Cordycepin analogues of 2',5'-oligoadenylate inhibit human immunodeficiency virus infection via inhibition of reverse transcriptase

Evaluation of Cordyceps militaris steroids as anti-inflammatory agents to combat the Covid-19 cytokine storm: a bioinformatics and structure-based drug designing approach

Since the SARS-CoV-2 epidemic, researchers have been working on figuring out ways to tackle multi-organ failure and hyperinflation, which are brought on by a cytokine storm. Angiotensin-converting enzyme 2 (ACE2), a SARS-CoV-2 spike glycoprotein's cellular receptor, is involved in complicated molecular processes that result in hyperinflammation. Cordyceps militaris is one of the traditional Chinese medicines that is used as an immune booster, and it has exhibited efficacy in lowering blood glucose levels, seminal emissions, and infertility. In the current study, we explored the potential of Cordyceps militaris steroids as key agents in managing the anger of cytokine storm in Covid-19 using network ethnopharmacological techniques and structure-based drug designing approaches. The steroids present in Cordyceps militaris were initially screened against the targets involved in inflammatory pathways. The results revealed that out of 16 steroids, 5 may be effective against 17 inflammatory pathways by targeting 11 pathological proteins. Among the five steroids, beta-sitosterol, Cholest-5-en-3β-ol, 3β, and 7α-Dihydroxycholest-5-ene were found to interact with thrombin (F2), an important protein reported to reduce the severity of inflammatory mediators and Cholest-4-en-3-one was found to target Glucocorticoid receptor (NR3C1). The top docked steroid displayed key interactions with both targets, which retained key interactions throughout the 100 ns simulation period. These compounds were also shown high binding free energy scores in water swap studies. Based on obtained results the current study suggests the use of Cordyceps militaris as an add-on therapy that may reduce the progression of inflammatory co-morbidities among patients infected with SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

In silico screening of potential inhibitors from Cordyceps species against SARS-CoV-2 main protease

Coronavirus disease 2019 (COVID-19) is a result of a retroviral infection of SARS-CoV-2. Due to its virulence and high infection rate, it is a matter of serious concern and a global health emergency. Currently available COVID-19 vaccines approved by regulatory bodies around the world have been shown to provide significant protection against COVID-19. But no vaccine is 100% effective at preventing infection, also they have varying efficacy rates and different side effects. However, the main protease (Mpro) of SARS-CoV-2 has been identified as a key drug target due to its essential role in viral infection and its minimal similarity with human proteases. Cordyceps mushrooms have been found to have various therapeutic properties that could effectively combat SARS-CoV-2, including improve lung functioning, anti-viral, immunomodulators, anti-infectious, and anti-inflammatory. The present study aims to screen and evaluate the inhibitory potential of the bioactive molecules from the Cordyceps species against the Mpro of SARS-CoV-2. The bioactive molecules were screened based on their docking score, molecular interactions in the binding pocket, ADME properties, toxicity, carcinogenicity, and mutagenicity. Among all the molecules that were tested, cordycepic acid was the most effective and promising candidate, with a binding affinity of -8.10 kcal/mol against Mpro. The molecular dynamics (MD) simulation and free binding energy calculations revealed that the cordycepic acid-Mpro complex was highly stable and showed fewer conformational fluctuations. These findings need to be investigated further through in-vitro and in-vivo studies for additional validation.Communicated by Ramaswamy H. Sarma.

Cordycepin enhances anti-tumor immunity in breast cancer by enhanceing ALB expression

Objective

The treatment of breast cancer still faces great challenges, and it is necessary to continuously explore effective drugs and targets to promote immune precision medicine. This study aims to investigate the immune-related regulatory mechanism of cordycepin in breast cancer.

Methods

Network pharmacology was employed to discovery the action of cordyceps on breast cancer targets, molecular docking was employed to analyze the interaction pattern between core components and targets, and biological information analysis was used to explore the target-related immune mechanism and verified in vitro experiments.

Results

The results of this study indicate that cordycepin can effectively inhibit breast cancer. The roles of cordycepin's active component and its target gene ALB were elucidated through the combined use of network pharmacology and molecular docking. Bioinformatics analysis revealed convincing associations between ALB and many immune pathway marker genes. ALB was inhibited in tumor expression, and cordycepin was found to enhance the expression of ALB in vitro to play an anti-tumor role.

Conclusion

Cordycepin regulates immune suppression of tumor, which is expected to open a new chapter of breast cancer immunotherapy.

Plant-Derived Epi-Nutraceuticals as Potential Broad-Spectrum Anti-Viral Agents

Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to their inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances in which vaccination is not accessible or in individuals with compromised immune systems, drugs can provide additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Moreover, targeting host factors allows us to develop compounds that are effective against different viral variants as well as against newly emerging virus strains. In recent years, the globe has experienced climate change, which may contribute to the emergence and spread of infectious diseases through a variety of factors. Warmer temperatures and changing precipitation patterns can increase the geographic range of disease-carrying vectors, increasing the risk of diseases spreading to new areas. Climate change may also affect vector behavior, leading to a longer breeding season and more breeding sites for disease vectors. Climate change may also disrupt ecosystems, bringing humans closer to wildlife that transmits zoonotic diseases. All the above factors may accelerate the emergence of new viral epidemics. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds, including those with anti-viral activity. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Interest in herbal antiviral products has increased. More than 50% of approved drugs originate from herbal sources. Plant-derived compounds offer diverse structures and bioactive molecules that are candidates for new drug development. Combining these therapies with conventional drugs could improve patient outcomes. Epigenetics modifications in the genome can affect gene expression without altering DNA sequences. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses recruit cellular epitranscriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we explore the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing their modulation processes and anti-viral effects on DNA and RNA viruses, as well as addressing future research objectives in this rapidly emerging field.

