Corilagin Protects Against HSV1 Encephalitis Through Inhibiting the TLR2 Signaling Pathways In Vivo and In Vitro

Corilagin inhibits human cytomegalovirus infection and replication via activating the cGAS-STING signaling pathway in vitro and in vivo

AIM

The existence of human cytomegalovirus (HCMV) is extremely widespread, causing serious diseases in patients with low immune function. The purpose of this study is to explore the efficacy and mechanism of Corilagin in the control of CMV infection, in order to provide scientific basis for the control of CMV infection.

METHODS

Our study employed an animal model in Balb/c mice, infected with MCMV, alongside cellular models in HFF cells and THP-1 cells, stimulated with HCMV. The expression of cGAS-STING signaling pathway molecules was detected in liver tissue, lung tissue, serum, cells and cell supernatant. The liver function and histopathological changes of mice were evaluated.

RESULTS

In vivo and in vitro experiments showed that Corilagin significantly inhibits CMV levels and attenuates pathological damage in liver and lung tissues in vivo, and similarly inhibits viral load in cells in vitro. Corilagin promotes the expression levels of STING and its downstream molecules in vivo and in vitro. Inhibition/down-regulation of STING significantly promotes CMV replication, on the contrary, activation/up-regulation of STING inhibits CMV replication, and Corilagin also promotes the expression levels of molecules related to the cGAS-STING signaling pathway in the above cases.

CONCLUSION

Corilagin could effectively inhibit the infection and replication of CMV in vitro and in vivo, which may be through the activation of cGAS-STING signaling pathway.

Corilagin relieves atherosclerosis via the toll-like receptor 4 signaling pathway in vascular smooth muscle cells

INTRODUCTION

Corilagin possesses a diverse range of pharmacologic bioactivities. However, the specific protective effects and mechanisms of action of corilagin in the context of atherosclerosis remain unclear. In this study, we investigated the impact of corilagin on the toll-like receptor (TLR)4 signaling pathway in a mouse vascular smooth muscle cell line (MOVAS) stimulated by oxidized low-density lipoprotein (ox-LDL). Additionally, we examined the effects of corilagin in Sprague-Dawley rats experiencing atherosclerosis.

METHODS

The cytotoxicity of corilagin was assessed using the CCK8 assay. MOVAS cells, pre-incubated with ox-LDL, underwent treatment with varying concentrations of corilagin. TLR4 expression was modulated by either downregulation through small interfering (si)RNA or upregulation via lentivirus transfection. Molecular expression within the TLR4 signaling pathway was analyzed using real-time polymerase chain reaction (PCR) and Western blotting. The proliferation capacity of MOVAS cells was determined through cell counting. In a rat model, atherosclerosis was induced in femoral arteries using an improved guidewire injury method, and TLR4 expression in plaque areas was assessed using immunofluorescence. Pathological changes were examined through hematoxylin and eosin staining, as well as Oil-Red-O staining.

RESULTS

Corilagin demonstrated inhibitory effects on the TLR4 signaling pathway in MOVAS cells pre-stimulated with ox-LDL, consequently impeding the proliferative impact of ox-LDL. The modulation of TLR4 expression, either through downregulation or upregulation, similarly influenced the expression of downstream molecules. In an in vivo context, corilagin exhibited the ability to suppress TLR4 and MyD88 expression in the plaque lesion areas of rat femoral arteries, thereby alleviating the formation of atherosclerotic plaques.

CONCLUSION

Corilagin can inhibit the TLR4 signaling pathway in VSMCs, possibly by downregulating TLR4 expression and, consequently, relieving atherosclerosis.

Specialized metabolites from plants as a source of new multi-target antiviral drugs: a systematic review

Viral infections have always been the main global health challenge, as several potentially lethal viruses, including the hepatitis virus, herpes virus, and influenza virus, have affected human health for decades. Unfortunately, most licensed antiviral drugs are characterized by many adverse reactions and, in the long-term therapy, also develop viral resistance; for these reasons, researchers have focused their attention on investigating potential antiviral molecules from plants. Natural resources indeed offer a variety of specialized therapeutic metabolites that have been demonstrated to inhibit viral entry into the host cells and replication through the regulation of viral absorption, cell receptor binding, and competition for the activation of intracellular signaling pathways. Many active phytochemicals, including flavonoids, lignans, terpenoids, coumarins, saponins, alkaloids, etc., have been identified as potential candidates for preventing and treating viral infections. Using a systematic approach, this review summarises the knowledge obtained to date on the in vivo antiviral activity of specialized metabolites extracted from plant matrices by focusing on their mechanism of action.

