Identification and evaluation of anti hepatitis C virus phytochemicals from Eclipta alba

Anti-Melanogenic and Anti-Inflammatory Effects of 2'-Hydroxy-4',6'-dimethoxychalcone in B16F10 and RAW264.7 Cells

Chalcone is a type of flavonoid compound that is widely biosynthesized in plants. Studies have shown that consuming flavonoids from fruits and vegetables or applying individual ingredients reduces the risk of skin disease. However, the effects of chalcone on melanogenesis and inflammation have not been fully investigated. The aim of this study was to evaluate the anti-melanogenic and anti-inflammatory effects of 2'-hydroxy-3,4'-dimethoxychalcone (3,4'-DMC), 2'-hydroxy-4,4'-dimethoxychalcone (4,4'-DMC), 2'-hydroxy-3',4'-dimethoxychalcone (3',4'-DMC), and 2'-hydroxy-4',6'-dimethoxychalcone (4',6'-DMC). Among the derivatives of 2'-hydroxy-4'-methoxychalcone, 4',6'-DMC demonstrated the most potent melanogenesis-inhibitory and anti-inflammatory effects. As evidenced by various biological assays, 4',6'-DMC showed no cytotoxicity and notably decreased the expression of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 enzymes. Furthermore, it reduced cellular melanin content and intracellular tyrosinase activity in B16F10 melanoma cells by downregulating microphthalmia-associated transcription factor (MITF), cAMP-dependent protein kinase (PKA), cAMP response element-binding protein (CREB), p38, c-Jun N-terminal kinase (JNK), β-catenin, glycogen synthase kinase-3β (GSK3β), and protein kinase B (AKT) proteins, while upregulating extracellular signal-regulated kinase (ERK) and p-β-catenin. Additionally, treatment with 4',6'-DMC significantly mitigated the lipopolysaccharide (LPS)-induced expression of NO, PGE2, inflammatory cytokines, COX-2, and iNOS proteins. Overall, 4',6'-DMC treatment notably alleviated LPS-induced damage by reducing nuclear factor kappa B (NF-κB), p38, JNK protein levels, and NF-kB/p65 nuclear translocation. Finally, the topical applicability of 4',6'-DMC was evaluated in a preliminary human skin irritation test and no adverse effects were found. These findings suggest that 4',6'-DMC may offer new possibilities for use as functional ingredients in cosmeceuticals and ointments.

The search for an antiviral lead molecule to combat the neglected emerging Oropouche virus

Oropouche virus (OROV) is a member of the Peribunyaviridae family and the causative agent of a dengue-like febrile illness transmitted by mosquitoes. Although mild symptoms generally occur, complications such as encephalitis and meningitis may develop. A lack of proper diagnosis, makes it a potential candidate for new epidemics and outbreaks like other known arboviruses such as Dengue, Yellow Fever and Zika virus. The study of natural molecules as potential antiviral compounds is a promising alternative for antiviral therapies. Wedelolactone (WDL) has been demonstrated to inhibit some viral proteins and virus replication, making it useful to target a wide range of viruses. In this study, we report the in silico effects of WDL on the OROV N-terminal polymerase and its potential inhibitory effects on several steps of viral infection in mammalian cells in vitro, which revealed that WDL indeed acts as a potential inhibitor molecule against OROV infection.

HR-MAS NMR Metabolomics Profile of Vero Cells under the Influence of Virus Infection and nsP2 Inhibitor: A Chikungunya Case Study

The arbovirus Chikungunya (CHIKV) is transmitted by Aedes mosquitoes in urban environments, and in humans, it triggers debilitating symptoms involving long-term complications, including arthritis and Guillain-Barré syndrome. The development of antiviral therapies is relevant, as no efficacious vaccine or drug has yet been approved for clinical application. As a detailed map of molecules underlying the viral infection can be obtained from the metabolome, we validated the metabolic signatures of Vero E6 cells prior to infection (CC), following CHIKV infection (CV) and also upon the inclusion of the nsP2 protease inhibitor wedelolactone (CWV), a coumestan which inhibits viral replication processes. The metabolome groups evidenced significant changes in the levels of lactate, myo-inositol, phosphocholine, glucose, betaine and a few specific amino acids. This study forms a preliminary basis for identifying metabolites through HR-MAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Ressonance Spectroscopy) and proposing the affected metabolic pathways of cells following viral infection and upon incorporation of putative antiviral molecules.

Inhibition of herpes simplex virus by wedelolactone via targeting viral envelope and cellular TBK1/IRF3 and SOCS1/STAT3 pathways

OBJECTIVES

Development of novel antiherpes simplex virus (HSV) agents with active mechanisms different from nucleoside analogues is of high importance. Herein, we investigated the anti-HSV activities and mechanisms of wedelolactone (WDL) both in vitro and in vivo.

METHODS

Cytopathic effect (CPE) inhibition assay, plaque assay, and western blot assay were used to evaluate the anti-HSV effects of WDL in vitro. The immunofluorescence assay, RT-PCR assay, plaque reduction assay, sandwich ELISA assay, syncytium formation assay, tanscriptome analysis and western blot assay were used to explore the anti-HSV mechanisms of WDL. The murine encephalitis and vaginal models of HSV infection were performed to evaluate the anti-HSV effects of WDL in vivo.

RESULTS

WDL possessed inhibitory effects against both HSV-1 and HSV-2 in different cells with low toxicity, superior to the effects of acyclovir. WDL can directly inactivate the HSV particle via destruction of viral envelope and block HSV replication process after virus adsorption, different from the mechanisms of acyclovir. WDL may influence the host genes and signaling pathways related to HSV infection and immune responses. WDL can mainly interfere with the TBK1/IRF3 and SOCS1/STAT3 pathways to reduce HSV infection and inflammatory responses. Importantly, WDL treatment markedly improved mice survival, attenuated inflammatory symptoms, and reduced the virus titres in both HSV-1 and HSV-2 infected mice.

CONCLUSIONS

Thus, the natural compound WDL has the potential to be developed into a novel anti-HSV agent targeting both viral envelope and cellular TBK1/IRF3 and SOCS1/STAT3 pathways.

Luteolin inhibits herpes simplex virus 1 infection by activating cyclic guanosine monophosphate-adenosine monophosphate synthase-mediated antiviral innate immunity

BACKGROUND

The successive outbreaks of large-scale infectious diseases due to virus infection have been a major threat to human health in recent decades. Herpes simplex virus I (HSV-1) is a widely-disseminated DNA virus that infects the central nervous system to cause herpes labialis, keratitis and herpes simplex virus encephalitis (HSE), resulting in recurrent lifelong clinical or subclinical episodes. Luteolin is a plant flavone that has been extensively used in the treatment of various human diseases, including carcinogenesis, inflammation and chronic degenerative diseases.

PURPOSE

The aim of this study was to investigate the antiviral molecular mechanism of luteolin against HSV-1 infection in vitro and in vivo.

METHODS

The antiviral effect of luteolin in cell lines was examined by viral plaque assay, RT-qPCR, Western blot and time-of-addition assay. The interaction between luteolin and cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) was evaluated by molecular modeling and semi-denaturing detergent agarose gel electrophoresis. The efficacy of luteolin on HSE was evaluated in the HSE mouse model by analyzing weight loss, neurodegenerative symptoms and histopathological scores. Cytokine expression and protein levels were examined by RT-qPCR, Western blot and ELISA.

