhibited the expression of TLR3 and its downstream mediators. Hematoxylin-eosin (HE) staining and immunohistochemical examinations of mouse brain tissues revealed that corilagin lessened the degree of brain inflammation. Altogether, these results suggest that corilagin may regulate the immune response in HSE and relieve inflammatory injury by interfering with the TLR3 signaling pathway.

Amelioration of bleomycin-induced pulmonary fibrosis by chlorogenic acid through endoplasmic reticulum stress inhibition

To investigate the inhibitory effects of chlorogenic acid on pulmonary fibrosis and the internal mechanisms in vivo and in vitro. 30 male BALB/C mice were randomized into 5 groups: control group, pulmonary fibrosis model group, low, middle and high dose of chlorogenic acid groups. Mice in pulmonary fibrosis model group were administered 5.0 mg/kg bleomycin with intracheal instillation and mice in 3 chlorogenic acid groups were treated with chlorogenic acid every day for 28 days after bleomycin administration. Lung tissue histology was observed using HE staining. Primary pulmonary fibroblasts were isolated and cultured. The expressions of fibrosis related factors (α-SMA and collagen I), as well as ER stress markers (CHOP and GRP78) were determined by both real-time PCR assay and Western blotting, while the expressions of other ER stress signaling pathway factors PERK, IRE-1, ATF-6 and protein levels of caspase-12, caspase-9, caspase-3, PARP were determined by Western blotting. RLE-6TN cell line induced by TGF-β1 was also used to verify the amelioration effects in vitro study. In both in vivo and in vitro studies, TUNEL staining was used to evaluate cell apoptosis. Expressions of collagen I, α-SMA, GRP78, and CHOP were significantly inhibited by chlorogenic acid in dose-dependent manner. Similarly, decreasing levels of cleaved caspase-12, caspase-9, caspase-3 and increasing level of uncleaved PARP were observed in chlorogenic acid groups compared with those in the fibrosis group both in vivo and in vitro. Chlorogenic acid could also significantly down-regulate the level of phosphorylation of PERK and cleaved ATF-6 in vivo study. Moreover, MTT assay demonstrated chlorogenic acid could enhance proliferation of RLE-6TN cells induced by TGFβ1 in vitro. And the apoptosis assays indicated that chlorogenic acid could significantly inhibit cell apoptosis both in vivo and in vitro studies. Chlorogenic acid could inhibit the pulmonary fibrosis through endoplasmic reticulum stress inhibition in vivo and in vitro.

Emodin Attenuates Lipopolysaccharide-Induced Acute Liver Injury via Inhibiting the TLR4 Signaling Pathway in vitro and in vivo

Aims: Emodin is an anthraquinone with potential anti-inflammatory properties. However, the possible molecular mechanisms and protective effects of emodin are not clear. The objective of this study was to investigate the possible molecular mechanisms and protective effects of emodin on lipopolysaccharide (LPS)-induced acute liver injury (ALI) via the Toll-like receptor 4 (TLR4) signaling pathway in the Raw264.7 cell line and in Balb/c mice. Methods: This study established an inflammatory cellular model and induced an ALI animal model. TLR4 was overexpressed by lentivirus and downregulated by small interfering RNA (siRNA) technology. The mRNA and protein levels of TLR4 and downstream molecules were detected in cells and liver tissue. The tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 levels in supernatant and serum were determined by ELISA. The distribution and expression of mannose receptor C type 1 (CD206) and arginase 1 (ARG1) in the liver were tested by immunofluorescence. Mouse liver function and histopathological observations were assessed. Results: Administration of emodin reduced the protein and/or mRNA levels of TLR4 and its downstream molecules following LPS challenge in Raw264.7 cells and in an animal model. Additionally, emodin suppressed the expression of TNF-α and IL-6 in cell culture supernatant and serum. The inhibitory effect of emodin was also confirmed in RAW264.7 cells, in which TLR4 was overexpressed or knocked down. Additionally, ARG1 and CD206 were elevated in the emodin groups. Emodin also decreased serum ALT and AST levels and alleviated the liver histopathological damage induced by LPS. Conclusion: Emodin showed excellent hepatoprotective effects against LPS-induced ALI, possibly by inhibiting TLR4 signaling pathways.