Cordycepin: A review of strategies to improve the bioavailability and efficacy

Cordycepin is a bioactive compound extracted from Cordyceps militaris. As a natural antibiotic, cordycepin has a wide variety of pharmacological effects. Unfortunately, this highly effective natural antibiotic is proved to undergo rapid deamination by adenosine deaminase (ADA) in vivo and, as a consequence, its half-life is shortened and bioavailability is decreased. Therefore, it is of critical importance to work out ways to slow down the deamination so as to increase its bioavailability and efficacy. This study reviews recent researches on a series of aspects of cordycepin such as the bioactive molecule's pharmacological action, metabolism and transformation as well as the underlying mechanism, pharmacokinetics and, particularly, the methods for reducing the degradation to improve the bioavailability and efficacy. It is drawn that there are three methods that can be applied to improve the bioavailability and efficacy: to co-administrate an ADA inhibitor and cordycepin, to develop more effective derivatives via structural modification, and to apply new drug delivery systems. The new knowledge can help optimize the application of the highly potent natural antibiotic-cordycepin and develop novel therapeutic strategies.

Research Progress on Cordycepin Synthesis and Methods for Enhancement of Cordycepin Production in Cordyceps militaris

C. militaris is an insect-born fungus that belongs to Ascomycota and Cordyceps. It has a variety of biological activities that can be applied in medicine, health-care products, cosmeceuticals and other fields. Cordycepin (COR) is one of the major bioactive components identified from C. militaris. Thus, C. militaris and COR have attracted extensive attention. In this study, chemical synthetic methods and the biosynthesis pathway of COR were reviewed. As commercially COR was mainly isolated from C. militaris fermentation, the optimizations for liquid and solid fermentation and genetic modifications of C. militaris to increase COR content were also summarized. Moreover, the research progress of genetic modifications of C. militaris and methods for separation and purification COR were introduced. Finally, the existing problems and future research direction of C. militaris were discussed. This study provides a reference for the production of COR in the future.

Potent Inhibitory Activities of the Adenosine Analogue Cordycepin on SARS-CoV-2 Replication

Nucleoside analogues are among the most successful bioactive classes of druglike compounds in pharmaceutical chemistry as they are well-known for their numerous effective bioactivities in humans, especially as antiviral and anticancer agents. Coronavirus disease 2019 (COVID-19) is still untreatable, with its causing virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continuing to wreak havoc on the ground everywhere. This complicated international situation urged all concerned scientists, including medicinal chemists and drug discoverers, to search for a potent anti-COVID-19 drug. Cordycepin (3′-deoxyadenosine) is a known natural adenosine analogue of fungal origin, which could also be synthetically produced. This bioactive phytochemical compound is characterized by several proven strong pharmacological actions that may effectively contribute to the comprehensive treatment of COVID-19, with the antiviral activities being the leading ones. Some new studies predicted the possible inhibitory affinities of cordycepin against the principal SARS-CoV-2 protein targets (e.g., SARS-CoV-2 spike (S) protein, main protease (M^pro) enzyme, and RNA-dependent RNA polymerase (RdRp) enzyme) based on the computational approach. Interestingly, the current research showed, for the first time, that cordycepin is able to potently inhibit the multiplication of the new resistant strains of SARS-CoV-2 with a very minute in vitro anti-SARS-CoV-2 EC₅₀ of about 2 μM, edging over both remdesivir and its active metabolite GS-441524. The ideal pharmacophoric features of the cordycepin molecule render it a typical inhibitor of SARS-CoV-2 replication, with its flexible structure open for most types of derivatization in the future. Briefly, the current findings further support and suggest the repurposing possibility of cordycepin against COVID-19 and greatly encourage us to confidently and rapidly begin its preclinical/clinical evaluations for the comprehensive treatment of COVID-19.

Antioxidant Activity of Mushroom Extracts/Polysaccharides-Their Antiviral Properties and Plausible AntiCOVID-19 Properties

Mushrooms have been long accomplished for their medicinal properties and bioactivity. The ancients benefitted from it, even before they knew that there was more to mushrooms than just the culinary aspect. This review addresses the benefits of mushrooms and specifically dwells on the positive attributes of mushroom polysaccharides. Compared to mushroom research, mushroom polysaccharide-based reports were observed to be significantly less frequent. This review highlights the antioxidant properties and mechanisms as well as consolidates the various antioxidant applications of mushroom polysaccharides. The biological activities of mushroom polysaccharides are also briefly discussed. The antiviral properties of mushrooms and their polysaccharides have been reviewed and presented. The lacunae in implementation of the antiviral benefits into antiCOVID-19 pursuits has been highlighted. The need for expansion and extrapolation of the knowns of mushrooms to extend into the unknown is emphasized.