RESULTS

Luteolin inhibited the early process of HSV-1 infection, without affecting the infection of acyclovir-resistant HSV-1 strains. In addition, luteolin enhanced antiviral type I interferon production and activated the cytoplasmic DNA-sensing cGAS-stimulator of interferon gene (STING) pathway. Luteolin directly bound the active substrate binding site and promoted the oligomerization of cGAS. Luteolin also inhibited HSE-related weight loss, neurodegeneration and neuroinflammation in mice caused by HSV-1 infection. Furthermore, luteolin enhanced type I interferon expression and stimulated the cGAS-STING signaling pathway in vivo.

CONCLUSION

Luteolin inhibited the post-entry process of HSV-1 by activating the cGAS-STING pathway to promote antiviral interferon production. These results provided the rationale for luteolin as a potent cGAS activator and antiviral agent.

Medicinal plant molecules against hepatitis C virus: Current status and future prospect

Hepatitis C virus (HCV), a global malady, causes acute and chronic hepatitis leading to permanent liver damage, hepatocellular carcinoma, and death. Modern anti-HCV therapies are efficient, but mostly inaccessible for residents of underdeveloped regions. To innovate more effective treatments at affordable cost, medicinal plant-based products need to be explored. The aim of this article is to review plant constituents in the light of putative anti-HCV mechanisms of action, and discuss existing problems, challenges, and future directions for their potential application in therapeutic settings. One hundred sixty literatures were collected by using appropriate search strings via scientific search engines: Google Scholar, PubMed, ScienceDirect, and Scopus. Bibliography was prepared using Mendeley desktop software. We found a substantial number of plants that were reported to inhibit different stages of HCV life cycle. Traditional medicinal plants such as Phyllanthus amarus Schumach. and Thonn., Eclipta alba (L.) Hassk., and Acacia nilotica (L.) Delile exhibited strong anti-HCV activities. Again, several phytochemicals such as epigallocatechin-3-gallate, honokilol, punicalagin, and quercetin have shown broad-spectrum anti-HCV effect. We have presented promising phytochemicals like silymarin, curcumin, glycyrrhizin, and camptothecin for nanoparticle-based hepatocyte-targeted drug delivery. Nevertheless, only a few animal studies have been performed to validate the anti-HCV effect of these plant products. Again, insufficient clinical evaluation of the safety and effectiveness of herbal medications remain a problem. Selected plants products could be developed as novel therapeutics for HCV patients only after scrupulous evaluation of their safety and efficacy in a clinical set-up.

Luteolin is a potential inhibitor of COVID-19: An in silico analysis

The severe respiratory syndrome 2019 novel coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread explosively, raising global health concerns. Luteolin shows antiviral properties, but its effect on SARS-CoV-2 and the associated mechanisms are not elucidated. We used network pharmacology, molecular docking and molecular dynamics to provide potential molecular support of luteolin (3,4,5,7-tetrahydroxyflavone) (LUT) against COVID-19. We employed network pharmacology, molecular docking, and molecular dynamics techniques to investigate how LUT affected COVID-19. Several databases were queried to determine potential target proteins related to LUT and COVID-19. Protein-protein interaction network was constructed, and core targets were filtered by degree value. Following that, functional enrichment was conducted. Molecular docking was utilized to ensure LUT was compatible with core target proteins. Finally, molecular dynamics was used to analyze the effects of the LUT on the optimal hub target. A total of 64 potential target genes for treating COVID-19 were identified, of which albumin, RAC-alpha serine/threonine-protein kinase, caspase-3, epidermal growth factor receptor, heat shock protein HSP 90-alpha, and mitogen-activated protein kinase 1 might be the most promising. In addition, molecular docking results showed that LUT could interact with SARS-CoV-2 major protease 3CL. LUT can bind to the active sites of 3CL protease and mitogen-activated protein kinase 1, showing an anti-SARS-CoV-2 potential.

Utilizing X-ray fluorescence (XRF) method to evaluate the content of metal elements in soil and their effects on the total phenolic and flavonoid contents of some medicinal plants

Soil factors, especially metal elements in the soil, play a significant role in forming and accumulating secondary metabolites, which determine the medicinal properties of medicinal herbs. In this study, the concentrations of some metal elements (K, Mn, Fe, Cu, Zn, and Cr) in Cam Mountain and Tinh Bien Town, An Giang Province, Vietnam, were determined using the XRF method. We simultaneously determined the total phenolic and flavonoid content of some medicinal herbs collected from the collected soil sample areas, thereby assessing the influence of these elements on the formation of secondary metabolites in medicinal plants. The results showed that K, Mn, and Cr were mainly concentrated in the topsoil and transition layers; Fe and Cu elements tended to concentrate in the transition layer and the subsoil when surveying the soil profile. K, Mn, Cu, and Cr concentrations were more focused in Tinh Bien area, while Fe and Zn had higher concentrations at Cam Mountain. Additionally, results from evaluating the relationship between the content of the elements in the soil and the content of two active compounds also showed the correlation regression model between Zn and flavonoid expression by level 4 at the 5% significance level. Thus, the nonlinear model is suitable for evaluating the relationship between the content of metal elements in the soil and the active compound in medicinal plants.

Luteolin Isolated from Juncus acutus L., a Potential Remedy for Human Coronavirus 229E

The COVID-19 pandemic, caused by SARS-CoV-2, addressed the lack of specific antiviral drugs against coronaviruses. In this study, bioguided fractionation performed on both ethyl acetate and aqueous sub-extracts of Juncus acutus stems led to identifying luteolin as a highly active antiviral molecule against human coronavirus HCoV-229E. The apolar sub-extract (CH₂Cl₂) containing phenanthrene derivatives did not show antiviral activity against this coronavirus. Infection tests on Huh-7 cells, expressing or not the cellular protease TMPRSS2, using luciferase reporter virus HCoV-229E-Luc showed that luteolin exhibited a dose-dependent inhibition of infection. Respective IC₅₀ values of 1.77 µM and 1.95 µM were determined. Under its glycosylated form (luteolin-7-O-glucoside), luteolin was inactive against HCoV-229E. Time of addition assay showed that utmost anti-HCoV-229E activity of luteolin was achieved when added at the post-inoculation step, indicating that luteolin acts as an inhibitor of the replication step of HCoV-229E. Unfortunately, no obvious antiviral activity for luteolin was found against SARS-CoV-2 and MERS-CoV in this study. In conclusion, luteolin isolated from Juncus acutus is a new inhibitor of alphacoronavirus HCoV-229E.

Insights into the pharmacological and therapeutic effects of apigenin in liver injuries and diseases

Background

Liver diseases are a spectrum of diseases that include hepatic steatosis, nonalcoholic fatty liver disease, hepatitis, liver fibrosis, cirrhosis, and hepatic cancer. These diseases not only severely decrease the quality of life for patients, but also cause financial burden. Although apigenin (APG) has recently become the primary treatment for liver injuries and diseases (LIADs), there has been no systematic review of its use.

Purpose

To review the existing literature and put forward novel strategies for future APG research on LIADs.

Methods

A search was conducted in PubMed, Science Direct, Research Gate, Web of Science, VIP, Wanfang, and CNKI, and 809 articles were obtained. After applying inclusion and exclusion criteria, 135 articles were included.

Results

APG is promising in treating LIADs via various mechanisms arising from its anti-inflammation, anti-proliferation, anti-infection, anti-oxidation, and anti-cancer properties.

