Current Status and Challenges in Anti-Hepatitis B Virus Agents Based on Inactivation/Inhibition or Elimination of Hepatitis B Virus Covalently Closed Circular DNA.

There has been over half a century since the discovery of hepatitis B virus (HBV) to now, but approximately 300 million patients with chronic hepatitis B (CHB) still live in the world, resulting in about one million deaths every year. Although currently approved antivirals (e.g., nucleoside analogues) are effective at reducing HBV replication, they have almost no impact on the existing HBV covalently closed circular DNA (cccDNA) reservoir. HBV cccDNA is a critical obstacle to the complete elimination of the virus via antiviral therapy. The true cure of HBV infection requires the eradication of viral cccDNA from HBV-infected cells; thus, the development of new agents directly or indirectly targeting HBV cccDNA is urgently needed due to the limitations of current available drugs against HBV infection. In this regard, it is the major focus of current anti-HBV research worldwide via different mechanisms to either inactivate/inhibit (functional cure) or eliminate (complete cure) HBV cccDNA. Therefore, this review discussed and summarized recent advances and challenges in efforts to inactivate/silence or eliminate viral cccDNA using anti-HBV agents from different sources, such as small molecules (including epigenetic drugs) and polypeptides/proteins, and siRNA or gene-editing approaches targeting/attenuating HBV cccDNA via different mechanisms, as well as future directions that may be considered in efforts to truly cure chronic HBV infection. In conclusion, no breakthrough has been made yet in attenuating HBV cccDNA, although a number of candidates have advanced into the phase of clinical trials. Furthermore, the overwhelming majority of the candidates function to indirectly target HBV cccDNA. No outstanding candidate directly targets HBV cccDNA. Relatively speaking, CCC_R08 and nitazoxanide may be some of the most promising agents to clear HBV infection in small molecule compounds. Additionally, CRISPR-Cas9 systems can directly target HBV cccDNA for decay and demonstrate significant anti-HBV activity. Consequently, gene-editing approaches targeting HBV cccDNA may be one of the most promising means to achieve the core goal of anti-HBV therapeutic strategies. In short, more basic studies on HBV infection need to be carried out to overcome these challenges.

Clinical characteristics and outcomes of patients hospitalized with heart failure with preserved ejection fraction and low NT-proBNP levels.

The aim of this study was to investigate the clinical characteristics and prognosis of patients hospitalized with heart failure with preserved ejection fraction (HFpEF) and low N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. Seven hundred ninety consecutive patients hospitalized with HFpEF from 2006 to 2017 were enrolled. Clinical characteristics and outcomes were compared between low NT-proBNP group (<300 ng/L) and elevated NT-proBNP group (≥300 ng/L). 108 HFpEF patients (13.7%) presented with low NT-proBNP levels. Age, body mass index, atrial fibrillation, New York Heart Association functional class, and albumin were independent predictors of low NT-proBNP levels in HFpEF patients. During the median follow-up duration of 1103 days, 11 patients (10.2%) in low NT-proBNP group suffered from primary endpoint event. Elevated NT-proBNP group had a higher risk of all-cause death or heart transplantation than low NT-proBNP group (adjusted HR [95%CI]: 2.36 [1.24,4.49], P = .009). Stratified analyses showed that the association between NT-proBNP (elevated NT-proBNP group vs low NT-proBNP group) and risk of all-cause death or heart transplantation was stronger in non-atrial fibrillation patients than in atrial fibrillation patients (P value for interaction = .025). Furthermore, the associations between NT-proBNP and risk of all-cause death or heart transplantation were stronger in younger and male patients than in older and female patients. However, both subgroups only reached borderline significant (P values for interaction = .062 and .084, respectively). Our findings suggest that low NT-proBNP levels were common in patients hospitalized with HFpEF. Patients with HFpEF and low NT-proBNP levels had a better prognosis than those with elevated NT-proBNP levels, particularly in younger, male, and non-atrial fibrillation patients.

[Prediction of PAHs Content in Soil Around Gas Stations in Beijing Based on BP Neural Network].

