A pharmacological profile of ribavirin and monitoring of its plasma concentration in chronic hepatitis C infection

Effect of HCV eradication by DAAs on liver steatosis, carotid atherosclerosis, and associated metabolic comorbidities: A systematic review

BACKGROUND AND AIMS

The beneficial effect of Hepatitis C virus (HCV) eradication by direct antiviral agents (DAAs) on liver fibrosis is well defined. Despite this, the impact of viral eradication in both hepatic and extra-hepatic metabolic features is underreached. This systematic review aimed to synthesize the evidence on the impact of HCV eradication by DAAs on liver steatosis, carotid atherosclerosis, glucidic impairment, dyslipidaemia, and weight gain.

METHODS

A systematic search of the existing literature (up to December 2022) identified 97 original studies that fulfilled the inclusion criteria.

RESULTS

Whereas total cholesterol and low-density lipoprotein (LDL) seem to increase after viral eradication, the cardiovascular damage expressed as carotid plaques and intima-media thickness seems to improve. Otherwise, the effect on liver steatosis, glucidic homeostasis, and weight seems to be strictly dependent on the presence of baseline metabolic disorders.

CONCLUSION

Despite high heterogeneity and relatively short follow-up of included studies, we can conclude that the presence of metabolic risk factors should be strictly evaluated due to their impact on liver steatosis, glucidic and lipid homeostasis, and on weight gain to better identify patients at risk of liver disease progression despite the virus eradication.

Ribavirin inhibits peste des petits ruminants virus proliferation in vitro

Peste des petits ruminants virus (PPRV), a member of the family Paramyxoviridae, belongs to the genus Morbillivirus. It causes devastating viral diseases in small ruminants and has been rapidly spreading over various regions in Africa, the Middle East, and Asia. Although vaccination is thought to be an effective management strategy against PPR infections, the heat sensitivity of PPRV vaccines severely restricts their use in regions with hot climates. In this research, we studied the antiviral activities of ribavirin and aimed to understand the potential mechanisms of action of ribavirin in the African green monkey kidney cells (Vero cells). In brief, the adsorption, intrusion, replication, and release of PPRV, as well as the mRNA expression level of RNA-dependent RNA polymerase (RdRp), were significantly inhibited in the ribavirin-treated Vero cells compared to those in the PPRV-infected cells that were not treated with ribavirin. Additionally, ribavirin has potential as an antiviral drug against PPRV, and its antiviral activity is mediated by the Janus kinase signal transducer and activator of transcription (JAK/STAT) and PI3K/AKT pathways.

COVID-19 and rheumatic diseases: A mini-review

Joint pain and arthralgia can be manifestations of COVID-19, and studies evaluating long COVID symptoms identified the persistence of these disorders. Moreover, some case reports highlighted the development of new inflammatory arthritis in patients with COVID-19, suggesting a possible relation. Viral infections and rheumatic diseases share a documented relationship; they have been associated with genetic and environmental risk factors responsible for some of them. There is crosstalk between viruses and the immune system during the development of several rheumatic diseases. Moreover, infections may participate in the pathogenesis of autoimmune rheumatic diseases and contribute to patient mortality. Therefore, it is crucial to provide a clearer insight into the interaction between viral infections and rheumatic diseases. Here, we provide a mini-review of the current literature with the aim of shedding light on the relationship between COVID-19 and rheumatic or musculoskeletal diseases, which is still unclear. Specifically, we examined several aspects: risk for the rheumatic population of acquiring the virus or developing severe symptoms, similarities of COVID-19 and arthritis, the possible rheumatic consequence of COVID-19, of rheumatic drugs and vaccines, and COVID-19 prevention in rheumatic patients through vaccination.

Effects of COVID-19 on the Musculoskeletal System: Clinician's Guide

The global pandemic caused by SARS-CoV-2, or COVID-19, continues to impact all facets of daily life. Clinical manifestations of COVID-19 commonly include musculoskeletal symptoms such as myalgias, arthralgias, and neuropathies/myopathies. The inflammatory response and its impact on the respiratory system have been the focus of most studies. However, the literature is more limited regarding the inflammatory response and its implications for other organ systems, specifically the musculoskeletal system. Previous studies have described how systemic inflammation may play a role in bone and joint pathology. Furthermore, it is important to understand the effects current therapeutics used in the treatment of COVID-19 may have on the musculoskeletal system. In this study, we will review the current understanding of the effect COVID-19 has on the musculoskeletal system, provide an overview of musculoskeletal symptoms of patients infected with the virus, and address key issues for clinicians to address during the care of COVID-19 patients.