Conclusion

This review summarizes the evidence supporting the use of APG as a treatment for LIADs and provides an insight into the intestinal microbiota, which may have important implications in its future clinical use.

Progression of Antiviral Agents Targeting Viral Polymerases

Viral DNA and RNA polymerases are two kinds of very important enzymes that synthesize the genetic materials of the virus itself, and they have become extremely favorable targets for the development of antiviral drugs because of their relatively conserved characteristics. There are many similarities in the structure and function of different viral polymerases, so inhibitors designed for a certain viral polymerase have acted as effective universal inhibitors on other types of viruses. The present review describes the development of classical antiviral drugs targeting polymerases, summarizes a variety of viral polymerase inhibitors from the perspective of chemically synthesized drugs and natural product drugs, describes novel approaches, and proposes promising development strategies for antiviral drugs.

RNA-dependent RNA polymerase (RdRp) natural antiviral inhibitors: a review

Viral diseases are the cause of many global epidemics, leading to deaths, affecting the quality of life of populations, and impairing public health. The limitations in the treatment of viral diseases and the constant resistance to conventional antiviral treatments encourage researchers to discover new compounds. In this perspective, this literature review presents isolated molecules and extracts of natural products capable of inhibiting the activity of the nonstructural protein that acts as the RNA-dependent RNA polymerase. The literature review presented natural compounds with the potential to be tested as alternative medicines or used in the development of synthetic drugs to prevent the replication of RNA viruses, such as COVID-19, hepatitis C, and dengue viruses, among others. Natural products are known to exhibit remarkable activities in mitigation of different viral diseases, in addition, they help to decrease the aggravation of infections. Consequently, reducing hospitalization time and deaths.

Natural flavonoids effectively block the CD81 receptor of hepatocytes and inhibit HCV infection: a computational drug development approach

Hepatitis C virus (HCV) infection is a major public health concern, and almost two million people are infected per year globally. This is occurred by the diverse spectrum of viral genotypes, which are directly associated with chronic liver disease (fibrosis, and cirrhosis). Indeed, the viral genome encodes three principal proteins as sequentially core, E1, and E2. Both E1 and E2 proteins play a crucial role in the attachment of the host system, but E2 plays a more fundamental role in attachment. The researchers have found the "E2-CD81 complex" at the entry site, and therefore, CD81 is the key receptor for HCV entrance in both humans, and chimpanzees. So, the researchers are trying to block the host CD81 receptor and halt the virus entry within the cellular system via plant-derived compounds. Perhaps that is why the current research protocol is designed to perform an in silico analysis of the flavonoid compounds for targeting the tetraspanin CD81 receptor of hepatocytes. To find out the best flavonoid compounds from our library, web-based tools (Swiss ADME, pKCSM), as well as computerized tools like the PyRx, PyMOL, BIOVIA Discovery Studio Visualizer, Ligplot+ V2.2, and YASARA were employed. For molecular docking studies, the flavonoid compounds docked with the targeted CD81 protein, and herein, the best-outperformed compounds are Taxifolin, Myricetin, Puerarin, Quercetin, and (-)-Epicatechin, and outstanding binding affinities are sequentially - 7.5, - 7.9, - 8.2, - 8.4, and - 8.5 kcal/mol, respectively. These compounds have possessed more interactions with the targeted protein. To validate the post docking data, we analyzed both 100 ns molecular dynamic simulation, and MM-PBSA via the YASARA simulator, and finally finds the more significant outcomes. It is concluded that in the future, these compounds may become one of the most important alternative antiviral agents in the fight against HCV infection. It is suggested that further in vivo, and in vitro research studies should be done to support the conclusions of this in silico research workflow.

Chemistry of Protein-Phenolic Interactions Toward the Microbiota and Microbial Infections

Along with health concerns, interest in plants as food and bioactive phytochemical sources has been increased in the last few decades. Phytochemicals as secondary plant metabolites have been the subject of many studies in different fields. Breakthrough for research interest on this topic is re-juvenilized with rising relevance in this global pandemics' era. The recent COVID-19 pandemic attracted the attention of people to viral infections and molecular mechanisms behind these infections. Thus, the core of the present review is the interaction of plant phytochemicals with proteins as these interactions can affect the functions of co-existing proteins, especially focusing on microbial proteins. To the best of our knowledge, there is no work covering the protein-phenolic interactions based on their effects on microbiota and microbial infections. The present review collects and defines the recent data, representing the interactions of phenolic compounds -primarily flavonoids and phenolic acids- with various proteins and explores how these molecular-level interactions account for the human health directly and/or indirectly, such as increased antioxidant properties and antimicrobial capabilities. Furthermore, it provides an insight about the further biological activities of interacted protein-phenolic structure from an antiviral activity perspective. The research on the protein-phenolic interaction mechanisms is of great value for guiding how to take advantage of synergistic effects of proteins and polyphenolics for future medical and nutritive approaches and related technologies.

Identification of phytochemicals from Eclipta alba and assess their potentiality against Hepatitis C virus envelope glycoprotein: virtual screening, docking, and molecular dynamics simulation study

Hepatitis C virus has a major role in spreading chronic liver disease and hepatocellular carcinoma. Factors such as high costs, pharmacological side effects, and the development of drug resistance strains require the development of new and potentially effective antiviral to treat the various stages of Hepatitis C. Bioactive chemicals have been extracted from medicinal plants and are utilized by humans for the goal of maintaining a healthy lifestyle. The goal of this work is to recognize phytochemicals from Eclipta alba and assess their potentiality activity against the hepatitis C virus envelope glycoprotein using in silico approaches. Phytochemicals from Eclipta alba were virtually screened by Auto dock raccoon and 12 compounds were selected for molecular docking to probe the active binding site. The top two compounds based on the binding score like ecliptalbine and oleanolic acid with HCV E2 glycoprotein exhibit binding energy -8.88 and -8.02 kcal/mol, respectively. The chemicals' usefulness was reinforced by positive pharmacokinetic data. The phytocompounds were identified as potent HCV inhibitors based on the drug likeness and ADMET properties. Both ecliptalbine and oleanolic acid underwent molecular dynamics simulations to determine features such as RMSD, RMSF, SASA, hydrogen-bond number, and MM-PBSA-based binding free energy. From the molecular docking and molecular dynamics simulation study revealed that oleanolic acid obtained from Eclipta alba can be used as inhibitors against Hepatitis C. The identified inhibitor from our study will be study in vitro and in vivo studies to check their efficacy against Hepatitis C.Communicated by Ramaswamy H. Sarma.

Tale of Viruses in Male Infertility

Male infertility is a condition where the males either become sterile or critically infertile. The World Health Organisation assessed that approximately 9% of the couple have fertility issues where the contribution of the male partner was estimated to be 50%. There are several factors that can amalgamate to give rise to male infertility. Among them are lifestyle factors, genetic factors and as well as several environmental factors. The causes of male infertility may be acquired, congenital or sometimes idiopathic. All these factors adversely affect the spermatogenesis process as well as they impart serious threats to male genital organs thus resulting in infertility. Viruses are submicroscopic pathogenic agents that rely on host for their replication and survival. They enter the host cell, hijack the host cell machinery to aid their own replication and exit the cell for a new round of infection. With the growing abundance of different types of viruses and the havoc they have stirred in the form of pandemics, it is very essential to decipher their route of entry inside the human body and understand their diverse functional roles in order to combat them. In this chapter, we will review how viruses invade the male genital system thus in turn leading to detrimental consequence on male fertility. We will discuss the tropism of various viruses in the male genital organs and explore their sexual transmissibility. This chapter will summarise the functional and mechanistic approaches employed by the viruses in inducing oxidative stress inside spermatozoa thus leading to male infertility. Moreover, we will also highlight the various antiviral therapies that have been studied so far in order to ameliorate viral infection in order to combat the harmful consequences leading to male infertility.