Cordyceps militaris: An Overview of Its Chemical Constituents in Relation to Biological Activity

Cordyceps spp. mushrooms have a long tradition of use as a natural raw material in Asian ethnomedicine because of their adaptogenic, tonic effects and their ability to reduce fatigue and stimulate the immune system in humans. This review aims to present the chemical composition and medicinal properties of Cordyceps militaris fruiting bodies and mycelium, as well as mycelium from in vitro cultures. The analytical results of the composition of C. militaris grown in culture media show the bioactive components such as cordycepin, polysaccharides, γ-aminobutyric acid (GABA), ergothioneine and others described in the review. To summarize, based on the presence of several bioactive compounds that contribute to biological activity, C. militaris mushrooms definitely deserve to be considered as functional foods and also have great potential for medicinal use. Recent scientific reports indicate the potential of cordycepin in antiviral activity, particularly against COVID-19.

Cordycepin as a Promising Inhibitor of SARS-CoV-2 RNA dependent RNA polymerase (RdRp)

BACKGROUND

SARS-CoV-2, which emerged in Wuhan, China, is a new global threat that has killed millions of people and continues to do so. This pandemic has not only threatened human life but has also triggered economic downturns across the world. Researchers have made significant strides in discovering molecular insights into SARS-CoV-2 pathogenesis and developing vaccines, but there is still no successful cure for SARS-CoV-2 infected patients.

OBJECTIVE

The present study has proposed a drug-repositioning pipeline for the design and discovery of an effective fungal-derived bioactive metabolite as a drug candidate against SARS-CoV-2.

METHODS

Fungal derivative "Cordycepin" was selected for this study to investigate the inhibitory properties against RNA-dependent RNA polymerase (RdRp) (PDB ID: 6M71) of SARS-CoV-2. The pharmacological profile, intermolecular interactions, binding energy, and stability of the compound were determined utilizing cheminformatic approaches. Subsequently, molecular dynamic simulation was performed to better understand the binding mechanism of cordycepin to RdRp.

RESULTS

The pharmacological data and retrieved molecular dynamics simulations trajectories suggest excellent drug-likeliness and greater structural stability of cordycepin, while the catalytic residues (Asp760, Asp761), as well as other active site residues (Trp617, Asp618, Tyr619, Trp800, Glu811) of RdRp, showed better stability during the overall simulation span.

CONCLUSION

Promising results of pharmacological investigation along with molecular simulations revealed that cordycepin exhibited strong inhibitory potential against SARS-CoV-2 polymerase enzyme (RdRp). Hence, cordycepin should be highly recommended to test in a laboratory to confirm its inhibitory potential against the SARS-CoV-2 polymerase enzyme (RdRp).

Cordycepin Inhibits Virus Replication in Dengue Virus-Infected Vero Cells

Dengue virus (DENV) infection causes mild to severe illness in humans that can lead to fatality in severe cases. Currently, no specific drug is available for the treatment of DENV infection. Thus, the development of an anti-DENV drug is urgently required. Cordycepin (3′-deoxyadenosine), which is a major bioactive compound in Cordyceps (ascomycete) fungus that has been used for centuries in Chinese traditional medicine, was reported to exhibit antiviral activity. However, the anti-DENV activity of cordycepin is unknown. We hypothesized that cordycepin exerts anti-DENV activity and that, as an adenosine derivative, it inhibits DENV replication. To test this hypothesis, we investigated the anti-DENV activity of cordycepin in DENV-infected Vero cells. Cordycepin treatment significantly decreased DENV protein at a half-maximal effective concentration (EC50) of 26.94 μM. Moreover, DENV RNA was dramatically decreased in cordycepin-treated Vero cells, indicating its effectiveness in inhibiting viral RNA replication. Via in silico molecular docking, the binding of cordycepin to DENV non-structural protein 5 (NS5), which is an important enzyme for RNA synthesis, at both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, was predicted. The results of this study demonstrate that cordycepin is able to inhibit DENV replication, which portends its potential as an anti-dengue therapy.

Cordycepin Attenuates IFN-γ-Induced Macrophage IP-10 and Mig Expressions by Inhibiting STAT1 Activity in CFA-Induced Inflammation Mice Model

Cordycepin, a natural derivative of adenosine, has been shown to exert pharmacological properties including anti-oxidation, antitumor, and immune regulation. It is reported that cordycepin is involved in the regulation of macrophage function. However, the effect of cordycepin on inflammatory cell infiltration in inflammation remains ambiguous. In this study, we investigated the potential role of cordycepin playing in macrophage function in CFA-induced inflammation mice model. In this model, we found that cordycepin prevented against macrophage infiltration in paw tissue and reduced interferon-γ (IFN-γ) production in both serum and paw tissue. Using luciferase reporter assay, we found that cordycepin suppressed IFN-γ-induced activators of transcription-1 (STAT1) transcriptional activity in a dose-dependent manner. Moreover, western blotting data demonstrated that cordycepin inhibited IFN-γ-induced STAT1 activation through attenuating STAT1 phosphorylation. Further investigations revealed that cordycepin inhibited the expressions of IFN-γ-inducible protein 10 (IP-10) and monokine induced by IFN-γ (Mig), which were the effector genes in IFN-γ-induced STAT1 signaling. Meanwhile, the excessive inflammatory cell infiltration in paw tissue was reduced by cordycepin. These findings demonstrate that cordycepin alleviates excessive inflammatory cell infiltration through down-regulation of macrophage IP-10 and Mig expressions via suppressing STAT1 phosphorylation. Thus, cordycepin may be a potential therapeutic approach to prevent and treat inflammation-associated diseases.