With the rapid development of urbanization in China, the number of gas stations in cities is increasing. The composition of oil products in gas stations is complex and diverse, and a series of pollutants will be generated in the process of oil diffusion. Polycyclic aromatic hydrocarbons (PAHs) produced by gas stations can pollute the nearby soil and affect human health. In this study, soil samples (0-20 cm) near 117 gas stations in Beijing were collected, and the contents of seven PAHs were analyzed. Based on the BP neural network model, the contents of PAHs in soil of Beijing gas stations in 2025 and 2030 were predicted. The results showed that the total concentrations of the seven PAHs were 0.01-3.53 mg·kg-1. The concentrations of PAHs were lower than the soil environmental quality risk control standard for soil contamination of development land (Trial) GB 36600-2018. At the same time, the toxic equivalent concentrations (TEQ) of the above seven PAHs were lower than the standard value (1 mg·kg-1) of the World Health Organization (WHO), which they indicate a lower risk to human health. The prediction results showed that the rapid development of urbanization had a positive correlation with the increase in soil PAHs content. By 2030, the content of PAHs in Beijing gas station soil will continue to grow. The predicted concentrations of PAHs in the soil of Beijing gas stations in 2025 and 2030 were 0.085-4.077 mg·kg-1and 0.132-4.412 mg·kg-1, respectively. The contents of seven PAHs were lower than the soil pollution risk screening value of GB 36600-2018; however, the concentration of PAHs increased over time.The contents of PAHs in Chaoyang, Fengtai, and Haidian were relatively higher, which requires further attention.

Availability, Functionality, and Safety as well as Quality Control of Hepatocytes as Seeding Cells in Liver Regenerative Medicine: State of the Art and Challenges.

Hepatic disease is one of the most common causes of death worldwide and has become a global health problem. Liver transplantation is the only effective treatment strategy for patients with hepatic function failure, but the insufficient number of donated healthy livers is the main obstacle limiting this process. To alleviate the demand for donor's livers, alternative approaches are being actively explored using liver tissue engineering principles. Liver tissue engineering consists of three elements, including seeding cells, extracellular matrix, and bioreactors. Among them, seeding cell is the most key factor. In this regard, hepatocyte-based tissue engineering can overcome the above shortages for tissue repair and regeneration in hepatic disorders. Primary human hepatocytes in liver regenerative medicine are the most preferred seeding cells, although limited access to a sufficient number of functional hepatocytes are a major issue due to the difficulties in long-term function maintenance of hepatocyte as well as the lack of availability of healthy donors. Hepatocyte-like cells (HLCs), derived from various stem cells, including non-liver-derived stem cells and liver-derived stem cells, as well as trans-differentiation of other cell types, may provide adequate cell sources and could replace primary human hepatocytes as seeding cells. However, it is still a great difficulty that HLCs generated by stem cell differentiation meet the quality required for clinical therapy. Furthermore, none of the standardized protocols to generate high-quality HLCs is available. Whether primary hepatocytes or HLCs are from various sources, preventing the functional deterioration of hepatocytes or generating fully functional hepatocytes is also a big challenge, respectively. In addition, the adoptions of three-dimensional co-culture systems and some small-molecule compounds contribute to maintaining the hepatic functionality of primary hepatocytes and enhancing the liver-specific functions of HLCs. In short, hepatocyte-based liver regenerative medicine is an attractive alternative strategy for liver diseases, notwithstanding some challenges still exist from bench to bedside. This review summarizes the current status, issues, and challenges in availability, functionality, and safety, as well as quality control of seeding hepatocytes with regard to liver tissue engineering in regenerative medicine for the treatment of liver disorders.

Potential Drug Targets Against Hepatitis B Virus Based on Both Virus and Host Factors.