Hepatoprotective Native Plants Documented in Brazilian Traditional Medicine Literature: Current Knowledge and Prospects

The native flora of Brazil covers a large biodiversity of plants, some of which have important pharmacological properties. Ethnobotanical studies have established that the folk use of plants for hepatobiliary disorders is very common in Brazil. This review aimed to compile, describe and discuss the main native Brazilian medicinal plants used as hepatoprotective agents listed on 25 books by authors from various regions in the country. Based on the 153 species found, a comprehensive analysis of the most relevant scientific studies is presented, including Piper umbellatum, Echinodorus macrophyllus, Fevillea trilobata and Achyrocline satureioides. Some medicinal plants share both a large number of citations and scientific evidence to corroborate their hepatoprotective effects, including Solanum paniculatum, Baccharis crispa and Phyllanthus niruri, which could be of interest to develop new phytomedicines. Additionally, some active ingredients are indicated as being responsible for the liver protective effects described, particularly phenolic compounds (flavonoids, coumestans and lignans).

Okicamelliaside targets the N-terminal chaperone pocket of HSP90 disrupts the chaperone protein interaction of HSP90-CDC37 and exerts antitumor activity

Heat shock protein 90 (HSP90) has been recognized as a crucial target in cancer cells. However, various toxic reactions targeting the ATP binding site of HSP90 may not be the best choice for HSP90 inhibitors. In this paper, an ellagic acid derivative, namely, okicamelliaside (OCS), with antitumor effects was found. To identify potential anti-cancer mechanisms, an OCS photosensitive probe was applied to target fishing and tracing. Chemical proteomics and protein-drug interaction experiments have shown that HSP90 is a key target for OCS, with a strong binding affinity (K_D = 6.45 μM). Mutation analysis of the target protein and molecular dynamics simulation revealed that OCS could competitively act on the key Glu-47 site at the N-terminal chaperone pocket of HSP90, where the co-chaperone CDC37 binds to HSP90, affect its stability and reduce the ∆G_bind of HSP90-CDC37. It was demonstrated that OCS destroys the protein-protein interactions of HSP90-CDC37; selectively affects downstream kinase client proteins of HSP90, including CDK4, P-AKT⁴⁷³, and P-ERK1/2; and exerts antitumor effects on A549 cells. Furthermore, tumor xenograft experiments demonstrated high antitumor activity and low toxicity of OCS in the same way. Our findings identified a novel N-terminal chaperone pocket natural inhibitor of HSP90, that is, OCS, which selectively inhibits the formation of the HSP90-CDC37 protein complex, and provided further insight into HSP90 inhibitors for anti-cancer candidate drugs.

Jasmonates promote enhanced production of bioactive caffeoylquinic acid derivative in Eclipta prostrata (L.) L. hairy roots

Eclipta prostrata (L.) L. is widely used in traditional medicine for treatment of hepatitis, poisoning from snake bites and viral infections. Pharmacological studies confirmed its antioxidant, anti-inflammatory and anticancer activities. The efficacy of E. prostrata (L.) L. extracts has been correlated to phenylpropanoids such as flavonoids, coumestans and caffeoylquinic acid derivatives. In this work, the production of wedelolactone, demethylwedelolactone and 3,5-di-O-caffeoylquinic acid (3,5-diCQA) in hairy root cultures of E. prostrata (L.) L. C19 clone was increased after addition of eliciting agents jasmonic acid (JA) or methyl jasmonate (MeJA) at multiple concentrations. Cultures elicited with 100 μM of JA saw a 5.2 fold increase in wedelolactone (from 0.72 to 3.72 mg/g d.w.), a 1.6 fold increase in demethylwedelolactone (from 5.54 to 9.04 mg/g d.w.) and a 2.47 fold increase in 3,5-diCQA (from 18.08 to 44.71 mg/g d.w.). Obtained data validate the potential of E. prostrata (L.) L. hairy root cultures as a production system of wedelolactone, demethylwedelolactone and especially 3,5-diCQA, which has recently been reported to possess activity against coronavirus disease (Covid-19) by in silico computational studies.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11240-021-02201-4.

Antiviral plant-derived natural products to combat RNA viruses: Targets throughout the viral life cycle

There is a need for new effective antivirals, particularly in response to the development of antiviral drug resistance and emerging RNA viruses such as SARS‐CoV‐2. Plants are a significant source of structurally diverse bioactive compounds for drug discovery suggesting that plant‐derived natural products could be developed as antiviral agents. This article reviews the antiviral activity of plant‐derived natural products against RNA viruses, with a focus on compounds targeting specific stages of the viral life cycle. A range of plant extracts and compounds have been identified with antiviral activity, often against multiple virus families suggesting they may be useful as broad‐spectrum antiviral agents. The antiviral mechanism of action of many of these phytochemicals is not fully understood and there are limited studies and clinical trials demonstrating their efficacy and toxicity in vivo. Further research is needed to evaluate the therapeutic potential of plant‐derived natural products as antiviral agents.

MicroRNA-155 and antiviral immune responses

The microRNA, miR-155 regulates both adaptive and innate immune responses. In viral infections, miR-155 can affect both innate immunity (interferon response, natural killer cell activity, and macrophage polarization) and adaptive immunity (including generation of anti-viral antibodies, CD8⁺ cytotoxic T lymphocytes, Th17, Th2, Th1, Tfh and Treg cells). In many viral infections, the proper and timely regulation of miR-155 expression is critical for the induction of an effective anti-virus immune response and viral clearance without any harmful immunopathologic consequences. MiR-155 may also exert pro-viral effects, mainly through the inhibition of the anti-viral interferon response. Thus, dysregulated expression of miR-155 can result in virus persistence and disruption of the normal response to viral infections. This review provides a thorough discussion of the role of miR-155 in immune responses and immunopathologic reactions during viral infections, and highlights its potential as a therapeutic target.

Wedelolactone protects against cisplatin-induced nephrotoxicity in mice via inhibition of organic cation transporter 2

The balance of cisplatin uptake and efflux, mediated mainly by organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1), respectively, determines the renal accumulation and nephrotoxicity of cisplatin. Using transporter-mediated cellular uptake assay, we identified wedelolactone (WEL), a medicinal plant-derived natural compound, is a competitive inhibitor of OCT2 and a noncompetitive inhibitor of MATE1. Wedelolactone showed a selectivity to inhibit OCT2 rather than MATE1. Cytotoxicity studies revealed that wedelolactone alleviated cisplatin-induced cytotoxicity in OCT2-overexpressing HEK293 cells, whereas it did not alter the cytotoxicity of cisplatin in various cancer cell lines. Additionally, wedelolactone altered cisplatin pharmacokinetics, reduced kidney accumulation of cisplatin, and ameliorated cisplatin-induced acute kidney injury in the Institute of Cancer Research mice. In conclusion, these findings suggest a translational potential of WEL as a natural therapy for preventing cisplatin-induced nephrotoxicity and highlight the need for drug-drug interaction investigations of WEL with other treatments which are substrates of OCT2 and/or MATE1.