Anti-feline immunodeficiency virus reverse transcriptase properties of some medicinal and edible mushrooms

Background and Aim

Feline immunodeficiency virus (FIV) causes AIDS-like symptoms in domestic and wild cats. Treatment of infected cats has been performed using human anti-HIV drugs, which showed some limitations. This study aimed to determine the anti-FIV potential of some mushrooms.

Materials and Methods

A total of 17 medicinal and edible mushrooms were screened to find their inhibitory effect against FIV reverse transcriptase (FIV-RT). Three solvents, water, ethanol, and hexane, were used to prepare crude mushroom extracts. Fluorescence spectroscopy was used to perform relative inhibition and 50% inhibitory concentrations (IC₅₀) studies.

Results

The ethanol extract from dried fruiting bodies of Inonotus obliquus showed the strongest inhibition with an IC₅₀ value of 0.80±0.16 μg/mL. The hexane extract from dried mycelium of I. obliquus and ethanol and water extracts from fresh fruit bodies of Phellinus igniarius also exhibited strong activities with the IC₅₀ values of 1.22±0.20, 4.33±0.39, and 6.24±1.42 μg/mL, respectively. The ethanol extract from fresh fruiting bodies of Cordyceps sinensis, hexane extracts from dried mycelium of I. obliquus, ethanol extracts of Ganoderma lucidum, hexane extracts of fresh fruiting bodies of Morchella esculenta, and fresh fruiting bodies of C. sinensis showed moderate anti-FIV-RT activities with IC₅₀ values of 29.73±12.39, 49.97±11.86, 65.37±14.14, 77.59±8.31, and 81.41±17.10 μg/mL, respectively. These mushroom extracts show anti-FIV potential.

Conclusion

The extracts from I. obliquus, P. igniarius, C. sinensis, and M. esculenta showed potential anti-FIV activity.

Cordycepin exhibits a suppressive effect on T cells through inhibiting TCR signaling cascade in CFA-induced inflammation mice model

Objective: Cordycepin has been shown to exhibit multiple pharmacological activities, such as antitumor, antifungi, antivirus, and immune-regulation activities, and is involved in the regulation of T cells. However, cordycepin that affects T cell activity is still not clear, and the molecular mechanism of cordycepin in regulation of TCR signaling has not yet been elucidated. In this study, the potential effect of cordycepin on T cells was observed in CFA-induced inflammation mice model, and the function of cordycepin in regulating TCR signaling cascade was investigated.Methods: A CFA-induced inflammation mice model was established for observing the effect of cordycepin on the thymus and spleen swellings, and T cell infiltration in paw tissue was detected by immunohistochemistry. The protein expression or phosphorilation was detected by western blotting, and the NFAT1 nuclear translocation was determined by fluorescence imaging. The cell proliferation, apoptosis, and IL-2 production were analyzed by CCK-8 method, flow cytometry, and ELISA.Results: In the mice model, the thymus and spleen swellings were suppressed and the T cell infiltration in paw tissue was inhibited by cordycepin at a concentration of 10 mg/kg. Although the expressions of ZAP70 and PLCγ1 were not significantly changed in the human T cell line Jurkat with cordycepin pretreatment, the CD3-antibody-induced phosphorylations of ZAP70 and PLCγ1 were markedly blocked. The protein level of p85 decreased when Jurkat cells were pretreated with cordycepin, and cordycepin blocked TCR downstream molecule Erk phosphorylation and NFAT1 nuclear translocation. Further investigation revealed that cordycepin inhibited T cell proliferation, reduced IL-2 production, and induced T cell apoptosis. Conclusions: These findings suggest that cordycepin regulates TCR signaling to inhibit excessive T cell activation in inflammation. Thus, cordycepin may be a potential therapeutic application in inflammation-associated diseases.

Cordycepin: A Biotherapeutic Molecule from Medicinal Mushroom

Cordyceps is one of the most well-known mushroom with numerous bioactive compounds possess wide range of biotherapeutic activities. This mushroom has been used for many years as medicinal food particularly in China and in different regions of south East Asia. Cordycepin is a nucleoside compound extracted from different species of Cordyceps and considered as one of the most important bioactive metabolites of this fungus. This low molecular weight compound exhibit several medicinal functions as anticancer, antitumor, antioxidant, anti-inflammatory, hypoglycemic, immunomodulatory agent. In this chapter we reviewed recent published research on the cordycepin chemistry, production, extraction, isolation, purification, biotherapeutic activities and applications.

Inhibition of Formation of Rev-RRE Complex by Pyronin Y

The interaction of pyronin Y, an RNA intercalating drug, with the binding of Rev protein from human immunodeficiency virus type 1 (HIV-1) to Rev-responsive element (RRE)-containing env RNA was studied. In gel retardation assays, recombinant Rev protein tightly bound to in vitro transcribed RRE RNA. Nitrocellulose-filter-binding studies revealed a dissociation constant of ≈(1–2) = 10−10M (Pfeifer et al., 1991). Pyronin Y efficiently suppressed formation of the Rev-RRE complex. At a concentration of 1 μg ml−1, complex formation was almost completely inhibited. Electron microscopy showed that Rev oligomerizes in the presence of RRE-containing RNA with the formation of short rod-like structures or long filaments, depending on the length of the transcript. Assembly of Rev protein along RRE-containing RNAs was abolished after addition of pyronin Y. Thus pyronin Y represents the first compound described to inhibit Rev-RRE complex formation.

