In vitro activity of cepharanthine hydrochloride against clinical wild-type and lamivudine-resistant hepatitis B virus isolates

Cepharanthine inhibits African swine fever virus replication by suppressing AKT-associated pathways through disrupting Hsp90-Cdc37 complex

African swine fever (ASF) represents one of the most economically important viral infectious diseases in the swine industry worldwide. Presently, there is an absence of commercially available therapeutic drugs and safe vaccines. Cepharanthine (CEP), one of the naturally occurring bisbenzylisoquinoline alkaloids, has been approved as a drug to treat various diseases such as leukopenia, bronchial asthma, and snake bites for 70 years in Japan. Most recently, CEP was reported to inhibit ASFV replication by suppressing endosomal/lysosomal function although the specific molecular mechanisms were not elucidated. In this study, we demonstrate for the first time that ASFV infection promotes co-chaperone Cdc37 expression and its binding to Hsp90, leading to increased AKT phosphorylation to benefit viral replication. Notably, CEP disrupts the Hsp90-Cdc37 complex, subsequently decreasing p-AKT and inhibiting ASFV replication. Furthermore, our investigation reveals that enhanced AKT phosphorylation amplifies glycolysis, resulting in increased lactate production, while it upregulates the NF-κB signaling pathway, resulting in increased expression of IL-1β and other inflammatory cytokines. Elevated lactate enhances ASFV replication, and IL-1β acts synergistically on the proviral effect of lactate. CEP reduces ASFV replication by disrupting the formation of the Hsp90-Cdc37 complex and suppressing its downstream AKT/glycolysis axis and AKT/NF-κB pathway, leading to reduced lactate and IL-1β production. Our findings suggest that CEP could serve as a promising ASFV inhibitor, and the Hsp90-Cdc37 complex and glycolysis represent novel antiviral targets against ASFV infections, offering novel avenues for further exploration in antiviral therapeutic strategies. As the in vivo environment is largely complicated from ex vivo PAMs, anti-ASFV efficacy evaluation of CEP in pigs is the most imperative work in the future.

Bis-benzylisoquinoline alkaloids inhibit flavivirus entry and replication by compromising endolysosomal trafficking and autophagy

Flaviviruses, such as dengue virus (DENV), Zika virus (ZIKV), and Japanese encephalitis virus (JEV), represent a substantial public health challenge as there are currently no approved treatments available. Here, we investigated the antiviral effects of bis-benzylisoquinoline alkaloids (BBAs) on flavivirus infections. We evaluated five specific BBAs-berbamine, tetrandrine, iso-tetrandrine, fangchinoline, and cepharanthine-and found that they effectively inhibited infections by ZIKV, DENV, or JEV by blocking virus entry and genome replication stages in the flavivirus life cycle. Furthermore, we synthesized a fluorophore-conjugated BBA and showed that BBAs targeted endolysosomes, causing lysosomal pH alkalization. Mechanistic studies on inhibiting ZIKV infection by BBAs revealed that these compounds blocked TRPML channels, leading to lysosomal dysfunction and reducing the expression of NCAM1, a key receptor for the entry of ZIKV into cells, thereby decreasing cells susceptibility to ZIKV infection. Additionally, BBAs inhibited the fusion of autophagosomes and lysosomes, significantly reducing viral RNA replication. Collectively, our results suggest that BBAs inhibit flavivirus entry and replication by compromising endolysosomal trafficking and autophagy, respectively, underscoring the potential of BBAs as therapeutic agents against flavivirus infections.

Bis-benzylisoquinoline alkaloids inhibit African swine fever virus internalization and replication by impairing late endosomal/lysosomal function

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a highly infectious disease afflicting domestic pigs and wild boars. It exhibits an alarming acute infection fatality rate of up to 100%. Regrettably, no commercial vaccines or specific drugs for combating this disease are currently available. This study evaluated the anti-ASFV activities in porcine alveolar macrophages, 3D4/21 cells, and PK-15 cells of four bis-benzylisoquinoline alkaloids (BBAs): cepharanthine (CEP), tetrandrine, fangchinoline, and iso-tetrandrine. Furthermore, we demonstrated that CEP, which exhibited the highest selectivity index (SI = 81.31), alkalized late endosomes/lysosomes, hindered ASFV endosomal transport, disrupted virus uncoating signals, and thereby inhibited ASFV internalization. Additionally, CEP disrupted ASFV DNA synthesis, leading to the inhibition of viral replication. Moreover, berbamine was labeled with NBD to synthesize a fluorescent probe to study the cellular location of these BBAs. By co-staining with Lyso-Tracker and lysosome-associated membrane protein 1, we demonstrated that BBAs target the endolysosomal compartments for the first time. Our data together indicated that BBAs are a class of natural products with significant inhibitory effects against ASFV infection. These findings suggest their potential efficacy as agents for the prevention and control of ASF, offering valuable references for the identification of potential drug targets.IMPORTANCEThe urgency and severity of African swine fever (ASF) underscore the critical need for effective interventions against this highly infectious disease, which poses a grave threat to domestic pigs and wild boars. Our study reveals the potent anti-African swine fever virus (ASFV) efficacy of bis-benzylisoquinoline alkaloids (BBAs), particularly evident in the absence of progeny virus production under a 5 µM concentration treatment. The structural similarity among cepharanthine, tetrandrine, fangchinoline, and iso-tetrandrine, coupled with their analogous inhibitory stages and comparable selectivity indexes, strongly suggests a shared antiviral mechanism within this drug category. Further investigation revealed that BBAs localize to lysosomes and inhibit the internalization and replication of ASFV by disrupting the endosomal/lysosomal function. These collective results have profound implications for ASF prevention and control, suggesting the potential of the investigated agents as prophylactic and therapeutic measures. Furthermore, our study offers crucial insights into identifying drug targets and laying the groundwork for innovative interventions.