The isolation of high-affinity ssDNA aptamer for the detection of ribavirin in chicken

The abuse of ribavirin, an antiviral drug, in poultry breeding can cause quality degradation and drug resistance. So it is of great importance to establish a simple and effective method for detecting ribavirin in foods. In this work, aptamers that could especially bind to ribavirin with high affinity were obtained by the Capture-SELEX method. After 15 rounds of enrichment, ssDNA library pool was enriched and then analyzed by high-throughput sequencing. The seven most enriched sequences were selected as candidate aptamers for affinity and specificity characterization. Among the candidate aptamers, APT-1 was proved to be the optimal aptamer. The dissociation constant (K_d) values of APT-1 obtained by the two methods of colorimetric and fluorescence were 34.34 ± 6.038 nmol L^-1, 61.19 ± 21.48 nmol L^-1, respectively. To study the binding mechanism of the selected aptamer, molecular docking was conducted and results indicated that hydrogen bonds were formed at binding sites located at G37, T38, A40, T53 and A54. Furthermore, to confirm the practicability of the selected aptamer, a fluorescence assay was designed, showing the liner range within 1.0-50 ng mL^-1 and the low detection limit of 0.67 ng mL^-1. Besides, the aptamer was applied for the detection of ribavirin in chicken samples and the recoveries ranged from 87.26% to 105.57%, which showed great application potential in food safety.

Drug repurposing approach to fight COVID-19

Currently, there are no treatment options available for the deadly contagious disease, coronavirus disease 2019 (COVID-19). Drug repurposing is a process of identifying new uses for approved or investigational drugs and it is considered as a very effective strategy for drug discovery as it involves less time and cost to find a therapeutic agent in comparison to the de novo drug discovery process. The present review will focus on the repurposing efficacy of the currently used drugs against COVID-19 and their mechanisms of action, pharmacokinetics, dosing, safety, and their future perspective. Relevant articles with experimental studies conducted in-silico, in-vitro, in-vivo, clinical trials in humans, case reports, and news archives were selected for the review. Number of drugs such as remdesivir, favipiravir, ribavirin, lopinavir, ritonavir, darunavir, arbidol, chloroquine, hydroxychloroquine, tocilizumab and interferons have shown inhibitory effects against the SARS-CoV2 in-vitro as well as in clinical conditions. These drugs either act through virus-related targets such as RNA genome, polypeptide packing and uptake pathways or target host-related pathways involving angiotensin-converting enzyme-2 (ACE2) receptors and inflammatory pathways. Using the basic knowledge of viral pathogenesis and pharmacodynamics of drugs as well as using computational tools, many drugs are currently in pipeline to be repurposed. In the current scenario, repositioning of the drugs could be considered the new avenue for the treatment of COVID-19.

Autoimmune and rheumatic musculoskeletal diseases as a consequence of SARS-CoV-2 infection and its treatment

The coronavirus disease-2019 (COVID-19) pandemic is likely to pose new challenges to the rheumatology community in the near and distant future. Some of the challenges, like the severity of COVID-19 among patients on immunosuppressive agents, are predictable and are being evaluated with great care and effort across the globe. A few others, such as atypical manifestations of COVID-19 mimicking rheumatic musculoskeletal diseases (RMDs) are being reported. Like in many other viral infections, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can potentially lead to an array of rheumatological and autoimmune manifestations by molecular mimicry (cross-reacting epitope between the virus and the host), bystander killing (virus-specific CD8 + T cells migrating to the target tissues and exerting cytotoxicity), epitope spreading, viral persistence (polyclonal activation due to the constant presence of viral antigens driving immune-mediated injury) and formation of neutrophil extracellular traps. In addition, the myriad of antiviral drugs presently being tried in the treatment of COVID-19 can result in several rheumatic musculoskeletal adverse effects. In this review, we have addressed the possible spectrum and mechanisms of various autoimmune and rheumatic musculoskeletal manifestations that can be precipitated by COVID-19 infection, its therapy, and the preventive strategies to contain the infection.