Pharmacological Mechanisms Underlying the Hepatoprotective Effects of Ecliptae herba on Hepatocellular Carcinoma

BACKGROUND

The number of hepatocellular carcinoma (HCC) cases worldwide has increased significantly. As a traditional Chinese medicine (TCM) with a long history, Ecliptae herba (EH) has been widely used in HCC patients in China, but its hepatoprotective mechanism is still unclear.

METHODS

In this study, we applied a network pharmacology-based strategy and experimental verification to systematically unravel the underlying mechanisms of EH against HCC. First, six active ingredients of EH were screened from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) by the ADME method. Subsequently, 52 potential targets of 6 active ingredients acting on HCC were screened from various databases, including TCMSP, DGIdb, SwissTargetPrediction, CTD, and GeneCards. Then, by constructing protein-protein interaction (PPI) network from STRING, we displayed the intricate connections among these 52 targets through Cytoscape software. We also applied enrichment analysis, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, to provide an outline and set of concepts for describing gene functions and the advanced functions of biological systems of these 52 targets from genomic and molecular level information. Finally, molecular docking and biological experiments were used to reconfirm these results.

RESULTS

We hypothesized that EH might exert anti-HCC activity by acting on hub genes, including RELA, MMP9, PTGS2, ESR1, EGFR, AR, AKT1, HIF1A, AHR, CYP3A4, ABCG2, and MMP2. Moreover, based on GO and KEGG analysis, we speculated that EH may exert hepatoprotective effects on HCC through the following mechanisms: regulation of the PI3K-AKT signaling pathway to promote apoptosis and inhibit the abnormal proliferation of HCC, downregulation of HIF-1A expression by activating the HIF-1 signaling pathway, prevention of HCC by regulating lipid metabolism, and inhibition of nonalcoholic fatty liver disease (NAFLD) by the cytochrome P450 subfamily. Subsequent biological experiments verified that EH inhibits the PI3K-AKT signaling pathway through its active ingredients, quercetin, and wedelolactone, thereby inhibiting the proliferation of HCC cells and promoting the apoptosis of HCC cells.

CONCLUSIONS

The network pharmacological strategy provides an efficient method to systematically explore the pharmacological mechanism of EH in HCC. Our study demonstrated that the anti-HCC proliferation activity of EH is mainly exerted by two active ingredients (quercetin and wedelolactone), which inhibit the proliferation of HCC cells (HepG2 and Huh-7) by inhibiting PI3K-AKT signaling.

Naturally occurring coumestans from plants, their biological activities and therapeutic effects on human diseases

Naturally occurring coumestans are known as a collection of plant-derived polycyclic aromatic secondary metabolites which are characterized by the presence of an oxygen heterocyclic four-ring system comprising a coumarin moiety and a benzofuran moiety sharing a C˭C bond. Recently, there is an increasing attention in excavating the medicinal potential of coumestans, particularly coumestrol, wedelolactone, psoralidin and glycyrol, in a variety of diseases. This review is a comprehensive inventory of the chemical structures of coumestans isolated from various plant sources during the period of 1956-2020, together with their reported biological activities. 120 molecules were collected and further classified as coumestans containing core skeleton, dimethylpyranocoumestans, furanocoumestans, O-glycosylated coumestans and others, which showed a wide range of pharmacological activities including estrogenic, anti-cancer, anti-inflammatory, anti-osteoporotic, organ protective, neuroprotective, anti-diabetic and anti-obesity, antimicrobial, immunosuppressive, antioxidant and skin-protective activities. Furthermore, this review focuses on the counteraction of coumestans against bone diseases and organ damages, and the involved molecular mechanisms, which could provide important information to better understand the medicinal values of these compounds. This review is intended to be instructive for the rational design and development of less toxic and more effective drugs with a coumestan scaffold.

Alkaloid and benzopyran compounds of Melicope latifolia fruit exhibit anti-hepatitis C virus activities

BACKGROUND

New agents for developing alternative or complementary medicine to treat the hepatitis C virus (HCV) are still needed due to high rates of HCV infection globally and the current limitations of available treatments. Treatment of HCV with a combination of direct acting antivirals have been shown to be approximately 90% effective but will be limited in the future due to the emergence of drug resistance and high cost. The leaves of Melicope latifolia have previously been reported to have anti-HCV activity and are a potential source of bioactive compounds for future novel drug development. This study aimed to evaluate the efficacy of the extract of M. latifolia fruit to treat HCV and to isolate its active compounds.

METHOD

M. latifolia fruit was extracted using methanol and purified using vacuum liquid chromatography (VLC) and Radial Chromatography. The anti-HCV activity was analyzed using cell culture lines Huh7it-1 and JFH1 (genotype 2a). Time-of-addition and immunoblotting studies were performed to identify the mode of action of the isolated active compounds. The structures of the active compounds were determined using nuclear magnetic resonance (NMR) spectra, UV, IR, and Mass Spectra.

RESULTS

Six known compounds were isolated from M. latifolia fruit: O-methyloktadrenolon, alloevodionol, isopimpinellin, alloxanthoxyletin, methylevodionol, and N-methylflindersine. N-methylflidersine was the most active compound with IC50 value of 3.8 μg/ml while methylevodionol, isopimpinellin, and alloevodionol were less active. O-methyloktadrenolon and alloxanthoxyletin were moderately active with IC50 values of 10.9 and 21.72 μg/ml, respectively. N-methylflidersine decreased level of HCV NS3 protein expression in the cells.

CONCLUSION

The alkaloid compound, N-methylflindersine which was isolated from M. latifolia possesses anti-HCV activity through post-entry inhibition and suppressed NS3 protein expression.

Luteolin inhibits respiratory syncytial virus replication by regulating the MiR-155/SOCS1/STAT1 signaling pathway

Background

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants, children, immunocompromised adults, and elderly individuals. Currently, there are few therapeutic options available to prevent RSV infection. The present study aimed to investigate the effects of luteolin on RSV replication and the related mechanisms.

Material and methods

We pretreated cells and mice with luteolin before infection with RSV, the virus titer, expressions of RSV-F, interferon (IFN)-stimulated genes (ISGs), and production of IFN-α and IFN-β were determined by plaque assay, RT-qPCR, and ELISA, respectively. The activation of Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) signaling pathway was detected by Western blotting and luciferase assay. Proteins which negatively regulate STAT1 were determined by Western blotting. Then cells were transfected with suppressor of cytokine signaling 1 (SOCS1) plasmid and virus replication and ISGs expression were determined. Luciferase reporter assay and Western blotting were performed to detect the relationship between SOCS1 and miR-155.

Results

Luteolin inhibited RSV replication, as shown by the decreased viral titer and RSV-F mRNA expression both in vitro and in vivo. The antiviral activity of luteolin was attributed to the enhanced phosphorylation of STAT1, resulting in the increased production of ISGs. Further study showed that SOCS1 was downregulated by luteolin and SOCS1 is a direct target of microRNA-155 (miR-155). Inhibition of miR-155 rescued luteolin-mediated SOCS1 downregulation, whereas upregulation of miR-155 enhanced the inhibitory effect of luteolin.

Conclusion

Luteolin inhibits RSV replication by regulating the miR-155/SOCS1/STAT1 signaling pathway.