A Reappraisal of the Antiviral Properties of and Immune Regulation through Dietary Phytochemicals

In the present era of the COVID-19 pandemic, viral infections remain a major cause of morbidity and mortality worldwide. In this day and age, viral infections are rampant and spreading rapidly. Among the most aggressive viral infections are ebola, AIDS (acquired immunodeficiency syndrome), influenza, and SARS (severe acute respiratory syndrome). Even though there are few treatment options for viral diseases, most of the antiviral therapies are ineffective owing to frequent mutations, the development of more aggressive strains, drug resistance, and possible side effects. Traditionally, herbal remedies have been used by healers, including for dietary and medicinal purposes. Many clinical and scientific studies have demonstrated the therapeutic potential of plant-derived natural compounds. Because of unsafe practices like blood transfusions and organ transplants from infected patients, medical supply contamination. Our antiviral therapies cannot achieve sterile immunity, and we have yet to find a cure for these pernicious infections. Herbs have been shown to improve therapeutic efficacy against a wide variety of viral diseases because of their high concentration of immunomodulatory phytochemicals (both immunoinhibitory and anti-inflammatory). Combined with biotechnology, this folk medicine system can lead to the development of novel antiviral drugs and therapies. In this Review, we will summarize some selected bioactive compounds with probable mechanisms of their antiviral actions, focusing on the immunological axis of these compounds.

Anti-hepatitis B virus activities of natural products and their antiviral mechanisms

Chronic hepatitis B (CHB) infections caused by the hepatitis B virus (HBV) continue to pose a significant global public health challenge. Currently, the approved treatments for CHB are limited to interferon and nucleos(t)ide analogs, both of which have their limitations, and achieving a complete cure remains an elusive goal. Therefore, the identification of new therapeutic targets and the development of novel antiviral strategies are of utmost importance. Natural products (NPs) constitute a class of substances known for their diverse chemical structures, wide-ranging biological activities, and low toxicity profiles. They have shown promise as potential candidates for combating various diseases, with a substantial number demonstrating anti-HBV properties. This comprehensive review focuses on the current applications of NPs in the fight against HBV and provides a summary of their antiviral mechanisms, considering their impact on the viral life cycle and host hepatocytes. By offering insights into the world of anti-HBV NPs, this review aims to furnish valuable information to support the future development of antiviral drugs.

Research progress on pharmacological effects and mechanisms of cepharanthine and its derivatives

Cepharanthine (CEP) is a bisbenzylisoquinoline alkaloid compound found in plants of the Stephania genus, which has biological functions such as regulating autophagy, inhibiting inflammation, oxidative stress, and apoptosis. It is often used for the treatment of inflammatory diseases, viral infections, cancer, and immune disorders and has great clinical translational value. However, there is no detailed research on its specific mechanism and dosage and administration methods, especially clinical research is limited. In recent years, CEP has shown significant effects in the prevention and treatment of COVID-19, suggesting its potential medicinal value waiting to be discovered. In this article, we comprehensively introduce the molecular structure of CEP and its derivatives, describe in detail the pharmacological mechanisms of CEP in various diseases, and discuss how to chemically modify and design CEP to improve its bioavailability. In summary, this work will provide a reference for further research and clinical application of CEP.

Pharmacological Effects and Clinical Prospects of Cepharanthine

Cepharanthine is an active ingredient separated and extracted from Stephania cepharantha Hayata, a Menispermaceae plant. As a bisbenzylisoquinoline alkaloid, cepharanthine has various pharmacological properties, including antioxidant, anti-inflammatory, immunomodulatory, antitumoral, and antiviral effects. Following the emergence of coronavirus disease 2019 (COVID-19), cepharanthine has been found to have excellent anti-COVID-19 activity. In this review, the important physicochemical properties and pharmacological effects of cepharanthine, particularly the antiviral effect, are systematically described. Additionally, the molecular mechanisms and novel dosage formulations for the efficient, safe, and convenient delivery of cepharanthine are summarized.

Cepharanthine Ameliorates Chondrocytic Inflammation and Osteoarthritis via Regulating the MAPK/NF-κB-Autophagy Pathway

Osteoarthritis is a worldwide joint disease caused by abnormal chondrocytic metabolism. However, traditional therapeutic methods aimed at anti-inflammation for early-stage disease are palliative. In the present study, we demonstrated that cepharanthine (CEP), extracted from the plant Stephania cepharantha, exerted protective medicinal efficacy on osteoarthritis for the first time. In our in vitro study, CEP suppressed the elevated expression of matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and inducible nitric oxide synthase (iNOS) stimulated by IL-1β or TNF-α by inhibiting the activation of MAPK and NF-κB signaling pathways, and upregulated the protein expression of aggrecan, collagen II, and Sox9. Also, CEP could reverse the reduced level of cellular autophagy in IL-1β or TNF-α–induced chondrocytes, indicating that the protective effect of CEP on osteoarthritis was achieved by restoring MAPK/NF-κB-mediated autophagy. Furthermore, in a murine OA model, CEP mitigated cartilage degradation and prevented osteoarthritis in the CEP-treated groups versus the OA group. Hence, our results revealed the therapeutic prospect of CEP for anti-osteoarthritic treatment.

Screening and Identification of HTNVpv Entry Inhibitors with High-throughput Pseudovirus-based Chemiluminescence

Hantaviruses, such as Hantaan virus (HTNV) and Seoul virus, are the causative agents of Hantavirus cardiopulmonary syndrome (HCPS) and hemorrhagic fever with renal syndrome (HFRS), and are important zoonotic pathogens. China has the highest incidence of HFRS, which is mainly caused by HTNV and Seoul virus. No approved antiviral drugs are available for these hantaviral diseases. Here, a chemiluminescence-based high-throughput-screening (HTS) assay was developed and used to screen HTNV pseudovirus (HTNV_pv) inhibitors in a library of 1813 approved drugs and 556 small-molecule compounds from traditional Chinese medicine sources. We identified six compounds with in vitro anti-HTNV_pv activities in the low-micromolar range (EC₅₀ values of 0.1–2.2 ​μmol/L; selectivity index of 40–900). Among the six selected compounds, cepharanthine not only showed good anti-HTNV_pv activity in vitro but also inhibited HTNV_pv-fluc infection in Balb/c mice 5 ​h after infection by 94% (180 ​mg/kg/d, P ​< ​0.01), 93% (90 ​mg/kg/d, P ​< ​0.01), or 92% (45 ​mg/kg/d, P ​< ​0.01), respectively, in a bioluminescent imaging mouse model. A time-of-addition analysis suggested that the antiviral mechanism of cepharanthine involves the membrane fusion and entry phases. Overall, we have established a HTS method for antiviral drugs screening, and shown that cepharanthine is a candidate for HCPS and HFRS therapy. These findings may offer a starting point for the treatment of patients infected with hantaviruses.