Toll-like receptor 2 signaling pathway activation contributes to a highly efficient inflammatory response in Japanese encephalitis virus-infected mouse microglial cells by proteomics

Thousands of people die each year from Japanese encephalitis (JE) caused by the Japanese encephalitis virus (JEV), probably due to exacerbation of the inflammatory response that impairs the course of the disease. Microglia are mononuclear phagocytic cells located within the parenchyma of the central nervous system; these play a key role in the innate immune response against JEV infections. However, the involvement of toll-like receptor 2 (TLR2) in the inflammatory response during the early stages of JEV infection in BV2 cells remains. Here, we evaluated protein profiles and determined the role of TLR2 in the inflammatory response of JEV-infected BV2 cells. High-depth tandem mass tags labeling for quantitative proteomics was used to assess JEV infected-BV2 cells and compare immune response profiles at 6, 12, and 24 h post-infection (hpi). In total, 212 upregulated proteins were detected at 6 hpi, 754 at 12 h, and 191 at 24 h. According to GO and KEGG enrichment analysis, the upregulated proteins showed enrichment for proteins related to the immune response. Parallel reaction monitoring tests, western blotting, and qPCR results showed that the adaptor protein MyD88 was not activated. The expression levels of key proteins downstream of MyD88, such as IRAK1, IRAK4, and TRAF6 did not increase; however, the expression levels of PI3K-AKT did increase. By inhibiting key proteins (TLR2, PI3K, and AKT) we confirmed that JEV activated TLR2, thus resulting in a robust inflammatory response. Consequently, the TLR2-PI3K-AKT signaling axis was proven to play a critical in the early stages of the JEV infection-induced inflammatory response in microglia.

Corilagin induces apoptosis and inhibits HMBG1/PI3K/AKT signaling pathways in a rat model of gastric carcinogenesis induced by methylnitronitrosoguanidine

Gastric cancer, invasive cancer of the gastrointestinal tract, found in developing countries. Chemotherapy to patients with advanced gastric cancer, exhibits greater drug resistance to standard chemotherapy drugs. Therefore, important to establish anti-cancer drugs that are successful for cancer therapy. Corilagin is a natural ellagitannin (ET) with profound pharmacological properties has been used for the study to assess its anticancer effects against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stimulated gastric cancer rats. Biochemical studies showed Thiobarbituric acid reactive substances (TBARS) and enzymatic and non-enzymatic antioxidants increased in corilagin treated animals compared with controls. Histopathologic evaluation revealed corilagin treated rats showed cell morphology similar that control showing its ameliorating effects. In corillagen treament mRNA protein expression levels of HIF-1α, AKT, PI3K, CT4, CD147 and HMGB1 were drastically lowered transcription factors triggering gastric cancer. In Western blot analysis showed released higher apoptotic marker of caspase-3, -9, Bax while Bcl-2 levels were significantly reduced confirming that corilagin triggers apoptosis in gastric cancer.

Phytochemicals of Euphorbia hirta L. and Their Inhibitory Potential Against SARS-CoV-2 Main Protease