Antiviral Properties of Flavonoids and Delivery Strategies

This review summarizes the latest advancements in phytochemicals as functional antiviral agents. We focused on flavonoids, like apigenin, vitexin, quercetin, rutin and naringenin, which have shown a wide range of biological effects including antiviral activities. The molecular mechanisms of their antiviral effects mainly consist in the inhibition of viral neuraminidase, proteases and DNA/RNA polymerases, as well as in the modification of various viral proteins. Mixtures of different flavonoids or combination of flavonoids with antiviral synthetic drugs provide an enhancement of their antiviral effects. Recent strategies in drug delivery significantly contribute to overcoming the low bioavailability of flavonoids. Frequent viral infections worldwide have led to the need for new effective antiviral agents, which can be identified among the various phytochemicals. In this light, screening the antiviral activities of a cocktail of flavonoids would be advantageous in order to prevent viral infections and improve current antiviral therapies.

Dual inhibitors of SARS-CoV-2 proteases: pharmacophore and molecular dynamics based drug repositioning and phytochemical leads

SARS-related coronaviruses poses continual threat to humanity by rapidly mutating and emerging as severe pandemic outbreaks, including the current nCoV-19 pandemic. Hence a rapid drug repositioning and lead identification strategy are required to mitigate these outbreaks. We report a pharmacophore and molecular dynamics-based approach for drug repositioning and lead identification against dual targets (3CLp and PLp) of SARS-CoV-2. The pharmacophore model of 3CLp inhibitors was apolar with two aromatic and two H-bond acceptors, whereas that of PLp was relatively polar, bearing one aromatic and three H-bond acceptors. Pharmacophore-based virtual screening yielded six existing FDA-approved drugs and twelve natural products with both the pharmacophoric features. Among them are nelfinavir, tipranavir and licochalcone-D, which has shown better binding characteristics with both the proteases compared to lopinavir. The molecular dynamics revealed that the connecting loop (residues 176–199) of 3CLp is highly flexible, and hence, inhibitors should avoid high-affinity interactions with it. Lopinavir, due to its high affinity with the loop region, exhibited unstable binding. Further, the van der Waals size of the 3CLp inhibitors positively correlated with their binding affinity with 3CLp. However, the van der Waals size of a ligand should not cross a threshold of 572ų, beyond which the ligands are likely to make high-affinity interaction with the loop and suffer unstable binding as observed in the case of lopinavir. Similarly, the total polar surface area of the ligands were found to be negatively correlated with their binding affinity with PLp.

Natural products for the management of the hepatitis C virus: a biochemical review

Chronic hepatitis C virus (HCV) infection is a significant public health problem, with a worldwide prevalence of approximately 170 million. Current therapy for HCV infection includes the prolonged administration of a combination of ribavirin and PEGylated interferon-α, for over a decade. This regimen is expensive and often associated with a poor antiviral response and unwanted side effects. A highly effective combination treatment is likely required for the future management of HCV infections and entry inhibitors could play an important role. Currently, no entry inhibitor has been licensed for the prophylactic treatment of hepatitis C. Therefore, additional agents that combat HCV infection are urgently needed and must be developed. Many phytochemical constituents have been identified that display considerable inhibition of HCV at some stage of the life cycle. This review will summarise the current state of knowledge on natural products and their possible activities in the context of HCV infection.

Antidiabetic Activity of Gold Nanoparticles Synthesized Using Wedelolactone in RIN-5F Cell Line

We synthesized the gold nanoparticles (AuNPs) using wedelolactone (WDL) and characterized them using UV-visible spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopic (TEM), energy dispersive X-ray diffraction, and atomic force microscopic (AFM) studies. The electronic spectrum exhibited an absorption peak at 535 nm. The FT-IR results proved that WDL was stabilized on the surface of AuNPs by acting as a capping or reducing agent. The crystalline structure was affirmed by XRD pattern and the spherical shape of WDL-AuNPs was evidenced by SEM, TEM, and AFM. The synthesized WDL-AuNPS were evaluated for anti-diabetic activity in pancreatic RIN-5F cell lines. In vitro results showed that WDL-AuNPs did not only improve the insulin secretion affected by di-(2-ethylhexyl) phthalate (DEHP), but also the cell viability in RIN5F cells. WDL-AuNPs treatment modulates the pro-apoptotic proteins and anti-apoptotic proteins expression to prevent the cells undergoing apoptosis in DEHP-exposed RIN-5F cells. The exposure of DEHP causes an increase in ROS production and lipid peroxidation levels. The free radical scavenging and antioxidant properties of WDL-AuNPs increase the deleterious effect caused by DEHP. On the other side, WDL-AuNPs increase mRNA expressions of insulin-signaling proteins in RIN-5F cells. This study concludes that WDL-AuNPs can be successfully used to regulate the expression of Bcl-2 family proteins, reduce lipid peroxidation, and to improve the secretion of antioxidants and insulin through the GLUT2 pathway in RIN-5F cell lines.

Wedelolactone inhibits human cytomegalovirus replication by targeting distinct steps of the viral replication cycle

Wedelolactone (WDL) is a coumestan present in the plants Eclipta prostrata and Wedelia calendulacea which are used for treatment of a multitude of health problems in traditional medicine. It has previously been shown that WDL exerts antiviral activity against human immunodeficiency virus and hepatitis C virus. In this study, we investigated the effect of WDL on lytic human cytomegalovirus (HCMV) infection. We demonstrate a strong interference with HCMV replication as analyzed in multi-round replication settings. A more detailed analysis of the underlying mechanisms revealed that WDL acts at two distinct steps of the viral replication cycle. During immediate early (IE) times, we observe an inhibition of IE1/IE2 expression. Although WDL was reported to interfere with NF-κB signaling our results suggest the existence of additional mechanisms that impede viral IE expression. During later time points of infection, WDL induced a disruption of the interaction between EZH2 and EED, components of the virus-supportive polycomb repressive complex 2 (PRC2). Thereby, the stability of the PRC2 complex as well as the related complex PRC1 was disturbed leading to diminished viral DNA synthesis. Taken together, we identify WDL as a potent agent against HCMV which interferes at two distinct steps of viral replication.

A review on traditional uses, phytochemistry and pharmacology of Eclipta prostrata (L.) L

ETHNOPHARMACOLOGICAL RELEVANCE

Eclipta prostrata, a traditional herbal medicine, has long been used in Asia and South America for the therapy of hemorrhagic diseases (e.g. hemoptysis, hematemesis, hematuria, epistaxis and uterine bleeding), skin diseases, respiratory disorders, coronary heart disease, hair loss, vitiligo, snake bite and those caused by the deficiency of liver and kidney.

AIM OF THE REVIEW

In this review, we highlight relatively comprehensive and up-to-date information of E. prostrata on traditional uses, phytochemistry, pharmacology and toxicity, along with featuring the gaps in current knowledge, aiming to provide references for future research and possible opportunities for well applications of this medicinal plant.

MATERIALS AND METHODS

Information on E. prostrata was gathered from scientific databases (Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed and CNKI). Information was also obtained from local books, Ph.D. theses and M.Sc. dissertations and Chinese Pharmacopoeia. The plant taxonomy was validated by the database "The Plant List".