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A chemiluminescence-based high-throughput-screening (HTS) assay was used to screen HTNV pseudovirus (HTNV_pv) inhibitors.

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Cepharanthine showed good anti-HTNV_pv activity in vitro and in vivo.

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A time-of-addition analysis suggested that cepharanthine involves the membrane fusion and entry phases.

The anti-hepatitis B virus and anti-hepatotoxic efficacies of solanopubamine, a rare alkaloid from Solanum schimperianum

Chronic liver disease caused by hepatitis B virus (HBV) remains an important health issue. Though there are effective HBV-polymerase inhibitors (e.g., lamivudine), their prolonged use leads to emergence of drug-resistant (polymerase mutant) strains. Several herbal formulations and phytochemicals have been therefore, reported as potential anti-HBV agents with no sign of resistance in experimental and clinical settings. In this study, we assessed the anti-HBV as well as hepatoprotective salutations of solanopubamine, a rare alkaloid isolated from S. schimperianum. In cultured HepG2.2.15 cells, solanopubamine showed marked anti-HBV activity in a time and dose-dependent manner. Solanopubamine (30 μM) efficiently inhibited HBsAg and HBeAg expressions by 66.5%, 70.5%, respectively as compared to 82.5% and 86.5% respective inhibition by lamivudine (2 μM) at day 5. Molecular docking analyses of solanopubamine revealed formations of stable complexes with lamivudine-sensitive as well as lamivudine-resistant polymerase through interactions of catalytic ‘YMDD/YIDD’ motif residues. Moreover, solanopubamine attenuated DCFH-induced oxidative and apoptotic damage and restored HepG2 cell viability by 28.5%, and downregulated caspase-3/7 activations by 33%. Further docking analyses of solanopubamine showed formation of stable complexes with caspase-3/7. Taken together, our data demonstrates promising anti-HBV and anti-hepatotoxic therapeutic potential of solanopubamine, and warrants further molecular and pharmacological studies.

Small Molecule Drug Candidates for Managing the Clinical Symptoms of COVID-19: a Narrative Review

Towards the end of 2019, an atypical acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China and subsequently named Coronavirus disease 2019 (COVID-19). The rapid dissemination of COVID-19 has provoked a global crisis in public health. COVID-19 has been reported to cause sepsis, severe infections in the respiratory tract, multiple organ failure, and pulmonary fibrosis, all of which might induce mortality. Although several vaccines for COVID-19 are currently being administered worldwide, the COVID-19 pandemic is not yet effectively under control. Therefore, novel therapeutic agents to eradicate the cause of the disease and/or manage the clinical symptoms of COVID-19 should be developed to effectively regulate the current pandemic. In this review, we discuss the possibility of managing the clinical symptoms of COVID-19 using natural products derived from medicinal plants used for controlling pulmonary inflammatory diseases in folk medicine. Diverse natural products have been reported to exert potential antiviral effects in vitro by affecting viral replication, entry into host cells, assembly in host cells, and release. However, the in vivo antiviral effects and clinical antiviral efficacies of these natural products against SARS-CoV-2 have not been successfully proven to date. Thus, these properties need to be elucidated through further investigations, including randomized clinical trials, in order to develop optimal and ideal therapeutic candidates for COVID-19.

Thirteen bisbenzylisoquinoline alkaloids in five Chinese medicinal plants: Botany, traditional uses, phytochemistry, pharmacokinetic and toxicity studies

RELEVANCE

Bisbenzylisoquinoline (BBIQ) alkaloids are generally present in plants of Berberidaceae, Monimiaceae and Ranunculaceae families in tropical and subtropical regions. Some species of these families are used in traditional Chinese medicine, with the effects of clearing away heat and detoxification, promoting dampness and defecation, and eliminating sores and swelling. This article offers essential data focusing on 13 representative BBIQ compounds, which are mainly extracted from five plants. The respective botany, traditional uses, phytochemistry, pharmacokinetics, and toxicity are summarized comprehensively. In addition, the ADME prediction of the 13 BBIQ alkaloids is compared and analyzed with the data obtained.

MATERIALS AND METHODS

We have conducted a systematic review of the botanical characteristics, traditional uses, phytochemistry, pharmacokinetics and toxicity of BBIQ alkaloids based on literatures collected from PubMed, Web of Science and Elsevier during 1999-2020. ACD/Percepta software was utilized to predict the pharmacokinetic parameters of BBIQ alkaloids and their affinity with enzymes and transporters.

RESULTS

Botany, traditional uses, phytochemistry, pharmacokinetic and toxicity of 13 alkaloids, namely, tetrandrine, dauricine, curine, trilobine, isotrilobine, cepharanthine, daurisoline, thalicarpine, thalidasine, isotetrandrine, liensinine, neferine and isoliensinine, have been summarized in this paper. It can't be denied that these alkaloids are important material basis of pharmacological effects of family Menispermaceae and others, and for traditional and local uses which has been basically reproduced in the current studies. The 13 BBIQ alkaloids in this paper showed strong affinity and inhibitory effect on P-glycoprotein (P-gp), with poor oral absorption and potent binding ability with plasma protein. BBIQ alkaloids represented by tetrandrine play a key role in regulating P-gp or reversing multidrug resistance (MDR) in a variety of tumors. The irrationality of their usage could pose a risk of poisoning in vivo, including renal and liver toxicity, which are related to the formation of quinone methide during metabolism.