BACKGROUND: Hepatitis B is a very harmful and epidemic disease caused by hepatitis B virus (HBV). Although an effective anti-HBV vaccine is available, chronic infection poses still a huge health burden in the whole world. The present anti-HBV drugs including nucleoside analogues and interferonalpha have their limitations without exception. There is no effective drug and therapeutic method that can really and truly cure hepatitis B so far. The variability of HBV genome results in that a significant number of patients develop drug resistance during the long-term use of anti-HBV drugs. Hence, it is urgently needed to discover novel targets and develop new drugs against hepatitis B. OBJECTIVE: The review aims to provide the theory support for designing of the anti-HBV innovative drugs by offering a summary of the current situation of antiviral potential targets. RESULTS AND CONCLUSION: Since HBV is obligate intracellular parasite, and as such it depends on host cellular components and functions to replicate itself. The targeting both virus and host might be a novel therapeutic option for hepatitis B. Accordingly, we analyse the advances in the study of the potential drug targets for anti-HBV infection, focusing on targeting virus genome, on targeting host cellular functions and on targeting virus-host proteins interactions, respectively. Meanwhile, the immune targets against chronic hepatitis B are also emphasized. In short, the review provides a summary of antiviral therapeutic strategies to target virus factors, host factors and immune factors for future designing of the innovative drug against HBV infection.

Vascular smooth muscle cell senescence and age-related diseases: State of the art.

Aging is a worldwide challenge, and it is accompanied by the accumulation of senescent cells. Cellular senescence is traditionally defined as permanent cell growth arrest and currently includes the senescence-associated secretory phenotype (SASP). There are two main types of cellular senescence, including telomere-dependent replicative senescence and stress-induced premature senescence. The process of cellular senescence is mainly controlled by two effector pathways, namely, the p53-p21 and p16-retinoblastoma protein (pRB) pathways. Vascular smooth muscle cells (VSMCs) are integral parts of arteries and play an important role in vascular structure and function. VSMC senescence may be triggered by many factors, such as angiotensin II, oxidative stress, inflammation, DNA damage, and small molecule compounds. These inducers are able to genetically and epigenetically regulate VSMC senescence. The senescence of VSMCs together with the SASP contributes to chronic vascular inflammation, the loss of arterial function, and the development of age-related diseases. Current evidence suggests that the senescence of VSMCs might be harmful to individual health, whereas its influence on the lifespan is not clear. The purpose of this paper was to review the current knowledge regarding VSMC senescence and its relevance to hypertension, atherosclerosis, and diabetes, as well as the potential mechanisms responsible for VSMC senescence in these age-related diseases.

[Chemical constituents from roots of Viburnum setigerum].

This experiment was to study the constituents of the roots of Viburnum setigerum through various column chromatographic techniques. Thirteen compounds were obtained and their structures were identified using chemical and spectroscopic methods as (7αH, 8'αH)-4, 4', 8α-trihydroxy-3, 3', 9-trimethoxy-7, 9'-epoxylignan (1), (7αH, 8'αH)-4, 4', 8α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (2), alashinol G (3), alashinol F (4), (-)-secoisolariciresinol (5), (7R, 7'R, 8R, 8'S)-3, 3'-dimethoxy-7, 7'-epoxylignane -4, 4', 9, 9'-tetraol (6), (7αH, 8αH, 8'ßH)-4, 4', 7'α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (7), loganin (8), dihydroquercetin (9), protocatechuic acid (10), 4-hydroxy-3-methoxy-benzoic acid (11), adoxoside (12), and catechin (13). Compound 1 was a new compound. Compounds 3-7 and 11 were reported from the genus Viburnum for the first time. All compounds were separated from this plant for the first time.

The Emerging Role of Circular RNAs in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) ranks the third leading cause of cancer death in the world and has a notably low survival rate. Circular RNAs (circRNAs) are newly classed non-coding RNA (ncRNA) members that are capable of regulating gene expression at transcription or post-transcription levels. Recent studies demonstrate that some circRNAs are differentially expressed in HCC, and the deregulation of these circRNAs is associated with the clinical pathological and prognostic significance. They also play essential roles in HCC progression, and contribute to cell proliferation, migration, invasion and metastasis by targeting different microRNAs (miRNAs) and protein-coding genes. In this review, we concentrate on recent progress of some important circRNAs in HCC, with an emphasis on their deregulation, functions and regulatory mechanisms, and discuss their potential utility as diagnostic and/or prognostic biomarkers or therapeutic targets for HCC.