A Polyphenol Rich Extract from Solanum melongena L. DR2 Peel Exhibits Antioxidant Properties and Anti-Herpes Simplex Virus Type 1 Activity In Vitro

DR2B and DR2C extracts, obtained by ethanolic maceration of peel from commercially and physiologically ripe aubergine berries, were studied for the antioxidative cytoprotective properties and anti-HSV-1 activity, in line with the evidence that several antioxidants can impair viral replication by maintaining reducing conditions in host cells. The antioxidative cytoprotective effects against tBOOH-induced damage were assessed in Caco2 cells, while antiviral activity was studied in Vero cells; polyphenolic fingerprints were characterized by integrated phytochemical methods. Results highlighted different compositions of the extracts, with chlorogenic acid and delphinidin-3-rutinoside as the major constituents; other peculiar phytochemicals were also identified. Both samples reduced reactive oxygen species (ROS) production and exhibited scavenging and chelating properties. DR2C partly counteracted the tBOOH-induced cytotoxicity, with a remarkable lowering of lactate metabolism under both normoxia and hypoxia; interestingly, it increased intracellular GSH levels. Furthermore, DR2C inhibited the HSV-1 replication when added for 24 h after viral adsorption, as also confirmed by the reduction of many viral proteins' expression. Since DR2C was able to reduce NOX4 expression during HSV-1 infection, its antiviral activity may be correlated to its antioxidant properties. Although further studies are needed to better characterize DR2C activity, the results suggest this extract as a promising new anti-HSV-1 agent.

Pudilan xiaoyan oral liquid alleviates LPS-induced respiratory injury through decreasing nitroxidative stress and blocking TLR4 activation along with NF-ΚB phosphorylation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pudilan xiaoyan oral liquid (PDL), collected in Chinese Pharmacopoeia, has been used clinically for treating inflammatory diseases such as upper respiratory tract infection diseases. However, its potential anti-inflammation and the mechanism are still unclear.

MATERIALS AND METHODS

lipopolysaccharide (LPS) was used to induce respiratory inflammation of mice by intratracheal administration. UPLC/MS was performed for components analysis of PDL. Enzyme-linked immune sorbent assay (ELISA) was conducted for determining interleukin-6(IL-6), interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) in serum and supernatant of tracheal tissue while Nitric oxide assay kit for nitric oxide (NO) content. Hematoxylin-Eosin (HE) staining was applied to evaluate pathological lesions. Western blotting analysis (WB) and Immunohistochemistry(IHC) were employed for the determination of Toll-like receptors 4(TLR4), TNF-α, IL-6, inducible nitric oxide synthase(iNOS) and nuclear factor-kappa B p65 (NF-κB p65) protein expressions.

RESULTS

Seven major compounds of PDL were analyzed simultaneously. The treatment of PDL could attenuate LPS-induced histopathological damage of tracheal tissues, followed by reducing pro-inflammation mediators including TNF-α and IL-6 in serum and supernatant of tracheal tissue. LPS-induced nitroxidative stress including NO content and iNOS expression was inhibited significantly by PDL. Furthermore, PDL also down-regulated NF-kB p65 phosphorylation and TLR4 expressions.

CONCLUSION

The results indicated that the PDL had a protective effect on LPS-induced respiratory inflammation injury in mice. Our findings for the first time provide experimental evidence for the application of PDL on respiratory inflammation injury in clinical practice.

Chlorogenic Acid Inhibits Liver Fibrosis by Blocking the miR-21-Regulated TGF-β1/Smad7 Signaling Pathway in Vitro and in Vivo

Aims: Chlorogenic acid (CGA) is a phenolic acid that has a wide range of pharmacological effects. However, the protective effects and mechanisms of CGA on liver fibrosis are not clear. This study explored the effects of CGA on miR-21-regulated TGF-β1/Smad7 liver fibrosis in the hepatic stellate LX2 cell line and in CCl4-induced liver fibrosis in Sprague-Dawley rats.