CONCLUSION

Although there is no further clinical evaluation of BBIQ alkaloids as MDR reversal agents, their effects on P-gp should not be ignored. Considering their diverse distribution, pharmacokinetic characteristics and toxicity reported during clinical therapy, the quality standards in different plant species and the drug dosage remain unresolved problems.

Alkaloids: Therapeutic Potential against Human Coronaviruses

Alkaloids are a class of natural products known to have wide pharmacological activity and have great potential for the development of new drugs to treat a wide array of pathologies. Some alkaloids have antiviral activity and/or have been used as prototypes in the development of synthetic antiviral drugs. In this study, eleven anti-coronavirus alkaloids were identified from the scientific literature and their potential therapeutic value against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is discussed. In this study, in silico studies showed an affinity of the alkaloids for binding to the receptor-binding domain of the SARS-CoV-2 spike protein, putatively preventing it from binding to the host cell. Lastly, several mechanisms for the known anti-coronavirus activity of alkaloids were discussed, showing that the alkaloids are interesting compounds with potential use as bioactive agents against SARS-CoV-2.

Cepharanthine and Curcumin inhibited mitochondrial apoptosis induced by PCV2

Background

Porcine circovirus type 2 (PCV2) is an immunosuppressive pathogen with high prevalence rate in pig farms. It has caused serious economic losses to the global pig industry. Due to the rapid mutation of PCV2 strain and co-infection of different genotypes, vaccination could not eradicate the infection of PCV2. It is necessary to screen and develop effective new compounds and explore their anti-apoptotic mechanism. The 13 natural compounds were purchased, with a clear plant origin, chemical structure and content and specific biological activities.

Results

The maximum no-cytotoxic concentration (MNTC) and 50% cytotoxic concentration (CC₅₀) of 13 tested compounds were obtained by the cytopathologic effect (CPE) assay and (3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method in PK-15 cells. The results of qPCR and Western blot showed that, compared with the PCV2 infected group, the expression of Cap in Paeonol (0.4 mg/mL and 0.2 mg/mL), Cepharanthine (0.003 mg/mL, 0.0015 mg/mL and 0.00075 mg/mL) and Curcumin (0.02 mg/mL, 0.001 mg/mL and 0.005 mg/mL) treated groups were significantly lowered in a dose-dependent manner. The results of Annexin V-FITC/PI, JC-1, Western blot and ROS analysis showed that the expression of cleaved caspase-3 and Bax were up-regulated Bcl-2 was down-regulated in Cepharanthine or Curcumin treated groups, while ROS and MMP value were decreased at different degrees and the apoptosis rate was reduced. In this study, Ribavirin was used as a positive control.

Conclusions

Paeonol, Cepharanthine and Curcumin have significant antiviral effect. And the PCV2-induced Mitochondrial apoptosis was mainly remitted by Cepharanthine and Curcumin.

Cepharanthine: a review of the antiviral potential of a Japanese-approved alopecia drug in COVID-19

Cepharanthine (CEP) is a naturally occurring alkaloid derived from Stephania cepharantha Hayata and demonstrated to have unique anti-inflammatory, antioxidative, immunomodulating, antiparasitic, and antiviral properties. Its therapeutic potential as an antiviral agent has never been more important than in combating COVID-19 caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) virus. Cepharanthine suppresses nuclear factor-kappa B (NF-κB) activation, lipid peroxidation, nitric oxide (NO) production, cytokine production, and expression of cyclooxygenase; all of which are crucial to viral replication and inflammatory response. Against SARS-CoV-2 and homologous viruses, CEP predominantly inhibits viral entry and replication at low doses; and was recently identified as the most potent coronavirus inhibitor among 2406 clinically approved drug repurposing candidates in a preclinical model. This review critically analyzes and consolidates available evidence establishing CEP’s potential therapeutic importance as a drug of choice in managing COVID-19 cases.

HBV replication inhibitors

Chronic Hepatitis B Virus infections afflict >250 million people and kill nearly 1 million annually. Current non-curative therapies are dominated by nucleos(t)ide analogs (NAs) that profoundly but incompletely suppress DNA synthesis by the viral reverse transcriptase. Residual HBV replication during NA therapy contributes to maintenance of the critical nuclear reservoir of the HBV genome, the covalently-closed circular DNA, and to ongoing infection of naive cells. Identification of next-generation NAs with improved efficacy and safety profiles, often through novel prodrug approaches, is the primary thrust of ongoing efforts to improve HBV replication inhibitors. Inhibitors of the HBV ribonuclease H, the other viral enzymatic activity essential for viral genomic replication, are in preclinical development. The complexity of HBV's reverse transcription pathway offers many other potential targets. HBV's protein-priming of reverse transcription has been briefly explored as a potential target, as have the host chaperones necessary for function of the HBV reverse transcriptase. Improved inhibitors of HBV reverse transcription would reduce HBV's replication-dependent persistence mechanisms and are therefore expected to become a backbone of future curative combination anti-HBV therapies.

A critical review: traditional uses, phytochemistry, pharmacology and toxicology of Stephania tetrandra S. Moore (Fen Fang Ji)

ABSTRACT

Stephania tetrandra S. Moore (S. tetrandra) is distributed widely in tropical and subtropical regions of Asia and Africa. The root of this plant is known in Chinese as "Fen Fang Ji". It is commonly used in traditional Chinese medicine to treat arthralgia caused by rheumatism, wet beriberi, dysuria, eczema and inflamed sores. Although promising reports have been published on the various chemical constituents and activities of S. tetrandra, no review comprehensively summarizes its traditional uses, phytochemistry, pharmacology and toxicology. Therefore, the review aims to provide a critical and comprehensive evaluation of the traditional use, phytochemistry, pharmacological properties, pharmacokinetics and toxicology of S. tetrandra in China, and meaningful guidelines for future investigations.