Euphorbia hirta L. is a medicinal plant widely used in the Philippines and across tropical Asia against various diseases, including respiratory disorders. In this study, the phytochemical components of E. hirta were investigated in silico for their potential to inhibit the severe acute respiratory syndrome-coronavirus-2 main protease (SARS-CoV-2 Mpro), a coronavirus disease 2019 (COVID-19) drug target that plays a critical role in the infection process of SARS-CoV-2. Phytochemical mining in tandem with virtual screening (PM-VS) was the strategy implemented in this study, which allows efficient preliminary in silico assessment of the COVID-19 therapeutic potential of the reported phytochemicals from the plant. The main rationale for considering E. hirta in the investigation was its reported efficacy against respiratory disorders. It is very promising to investigate the phytochemicals of E. hirta for their potential efficacy against diseases, such as COVID-19, that also target the respiratory system. A total of 298 E. hirta phytochemicals were comprehensively collected from the scientific literature. One hundred seventy of these phytochemicals were computed through molecular docking and were shown to have comparable or better binding properties (promising inhibitors) toward SARS-CoV-2 Mpro than known in vitro inhibitors. In connection to our previous work considering different medicinal plants, antiviral compounds were also rediscovered from the phytochemical composition of E. hirta. This finding provides additional basis for the potential of the plant (or its phytochemicals) as a COVID-19 therapeutic directly targeting drug targets such as SARS-CoV-2 Mpro and/or addressing respiratory-system-related symptoms. The study also highlights the utility of PM-VS, which can be efficiently implemented in the preliminary steps of drug discovery and development.

Mechanistic insight into immunomodulatory effects of food-functioned plant secondary metabolites

Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted.

Cytokines and chemokines expression pattern in herpes simplex virus type-1 encephalitis

To explore the differently expressed cytokines and chemokines to understand the pathways that lead to herpes simplex encephalitis (HSE). Mice in the experimental group were inoculated intracranially with HSV-1. A high-throughput cytokine chip assay was employed to assess the expression of cytokines/chemokines in the mice brain. GO, KEGG, and PPIs analyses were used to investigate the biological process (BP), pathways and interaction network of the differently expressed proteins (DEPs) in HSE. 13 DEPs and various proteins-related signal pathways were identified in HSE, including three new factors (IL-1α, MIP-1γ, and sTNF RI). The proteins were mainly implicated in leukocyte activation and chemotaxis. Additionally, the DEPs constituted a pivotal protein interaction network where IL-6 might be a mediator. 13 DEPs and a series of related signal pathways were associated with the pathophysiological mechanisms responsible for HSE. IL-6 might be a key mediator in the inflammatory responses to the disease.

Ainsliaea fragrans champ. Extract prevents cervicitis in BALB/c mice and regulates MyD88-NF-κB signaling pathway in MALP-2-stimulated RAW264.7 cells

Ethnopharmacological relevance Ainsliaea fragrans Champ. (A. fragrans) is used to treat infection of the lower genital tract in gynecology, such as cervicitis and pelvic inflammatory disease. This study analyzed the therapeutic efficiency of A. fragrans on cervicitis and the inhibition mechanism of AF-p2 in MALP-2-stimulated RAW264.7 cells. Materials and methods The anti- Ureaplasma urealyticum (Uu) activity of A. fragrans and AF-p2 were determined by antimicrobial susceptibility testing. The activity of A. fragrans extracts (AFext) was evaluated in female BALB/c mice with cervicitis induced by Uu. Furthermore, the therapeutic mechanism of AFext and AF-p2 on myeloid differentiation factor 88 (MyD88) pathway were studied in macrophage activating lipopeptide-2 (MALP-2) irritated RAW264.7 cells. Results AFext could suppress the proliferation of Uu in vitro, including the azithromycin resistant strains. Meanwhile, AFext prevented cervicitis caused by Uu infection in BALB/c mice. Moreover, both AFext and AF-p2 could significantly suppress the nitric oxide (NO) production as well as other proinflammatory cytokines (IL-1β,IL-6,TNF-α) in MALP-2 stimulated RAW264.7 cells. Moreover, AF-p2 also down-regulated iNOS, p65, Iκ-Bα, MyD88 and cyclooxygenase-2 (COX-2) levels in RAW264.7 cells. Conclusion This study indicated that AFext had a therapeutic effect in cervicitis induced by Uu infection. Furthermore, the lead compound AF-p2 showed an anti-infectious effect in MALP-2 irritated RAW264.7 cells through downregulating MyD88-NF-κB signaling pathway.