Synergistic Anti-Human Immunodeficiency Viral (HIV-1) Effect of the Immunomodulator Ampligen (Mismatched Double-Stranded RNA) with Inhibitors of Reverse Transcriptase and HIV-1 Regulatory Proteins

The potent antiviral effect of double stranded RNA, such as the mismatched poly(l)·poly(C12U) [Ampligen], 2′,3′-dideoxy-3′-fluorothymidine (FddThd) and antisense oligodeoxynucleotides (ODN) has been established in in vitro systems using cells infected with the human immunodeficiency virus type 1 (HIV-1). We report here that the immunomodulator poly(l)·poly(C12U) interacts synergistically with (1) the reverse transcriptase inhibitor FddThd (FIC value: 0.43), (2) the modified (5′- and 3′-end capped thioates) antisense ODN-4 directed against the splice acceptor site of the HIV-1/ tat gene (FIC value: 0.66) and (3) also with pyronin Y, a compound which prevents binding of HIV-1 Rev protein to the HIV-1 RRE element. These data suggest that combinations of poly(l)·poly(C12U), a stimulator of the natural antiviral protection system of the cells, with compounds targeting HIV1-specific processes should be considered as candidate treatments of AIDS patients.

Cordycepin induces cell cycle arrest and apoptosis by inducing DNA damage and up-regulation of p53 in Leukemia cells

Cordycepin, an adenosine analog derived from Cordyceps militaris has been shown to exert anti-tumor activity in many ways. However, the mechanisms by which cordycepin contributes to the anti-tumor still obscure. Here our present work showed that cordycepin inhibits cell growth in NB-4 and U937 cells by inducing apoptosis. Further study showed that cordycepin increases the expression of p53 which promotes the release of cytochrome c from mitochondria to the cytosol. The released cytochrome c can then activate caspase-9 and trigger intrinsic apoptosis. Cordycepin also blocks MAPK pathway by inhibiting the phosphorylation of ERK1/2, and thus sensitizes the apoptosis. In addition, our results showed that cordycepin inhibits the expression of cyclin A2, cyclin E, and CDK2, which leads to the accumulation of cells in S-phase. Moreover, our study showed that cordycepin induces DNA damage and causes degradation of Cdc25A, suggesting that cordycepin-induced S-phase arrest involves activation of Chk2-Cdc25A pathway. In conclusion, cordycepin-induced DNA damage initiates cell cycle arrest and apoptosis which leads to the growth inhibition of NB-4 and U937 cells.

Cordycepin is a novel chemical suppressor of Epstein-Barr virus replication

Cordyceps species are known to produce numerous active components and are used for diverse medicinal purposes because of their varied physiological activities, including their ability to protect the liver from damage as well as their anticancer, antidepressant, anti-inflammatory, hypoglycemic, antimicrobial effects. Cordycepin, an adenosine derivative, differs from adenosine in that its ribose lacks an oxygen atom at the 3′ position. Several research groups have reported that cordycepin has antiviral activity against several viruses including influenza virus, plant viruses, human immunodeficiency virus(HIV), murine leukemia virus, and Epstein-Barr virus (EBV). In this study, we identify the epigenetic mechanisms by which cordycepin exerts its anti-gammaherpesvirus effects. We show that cordycepin possesses antitumor and antiviral activity against gastric carcinoma and EBV, respectively. A comparison of the CD₅₀ values of cordycepin and its analogs showed that the lack of a 2′-hydroxyl group in cordycepin was critical for its relatively potent cytotoxicity. Cordycepin treatment decreased the rate of early apoptosis in SNU719 cells by up to 64%, but increased late apoptosis/necrosis by up to 31%. Interestingly, cordycepin increased BCL7A methylation in SNU719 cells by up to 58% and decreased demethylation by up to 37%. Consistent with these changes in methylation, cordycepin treatment significantly downregulated most EBV genes tested. Under the same conditions, cordycepin significantly decreased the frequency of Q and F promoter usage, and H3K4me3 histone enrichment was significantly reduced at several important EBV genomic loci. Extracellular and intracellular EBV genome copy numbers were reduced by up to 55% and 30%, respectively, in response to 125 μM cordycepin treatment.

Finally, cordycepin significantly suppressed the transfer of EBV from LCL-EBV-GFP to AGS cells, indicating that EBV infection of gastric epithelial cells was inhibited. These results suggest that cordycepin has antiviral and antitumor activities against gammaherpesviruses and host cells latently infected with virus.

Cordycepin increases sensitivity of Hep3B human hepatocellular carcinoma cells to TRAIL-mediated apoptosis by inactivating the JNK signaling pathway

Resistance to tumor necrosis factor-related apoptosis‑inducing ligand (TRAIL)-induced apoptosis has been reported in various cancer cells. Cordycepin, a specific polyadenylation inhibitor, is the main functional component in Cordyceps militaris, which possesses many pharmacological activities including antitumor and anti-inflammation. In the present study, we demonstrated that treatment of cordycepin sensitized TRAIL-resistant Hep3B human hepatocellular carcinoma cells to TRAIL-mediated apoptosis as evidenced by formation of apoptotic bodies, chromatin condensation and accumulation of cells in the sub-G1 phase. The induction of apoptosis following co-treatment with cordycepin and TRAIL in Hep3B cells appeared to be correlated with modulation of Bcl-2 family protein expression and activation of the caspase cascade, which resulted in the cleavage of poly(ADP-ribose) polymerase and β-catenin. In addition, cordycepin treatment also inhibited activation of c-Jun N-terminal kinase (JNK). Pretreatment with SP600125, a JNK inhibitor, resulted in a significantly increased sub-G1 population and caspase activity in cordycepin plus TRAIL-mediated apoptosis. Taken together, these results indicate that JNK acts as a key regulator of apoptosis in response to combined treatment with cordycepin and TRAIL in human hepatocellular carcinoma Hep3B cells.