Methods: The mRNA expression of miR-21, Smad7, connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase 1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and transforming growth factor-β1 (TGF-β1) and the protein levels of Smad2, p-Smad2, Smad3, p-Smad3, Smad2/3, p-Smad2/3, Smad7, CTGF, α-SMA, TIMP-1, MMP-9 and TGF-β1 were assayed in LX2 cells and liver tissue. The effects of CGA after miR-21 knockdown or overexpression were analyzed in LX2 cells. The liver tissue and serum were collected for histopathological examination, immunohistochemistry (IHC) and ELISA.

Results: The mRNA expression of miR-21, CTGF, α-SMA, TIMP-1, and TGF-β1 and the protein expression of p-Smad2, p-Smad3, p-Smad2/3, CTGF, α-SMA, TIMP-1, and TGF-β1 were inhibited by CGA both in vitro and in vivo. Meanwhile, CGA elevated the mRNA and protein expression of Smad7 and MMP-9. After miR-21 knockdown and overexpression, the downstream molecules also changed accordingly. CGA also lessened the degree of liver fibrosis in the pathological manifestation and reduced α-SMA and collagen I expression in liver tissue and TGF-β1 in serum. Conclusion: CGA might relieve liver fibrosis through the miR-21-regulated TGF-β1/Smad7 signaling pathway, which suggests that CGA might be a new anti-fibrosis agent that improves liver fibrosis.

Microglia at center stage: a comprehensive review about the versatile and unique residential macrophages of the central nervous system

Microglia cells are the unique residential macrophages of the central nervous system (CNS). They have a special origin, as they derive from the embryonic yolk sac and enter the developing CNS at a very early stage. They play an important role during CNS development and adult homeostasis. They have a major contribution to adult neurogenesis and neuroinflammation. Thus, they participate in the pathogenesis of neurodegenerative diseases and contribute to aging. They play an important role in sustaining and breaking the blood-brain barrier. As innate immune cells, they contribute substantially to the immune response against infectious agents affecting the CNS. They play also a major role in the growth of tumours of the CNS. Microglia are consequently the key cell population linking the nervous and the immune system. This review covers all different aspects of microglia biology and pathology in a comprehensive way.

Corilagin Counteracts IL-13Rα1 Signaling Pathway in Macrophages to Mitigate Schistosome Egg-Induced Hepatic Fibrosis

The IL-13Rα1 signaling pathway and M2 macrophages play crucial roles in schistosome egg-induced hepatic fibrosis via the expression of pro-fibrotic molecules. This study aims to investigate the inhibitory effect and mechanism of action of corilagin on schistosome egg-induced hepatic fibrosis via the IL-13Rα1 signaling pathway in M2 macrophages in vitro and in vivo. The mRNA and protein expression of IL-13Rα1, PPARγ, KLF4, SOCS1, STAT6, p-STAT6, and TGF-β was measured in vitro with corilagin treatment after IL-13 stimulation and in vivo corilagin treatment after effectively killing the adult schistosomes in schistosome-infected mice. Histological analysis of liver tissue was assessed for the degree of hepatic fibrosis. The results revealed that corilagin significantly reduced the expression of PPARγ, KLF4, SOCS1, p-STAT6, and TGF-β compared with model group and praziquantel administration (p < 0.01 or p < 0.05) in vivo and in vitro, which indicated a strong inhibitory effect of corilagin on IL-13Rα1 signaling pathway. As well, the inhibitory effect of corilagin showed a significant dose-dependence (p < 0.05). The area of fibrosis and distribution of M2 macrophages in mouse liver tissue were reduced significantly and dose-dependently with corilagin treatment compared to model group or praziquantel administration (p < 0.01 or p < 0.05), indicating that corilagin suppressed IL-13Rα1 signaling pathway and M2 macrophage polarization effectively in vivo. Furthermore, the anti-fibrogenic effect persisted even when IL-13Rα1 was up- or down-regulated in vitro. In conclusion, corilagin can suppress schistosome egg-induced hepatic fibrosis via inhibition of M2 macrophage polarization in the IL-13Rα1 signaling pathway.