RESULTS

Various phytochemical classes has been identified and isolated from the plant covering triterpenes, flavonoids, thiopenes, coumestans, steroids and others. Among these, coumestans are reported as the most common ingredients. The isolated crude extracts and individual compounds have been reported to exhibit promising pharmacological properties, such as hepatoprotective, osteoprotective, cytotoxic, hypoglycaemic, anti-inflammatory, anti-microbial, hypolipidemic, promoting hair growth, rejuvenative and neuroprotective effects.

CONCLUSIONS

Until now, significant progress has been witnessed in phytochemistry and pharmacology of E. prostrata. Thus, some traditional uses has been well supported and clarified by modern pharmacological studies. Moreover, E. prostrata also showed therapeutic potential in some refractory diseases such as cancer, dementia and diabetes. But, present findings are still insufficient that cannot satisfactorily explain some mechanisms of action. More well-designed studies in vitro especially in vivo are required to establish links between the traditional uses and bioactivities, discover new skeletons and activity molecules, as well as ensure safety before clinical use.

Phytochemistry and neuroprotective effects of Eclipta alba (L.) Hassk

Eclipta alba (L.) Hassk. or Eclipta prostrata (Linn.) or Eclipta erecta (Linn.) is an herbaceous plant well known in Asian as African traditional medicines. These extracts are used in traditional medicine for treatment of microbial diseases and certain metabolic disorders. This review aimed to investigate phytochemical profile and neuroprotective effects of E. alba (L.) Hassk. Several compounds belonging to the families of phenolics, alkaloids, terpenoids and polysaccharides have been isolated, identified or characterized from E. alba extracts. This plant has a diverse neuropharmacological profile. Thus, its extract improves cognitive deficits and also attenuated epileptic seizures. Phytomolecules implicated in these potentials are Eclalbasaponin II and luteolin, respectively. This document updates isolated and identified organic compounds from the extracts of E. alba and reviews their neuropharmacological activities.

Wedelolactone Attenuates Pulmonary Fibrosis Partly Through Activating AMPK and Regulating Raf-MAPKs Signaling Pathway

Pulmonary fibrosis is common in a variety of inflammatory lung diseases, there is currently no effective clinical drug treatment. It has been reported that the ethanol extract of Eclipta prostrata L. can improve the lung collagen deposition and fibrosis pathology induced by bleomycin (BLM) in mice. In the present study, we studied whether wedelolactone (WEL), a major coumarin ingredient of E. prostrata, provided protection against BLM-induced pulmonary fibrosis. ICR or C57/BL6 strain mice were treated with BLM to establish lung fibrosis model. WEL (2 or 10 mg/kg) was given daily via intragastric administration for 2 weeks starting at 7-day after intratracheal instillation. WEL at 10 mg/kg significantly reduced BLM-induced inflammatory cells infiltration, pro-inflammatory factors expression, and collagen deposition in lung tissues. Additionally, treatment with WEL also impaired BLM-induced increases in fibrotic marker expression (collagen I and α-SMA) and decrease in an anti-fibrotic marker (E-cadherin). Treatment with WEL significantly prevented BLM-induced increase in TGF-β1 and Smad2/3 phosphorylation in the lungs. WEL administration (10 mg/kg) also significantly promoted AMPK activation compared to model group in BLM-treated mice. Further investigation indicated that activation of AMPK by WEL can suppressed the transdifferentiation of primary lung fibroblasts and the epithelial mesenchymal transition (EMT) of alveolar epithelial cells, the inhibitive effects of WEL was significantly blocked by an AMPK inhibitor (compound C) in vitro. Together, these results suggest that activation of AMPK by WEL followed by reduction in TGFβ1/Raf-MAPK signaling pathways may have a therapeutic potential in pulmonary fibrosis.

Development and Validation of an Ultra-Performance Liquid Chromatography Method for the Determination of Wedelolactone in Rat Plasma and its Application in a Pharmacokinetic Study

Wedelolactone is a coumarin ether with significant hepatoprotective effects. However, there are few pharmacokinetic studies of wedelolactone, which will affect the studies of its efficacy and potential toxicity. In this study, a selective ultra-performance liquid chromatography (UPLC) method was developed to confirm the pharmacokinetic parameters of wedelolactone in rat plasma. The chromatographic separation was carried out on a Kromasil C₁₈ UPLC column (250 × 4.6 mm; 5.0 μm) by gradient mobile phase of methanol-water containing 0.5% acetic acid (v/v). Perfect linearity was obtained and the samples were stable under different conditions. The intra-day and inter-day precisions (relative standard deviation, %) were within 3.81% and accuracies (relative error, %) ranged from -4.01% to 7.12%. The extraction recoveries in rat plasma ranged from 95.98% to 108.93%. This rapid method was successfully applied in the pharmacokinetic study of wedelolactone in rat plasma. Following the oral administration of 5.00 mg/kg wedelolactone, the wedelolactone was rapidly absorbed. Pharmacokinetic parameters were used to quantitatively describe the dynamic changes of wedelolactone in vivo, providing a theoretical basis for pharmacological research on drugs and preclinical medication. The study of wedelolactone can provide a theoretical basis and quick analysis for the study of other traditional Chinese medicine. This may lead to breakthroughs in the pharmacokinetic study of complex Chinese medicines.

Ultra-high-pressure-assisted extraction of wedelolactone and isodemethylwedelolactone from Ecliptae Herba and purification by high-speed counter-current chromatography

Ultra-high-pressure extraction combined with high-speed counter-current chromatography was employed to extract and purify wedelolactone and isodemethylwedelolactone from Ecliptae Herba. The operating conditions of ultra-high-pressure extraction were optimized using an orthogonal experimental design. The optimal conditions were 80% aqueous methanol solvent, 200 MPa pressure, 3 min extraction time and 1:20 (g/mL) solid-liquid ratio for extraction of wedelolactone and isodemethylwedelolactone. After extraction by ultra-high pressure, the extraction solution was concentrated and subsequently extracted with ethyl acetate; a total of 2.1 g of crude sample was obtained from 100 g of Ecliptae Herba. A two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (3:7:5:5, v/v) was used for high-speed counter-current chromatography separation, by which 23.5 mg wedelolactone, 6.8 mg isodemethylwedelolactone and 5.5 mg luteolin with purities >95% were purified from 300 mg crude sample in a one-step separation. This research demonstrated that ultra-high-pressure extraction combined with high-speed counter-current chromatography was an efficient technique for the extraction and purification of coumestans from plant material.

Anti-hepatitis C virus activity and synergistic effect of Nymphaea alba extracts and bioactive constituents in liver infected cells

BACKGROUND

Without an effective vaccine, hepatitis C virus (HCV) remains a global threat, inflicting 170-300 million carriers worldwide at risk of cirrhosis and hepatocellular carcinoma (HCC). Though various direct acting antivirals have been redeemed the hepatitis C treatment, a few restraints persist including possible side effects, viral resistance emergence, excessive cost which restricts its availability to a common person.

HYPOTHESIS

There is no preventive HCV vaccine available today so the discovery of potent antiviral natural flora and their bioactive constituents may help to develop preventive cures against HCV infection.

STUDY DESIGN

In current study, we aim to clarify anti-HCV activity of methanol and acetone extracts along with the purified fractions of Pakistani local plant, Nymphaea alba L (N. alba) using Huh-7 cell line as transfection model. Synergistic study of purified fractions with interferon was performed using MDBK cell line (expressing interferon receptors) as transfection model.