The genus Cordyceps: a chemical and pharmacological review

Objectives

Natural remedies are becoming increasingly popular and important in the public and scientific communities. Historically, natural remedies have been shown to present interesting biological and pharmacological activity and are used as chemotherapeutic agents. For centuries Cordyceps, which is a genus of more than 400 species in the family Clavicipitaceae, has been used in traditional Chinese medicine. This study highlights the chemistry and pharmacology of Cordyceps, especially Cordyceps sinensis (Berk.) Sacc. and C. militaris (Fr.) L. Information was obtained from Google Scholar and the journal databases PubMed and Scopus.

Key findings

Many bioactive components of Cordyceps have been extracted, such as cordycepin, cordycepic acid, ergosterol, polysaccharides, nucleosides and peptides. Studies show that Cordyceps and its active principles possess a wide range of pharmacological actions, such as anti-inflammatory, antioxidant, antitumour, antihyperglycaemic, antiapoptosis, immunomodulatory, nephroprotective, and hepatoprotective.

Summary

More research is required to discover the full extent of the activity of Cordyceps.

Anti-hyperglycemic Activity of Natural and Fermented Cordyceps sinensis in Rats with Diabetes Induced by Nicotinamide and Streptozotocin

Our previous study demonstrated that the fruiting bodies of Cordyceps sinensis, a traditional Chinese medicine, attenuated diabetes-induced weight loss, polydipsia, and hyperglycemia in rats. In the present study, we further compared the anti-hyperglycemic activity of the fermented mycelia and broth of Cordyceps sinensis with that of the fruiting bodies. Male Wistar rats orally administered a placebo (STZ group), fruiting bodies (FB group, 1 g/day), fermented mycelia (MCS group, 1 g/day), fermented broth (BCS group, 1 g/day), or fermented mycelia plus broth (XCS group, 0.5 g/day of each) of Cordyceps sinensis (d1 to d28) were injected with nicotinamide (200 mg/kg) and streptozotocin (65 mg/kg) on d15. Rats fed with a placebo and injected with saline served as the control (CON) group. The amount of water and food consumption (d15 to d29), the 2-hour-postprandial blood glucose concentrations (d21 and d28), and the serum concentrations of fructosamine (d29) were significantly lower in the FB, MCS, BCS, and XCS groups than in the STZ group (one-way ANOVA, p < 0.05). The diabetic rats had significantly higher blood glucose concentrations as measured by the oral glucose tolerance test than the control rats; moreover, these changes were significantly reduced by ingesting the fruiting bodies, fermented mycelia and/or broth of Cordyceps sinensis. Our results revealed that the fermented mycelia and broth of Cordyceps sinensis have anti-hyperglycemic activities similar to those of the fruiting bodies. Therefore, the fermented products of Cordyceps sinensis could be developed as potential anti-diabetic agents or functional foods for persons with a high risk of diabetes mellitus.

Activation of human RNase L by 2'- and 5'-O-methylphosphonate-modified oligoadenylates

To determine the influence of internucleotide linkage and sugar ring conformation, and the role of 5'-terminal phosphate, on the activation of human RNase L, a series of 2'- and 5'-O-methylphosphonate-modified tetramers were synthesized from appropriate monomeric units and evaluated for their ability to activate human RNase L. Tetramers pAAAp(c)X modified by ribo, arabino or xylo 5'-phosphonate unit p(c)X activated RNase L with efficiency comparable to that of natural activator. Moreover, incorporation of phosphonate linkages ensured the stability against cleavage by nucleases. The substitution of 5'-terminal phosphate for 5'-terminal phosphonate in tetramer p(c)XAAA afforded tetramers with excellent activation efficiency and with complete stability against cleavage by phosphomonoesterases.

Isolation of adenosine, iso-sinensetin and dimethylguanosine with antioxidant and HIV-1 protease inhibiting activities from fruiting bodies of Cordyceps militaris

According to previous studies, a close relationship between oxidative stress and AIDS suggests that antioxidants might play an important role in the treatment of AIDS. Cordyceps militaris was selected from nine edible mushrooms by assay of inhibition of erythrocyte hemolysis. Macroporous adsorption resin and HPLC were used to purify three micromolecular compounds named L3a, L3b and L3c. L3a was identified to be adenosine with the molecular formula C(10)H(13)N(5)O(4); L3b was 6,7,2',4',5'-pentamethoxyflavone with the molecular formula C(20)H(20)O(7), and L3c was dimethylguanosine with the molecular formula C(12)H(17)N(5)O(5). The compound 6,7,2',4',5'-pentamethoxyflavone was first isolated from C. militaris. The assay of inhibition of HIV-1 protease (HIV-1 PR) was based on the fact that the expression of this enzyme can inhibit the growth of E. coli. This is a new screening system for HIV-1 PR inhibitors. Both L3a and L3b showed high inhibition to HIV-1 PR. These compounds could be new anti-HIV-1 PR drugs.