Difference in the Inhibitory Effect of Temozolomide on TJ905 Glioma Cells and Stem Cells

This study aims to determine the difference in the inhibitory effect of temozolomide (TMZ) on TJ905 glioma cells and stem cells. TJ905 cancer stem cells were isolated. Livin is a member of the inhibitor of apoptosis protein family. The TJ905 cells and cancer stem cells were transfected with a Livin-shRNA and negative-shRNA, respectively, and then treated with TMZ. At 48 h post-transfection, a cell counting kit 8 assay, flow cytometry, and real-time qPCR were performed to detect cell proliferation, the cell cycle, and the expression of the Caspase-3, -7, and -9 mRNAs, respectively. As a result, the suppressive effect of TMZ on TJ905 cells was more significant than its effect on TJ905 cancer stem cells. TMZ exerted an inhibitory effect on the growth of TJ905 glioma cells by arresting them at G0/G1 phase and arresting cancer stem cells at S phase in a dose-dependent manner. TMZ inhibited Livin mRNA expression and increased the expression of the Caspase-3, -7, and -9 mRNAs. Low Livin mRNA expression induced high levels of Caspase-3, -7, and -9 expressions, thus promoting the apoptosis of both TJ905 cells and cancer stem cells in response to TMZ treatment. The TJ905 cells transfected with the Livin-shRNA were more sensitive to TMZ, whereas the TJ905 glioma stem cells transfected with the Livin-shRNA showed no significant changes in their sensitivity to TMZ. In conclusion, the Livin gene may play an important role in the resistance mechanisms of TJ905 glioma cells and cancer stem cells. However, Livin had a more distinct role in TMZ resistance, cell proliferation, and the cell cycle in TJ905 glioma cells than in cancer stem cells.

The Neuroprotective Effects of Phenolic Acids: Molecular Mechanism of Action

The neuroprotective role of phenolic acids from food has previously been reported by many authors. In this review, the role of phenolic acids in ameliorating depression, ischemia/reperfusion injury, neuroinflammation, apoptosis, glutamate-induced toxicity, epilepsy, imbalance after traumatic brain injury, hyperinsulinemia-induced memory impairment, hearing and vision disturbances, Parkinson’s disease, Huntington’s disease, anti-amyotrophic lateral sclerosis, Chagas disease and other less distributed diseases is discussed. This review covers the in vitro, ex vivo and in vivo studies concerning the prevention and treatment of neurological disorders (on the biochemical and gene expression levels) by phenolic acids.

Protective effect of chlorogenic acid on the focal cerebral ischemia reperfusion rat models

Objective

The aim of the study was to investigate the protective characteristic of chlorogenic acid, a natural glucosyl xanthone found in Lonicera Japonica on the cerebral ischemia reperfusion injury and the underlying mechanism.

Methods

Focal cerebral ischemia reperfusion model was built by blocking the left middle cerebral artery in rats by using the suture-occluded method. Before operation, the corresponding drugs were given for each group once a day for 7 days. After 1 h of final administration, the model was built, after operation, reperfusion was conducted for 22 h, Before the reperfusion 10 min tail vein injection of large, medium and small dose of chlorogenic acid and then mortality was calculated, and Neurological deficit score (NDS) was conducted, and serum was collected to measure the NSE level; a 2 mm thick brain slice located at the intersection of optic nerves was collected for TTC staining, and the percentage of cerebral infarction area was calculated; brain homogenate was collected to measure the ICAM-1, VCAM-1, EPO and HIF-1α levels in brain tissue of cerebral ischemia reperfusion rat models; NGF was detected using immunohistochemical method; the morphological changes in brain tissue was observed with HE staining.

Results

All focal cerebral ischemia reperfusion rat models were duplicated successfully. Every chlorogenic acid group with different dosage can significantly reduce the mortality, NDS and cerebral infarction area of rats, and significantly increase the EPO, HIF-1α and NGF levels in brain tissue; significantly improve the pathological lesions of hippocampus and cortex in brain tissue.

Conclusion

The results showed that chlorogenic acid could protect the focal cerebral ischemia reperfusion injury rat models by adjusting the inflammatory factor, hypoxia factor and nerve growth factor.