Structure Properties and Mechanisms of Action of Naturally Originated Phenolic Acids and Their Derivatives against Human Viral Infections.

BACKGROUND: A great effort has been made to develop efficacious antiviral drugs, but many viral infections are still lack of efficient antiviral therapies so far. The related exploration of natural products to fight viruses has been raised in recent years. Natural compounds with structural diversity and complexity offer a great chance to find new antiviral agents. Particularly, phenolic acids have attracted considerable attention owing to their potent antiviral abilities and unique mechanisms. The aim of this review is to report new discoveries and updates pertaining to antiviral phenolic acids. METHODS: The relevant references on natural phenolic acids were searched. The antiviral phenolic acids were classified according to their structural properties and antiviral types. Meanwhile, the antiviral characteristics and structure-activity relationships of phenolic acids and their derivatives were summarized. RESULTS: The review finds that natural phenolic acids and their derivatives possessed potent inhibitory effects on multiple virus in humans such as human immunodeficiency virus, hepatitis C virus, hepatitis B virus, herpes simplex virus, influenza virus and respiratory syncytial virus. In particular, caffeic acid/gallic acid and their derivatives exhibited outstanding antiviral properties by a variety of modes of action. CONCLUSION: Naturally derived phenolic acids especially caffeic acid/gallic acid and their derivatives may be regarded as novel promising antiviral leads or candidates. Additionally, scarcely any of these compounds has been used as antiviral treatment in clinical practice. Therefore, these phenolic acids with diverse skeletons and mechanisms provide us an excellent resource for finding novel antiviral drugs.

Naturally derived anti-hepatitis B virus agents and their mechanism of action.

Despite that some approved drugs and genetically engineered vaccines against hepatitis B virus (HBV) are available for HBV patients, HBV infection is still a severe public health problem in the world. All the approved therapeutic drugs (including interferon-alpha and nucleoside analogues) have their limitations. No drugs or therapeutic methods can cure hepatitis B so far. Therefore, it is urgently needed to discover and develop new anti-HBV drugs, especially non-nucleoside agents. Naturally originated compounds with enormous molecular complexity and diversity offer a great opportunity to find novel anti-HBV lead compounds with specific antiviral mechanisms. In this review, the natural products against HBV are discussed according to their chemical classes such as terpenes, lignans, phenolic acids, polyphenols, lactones, alkaloids and flavonoids. Furthermore, novel mode of action or new targets of some representative anti-HBV natural products are also discussed. The aim of this review is to report new discoveries and updates pertaining to anti-HBV natural products in the last 20 years, especially novel skeletons and mode of action. Although many natural products with various skeletons have been reported to exhibit potent anti-HBV effects to date, scarcely any of them are found in the list of conventional anti-HBV drugs worldwide. Additionly, in anti-HBV mechanism of action, only a few references reported new targets or novel mode of action of anti-HBV natural products.

[Research on Chemical Constituents and Anti-tumor Activity of Eupatorium chinense].

Objective: To study the chemical constituents and their anti-tumor activity of Eupatorium chinense. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Conclusion: Compounds 2 ~ 5 are isolated from the Eupatorium chinense for the first time,and compound 2 has significant cytotoxic activity against HGC-27 cell line.

[Effect of echinacoside on replication and antigen expression of hepatitis B virus].