Antitumor effects of ribavirin in combination with TMZ and IFN-β in malignant glioma cells

The prognosis of gioblastoma, the standard chemotherapy agent for which is temozolomide (TMZ), remains poor despite recent advances in multimodal treatments. Therefore, it is necessary to identify and develop novel therapeutics for this malignant disease. Ribavirin, an anti-viral agent which is one of the standard agents for treatment of chronic hepatitis C in combination with interferon (IFN), was recently revealed to have an antitumor potential towards various tumor cells, including malignant glioma cells. The aim of the present study was to examine the antitumor effect of ribavirin in combination with TMZ and IFN-β on glioma cells and to evaluate the possibility that such combinations might represent a novel candidate for glioblastoma therapy. The combination of ribavirin with TMZ and IFN-β displayed a significant cell growth inhibitory effect with a ribavirin dose-dependency, including a relatively low concentration of ribavirin, on not only TMZ-sensitive but also TMZ-resistant malignant glioma cells. The antitumor efficacy of such a combination further indicated a synergistic interaction when assessed by the Chou-Talalay method. Furthermore, flow cytometry analysis suggested that apoptosis induction was one of the possible biological processes underlying the synergistic antitumor effect of these triple combination treatments. Therefore, such combinations may be potentially important in the clinical setting for glioblastoma treatment, although further detailed studies, e.g. on the adverse effects, are required.

Dosing ribavirin in hepatitis E-infected solid organ transplant recipients

Hepatitis E virus (HEV) is the most common cause of viral hepatitis worldwide. Genotypes 1 and 2 (GT1 and GT2) are mainly present in developing countries, while GT3 and GT4 are prevalent in developed and high-income countries. In the majority of cases, HEV causes a self-limiting hepatitis. GT3 and GT4 can be responsible for a chronic hepatitis that can lead to cirrhosis in immunocompromized patients, i.e. solid-organ- and stem-cell-transplant-patients, human immunodeficiency virus-infected patients, and patients receiving chemotherapy or immunotherapy. HEV has also been associated with extra-hepatic manifestations such as neurologic disorders (Guillain-Barré Syndrome and neuralgic amyotrophy) and kidney disease. In patients with chronic hepatitis, reduction of immunosuppression, when possible, is the first therapeutic option. In the remaining patients, ribavirin therapy has been shown to very efficient for treating HEV infection leading to a sustained virological response in nearly 80-85% of patients. However, the mechanism of action of ribavirin in this setting is still unknown, as is the impact of HEV RNA polymerase mutations. There are unmet needs with regard to the treatment of chronic HEV with ribavirin. These include the optimal dosing and duration of treatment, and the potential beneficial effects of therapeutic drug monitoring on the virological response and the incidence of side effects. In the present review, we will provide an overview of HEV epidemiology, its mode of transmission and clinical manifestations, as well as its treatment by ribavirin with a focus on the drug's pharmacokinetics and dosing.

Efficacy of ribavirin against malignant glioma cell lines: Follow-up study

Ribavirin, a nucleic acid analog, has been employed as an antiviral agent against RNA and DNA viruses and has become the standard agent used for chronic hepatitis C in combination with interferon-α2a. Furthermore, the potential antitumor efficacy of ribavirin has attracted increasing interest. Recently, we demonstrated a dose-dependent antitumor effect of ribavirin for seven types of malignant glioma cell lines. However, the mechanism underlying the antitumor effect of ribavirin has not yet been fully elucidated. Therefore, the main aim of the present study was to provide further relevant data using two types of malignant glioma cell lines (U-87MG and U-138MG) with different expression of MGMT. Dotted accumulations of γH2AX were found in the nuclei and increased levels of ATM and phosphorylated ATM protein expression were also observed following ribavirin treatment (10 µM of ribavirin, clinical relevant concentration) in both the malignant glioma cells, indicating double-strand breaks as one possible mechanism underlying the antitumor effect of ribavirin. In addition, based on assessements using FACS, ribavirin treatment tended to increase the G₀/G₁ phase, with a time-lapse, indicating the induction of G₀/G₁-phase arrest. Furthermore, an increased phosphorylated p53 and p21 protein expression was confirmed in both glioma cells. Additionally, analysis by FACS indicated that apoptosis was induced following ribavirin treatment and caspase cascade, downstream of the p53 pathway, which indicated the activation of both exogenous and endogenous apoptosis in both malignant glioma cell lines. These findings may provide an experimental basis for the clinical treatment of glioblastomas with ribavirin.