Antiviral activity of chlorogenic acid against influenza A (H1N1/H3N2) virus and its inhibition of neuraminidase

Lonicera japonica Thunb, rich in chlorogenic acid (CHA), is used for viral upper respiratory tract infection treatment caused by influenza virus, parainfluenza virus, and respiratory syncytial virus, ect in China. It was reported that CHA reduced serum hepatitis B virus level and death rate of influenza virus-infected mice. However, the underlying mechanisms of CHA against the influenza A virus have not been fully elucidated. Here, the antiviral effects and potential mechanisms of CHA against influenza A virus were investigated. CHA revealed inhibitory against A/PuertoRico/8/1934(H1N1) (EC₅₀ = 44.87 μM), A/Beijing/32/92(H3N2) (EC₅₀ = 62.33 μM), and oseltamivir-resistant strains. Time-course analysis showed CHA inhibited influenza virus during the late stage of infectious cycle. Indirect immunofluorescence assay indicated CHA down-regulated the NP protein expression. The inhibition of neuraminidase activity confirmed CHA blocked release of newly formed virus particles from infected cells. Intravenous injection of 100 mg/kg/d CHA possessed effective antiviral activity in mice, conferring 60% and 50% protection from death against H1N1 and H3N2, reducing virus titres and alleviating inflammation in the lungs effectively. These results demonstrate that CHA acts as a neuraminidase blocker to inhibit influenza A virus both in cellular and animal models. Thus, CHA has potential utility in the treatment of the influenza virus infection.

In vivo and in vitro anti-inflammatory effects of ethanol fraction from Periploca forrestii Schltr

OBJECTIVE

To determine the anti-inflflammatory effects of an ethanol fraction of Periploca forrestii Schltr. (EFPF) and to investigate the potential mechanisms underlying in vivo and in vitro models.

METHODS

The antiinflflammatory effects of EFPF were evaluated using the xylene-induced mouse ear edema and carrageenan-induced rat paw edema models in vivo. In vitro, RAW264.7 cells were exposed to 0-800 μg/mL EFPF and the cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Then cells were treated with different concentrations of EFPF (100-400 μg/mL) and stimulated with lipopolysaccharide (LPS, 1 μg/mL) for 24 h. The supernatant was analyzed for nitric oxide (NO) using the Griess reagent, and the levels of inflflammatory mediators and cytokines were determined using enzyme-linked immunosorbent assays for prostaglandin E₂ (PGE₂), tumor necrosis factor α (TNF-α), interleukin (IL) 6, and IL-10. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor κB (NF-κB), and mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK were examined by Western blot.

RESULTS

Compared with the control group, EFPF signifificantly reduced mouse ear edema and rat paw edema rate (P<0.05 or P<0.01). Compared with the LPS group, EFPF signifificantly inhibited the LPS-stimulated production of NO, PGE₂, TNF-α and IL-6 (P<0.05 or P<0.01), and increased the IL-10 production (P<0.05). EFPF also signifificantly inhibited LPS-induced protein expressions of iNOS and COX-2, suppressed the phosphorylation and degradation of inhibitor of NF-κB-α, decreased p65 level, and inhibited the phosphorylation of p38, ERK1/2 and JNK P<0.05 or P<0.01).

CONCLUSION

EFPF exerted anti-inflflammatory effect by reducing protein expressions of iNOS and COX-2 and the production of the inflflammation factors, including TNF-α, IL-6, NO and PGE₂, mainly through inhibition of LPS-mediated stimulation of NF-κB and MAPK signaling pathways.

TIR-Domain-Containing Adapter-Inducing Interferon-β (TRIF) Is Essential for MPTP-Induced Dopaminergic Neuroprotection via Microglial Cell M1/M2 Modulation

Dynamic changes of two phenotypes of microglia, M1 and M2, are critically associated with the neurodegeneration of Parkinson's disease. However, the regulation of the M1/M2 paradigm is still unclear. In the MPTP induced neurodegeneration model, we examined the concentration of dopamine (DA) related metabolites and the survival of tyrosine hydroxylase (TH) positive cells in WT and Trif^−/− mice. In in vitro experiments, MN9D cells were co-cultured with BV2 cells to mimic the animal experiments. Inhibition of TRIF aggravated TH+ cell loss, and DA-related metabolites decreased. TRIF inhibition was able to interrupt the microglial M1/M2 dynamic transformation. More BV2 cells were activated and migrated across the membrane of transwell plates by siTRIF treatment. Also, TRIF interruption inhibits the transformation of BV2 cells from the M1 to M2 phenotype which played a beneficial role in neuronal degenerative processes, and increased MN9D apoptosis. Moreover, MPP+ treatment decreases the (DAT) dopamine transporter and TH synthesis by MN9D. Taken together, the current results suggest that TRIF plays a key switch function in contributing to the microglial M1/M2 phenotype dynamic transformation. The interruption of TRIF may decrease the survival of MN9D cells as well as DAT and TH protein production. The current study sheds some light on the PD mechanism research by innate inflammation regulation.