Corilagin induces apoptosis and autophagy in NRF2‑addicted U251 glioma cell line

Corilagin, extracted from the Euphorbiaceae and Phyllanthus plants, inhibits the growth of a number of types of tumors. Compared with temozolomide, the traditional chemotherapy drug, corilagin has demonstrated stronger antitumor activity. However, the pharmaceutical mechanism of corilagin in glioma remains unclear. Nuclear factor erythroid 2 like 2 (NFE2L2 or NRF2) is positively associated with several types of tumor including glioma. In the present study, NRF2 expression was higher in glioma tissues compared with non-glioma specimens. Therefore, it was hypothesized that corilagin targets NRF2 regulation of U251 cell apoptosis. The present study used Hoechst 33258 staining to demonstrate that corilagin induced glioma cell apoptosis and observed that the expression of the apoptosis-related gene Bcl-2 was reduced. In addition, corilagin induced autophagy and promoted the conversion of light chain 3 (LC3) protein from LC3I to LC3II. NRF2 expression was downregulated by corilagin stimulation. Furthermore, the gene expression pattern following knockdown of NRF2 in U251 cells using siRNA was consistent with corilagin stimulation. Therefore, it was preliminarily concluded that corilagin induces apoptosis and autophagy by reducing NRF2 expression.

Corilagin Ameliorates Atherosclerosis in Peripheral Artery Disease via the Toll-Like Receptor-4 Signaling Pathway in vitro and in vivo

We investigated if corilagin can ameliorate or reverse atherosclerotic development via the toll-like receptor 4 (TLR4) signaling pathway in vitro and in vivo. Ana-1 cells or mouse peritoneal macrophages (MPMs) were stimulated with oxidized low-density lipoprotein followed by corilagin treatment. TLR4 expression in Ana-1 cells was upregulated by lentiviral transduction and downregulated by small interfering RNA. Peripheral blood mononuclear cells (PBMCs), plasma samples, and femoral arteries were collected from rats exhibiting peripheral artery disease (PAD). mRNA and protein expression of TLR4 and downstream molecules were decreased significantly by corilagin treatment in Ana-1 cells, MPMs, and rat PBMCs, and the reduction remained irrespective of downregulation or upregulation of TLR4 expression in Ana-1 cells. Corilagin also exerted a prominent effect on changes in plasma levels of cytokines and the pathologic manifestation of atherosclerosis in femoral arteries. Corilagin could ameliorate the development of atherosclerotic plaques by inhibiting the TLR4 signaling pathway in monocyte/macrophages and reduce the release of proinflammatory cytokines. This study provides a new therapeutic target and new niche targeting drug to oppose atherosclerosis and reveals the enormous potential of corilagin for control of PAD in humans.

High Throughput Virtual Screening to Discover Inhibitors of the Main Protease of the Coronavirus SARS-CoV-2

We use state-of-the-art computer-aided drug design (CADD) techniques to identify prospective inhibitors of the main protease enzyme, 3CLpro of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19. From our screening of over one million compounds including approved drugs, investigational drugs, natural products, and organic compounds, and a rescreening protocol incorporating enzyme dynamics via ensemble docking, we have been able to identify a range of prospective 3CLpro inhibitors. Importantly, some of the identified compounds had previously been reported to exhibit inhibitory activities against the 3CLpro enzyme of the closely related SARS-CoV virus. The top-ranking compounds are characterized by the presence of multiple bi- and monocyclic rings, many of them being heterocycles and aromatic, which are flexibly linked allowing the ligands to adapt to the geometry of the 3CLpro substrate site and involve a high amount of functional groups enabling hydrogen bond formation with surrounding amino acid residues, including the catalytic dyad residues H41 and C145. Among the top binding compounds we identified several tyrosine kinase inhibitors, which include a bioflavonoid, the group of natural products that binds best to 3CLpro. Another class of compounds that decently binds to the SARS-CoV-2 main protease are steroid hormones, which thus may be endogenous inhibitors and might provide an explanation for the age-dependent severity of COVID-19. Many of the compounds identified by our work show a considerably stronger binding than found for reference compounds with in vitro demonstrated 3CLpro inhibition and anticoronavirus activity. The compounds determined in this work thus represent a good starting point for the design of inhibitors of SARS-CoV-2 replication.

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.