Cordycepin induces apoptosis by enhancing JNK and p38 kinase activity and increasing the protein expression of Bcl-2 pro-apoptotic molecules

OBJECTIVE

To explore the molecular mechanism by which cordycepin inhibits cell proliferation and induces apoptosis of human colorectal cancer cells.

METHODS

Cell counting and MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, inner salt) method were used to monitor the effects of cordycepin on cell proliferation. Flow cytometry (FCM) was used to analyze the effects of cordycepin on the cell cycle progress. Annexin V-fluorescein isothiocyanate (FITC) analysis was used to detect apoptosis at a very early stage. Caspase-Glo was used to determine caspase activity and Western blot was used to measure protein expression levels of c-Jun N-terminal kinase (JNK), p38, and Bcl-2 pro-apoptosis family.

RESULTS

The numbers of viable SW480 and SW620 cells and the proliferation of these cells were significantly reduced with increases in cordycepin concentration (P<0.01). The cell cycle progression of SW480 and SW620 was arrested at the G0/G1 phase by the addition of cordycepin, and apoptosis rates of cordycepin treatments were increased compared with the control group. Cordycepin-treated cells showed phosphatidylserine valgus, suggesting the existence of early apoptosis. Caspase-3/7 and -9 activity significantly increased and the protein expression levels of JNK, p38, and Bax, Bid, Bim, and Puma from Bcl-2 pro-apoptosis molecules also increased after the treatment with cordycepin.

CONCLUSIONS

Cordycepin can inhibit SW480 and SW620 cell proliferation and induce apoptosis. Apoptosis might be induced by enhancing JNK and p38 kinase activity and increasing the protein expression of Bcl-2 pro-apoptotic molecules.

Binding of cordycepin monophosphate to AMP-activated protein kinase and its effect on AMP-activated protein kinase activation

It had been reported that cordycepin could activate AMP-activated protein kinase. One possible mechanism is that cordycepin mediated AMP-activated protein kinase activation by conversion into cordycepin monophosphate, which acts as an AMP analog to activate AMP-activated protein kinase. To confirm the aforementioned hypothesis, we investigate the binding of cordycepin monophosphate to AMP-activated protein kinase using molecular docking. The modeling results indicate that cordycepin monophosphate binds to AMP-activated protein kinase with high affinity. The hydrogen bonds provide attractive forces between molecules. Our results further identify the key residues contributing to the interaction. Also, the modeling results predict that cordycepin monophosphate and AMP would have similar binding modes with AMP-activated protein kinase. Further investigation of AMP-activated protein kinase activation in vitro provides the evidence that cordycepin monophosphate functioned as an AMP mimic to activate AMP-activated protein kinase.

Medicinal uses of the mushroom Cordyceps militaris: current state and prospects

Cordyceps militaris is a potential harbour of bio-metabolites for herbal drugs and evidences are available about its applications for revitalization of various systems of the body from ancient times. Amongst all the species, C. militaris is considered as the oldest source of some useful chemical constituents. Besides their popular applications for tonic medicine by the all stairs of the community, the constituents of C. militaris are now used extensively in modern systems of medicine. The current survey records the mysterious potentials of C. militaris are boosting up the present herbal treatments, as well as gearing up the green pharmacy revolution, in order to create a friendly environment with reasonable safety. Evidence showed that the active principles of C. militaris are beneficial to act as pro-sexual, anti-inflammatory, anti-oxidant/anti-aging, anti-tumour/anti-cancer/anti-leukemic, anti-proliferative, anti-metastatic, immunomodulatory, anti-microbial, anti-bacterial, anti-viral, anti-fungal, anti-protozoal, insecticidal, larvicidal, anti-fibrotic, steroidogenic, hypoglacaemic, hypolipidaemic, anti-angiogenetic, anti-diabetic, anti-HIV, anti-malarial, anti-fatigue, neuroprotective, liver-protective, reno-protective as well as pneumo-protective, let alone their other synergistic activities, which let it be marketable in the western countries as over-the-counter medicine. A number of culture techniques for this mushroom have been noticed, for example, storage/stock culture, pre-culture, popular/indigenous culture (spawn culture, husked rice culture and saw dust culture) and, special/laboratory culture (shaking culture, submerged culture, surface liquid culture and continuous/repeated batch culture). The prospects for herbal biotechnology regarding drug discovery using C. militaris delivering what it has promised are high, as the technology is now extremely more powerful than before. This study chiefly highlights the medicinal uses of the mushroom C. militaris including its culture techniques, also aiming to draw sufficient attention of the researchers to the frontier research needs in this context.

Inhibition of HIV type 1 replication in CD4+ and CD14+ cells purified from HIV type 1-infected individuals by the 2-5A agonist immunomodulator, 2-5A(N6B)