Sphingosine Kinase-1 Involves the Inhibitory Action of HIF-1α by Chlorogenic Acid in Hypoxic DU145 Cells

Hypoxia enhances cancer development in a solid tumor. Hypoxia-inducible factor-1 α (HIF-1α) is a transcription factor that is dominantly expressed under hypoxia in solid tumor cells and is a key factor that regulates tumor. HIF-1α regulates several target genes involved in many aspects of cancer progression, including angiogenesis, metastasis, anti-apoptosis and cell proliferation as well as imparts resistance to cancer treatment. In this study, we assessed Crataegus Pinnatifida Bunge var. typical Schneider ethanol extract (CPE) for its anti-cancer effects in hypoxia-induced DU145 human prostate cancer cell line. CPE decreased the abundance of HIF-1α and sphingosine kinase-1 (SPHK-1) in hypoxia-induced prostate cancer DU145 cells. CPE decreased HIF-1α and SPHK-1 as well as SPHK-1 activity. Chlorogenic acid (CA) is one of four major compounds of CPE. Compared to CPE, CA significantly decreased the expression of HIF-1α and SPHK-1 as well as SPHK-1 activity in hypoxia-induced DU145 cells. Furthermore, CA decreased phosphorylation AKT and GSK-3β, which are associated with HIF-1α stabilization and affected SPHK-1 in a concentration-dependent manner. We confirmed the mechanism of CA-induced inhibition of HIF-1α by SPHK-1 signaling pathway using SPHK-1 siRNA and SPHK inhibitor (SKI). CA decreased the secretion and cellular expression of VEGF, thus inhibiting hypoxia-induced angiogenesis. Treatment of DU145cells with SPHK1 siRNA and CA for 48 h decreased cancer cell growth, and the inhibitory action of SPHK siRNA and CA on cell growth was confirmed by decrease in the abundance of Proliferating cell nuclear antigen (PCNA).

Antischistosomiasis Liver Fibrosis Effects of Chlorogenic Acid through IL-13/miR-21/Smad7 Signaling Interactions In Vivo and In Vitro

This study investigated the antischistosomiasis liver fibrosis effects of chlorogenic acid (CGA) on interleukin 13 (IL-13)/microRNA-21 (miR-21)/Smad7 signaling interactions in the hepatic stellate LX2 cell line and schistosome-infected mice. The transfection was based on the ability of the GV273-miR-21-enhanced green fluorescent protein (EGFP) and GV369-miR-21-EGFP lentiviral system to up- or downregulate the miR-21 gene in LX2 cells. The mRNA expression of miR-21, Smad7, and connective tissue growth factor (CTGF) and the protein expression of Smad7, CTGF, Smad1, phosphor-Smad1 (p-Smad1), Smad2, p-Smad2, Smad2/3, p-Smad2/3, transforming growth factor β (TGF-β) receptor I, and α-smooth muscle actin (α-SMA) was assayed. Pathological manifestation of hepatic tissue was assessed for the degree of liver fibrosis in animals. The results showed that CGA could inhibit the mRNA expression of miR-21, promote Smad7, and inhibit CTGF mRNA expression. Meanwhile, CGA could significantly lower the protein levels of CTGF, p-Smad1, p-Smad2, p-Smad2/3, TGF-β receptor I, and α-SMA and elevate the Smad7 protein level. In vivo, with treatment with CGA, the signaling molecules of IL-13/miR-21/Smad7 interactions were markedly regulated. CGA could also reduce the degree of liver fibrosis in pathological manifestations. In conclusion, CGA could inhibit schistosomiasis-induced hepatic fibrosis through IL-13/miR-21/Smad7 signaling interactions in LX2 cells and schistosome-infected mice and might serve as an antifibrosis agent for treating schistosomiasis liver fibrosis.