Cepharanthine: An update of its mode of action, pharmacological properties and medical applications

BACKGROUND

Cepharanthine (CEP) is a drug used in Japan since the 1950s to treat a number of acute and chronic diseases, including treatment of leukopenia, snake bites, xerostomia and alopecia. It is the only approved drug for Human use in the large class of bisbenzylisoquinoline alkaloids. This natural product, mainly isolated from the plant Stephania cephalantha Hayata, exhibits multiple pharmacological properties including anti-oxidative, anti-inflammatory, immuno-regulatory, anti-cancer, anti-viral and anti-parasitic properties.

PURPOSE

The mechanism of action of CEP is multifactorial. The drug exerts membrane effects (modulation of efflux pumps, membrane rigidification) as well as different intracellular and nuclear effects. CEP interferes with several metabolic axes, primarily with the AMP-activated protein kinase (AMPK) and NFκB signaling pathways. In particular, the anti-inflammatory effects of CEP rely on AMPK activation and NFκB inhibition.

CONCLUSION

In this review, the historical discovery and development of CEP are retraced, and the key mediators involved in its mode of action are presented. The past, present, and future of CEP are recapitulated. This review also suggests new opportunities to extend the clinical applications of this well-tolerated old Japanese drug.

Cepharanthine Hydrochloride Improves Cisplatin Chemotherapy and Enhances Immunity by Regulating Intestinal Microbes in Mice

Chemotherapy is one of the major treatment strategies for esophageal squamous cell carcinoma (ESCC). Unfortunately, most chemotherapeutic drugs have significant impacts on the intestinal microbes, resulting in side effects and reduced efficiency. Therefore, new strategies capable of overcoming these disadvantages of current chemotherapies are in urgent need. The natural product, Cepharanthine hydrochloride (CEH), is known for its anticancer and immunoregulatory properties. By sequencing the V4 region of 16S rDNA, we characterized the microbes of tumor-bearing mice treated with different chemotherapy strategies, including with CEH. We found that CEH improved the therapeutic effect of CDDP by manipulating the gut microbiota. Through metagenomic analyses of the microbes community, we identified a severe compositional and functional imbalance in the gut microbes community after CDDP treatment. However, CEH improved the effect of chemotherapy and ameliorated CDDP treatment-induced imbalance in the intestinal microbes. Mechanically, CEH activated TLR4 and MYD88 innate immune signaling, which is advantageous for the activation of the host's innate immunity to exert a balanced intestinal environment as well as to trigger a better chemotherapeutic response to esophageal cancer. In addition, TNFR death receptors were activated to induce apoptosis. In summary, our findings suggest that chemotherapy of CDDP combined with CEH increased the effect of chemotherapy and reduced the side effects on the microbes and intestinal mucosal immunity. We believe that these findings provide a theoretical basis for new clinical treatment strategies.

Design, synthesis, and biological evaluation of novel 2'-deoxy-2'-fluoro-2'-C-methyl 8-azanebularine derivatives as potent anti-HBV agents

Hepatitis B virus (HBV) is a global health problem requiring more efficient and better tolerated anti-HBV agent. In this paper, a series of novel 2'-deoxy-2'-fluoro-2'-C-methyl-β-d-arabinofuranosyl 8-azanebularine analogues (1 and 2a) and N⁴-substituted 8-azaadenosine derivatives (2b-g) were designed, synthesized and screened for in vitro anti-HBV activity. Two concise and practical synthetic routes were developed toward the structural motif construction of 2'-deoxy-2'-fluoro-2'-C-methyl-β-d-arabinofuranosyl 8-azainosine from the ribonolactone 3 under mild conditions. The in vitro anti-HBV screening results showed that these 8-azanebularine analogues had a significant inhibitory effect on the expression of HBV antigens and HBV DNA at a concentration of 20 μM. Among them, halogen-substituted 8-azaadenosine derivative 2g displayed activities comparable to that of 3TC. In particular, 2g retained excellent activity against lamivudine-resistant HBV mutants.

Association between serum S100A9 levels and liver necroinflammation in chronic hepatitis B

BACKGROUND

S100A9 protein, which is recently classified as a novel damage associated molecular pattern, is released from stressed cells undergoing necrosis or secreted by living cells undergoing a stress that act as endogenous danger signal associated with infection, tissue damage and cancer. Here, we evaluated the relationship of serum S100A9 with viral replication and liver necroinflammation in patients with chronic hepatitis B (CHB) infection.

METHODS

A total of one hundred and eighty-three recruited patients with CHB infection underwent liver biopsy for grading of necroinflammation (G) and staging of fibrosis (S). Forty-nine healthy individuals were included as healthy controls (HCs). Serum S100A9 levels were determined by enzyme-linked immunosorbent assay. Correlations of serum S100A9 with viral replication and liver necroinflammation were analyzed. The receiver operating characteristic curve was used to assess the discriminating power of serum S100A9 to grade liver necroinflammation (G). Liver normal L02 cells were transfected with a HBV plasmid, and S100A9 levels were determined.

RESULTS

Serum S100A9 levels were increased in CHB patients compared to HCs. Intrahepatic immunoreactivity for S100A9 was enhanced in liver sample from CHB patients. Infection of HBV also resulted in an elevated S100A9 expression in L02 cells. Serum S100A9 was correlated with the serum HBV DNA levels. CHB patients with moderate-to-severe liver necroinflammation (G ≥ 2) showed significantly higher serum S100A9 levels than those without or with mild necroinflammation (G < 2). In patients with normal ALT levels, the area under the curve (AUC) of S100A9 for discriminating patients with moderate-to-severe necroinflammation (G ≥ 2) was 0.791 [95% confidence interval (CI), 0.670-0.913] with 91.7% sensitivity, 65.0% specificity and 78.3% accuracy. In patients with an alanine aminotransferase (ALT) < 2 upper limit of normal, the AUC of S100A9 for discriminating patients with moderate-to-severe necroinflammation (G ≥ 2) was 0.826 (95% CI, 0.729-0.923) with 87.9% sensitivity, 72.5% specificity and 80.2% accuracy.

CONCLUSIONS

HBV infection may enhance S100A9 expression. Serum S100A9 levels are correlated with viral load. Serum S100A9 has potential to discriminate the grades of liver necroinflammation, particularly in CHB patients with normal or mildly increased ALT levels.