Immunomodulatory Strategies in Herpes Simplex Virus Encephalitis

Herpes simplex virus 1 (HSV-1) can be responsible for life-threatening HSV encephalitis (HSE). The mortality rate of patients with HSE who do not receive antiviral treatment is 70%, with most survivors suffering from permanent neurological sequelae. The use of intravenous acyclovir together with improved diagnostic technologies such as PCR and magnetic resonance imaging has resulted in a reduction in the mortality rate to close to 20%. However, 70% of surviving patients still do not recover complete neurological functions. Thus, there is an urgent need to develop more effective treatments for a better clinical outcome. It is well recognized that cerebral damage resulting from HSE is caused by viral replication together with an overzealous inflammatory response. Both of these processes constitute potential targets for the development of innovative therapies against HSE. In this review, we discuss recent progress in therapy that may be used to ameliorate the outcome of patients with HSE, with a particular emphasis on immunomodulatory agents. Ideally, the administration of adjunctive immunomodulatory drugs should be initiated during the rise of the inflammatory response, and its duration should be limited in time to reduce undesired effects. This critical time frame should be optimized by the identification of reliable biomarkers of inflammation.

Modulation of cell signaling pathways by Phyllanthus amarus and its major constituents: potential role in the prevention and treatment of inflammation and cancer

The causal and functional connection between inflammation and cancer has become a subject of much research interest. Modulation of cell signaling pathways, such as those involving mitogen activated protein kinases (MAPKs), nuclear factor kappa β (NF-κB), phosphatidylinositol 3-kinase and protein kinase B (PI3K/Akt), and Wnt, and their outcomes play a fundamental role in inflammation and cancer. Activation of these cell signaling pathways can lead to various aspects of cancer-related inflammation. Hence, compounds able to modulate inflammation-related molecular targets are sought after in anticancer drug development programs. In recent years, plant extracts and their metabolites have been documented with potential in the prevention and treatment of cancer and inflammatory ailments. Plants possessing anticancer and anti-inflammatory properties due to their bioactive constituents have been reported to modulate the molecular and cellular pathways which are related to inflammation and cancer. In this review we focus on the flavonoids (astragalin, kaempferol, quercetin, rutin), lignans (phyllanthin, hypophyllanthin, and niranthin), tannins (corilagin, geraniin, ellagic acid, gallic acid), and triterpenes (lupeol, oleanolic acid, ursolic acid) of Phyllanthus amarus, which exert various anticancer and anti-inflammatory activities via perturbation of the NF-κB, MAPKs, PI3K/Akt, and Wnt signaling networks. Understanding the underlying mechanisms involved may help future research to develop drug candidates for prevention and new treatment for cancer and inflammatory diseases.

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.

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.

Mannan-Binding Lectin Suppresses Peptidoglycan-Induced TLR2 Activation and Inflammatory Responses

Peptidoglycan (PGN), as the major components of the bacterial cell wall, is known to cause excessive proinflammatory cytokine production. Toll-like receptor 2 (TLR2) is abundantly expressed on immune cells and has been shown to be involved in PGN-induced signaling. Although more and more evidences have indicated that PGN is recognized by TLR2, the role of TLR2 PGN recognition is controversial. Mannan-binding lectin (MBL), a plasma C-type lectin, plays a key role in innate immunity. More and more evidences show that MBL could suppress the amplification of inflammatory signals. Whether MBL can alter PGN-elicited cellular responses through TLR2 in macrophages is still unknown, and possible mechanism underlying it should be investigated. In this study, we found that MBL significantly attenuated PGN-induced inflammatory cytokine production, including TNF-α and IL-6, in PMA-stimulated THP-1 cells at both mRNA and protein levels. The expression of TLR2 was strongly induced by PGN stimulation. Furthermore, the administration of TLR2-neutralized antibody effectively suppressed PGN-induced TNF-α and IL-6 expression. These results supplied the evidence that PGN from Saccharomyces cerevisiae could be recognized by TLR2. In addition, we also found that MBL decreased PGN-induced TLR2 expression and suppressed TLR2-mediated downstream signaling, including the phosphorylation of IκBα, nuclear translocation of NF-κBp65, and phosphorylation of MAPK p38 and ERK1/2. Administration of MBL alone did not have an effect on the expression of TLR2. Finally, our data showed that PGN-mediated immune responses were more severely suppressed by preincubation with MBL and indicated that MBL can combine with both TLR2 and PGN to block the inflammation cytokine expression induced by PGN. All these data suggest that MBL could downregulate inflammation by modulating PGN/TLR2 signaling pathways. This study supports an important role for MBL in immune regulation and signaling pathways involved in inflammatory responses.