Corilagin ameliorates the extreme inflammatory status in sepsis through TLR4 signaling pathways

Background

Sepsis is one of the serious disorders in clinical practice. Recent studies found toll-like receptors 4 (TLR4) played an important role in sepsis. In this study, we tried to find the influence of Corilagin on TLR4 signal pathways in vitro and in vivo.

Methods

The cellular and animal models of sepsis were established by LPS and then interfered with Corilagin. Real-time PCR and western blot were employed to detect the mRNA and protein expressions of TLR4, MyD88, TRIF and TRAF6. ELISA was used to determine the IL-6 and IL-1β levels in supernatant and serum.

Results

The survival rate was improved in the LPS + Corilagin group, and the mRNA and protein expressions of TLR4, MyD88, TRIF and TRAF6 were significantly decreased than that in the LPS group both in cellular and animal models (P < 0.01). The pro-inflammatory cytokines IL-6 and IL-1β were greatly decreased in the LPS + Corilagin group both in supernatant and serum (P < 0.01).

Conclusions

Corilagin exerts the anti-inflammatory effects by down-regulating the TLR4 signaling molecules to ameliorate the extreme inflammatory status in sepsis.

Mechanism of Corilagin interference with IL-13/STAT6 signaling pathways in hepatic alternative activation macrophages in schistosomiasis-induced liver fibrosis in mouse model

This study tried to find the mechanism of Corilagin interference with interleukin (IL)-13/signal transducer and activator of transcription (STAT) 6 signaling pathways in IL-13-activated liver alternative activation macrophages in schistosomiasis-induced liver fibrosis in Balb/c mice. As a result, IL-13 in serum and the mRNA expression of IL-13 Receptor α1, IL-4 Receptor α and downstream mediators supressor of cytokine signaling (SOCS) 1, Kruppel-like factor (KLF) 4, peroxisome proliferator-activated receptor (PPAR) δ in the liver tissue were significantly inhibited by Corilagin (P<0.05 or 0.01). The protein expression of IL-13 Receptor α1, IL-4 Receptor α, SOCS1, KLF4, PPARγ, PPARδ and Phospho-STAT6 (P-STAT6) in Corilagin group were also markedly suppressed when compared with the model group (P<0.05 or 0.01). Furthermore, the inhibitory effect was enhanced when the concentration of Corilagin increased (P<0.05). By hematoxylin and eosin (HE) staining, when compared with the model group, the Corilagin group showed smaller granulomas (P<0.05 or 0.01). The area of positive cells and integrated optical density (IOD) of CD68, CD206 and KLF4 was significantly decreased by Corilagin stained by IHC (P<0.05 or 0.01). In conclusion, Corilagin had potential to relieve hepatic fibrosis caused by egg granuloma in Schistosoma japonicum infection by decreasing the expression of molecules associated with IL-13/STAT6 signaling pathway in liver alternative activation macrophages.

Preliminary study on Emodin alleviating alpha-naphthylisothiocyanate-induced intrahepatic cholestasis by regulation of liver farnesoid X receptor pathway

The aim of this study is to investigate Emodin on alleviating intrahepatic cholestasis by regulation of liver farnesoid X receptor (FXR) pathway. Cell and animal models of intrahepatic cholestatis were established. Biochemical tests and histomorphology were performed. The messenger RNA (mRNA) and protein expression of FXR, small heterodimer partner (SHP), uridine diphosphate glucuronosyltransferase 2 family polypeptide B4 (UGT2B4), and bile salt export pump (BSEP) was detected. As a result, compared with the model group, the serum levels of biochemical test were significantly lower in the Emodin group (P <0.01). The histopathological changes were remitted significantly by Emodin treatment. In the model group, the mRNA and protein expression of FXR, SHP, UGT2B4, and BSEP was significantly lower than in the normal group in cell models (P <0.05). With Emodin intervention, the expression of FXR, SHP, UGT2B4, and BSEP was notably increased (P <0.05). In conclusion, Emodin plays a protective role in intrahepatic cholestasis by promoting FXR signal pathways.