Cepharanthine Prevents Estrogen Deficiency-Induced Bone Loss by Inhibiting Bone Resorption

Osteoporosis is a common health problem worldwide caused by an imbalance of bone formation vs. bone resorption. However, current therapeutic approaches aimed at enhancing bone formation or suppressing bone resorption still have some limitations. In this study, we demonstrated for the first time that cepharanthine (CEP, derived from Stephania cepharantha Hayata) exerted a protective effect on estrogen deficiency-induced bone loss. This protective effect was confirmed to be achieved through inhibition of bone resorption in vivo, rather than through enhancement of bone formation in vivo. Furthermore, the in vitro study revealed that CEP attenuated receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast formation, and suppressed bone resorption by impairing the c-Jun N-terminal kinase (JNK) and phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathways. The inhibitory effect of CEP could be partly reversed by treatment with anisomycin (a JNK and p38 agonist) and/or SC79 (an AKT agonist) in vitro. Our results thus indicated that CEP could prevent estrogen deficiency-induced bone loss by inhibiting osteoclastogenesis. Hence, CEP might be a novel therapeutic agent for anti-osteoporosis therapy.

CRISPR-Cas Targeting of Host Genes as an Antiviral Strategy

Currently, a new gene editing tool-the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) associated (Cas) system-is becoming a promising approach for genetic manipulation at the genomic level. This simple method, originating from the adaptive immune defense system in prokaryotes, has been developed and applied to antiviral research in humans. Based on the characteristics of virus-host interactions and the basic rules of nucleic acid cleavage or gene activation of the CRISPR-Cas system, it can be used to target both the virus genome and host factors to clear viral reservoirs and prohibit virus infection or replication. Here, we summarize recent progress of the CRISPR-Cas technology in editing host genes as an antiviral strategy.

Structure-activity relationships of cryptopleurine analogs with E-ring modifications as anti-hepatitis C virus agents

The tylophorine analog rac-cryptopleurine exhibited potent anti-hepatitis C virus (HCV) activity through allosteric regulation of ATPase activity of heat shock cognate protein 70 (Hsc70). We evaluated the impact of modifications on the E-ring of rac-cryptopleurine to the inhibitory activity against HCV replication and regulation of ATPase activity of Hsc70. Cryptopleurine analog YXM-110 with a 13α-hydroxyl group maintained activity against HCV and promoted ATP/ADP turnover of Hsc70; however, compounds with hydroxyl groups at other positions or with other orientations (YXM-109, YXM-139, and YXM-140) did not exhibit similar activities. Size modification or heteroatom incorporation of the E-ring led to loss of anti-HCV activity. Promotion of the chaperone activity of Hsc70 with carboxyl terminus Hsc70 interacting protein (CHIP) further enhanced the anti-HCV activity of rac-cryptopleurine and XYM-110. This structure-activity relationship (SAR) study refined structural design and optimization for developing rac-crytopleurine analogs as potent anti-HCV agents targeted against the host factor involved in HCV replication.

Design, synthesis, and biological evaluation of new 1,2,3-triazolo-2'-deoxy-2'-fluoro- 4'-azido nucleoside derivatives as potent anti-HBV agents

Novel drugs are urgently needed to combat hepatitis B virus (HBV) infection due to drug-resistant virus. In this paper, a series of novel 4-monosubstituted 2'-deoxy-2'-β-fluoro-4'-azido-β-d-arabinofuranosyl 1,2,3-triazole nucleoside analogues (1a-g) were designed, synthesized and screened for in vitro anti-HBV activity. At 5.0 μM in the cellular model, all the synthetic compounds display activities comparable to that of the positive control, lamivudine at 20 μM. Of the compounds tested, the amide-substituted analogue (1a) shows the most promising anti-HBV activity and low cytotoxicity in the cell model. In particular, it retains excellent activity against lamivudine-resistant HBV mutants. In duck HBV (DHBV)-infected duck models, both the serum and liver DHBV DNA levels (67.4% and 53.3%, respectively) were reduced markedly by the treatment with 1a. Analysis of the structure of HBV polymer/1a-triphosphate (1a-TP) complex shows that 1a-TP is stabilized by specific van der Waals interactions with the enzyme residues arising from 4-amino-1,2,3-triazole and the 4'-azido group.

Identification of a novel autophagic inhibitor cepharanthine to enhance the anti-cancer property of dacomitinib in non-small cell lung cancer

Inhibition of autophagy is a promising strategy for non-small cell lung cancer (NSCLC) treatment, which is in the clinical trials. However, only chloroquine is used in clinic as an autophagic inhibitor and the inhibitory effect of chloroquine on autophagy is finite. Therefore, the development of an alternative autophagic inhibitor for NSCLC therapy becomes necessary. In the present study, cepharanthine (CEP), an alkaloid extracted from Stephania cepharantha Hayata, was identified as a novel autophagic inhibitor in NSCLC cells. The potential mechanism of the CEP-inhibited autophagy was by blockage of autophagosome-lysosome fusion and inhibition of lysosomal cathepsin B and cathepsin D maturation. Furthermore, we found for the first time that dacomitinib (DAC), a second-generation epidermal growth factor receptor inhibitor that in the phase III clinical trials for NSCLC treatment, induced a protective autophagy to decrease its anti-cancer effect. Combined treatment with CEP increased the anti-proliferative and apoptotic effects of DAC in vitro and enhanced the anti-cancer effect of DAC in NCI-H1975 xenograft mice. Collectively, CEP might be further developed as an autophagic inhibitor, and combined treatment of CEP and DAC could offer an effective strategy for NSCLC treatment.