Corilagin induces apoptosis, autophagy and ROS generation in gastric cancer cells in vitro

Corilagin, a unique component of the tannin family, has been identified in several medicinal plants. In previous literature, corilagin exhibited a marked anticancer property in a variety of human cancer cells. However, the biological effects of corilagin on gastric cancer and the mechanisms involved remain to be fully elucidated. In the present study, it was reported that corilagin induced inhibition of cell growth in SGC7901 and BGC823 cells in a concentration-dependent manner. It was found that corilagin exhibited less toxicity towards normal GES-1 cells. Furthermore, the study showed that corilagin induced the apoptosis of gastric cancer cells mainly via activating caspase-8, -9, -3 and poly ADP-ribose polymerase proteins. Simultaneously, it was verified that corilagin triggered autophagy in gastric cancer cells and the inhibition of autophagy improved the activity of corilagin on cell growth suppression. In addition, corilagin significantly increased intracellular reactive oxygen species production, which is important in inhibiting the growth of gastric cancer cells. Finally, it was shown that necroptosis cannot be induced by corilagin-incubation in SGC7901 and BGC823 cell lines. Consequently, these findings indicate that corilagin may be developed as a potential therapeutic drug for gastric cancer.

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.

Effects of corilagin on alleviating cholestasis via farnesoid X receptor-associated pathways in vitro and in vivo

BACKGROUND AND PURPOSE

The aim of this study was to investigate the ameliorative effects of corilagin on intrahepatic cholestasis induced by regulating liver farnesoid X receptor (FXR)-associated pathways in vitro and in vivo.

EXPERIMENTAL APPROACH

Cellular and animal models were treated with different concentrations of corilagin. In the cellular experiments, FXR expression was up-regulated by either lentiviral transduction or GW4064 treatment and down-regulated by either siRNA technology or treatment with guggulsterones. Real-time PCR and Western blotting were employed to detect the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, CYP7A1, CYP7B1, NTCP, MRP2 and SULT2A1. Immunohistochemistry was used to examine the expression of BSEP in liver tissues. Rat liver function and pathological changes in hepatic tissue were assessed using biochemical tests and haematoxylin and eosin staining.

RESULTS

Corilagin increased the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, MRP2 and SULT2A1, and decreased those of CYP7A1, CYP7B1 and NTCP. After either up- or down-regulating FXR using different methods, corilagin could still increase the mRNA and protein levels of FXR, SHP1, SHP2, UGT2B4, BSEP, MRP2 and SULT2A1 and decrease the protein levels of CYP7A1, CYP7B1 and NTCP, especially when administered at a high concentration. Corilagin also exerted a notable effect on the pathological manifestations of intrahepatic cholestasis, BSEP staining in liver tissues and liver function.

CONCLUSIONS AND IMPLICATIONS

Corilagin exerts a protective effect in hepatocytes and can prevent the deleterious activities of intrahepatic cholestasis by stimulating FXR-associated pathways.

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.

Phenylpropionamides, Piperidine, and Phenolic Derivatives from the Fruit of Ailanthus altissima

Four novel compounds—two phenylpropionamides, one piperidine, and one phenolic derivatives—were isolated and identified from the fruit of a medicinal plant, Ailanthus altissima (Mill.) Swingle (Simaroubaceae), together with one known phenylpropionamide, 13 known phenols, and 10 flavonoids. The structures of the new compounds were elucidated as 2-hydroxy-N-[(2-O-β-d-glucopyranosyl)phenyl]propionamide (1), 2-hydroxy-N-[(2-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)phenyl]propionamide (2), 2β-carboxyl-piperidine-4β-acetic acid methyl ester (4), and 4-hydroxyphenyl-1-O-[6-(hydrogen-3-hydroxy-3-methylpentanedioate)]-β-d-glucopyranoside (5) based on spectroscopic analysis. All the isolated compounds were evaluated for their inhibitory activity against Tobacco mosaic virus (TMV) using the leaf-disc method. Among the compounds isolated, arbutin (6), β-d-glucopyranosyl-(1→6)-arbutin (7), 4-methoxyphenylacetic acid (10), and corilagin (18) showed moderate inhibition against TMV with IC₅₀ values of 0.49, 0.51, 0.27, and 0.45 mM, respectively.