Two major interferon (IFN)-mediated antiviral defense enzymes are double-stranded (ds)RNA-dependent 2',5'-oligoadenylate (2-5A) synthetase (2-5OAS) and p68 kinase (PKR). When activated by dsRNA, 2-5OAS synthesizes 2-5A, which binds to and activates RNase L. Activated RNase L hydrolyzes single-stranded viral RNA, thereby inhibiting viral protein synthesis. HIV-1 inhibits the IFN-mediated intracellular antiviral pathways. We have reported the synthesis and characterization of a nuclease-resistant 2-5A agonist (2-5A(N6B)) that overcomes the HIV-1 induced blockades by restoring the 2-5OAS/RNase L antiviral pathway (Homan JW, et al., J Acquir Immune Defic Syndr 2002;30:9-20). The objective of this study was to test the effect of 2-5A(N6B) on chronically infected CD4(+) T lymphocytes and CD14(+) monocytes derived from HIV-1-seropositive individuals. Wild-type HIV-1 replication was effectively inhibited by 2-5A(N6B) in CD4(+) T lymphocytes and CD14(+) monocytes purified from HIV-1 seropositive individuals (n = 18) compared to untreated cells. We also assessed the cytotoxicity of 2-5A(N6B) and report that 2-5A(N6B) exerts its anti-HIV-1 activity with no evidence of cytotoxicity (IC(90) > 100,000 nM). Furthermore, 2-5A(N6B) did not alter the cellular RNA profile, affect CCR5 or CXCR4 coreceptor expression, or activate caspase-dependent apoptosis. Evidence is also provided to show that 2-5A(N6B), and naturally occurring 2-5A(4), act as ligands to activate human Toll-like receptor 4. These results indicate that the 2-5A agonist 2-5A(N6B) has the potential to enhance host cell innate and acquired immune defense mechanisms against HIV-1 infection.

ANTITUMOUR ACTIVITY OF CORDYCEPIN IN MICE

1. The antitumour effect of orally administered cordycepin, a component isolated from water extracts of Cordyceps sinensis, was examined in mice inoculated with B16 melanoma (B16-BL6) cells. 2. B16-BL6 (1 x 10(6)) cells were inoculated subcutaneously into the right footpad of mice. At 2 weeks after the cell inoculation, the enlarged primary tumour lump was weighed. Cordycepin (0, 5 and 15 mg/kg per day) was administered orally to the mice for 2 weeks from the date of tumour inoculation. Cordycepin (15 mg/kg per day) significantly reduced by 36% the wet weight of the primary tumour lump compared to that of the untreated control mice, without any loss of bodyweight or systemic toxicity. 3. Cordycepin (15 mg/kg per day) administered orally for 2 weeks inhibited the tumour enlargement in the right thigh inoculated with B16-BL6 cells premixed with extracellular matrix (Matrigel). 4. These results indicate that orally administered cordycepin inhibits melanoma cell growth in mice with no adverse effects.

The anti-hyperglycemic activity of the fruiting body of Cordyceps in diabetic rats induced by nicotinamide and streptozotocin

Little scientific evidence exists to support the numerous herbs used to improve diabetes-related metabolic disorders. Cordyceps, a Chinese herbal medicine with fruiting body and carcass, has been proposed to have multiple medicinal activities. The objective of this study was to investigate the effects of fruiting body and carcass of Cordyceps on hyperglycemia. Male Wistar rats administered with placebo (STZ group), 1 g of fruiting body (FB group), 1 g of carcass (CC group), or 1g of fruiting body plus carcass (CF group) of Cordyceps for four weeks (d1 to d28) were injected with nicotinamide (200 mg/kg) and streptozotocin (65 mg/kg) on d15. Animals fed with placebo and injected with saline acted as the controls (CON group). The results showed that water intake (d15 to d29), changes in fasting blood glucose concentration (d15 to d26), and serum concentrations of fructosamine (d29) were significantly greater in the STZ, CC and CF groups than in the CON and FB groups (one-way ANOVA, P < 0.05). The diabetic rats had significantly lower weight gain and higher blood glucose response in oral glucose tolerance test than the control rats; and these changes were significantly reduced by administrating the fruiting body of Cordyceps. Our results revealed that fruiting body, not carcass, of Cordyceps attenuated the diabetes-induced weight loss, polydipsia and hyperglycemia, and these improvements suggest that fruiting body of Cordyceps has a potential to be the functional food for diabetes.

Conformational properties of 2',5' linked Rp- and Sp-phosphorothioate oligoadenylates studied by circular dichroism and NMR

2',5'-Linked oligoadenylates (2-5A) are involved in the antiviral action of interferon. The 2-5A binds and activates 2-5A dependent RNase (RNase L), which degrades viral mRNA, resulting in the inhibition of protein synthesis. 2',5'-Linked phosphorothioate oligoadenylates with an Rp configuration bind to and activate the RNase L. On the other hand, 2',5' phosphorothioate oligoadenylate with an Sp configuration weakly binds to the RNase L and is devoid of the RNase L activation ability. Comparative circular dichroism (CD) and NMR studies are carried out to characterize the difference in properties between the two configurations of the 2',5' phosphorothioate oligoadenylates. 2',5' Rp-Phosphorothioate oligoadenylates showed CD spectra similar to those of the corresponding native 2',5' oligoadenylates, while the 2',5' Sp-phosphorothioate oligoadenylates exhibited a weaker CD band compared to the former two, indicating the weaker base-stacking interaction of the 2',5' Sp-phosphorothioate oligoadenylates. The temperature-dependent change in the CD revealed that 2',5' phosphorothioate oligoadenylates showed larger DeltaH(0) and DeltaS(0) values for the thermal transition of the conformation than the corresponding native 2',5' oligoadenylates. The NMR spectral assignment was accomplished by several NMR measuring techniques. The 2'-H of the ribose ring linked to the 2',5' Sp-phosphorothioate showed a higher field chemical shift of the proton NMR than that linked to the corresponding 2',5' Rp-phosphorothioate. 2',5' Rp- and Sp-phosphorothioate oligoadenylates possess a sugar conformation similar to that of the corresponding native 2',5' oligoadenylates.