Cepharanthine hydrochloride reverses P‑glycoprotein-mediated multidrug resistance in human ovarian carcinoma A2780/Taxol cells by inhibiting the PI3K/Akt signaling pathway

Ovarian cancer has the highest mortality rate among gynecologic malignant tumors. The major obstacle to treatment success is multidrug resistance (MDR) to chemotherapy drugs. Cepharanthine hydrochloride (CH), a natural alkaloid-derived compound, has shown MDR reversal potency in several tumor cell lines; however, the molecular mechanism is not entirely known. In the present study, we assessed whether CH sensitized malignant cells to chemotherapy drugs in ovarian cancer and explored the relevant mechanism. We found that CH reduced the IC50 value of paclitaxel and increased intracellular rhodamine-123 accumulation in human ovarian cancer A2780/Taxol cells in a concentration-dependent manner. Reverse transcription polymerase chain reaction and western blot assay demonstrated that CH inhibited MDR1 expression as indicated by reduced mRNA and protein levels in A2780/Taxol cells. In addition, the inhibitory effect was strengthened after CH was combined with the specific PI3K/Akt signaling pathway inhibitor LY294002. Furthermore, p‑Akt expression decreased gradually with the concentration of CH (2, 4 and 8 µM). Taken together, these findings indicated that CH reversed P‑glycoprotein-mediated MDR in A2780/Taxol cells by inhibiting the PI3K/Akt signaling pathway.

Advance in studies on traditional Chinese medicines to treat infection with the hepatitis B virus and hepatitis C virus

Traditional Chinese medicine (TCM), as a type of complementary and alternative medicine (CAM), is a sophisticated and time-honored form of healthcare in China. Many TCMs are widely used to treat hepatitis B and hepatitis C in countries like China, Japan, and South Korea. Since conventional clinical preparations like interferon-α cause obvious dose-dependent adverse reactions and drug resistance, TCMs and related bioactive compounds have garnered increasing attention from physicians and medical researchers. Thus far, a number of TCMs and compounds have been used to inhibit the hepatitis B virus (HBV) or hepatitis C virus (HCV) in vitro, in vivo, and even in clinical trials. The current review summarizes TCMs and related compounds that have been used to inhibit HBV or HCV. Most of these medicines are derived from herbs. HepG2.2.15 cells have been used to study HBV in vitro and Huh7.5 cells have been similarly used to study HCV. Ducks have been used to study the anti-HBV effect of new medication in vivo, but there are few animal models for anti-HCV research at the present time. Thus far, a number of preclinical studies have been conducted but few clinical trials have been conducted. In addition, a few chemically modified compounds have displayed greater efficacy than natural products. However, advances in TCM research are hampered by mechanisms of action of many bioactive compounds that have yet to be identified. In short, TCMs and related active compounds are a CAM that could be used to treat HBV and HCV infections.

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.

Inhibition of duck hepatitis B virus replication by mimic peptides in vitro

The aim of the present study was to investigate the inhibitory effect of specific mimic peptides targeting duck hepatitis B virus polymerase (DHBVP) on duck hepatitis B virus (DHBV) replication in primary duck hepatocytes. Phage display technology (PDT) was used to screen for mimic peptides specifically targeting DHBVP and the associated coding sequences were determined using DNA sequencing. The selected mimic peptides were then used to treat primary duck hepatocytes infected with DHBV in vitro. Infected hepatocytes expressing the mimic peptides intracellularly were also prepared. The cells were divided into mimic peptide groups (EXP groups), an entecavir-treated group (positive control) and a negative control group. The medium was changed every 48 h. Following a 10-day incubation, the cell supernatants were collected. DHBV-DNA in the cellular nucleus, cytoplasm and culture supernatant was analyzed by quantitative polymerase chain reaction (qPCR). Eight mimic peptides were selected following three PDT screening rounds for investigation in the DHBV-infected primary duck hepatocytes. The qPCR results showed that following direct treatment with mimic peptide 2 or 7, intracellular expression of mimic peptide 2 or 7, or treatment with entecavir, the DHBV-DNA levels in the culture supernatant and cytoplasm of duck hepatocytes were significantly lower than those in the negative control (P<0.05). The cytoplasmic DHBV-DNA content of the cells treated with mimic peptide 7 was lower than that in the other groups (P<0.05). In addition, the DHBV-DNA content of the nuclear fractions following the intracellular expression of mimic peptide 7 was significantly lower than that in the other groups (P<0.05). Mimic peptides specifically targeting DHBVP, administered directly or expressed intracellularly, can significantly inhibit DHBV replication in vitro.

The sterile inflammation in the exacerbation of HBV-associated liver injury

Exacerbation of hepatitis B virus-associated liver injury is characterized by abnormal immune response which not only mobilizes specific antiviral effects but also poses a potentially lethal nonspecific sterile inflammation to the host. How nonspecific sterile inflammation is triggered after the preexisting injury caused by specific immune injury remains elusive. In the setting of sterile inflammation, endogenous damage-associated molecular patterns are released by stressed and dying hepatocytes, which alarm the immune system through their potential pattern recognition receptors and related signaling pathways, orchestrate the influx of diverse cytokines, and ultimately amplify liver destruction. This review highlights current knowledge about the sterile hepatic inflammation in the exacerbation of chronic hepatitis B.

Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour

ETHNOPHARMACOLOGICAL RELEVANCE

Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea.

AIM OF THE REVIEW

To provide an up-to-date, comprehensive overview and analysis of the ethnobotany, phytochemistry, and pharmacology of Stephania rotunda for its potential benefits in human health, as well as to assess the scientific evidence of traditional use and provide a basis for future research directions.

MATERIAL AND METHODS

Peer-reviewed articles on Stephania rotunda were acquired via an electronic search of the major scientific databases (Pubmed, Google Scholar, and ScienceDirect). Data were collected from scientific journals, theses, and books.

RESULTS

The traditional uses of Stephania rotunda were recorded in countries throughout Southeast Asia (Cambodia, Vietnam, Laos, and India). Different parts of Stephania rotunda were used in traditional medicine to treat about twenty health disorders. Phytochemical analyses identified forty alkaloids. The roots primarily contain l-tetrahydropalmatine (l-THP), whereas the tubers contain cepharanthine and xylopinine. Furthermore, the chemical composition differs from one region to another and according to the harvest period. The alkaloids exhibited approximately ten different pharmacological activities. The main pharmacological activities of Stephania rotunda alkaloids are antiplasmodial, anticancer, and immunomodulatory effects. Sinomenine, cepharanthine, and l-stepholidine are the most promising components and have been tested in humans. The pharmacokinetic parameters have been studied for seven compounds, including the three most promising compounds. The toxicity has been evaluated for liriodenine, roemerine, cycleanine, l-tetrahydropalmatine, and oxostephanine.