To verify the effect of echinacoside on replication and antigen expression of hepatitis B virus (HBV) by using HBV-transfected HepG2. 2. 15 cells as the in vitro model. The ELISA method was used to determine HBeAg and HBsAg levels in cellular supernatants. The effect of echinacoside on HBV replication was studied by using HBV transgenic mice as the in vivo model. First of all, the HBV DNA level in hepatic tissues was quantified with PCR method. Meanwhile, the serum transaminase levels and hepatic pathological changes were also evaluated. Subsequently, HBV transgenic mice were divided into five groups: the control group, the lamivudine group (50 mg · kg(-1)) and echinacoside high, medium and low dose group (50, 25 and 12.5 mg · kg(-1)). The mice were orally administered with drugs once per day for 30 days. At the 31st day, the mice serum was separated to measure HBsAg, HBeAg and HBV DNA. Additionally, the liver HBV DNA level and histopathological change were detected. The results indicated that echinacoside at 50 and 100 mg · L(-1) suppressed significantly HBsAg and HBeAg expressions on the sixth day, with the maximum inhibition ratios of 42.68% and 46.29%; And echinacoside at 100 mg · L(-1) also showed an inhibitory effect on HBV DNA. Besides, echinacoside at 50 mg · kg(-1) inhibited significantly HBsAg and HBeAg expressions of HBV transgenic mice, with the inhibition ratios of 42.82% and 29.12%, and reduced markedly the serum HBV DNA level in HBV transgenic mice. In conclusion, the study suggested that echinacoside has a strong effect against HBV replication and antigen expression.

Dynamic correlation between induction of the expression of heme oxygenase-1 and hepatitis B viral replication.

Heme oxygenase­1 (HO­1) possesses significant potential as a drug target for hepatitis B, which may be transferable to patient therapy. The aim of the present study was to clarify the dynamic correlation between the hepatitis B virus (HBV) and HO­1. The levels of HBV replication and expression of HO­1 were investigated in HepG2.2.15 hepatoma cells following exposure to 5­50 µM hemin for 1­6 days. The mRNA expression levels of HO­1 were then detected using reverse transcription­quantitative polymerase chain reaction (RT­qPCR). HBV replication levels were determined by enzyme­immunoassay and a PCR­fluorescence quantitation assay. The results of the present study demonstrated that the mRNA expression levels of HO­1 increased in a dose­dependent manner in the HepG2.2.15 cells, following exposure to 5­50 µM hemin. The mRNA expression levels of HO­1 reached a peak following exposure of the cells to hemin for three days, subsequently the expression of HO­1 decreased. Following exposure to hemin at an optimal concentration of 50 µM for 1­6 days, the levels of the hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in the cells were significantly reduced. This marked reduction in the expression of HBsAg and HBeAg reached its peak on the first day, following which the inhibition weakened as the duration of exposure increased. In addition, the inhibition of HBV DNA replication increased with the a longer duration of exposure. Furthermore, HBV DNA levels were significantly decreased following exposure to hemin for 3­6 days. In conclusion, the present study demonstrated that induced expression of HO­1 interfered with HBV replication in a dose and time­dependent manner, implying that a reduction of the HBV viral load may contribute to upregulation in the expression of HO­1.

Evaluation of hepatocyteprotective and anti-hepatitis B virus properties of Cichoric acid from Cichorium intybus leaves in cell culture.

Hepatitis B is the most common serious liver infection in the world. To date, there is still no complete cure for chronic hepatitis B. Natural caffeic acid analogues possess prominent antiviral activity, especially anti-hepatitis B virus (HBV) and anti-human immunodeficiency virus effects. Cichoric acid is a caffeic acid derivative from Cichorium intybus. In the study, the anti-hepatitis B property of cichoric acid was evaluated by the D-galactosamine (D-GalN)-induced normal human HL-7702 hepatocyte injury model, the duck hepatitis B virus (DHBV)-infected duck fetal hepatocytes and the HBV-transfected cell line HepG2.2.15 cells, respectively. The results showed that cichoric acid attenuated significantly D-GalN-induced HL-7702 hepatocyte injury at 10-100 µg/mL and produced a maximum protection rate of 56.26%. Moreover, cichoric acid at 1-100 µg/mL inhibited markedly DHBV DNA replication in infected duck fetal hepatocytes. Also, cichoric acid at 10-100 µg/mL reduced significantly the hepatitis B surface and envelope antigen levels in HepG2.2.15 cells and produced the maximum inhibition rates of 79.94% and 76.41%, respectively. Meanwhile, test compound at 50-100 µg/mL inhibited markedly HBV DNA replication. In conclusion, this study verifies the anti-hepatitis B effect of cichoric acid from Cichorium intybus leaves. In addition, cichoric acid could be used to design the antiviral agents.