MATERIALS AND METHODS

Recent study by our research group has observed potent anti-HCV NS3 protease activity of methanol and acetone extracts of N. alba. Effect of N. alba extracts, its fractions precisely, the N1 and N8 fractions on HCV replication was demonstrated by analyzing viral gene expression using in vitro transfection model. Considering NS3 protease as a dynamic drug target, fourteen phytochemicals of N. alba were selected as ligands for interaction with NS3 protein using Molecular Operating Environment (MOE) software. Boceprevir, FDA approved NS3 protease inhibitor, was used as standard for comparative study in docking screening.

RESULTS

Herein we report 84% and 94% reduction of 3a genotype of HCV NS3/4A gene expression at mRNA level at non-toxic concentration. Specifically, two fractions 'N1' & 'N8' isolated from acetone extract suppressed HCV NS3 gene expression in transfected target cells with an EC₅₀ value of 37 ± 0.03 μg/ml and 20 ± 0.02 μg/ml respectively. Similarly, viral genotype 1a replication is strongly suppressed in target cells by N. alba flower extracts and purified fractions. Moreover, combination of fractions with standard antiviral drug displayed synergistic effects for inhibition of HCV replication. Phytochemicals including Isoquercetin, Hyperoside, Quercetin, Reynoutrin, Apigenin and Isokaempferide displayed minimum binding energies as compared to standard protease inhibitor.

CONCLUSION

N. alba and its purified phytochemicals with new scaffolds might significantly serve as valuable and alternative regimen against HCV either alone or in combination with other potential anti-HCV agents.

Hepatoprotective Effect of Wedelolactone against Concanavalin A-Induced Liver Injury in Mice

Eclipta prostrata L. is a traditional Chinese herbal medicine that has been used in the treatment of liver diseases. However, its biological mechanisms remain elusive. The current study aimed to investigate the hepatoprotective effect of wedelolactone, a major coumarin ingredient of Eclipta prostrata L., on immune-mediated liver injury. Using the well-established animal model of Concanavalin A (ConA)-induced hepatitis (CIH), we found that pretreatment of mice with wedelolactone markedly reduced both the serum levels of transaminases and the severity of liver damage. We further investigated the mechanisms of the protective effect of wedelolactone. In mice treated with wedelolactone prior to the induction of CIH, increases of serum concentrations of tumor necrosis factor (TNF)-[Formula: see text], interferon (IFN)-[Formula: see text], and interleukin (IL)-6 were dramatically attenuated. Additionally, expressions of the interferon-inducible chemokine (C-X-C motif) ligand 10 gene CXCL10 and intercellular adhesion molecule 1 gene ICAM1 were lower in livers of the treated mice. Moreover, wedelolactone-treated CIH mice exhibited reduced leukocyte infiltration and T-cell activation in liver. Furthermore, wedelolactone suppressed the activity of nuclear factor-kappa B (NF-[Formula: see text]B), a critical transcriptional factor of the above-mentioned inflammatory cytokines by limiting the phosphorylation of I kappa B alpha (I[Formula: see text]B[Formula: see text] and p65. In conclusion, these findings demonstrate the inhibitory potential of wedelolactone in immune-mediated liver injury in vivo, and show that this protection is associated with modulation of the NF-[Formula: see text]B signaling pathway.

Antiviral effect of <em>Archidendron pauciflorum</em> leaves extract to hepatitis C virus: An <em>in vitro</em> study in JFH-1 strain

Background: Hepatitis C virus (HCV) is a leading cause of chronic liver diseases. Drug resistance to the regimen is also increasing. Hence, there is a need for new anti-HCV agents that are less toxic and more efficacious. The aim of this study is to evaluate the  possibility of A. pauciflorum extracts can be a antiviral drug.Methods: Huh-7it cells were infected with the HCV genotype 2a strain JFH-I in the presence of methanol extracts of Archidenron pauciflorum. The methanol extract further partition used n-hexane, ethyl acetate, n-butanol, and water showed in which butanol extracts exerted the strongest IC50 (6.3 g/ml). Further, the butanol fraction was fractionated and yielded into 13 fractions.Results: The methanol extract of the leaves of A. pauciflorum exhibited concentration dependent inhibition against the JFH1 strain of HCV genotype 2a with an IC50 is 72.5 μg/ml. The butanol fraction exhibited the highest anti-HCV activity with an IC50 is 6.3 μg/ml. The butanol fraction was fractionated which yielded 13 fractions. Fractions 5 and 13 exhibited high anti-HCV activities with IC50 is 5.0 μg/ml and 8.5 μg/ml and a time-of-addition study demonstrated that fraction 5 inhibited viral infection at the post-entry step, whereas fraction 13 primarily inhibited the viral entry step.Conclusion: The extract A. pauciflorum can be used as a herbal-based antiviral drug.

Aeginetia indica Decoction Inhibits Hepatitis C Virus Life Cycle

Chronic hepatitis C virus (HCV) infection is still a global epidemic despite the introduction of several highly effective direct-acting antivirals that are tagged with sky-high prices. The present study aimed to identify an herbal decoction that ameliorates HCV infection. Among six herbal decoctions tested, the Aeginetia indica decoction had the most profound effect on the HCV reporter activity in infected Huh7.5.1 liver cells in a dose- and time-dependent manner. The Aeginetia indica decoction exerted multiple inhibitory effects on the HCV life cycle. Pretreatment of the cells with the Aeginetia indica decoction prior to HCV infection reduced the HCV RNA and non-structural protein 3 (NS3) protein levels in the infected cells. The Aeginetia indica decoction reduced HCV internal ribosome entry site-mediated protein translation activity. It also reduced the HCV RNA level in the infected cells in association with reduced NS5A phosphorylation at serine 235, a predominant phosphorylation event indispensable to HCV replication. Thus, the Aeginetia indica decoction inhibits HCV infection, translation, and replication. Mechanistically, the Aeginetia indica decoction probably reduced HCV replication via reducing NS5A phosphorylation at serine 235.

Wedelolactone, a plant coumarin, prevents vascular smooth muscle cell proliferation and injury-induced neointimal hyperplasia through Akt and AMPK signaling

Wedelolactone (WDL) is a natural compound derived from Chinese herbal medicine Eclipta prostrate L, and has been reported to exhibit various effects potentially beneficial for human health. However, the possible preventive effects of WDL toward vascular remodeling and mechanisms involved have not been investigated to date. In this study, we investigated the effects of WDL on proliferation induced by platelet-derived growth factor (PDGF) in primary rat aortic smooth muscle cells (VSMCs) and on neointimal hyperplasia resulted from balloon injury in rats. WDL exhibited strong inhibitory effects against PDGF-induced VSMC proliferation. Cell cycle analysis revealed that WDL induced G0/G1 arrest and prevented cell cycle from entering S phase. Immunoblot analysis suggested that the cell cycle arrest induced by WDL was through Akt suppression and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation, with a subsequent cyclin-dependent kinase inhibitor p21 induction and cyclin D1 inhibition. We also observed that WDL notably reduced neointima-to-media area ratio of balloon-injured rat common carotid arteries (CCAs) in comparison with those untreated balloon-injured CCAs. The regulation of WDL on protein expressions of Akt, AMPK and cyclin D1 in vivo were also consistent with that in vitro. Taken together, our results suggest WDL exhibits potential preventive effects toward vascular remodeling and neointimal hyperplasia through the reduction of VSMC proliferation via inhibition of Akt and activation of AMPK.