CONCLUSION

Stephania rotunda is traditionally used for the treatment of a wide range of ailments. Pharmacological investigations have validated different uses of Stephania rotunda in folk medicine. The present review highlights the three most promising compounds of Stephania rotunda, which could constitute potential leads in various medicinal fields, including malaria and cancer.

Cloning, molecular characterization and expression analysis of heat shock cognate 70 (Hsc70) cDNA from turbot (Scophthalmus maximus)

As an essential member of the HSP70 family, heat shock cognate 70 (Hsc70) is a constitutively expressed molecular chaperone involved in protein metabolism. In this paper, turbot Hsc70 was cloned and the expression profile was also analyzed. The full-length cDNA of the turbot Hsc70 was 2,292 bp in length, including a 113-bp 5' UTR, a 223-bp 3' UTR and a 1,956-bp open reading frame coding a protein with 651 amino acid residues. Comparison of amino acid sequence revealed the existence of three classical HSP70 family signature motifs, a signature nonapeptide and one repeat of tetrapeptide in turbot Hsc70. The turbot Hsc70-deduced amino acids sequence exhibited 75.4-96.8 % homology with Hsp70s/Hsc70s of 24 other known sequences. In particular, the strongest homology was found with the cognate members of Hsc70 subfamily and the highest identity was found with Japanese flounder Hsc70. Semi-quantitative RT-PCR revealed that turbot Hsc70 transcripts were stably expressed in all tested tissues under normal physiological condition, while the expression levels also increased (~1.5-fold to ~threefold) after heat shock and bacterial infection. In addition, Hsc70 transcripts were detected throughout embryonic development and in turbot embryonic cell line (TEC) in the absence of any stress. Meanwhile, it was also heat inducible, but not cold inducible in TEC. These results suggest that Hsc70 gene may be involved in embryogenesis and cellular protection events under normal and stress condition.

Detection of HBV resistance to lamivudine in patients with chronic hepatitis B using Zip nucleic acid probes in Kerman, southeast of Iran

HBV infection is contagious and may be transmitted vertically or horizontally by blood products and body secretions. Over 50% of Iranian carriers have contracted the infection prenatally, making this the most likely route of transmission of HBV in Iran. This study assesses the resistance to Lamivudine in patients with chronic hepatitis B infection using a new ZNA probe Real Time PCR method. To evaluate the effectiveness of Lamivudine therapy for chronic hepatitis B infection, a study was conducted on 70 patients (63 men and 7 women), who had received the drug first line. All patients were tested for the presence of HBsAg and HBeAg, the serum ALT level and the HBV DNA load before and after treatment. In all samples resistance to Lamivudine was tested with the ZNA Probe. Our results showed that ZNA Probe Real Time PCR method could detect wild type,YMDD, and its mutants, tyrosine-isoleucine-aspartate-aspartate and tyrosine-valine-aspartate-Aspartate. Among an estimated seventy patients with chronic hepatitis B infection, 18 (25.7%) were resistant to lamivudine. Only one patient was negative for presence of HBS-Ag (5.6%) and two patients were negative for HBe-Ag (11.1%). Real-time PCR with Zip nucleic acid probes is a sensitive, specific and rapid detection method for mutations in the YMDD motif, which will be essential for monitoring patients undergoing Lamivudine antiviral therapy.

Anti-HBV agents derived from botanical origin

There are 350,000 hepatitis B virus (HBV) carriers all over the world. Chronic HBV infection is at a high risk of developing liver cirrhosis and hepatocelluar carcinoma (HCC), and heavily threatened people's health. Two kinds of drugs approved by FDA for anti-HBV therapy are immunomodulators (interferon α, pegylated-interferon α) and nucleos(t)ide analogues (lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxil fumarate). These drugs have been proved to be far from being satisfactory due to their low specificity, side effects, and high rate of drug resistance. There is an urgent need to discover and develop novel effective anti-HBV drugs. With vast resources, various structures, diverse biological activities and action mechanisms, as well as abundant clinical experiences, botanical agents become a promising source of finding new anti-HBV drugs. This review summarizes the recent research and development of anti-HBV agents derived from botanical origin on their sources and active components, inhibitory effects and possible toxicities, as well as action targets and mechanisms, and also addresses the advantages and the existing shortcomings in the development of botanical inhibitors. This information may not only broaden the knowledge of anti-HBV therapy, and offer possible alternative or substitutive drugs for CHB patients, but also provides considerable information for developing new safe and effective anti-HBV drugs.

Comprehensive review on the HSC70 functions, interactions with related molecules and involvement in clinical diseases and therapeutic potential

Heat shock cognate protein 70 (HSC70) is a constitutively expressed molecular chaperone which belongs to the heat shock protein 70 (HSP70) family. HSC70 shares some of the structural and functional similarity with HSP70. HSC70 also has different properties compared with HSP70 and other heat shock family members. HSC70 performs its full functions by the cooperation of co-chaperones. It interacts with many other molecules as well and regulates various cellular functions. It is also involved in various diseases and may become a biomarker for diagnosis and potential therapeutic targets for design, discovery, and development of novel drugs to treat various diseases. In this article, we provide a comprehensive review on HSC70 from the literatures including the basic general information such as classification, structure and cellular location, genetics and function, as well as its protein association and interaction with other proteins. In addition, we also discussed the relationship of HSC70 and related clinical diseases such as cancer, cardiovascular, neurological, hepatic and many other diseases and possible therapeutic potential and highlight the progress and prospects of research in this field. Understanding the functions of HSC70 and its interaction with other molecules will help us to reveal other novel properties of this protein. Scientists may be able to utilize this protein as a biomarker and therapeutic target to make significant advancement in scientific research and clinical setting in the future.