Nature and mechanisms of hepatocyte apoptosis induced by D-galactosamine/lipopolysaccharide challenge in mice.

Apoptosis plays a role in the normal development of liver. However, overactivation thereof may lead to hepatocellular damage. The aim of this study was to assess D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced hepatocyte apoptotic changes in mice and clarify the mechanisms involved in this process. DNA ladder detection was employed to determine the induction condition of hepatic apoptosis. An initial test indicated that typical hepatocyte apoptosis was observed at 6-10 h after the intraperitoneal injection of D-GalN (700 mg/kg) and LPS (10 µg/kg). Subsequently, we evaluated hepatocyte apoptosis at 8 h after administering D-GalN/LPS by histopathological analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end­labeling (TUNEL) detection, flow cytometry and electron microscopy analysis. To clarify the apoptosis-related gene expression, the expression levels of tumor necrosis factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1), caspase-3, and Fas/Fas ligand (FasL) were determined by serum enzyme immunoassay, immunohistochemistry and western blot analysis. Strong apoptotic positive signals following D-GalN/LPS injection were observed from the results of the serum analysis, histopathological and immunohistochemical analyses, DNA ladder detection, TUNEL detection, flow cytometry and electron microscopy analysis. Additionally, apoptotic hepatocytes were mainly at the late stage of cell apoptosis. The expression of TNF-α, TGF-ß1, caspase-3 and Fas/FasL was significantly increased. In conclusion, this study evaluated the D-GalN/LPS-induced hepatocyte apoptotic changes and clarified the apoptosis-related gene expression in mice. The hepatocyte apoptosis induced by D-GalN/LPS may be mainly regulated by the death receptor pathway. TGF-ß signaling pathway may also play a vital role in this process of hepatocyte apoptosis.

Taraxacum mongolicum extract exhibits a protective effect on hepatocytes and an antiviral effect against hepatitis B virus in animal and human cells.

In order to validate the antiviral effect against hepatitis B virus (HBV) of Taraxacum mongolicum (T. mongolicum), the protective effect on hepatocytes, and antiviral properties against duck hepatitis B virus (DHBV) and HBV of T. mongolicum extract (TME) were evaluated in chemically-injured neonatal rat hepatocytes, DHBV-infected duck fetal hepatocytes and HBV-transfected HepG2.2.15 cells, respectively. The results demonstrated that TME at 50-100 µg/ml improved D-galactosamine (D-GalN), thioacetamide (TAA) and tert-butyl hydroperoxide (t-BHP)-injured rat hepatocytes, and produced protection rates of 42.2, 34.6 and 43.8% at 100 µg/ml, respectively. Furthermore, TME at 1-100 µg/ml markedly inhibited DHBV DNA replication. Additionally, TME at 25-100 µg/ml reduced HBsAg and HBeAg levels and produced inhibition rates of 91.39 and 91.72% at 100 µg/ml, respectively. TME markedly inhibited HBV DNA replication at 25-100 µg/ml. The results demonstrate the potent antiviral effect of T. mongolicum against HBV effect. The protective of TME effect on hepatocytes may be achieved by its ability to ameliorate oxidative stress. The antiviral properties of TME may contribute to blocking protein synthesis steps and DNA replication. Furthermore, major components of TME were quantificationally analyzed. These data provide scientific evidence supporting the traditional use of TME in the treatment of hepatitis.

Artemisinin-polypyrrole conjugates: synthesis, DNA binding studies and preliminary antiproliferative evaluation.

Greater than the sum of its parts: Artemisinins are currently in phase I-II clinical trials against breast, colorectal and non-small-cell lung cancers. In an attempt to offer increased specificity, a series of hybrid artemisinin-polypyrrole minor groove binder conjugates are described. DNA binding/modelling studies and preliminary biological evaluation give insights into their mechanism of action and the potential of this strategy.