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.

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.

Protective Role of Corilagin on Aβ25-35-Induced Neurotoxicity: Suppression of NF-κB Signaling Pathway

Aggregation and deposition of beta-amyloid peptides (Aβ), a pathological hallmark of Alzheimer's disease, has been recognized as a potent activator of neuroinflammation and neuronal dysfunction. In this study, the underlying molecular mechanisms responsible for the neuroprotective effects of corilagin against Aβ_25-35-triggered neurotoxicity and inflammatory responses were investigated in PC12 cells. Pretreatment with corilagin effectively protected PC12 cells against Aβ_25-35-induced damage and apoptosis. Aβ_25-35 induced damage in PC12 cells as revealed by increased production of reactive oxygen species, caspase-3 activity, and cell cycle arrest was attenuated by corilagin pretreatment. Corilagin not only significantly suppressed the production of neurotoxic inflammatory mediators such as tumor necrosis factor-α, nitric oxide, and prostaglandin E₂ but also downregulated cyclooxygenase-2 and inducible nitric oxide synthase expression in PC12 cells. It also exerted a beneficial effect by suppressing the degradation of inhibitor of κB (IκB)-α and subsequent activation of transcription factor nuclear factor κB (NF-κB), mostly through inhibition of extracellular signal-regulated kinase activity in comparison to c-Jun N-terminal kinase and p38 MAP kinase (p38) mitogen-activated protein kinase activity. These findings suggest that attenuation of Aβ_25-35-induced inflammatory responses by downregulating the NF-κB signaling pathway might be a valuable strategy for both Alzheimer's disease prevention and/or treatment.

Transport of Corilagin, Gallic Acid, and Ellagic Acid from Fructus Phyllanthi Tannin Fraction in Caco-2 Cell Monolayers

Objective. To investigate the absorption property of the representative hydrolyzable tannin, namely corilagin, and its hydrolysates gallic acid (GA) and ellagic acid (EA) from the Fructus Phyllanthi tannin fraction (PTF) in vitro. Methods. Caco-2 cells monolayer model was established. Influences of PTF on Caco-2 cells viability were detected with MTT assay. The transport across monolayers was examined for different time points, concentrations, and secretory directions. The inhibitors of P-glycoprotein (P-gp), multidrug resistance proteins (MRPs), organic anion transporting polypeptide (OATP) and sodium/glucose cotransporter 1 (SGLT1), and tight junction modulators were used to study the transport mechanism. LC-MS method was employed to quantify the absorption concentration. Results. The apparent permeability coefficient (P_app) values of the three compounds were below 1.0 × 10^-6 cm/s. The absorption of corilagin and GA were much lower than their efflux, and the uptake of both compounds was increased in the presence of inhibitors of P-gp and MRPs. The absorption of EA was decreased in the company of OATP and SGLT1 inhibitors. Moreover, the transport of corilagin, GA, and EA was enhanced by tight junction modulators. Conclusion. These observations indicated that the three compounds in PTF were transported via passive diffusion combined with protein mediated transport. P-gp and MRPs might get involved in the transport of corilagin and GA. The absorption of EA could be attributed to OATP and SGLT1 protein.