Hepatoprotective and antiviral properties of isochlorogenic acid A from Laggera alata against hepatitis B virus infection.

ETHNOPHARMACOLOGICAL RELEVANCE: The aim of this study was to determine the anti-hepatitis B effect of isochlorogenic acid A isolated from Laggera alata (Asteraceae), a traditional Chinese herbal medicine. MATERIALS AND METHODS: The anti-hepatitis B activity of isochlorogenic acid A was evaluated by the D-galactosamine (D-GalN)-induced HL-7702 hepatocyte damage model and the HBV-transfected HepG2.2.15 cells. RESULTS: Isochlorogenic acid A significantly improved HL-7702 hepatocyte viability and markedly inhibited the productions of HBsAg and HBeAg. The inhibitory rates of isochlorogenic acid A on the HBsAg and HBeAg expressions were 86.9% and 72.9%, respectively. In addition, isochlorogenic acid A declined markedly the content of hepatitis B virus covalently closed circular DNA (HBV cccDNA) and induced significantly the heme oxygenase-1 (HO-1) expression in HepG2.2.15 cells. CONCLUSIONS: Isochlorogenic acid A was verified to possess the potent anti-hepatitis B activity. The anti-HBV target of isochlorogenic acid A is probably associated with blocking the translation step of the HBV replication. Overexpression of HO-1 may contribute to the anti-HBV activity of isochlorogenic acid A by reducing the stability of the HBV core protein and thus blocking the refill of nuclear HBV cccDNA. Additionally, the hepatoprotective effect of isochlorogenic acid A could be achieved by its antioxidative property and induction of HO-1.

Protective Properties of Laggera alata Extract and its Principle Components Against d-Galactosamine-Injured Hepatocytes.

Laggera alata extract (LAE) was quantitatively analyzed, and its principle components isochlorogenic acids were isolated and authenticated. Protective properties of LAE were studied using a d-galactosamine (d-GalN)-induced injury model in neonatal rat hepatocytes and a d-GalN-induced acute liver damage model in mice. Meanwhile, the effect of isochlorogenic acids derived from LAE on d-GalN-induced hepatocyte injury were also measured in vitro. LAE at concentrations of 10-100 µg/ml significantly reduced cellular leakage of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and improved cell viability. The isochlorogenic acids (4,5-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid and 3,4-O-dicaffeoylquinic acid) at concentrations of 1-100 µg/ml also remarkably improved viability of hepatocytes. The oral treatment of LAE at doses of 50, 100 and 200 mg/kg markedly reduced the serum AST and ALT activity of mice and resulted in significant recovery of hepatocytes in liver sections.

Anti-hepatitis B virus effect and possible mechanism of action of 3,4-o-dicaffeoylquinic Acid in vitro and in vivo.

The anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid isolated from Laggera alata was studied using the D-galactosamine- (D-GalN-) induced hepatocyte damage model, HepG2.2.15 cells, and with HBV transgenic mice. In vitro results showed that 3,4-O-dicaffeoylquinic acid improved HL-7702 hepatocyte viability and markedly inhibited the production of HBsAg and HBeAg. At a concentration of 100 µg/mL, its inhibitory rates on the expression levels of HBsAg and HBeAg were 89.96% and 81.01%, respectively. The content of hepatitis B virus covalently closed circular DNA (HBV cccDNA) in HepG2.2.15 cells was significantly decreased after the cells were treated with the test compound. In addition, 3,4-O-dicaffeoylquinic acid significantly increased the expression of heme oxygenase-1 (HO-1) in HepG2.2.15 cells. In vivo results indicated that the test compound at concentrations of 100 µg/mL significantly inhibited HBsAg production and increased HO-1 expression in HBV transgenic mice. In conclusion, this study verifies the anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid. The upregulation of HO-1 may contribute to the anti-HBV effect of this compound by reducing the stability of the HBV core protein, which blocks the refill of nuclear HBV cccDNA. Furthermore, the hepatoprotective effect of this compound may be mediated through its antioxidative/anti-inflammatory properties and by the induction of HO-1 expression.