Corilagin ameliorates schistosomiasis hepatic fibrosis through regulating IL-13 associated signal pathway in vitro and in vivo

Interleukin (IL)-13-associated signal pathway plays an important role in schistosomiasis hepatic fibrosis. In this study we tried to investigate the effects of corilagin to ameliorate schistosomiasis hepatic fibrosis through regulating IL-13-associated signal pathway in vitro and in vivo. Cellular model was set up with hepatic stellate cells-T6 cells stimulated by rIL-13 and male Balb/c mice were infected with Schistosoma japonicum cercariaeas as animal model. Liver histological changes were observed with haematoxylin and eosin staining. Masson staining was employed to observe the change of egg granulomas. Expression of Col (collagen) and Col III were examined with Immunohistochemistry. Western bolt was employed to detect the JAK-1 and IL13Rα1 proteins. The mRNA expression of Col I, Col III, IL-13, JAK-1 and IL13Rα1 were tested by quantitative polymerase chain reaction. As a result, less inflammatory changes were found in all corilagin groups compared with model group and praziquantel group. The mRNA levels of Col I, Col III, IL-13, JAK-1 and IL13Rα1 were significantly decreased after corilagin intervention (P < 0·01). JAK-1 and IL-13Rα1 protein levels were also greatly decreased in the corilagin groups (P < 0·01). In conclusion, corilagin could ameliorate schistosomiasis hepatic fibrosis by down-regulating the expression of IL-13 and signal molecules in IL-13 pathway.

Corilagin Attenuates Radiation-Induced Brain Injury in Mice

Cranial irradiation-induced inflammation plays a critical role in the initiation and progression of radiation-induced brain injury (RIBI). Anti-inflammation treatment may provide therapeutic benefits. Corilagin (beta-1-O-galloyl-3, 6-(R)-hexahydroxydiphenoyl-D-glucose, C₂₇H₂₂O₁₈) was a novel member of the tannin family with anti-inflammatory properties and is isolated from some medicinal plants, such as Phyllanthus amarus and Caesalpinia coriaria. In this study, the effect of Corilagin on RIBI was investigated and the underlying mechanisms were explored. Spatial learning and memory ability of mice were investigated by the Morris water maze test. Evans blue leakage and electron microscopy were used to assess the integrity of blood-brain barrier (BBB). The mRNA and protein expressions of inflammatory cytokines, TNF-α and IL-1β, were measured by using real-time PCR and Western blotting. The activation of microglial cells and expression of TNF-α were examined by immunofluorescence staining. Phosphorylated signal transducers and activators of transcription 3 (p-STAT3) and IκBα, and the translocation of p65 from cytoplasm to nucleus were detected by using Western blotting. Morris water maze test showed that Corilagin ameliorated the neurocognitive deficits in RIBI mice. Evans blue leakage and electron microscopy exhibited that Corilagin partially protected the BBB integrity from cranial irradiation-caused damage; immunofluorescence staining showed that Corilagin could inhibit microglial activation and TNF-α expression. Real-time PCR and Western blotting revealed that Corilagin downregulated the expression of TNF-α and IL-1β and inhibited the irradiation-induced activation of NF-κB pathways by upregulating p-STAT3 expression. In conclusion, Corilagin could attenuate RIBI through inhibiting microglial activation and the expressions of inflammatory cytokines. Corilagin might inhibit the activation of NF-κB pathway in a STAT3-associated manner, thereby downregulating the inflammatory cytokine expressions.

Drug Discovery of Host CLK1 Inhibitors for Influenza Treatment

The rapid evolution of influenza virus makes antiviral drugs less effective, which is considered to be a major bottleneck in antiviral therapy. The key proteins in the host cells, which are related with the replication cycle of influenza virus, are regarded as potential drug targets due to their distinct advantage of lack of evolution and drug resistance. Cdc2-like kinase 1 (CLK1) in the host cells is responsible for alternative splicing of the M2 gene of influenza virus during influenza infection and replication. In this study, we carried out baculovirus-mediated expression and purification of CLK1 and established a reliable screening assay for CLK1 inhibitors. After a virtual screening of CLK1 inhibitors was performed, the activities of the selected compounds were evaluated. Finally, several compounds with strong inhibitory activity against CLK1 were discovered and their in vitro anti-influenza virus activities were validated using a cytopathic effect (CPE) reduction assay. The assay results showed that clypearin, corilagin, and pinosylvine were the most potential anti-influenza virus compounds as CLK1 inhibitors among the compounds tested. These findings will provide important information for new drug design and development in influenza treatment, and CLK1 may be a potent drug target for anti-influenza drug screening and discovery.