Ribavirin suppresses bacterial virulence by targeting LysR-type transcriptional regulators

Targeting bacterial virulence mechanisms without compromising bacterial growth is a promising strategy to prevent drug resistance. LysR-type transcriptional regulators (LTTRs) possess structural conservation across bacterial species and regulate virulence in numerous pathogens, making them attractive targets for antimicrobial agents. We targeted AphB, a Vibrio cholerae LTTR, which regulates the expression of genes encoding cholera toxin and toxin-co-regulated pilus for inhibitor designing. Since AphB ligand is unknown, we followed a molecular fragment-based approach for ligand designing using FDA-approved drugs and subsequent screen to identify molecules that exhibited high-affinity binding to AphB ligand-binding pocket. Among the identified compounds, ribavirin, an anti-viral drug, antagonized AphB functions. Ribavirin perturbed Vibrio cholerae pathogenesis in animal models. The inhibitory effects of the drug was limited to the bacteria expressing wild type AphB, but not its constitutively active mutant (AphB_N100E), which represents the ligand-bound state, suggesting that ribavirin binds to the active site of AphB to exert its inhibitory role and there exists no AphB-independent mechanism of its action. Similarly, ribavirin suppressed the functions of Salmonella Typhi LTTR Hrg, indicating its broad spectrum efficacy. Moreover, ribavirin did not affect the bacterial viability in culture. This study cites an example of drug repurposing for anti-infective therapy.

Safety, Tolerability, and Efficacy of Sofosbuvir Plus Ribavirin in Elderly Patients Infected with Hepatitis C Virus Genotype 2

BACKGROUND

An interferon-free regimen including sofosbuvir and ribavirin (RBV) for patients with hepatitis C virus (HCV) genotype 2 (G2) infection leads to a drastic improvement of sustained virological response (SVR). However, the safety, tolerability, and efficacy in patients aged 75 or older have not been completely understood.

SUMMARY

Fifty-six patients with HCV G2 infection who were treated with sofosbuvir and weight-based dose of RBV were enrolled. Thirty-seven patients aged ≥75 and 19 patients aged ≤74 were classified as the aged and non-aged groups, respectively. The aged group was characterized by significantly more number of women, history of hepatocellular carcinoma, low serum albumin (ALB) level, low hemoglobin (Hb) concentration, low estimated glomerular filtration rate (eGFR), and high fibrosis-4 index (p = 0.0029). Forty-one patients were evaluated for SVR at 12 weeks after the end of therapy (SVR12); of them, all but one completed the treatment scheduled for 12 weeks. The aged group showed lower SVR12 rate than the non-aged group (81.3% for aged and 96.0% for non-aged groups). Although the Hb concentration and eGFR are significantly lower in the aged group throughout the clinical course, all patients in the aged group completed the 12-week treatment with a gradual increase of serum ALB level. Key Messages: The combination of sofosbuvir plus RBV is tolerable and beneficial in patients aged >75. However, intensive management of anemia by dose reduction of RBV is necessary, which could lead to a low SVR12 rate compared to that observed in patients younger than 75 years.

Broad-spectrum antiviral agents

Development of highly effective, broad-spectrum antiviral agents is the major objective shared by the fields of virology and pharmaceutics. Antiviral drug development has focused on targeting viral entry and replication, as well as modulating cellular defense system. High throughput screening of molecules, genetic engineering of peptides, and functional screening of agents have identified promising candidates for development of optimal broad-spectrum antiviral agents to intervene in viral infection and control viral epidemics. This review discusses current knowledge, prospective applications, opportunities, and challenges in the development of broad-spectrum antiviral agents.

Narrow therapeutic window of ribavirin as an inhibitor of nitric oxide synthesis is broadened by macromolecular prodrugs

Ribavirin (RBV), a broad-spectrum antiviral agent, is a standard medication against hepatitis C virus (HCV). However, despite the decades of clinical success, the mechanism of action of this drug against HCV remains a subject of debate. Furthermore, the appeal of this therapeutic agent is considerably lessened by unfavorable pharmacokinetics. This interdisciplinary study contributes to the understanding of intracellular effects exerted by RBV and presents a successful design of macromolecular prodrugs of RBV to achieve a safer treatment. Specifically, we demonstrate that RBV exhibits a pronounced anti-inflammatory activity in cultured macrophages as is evidenced by a 2-fold decrease in the levels of produced nitric oxide achieved using a clinically relevant concentration of this drug. However, this effect was characterized by a rather narrow therapeutic window with experimental values of EC50 and IC50 being 7 and 19 μM, respectively. Macromolecular prodrugs were obtained using an acrylate derivative of RBV, RAFT polymerization technique, and N-vinyl pyrrolidone as a partner monomer. The synthesized polymers were characterized with uniform molecular weights, relatively narrow polydispersities, and gradually increasing content of RBV. The resulting polymer therapeutics were effective in delivering their payload to the cultured macrophages and afforded a significantly wider therapeutic window, as much as >1000 μM (18-fold in relative values). Taken together, this work contributes significantly to the development of safer methods for delivery of RBV, as well as understanding the mechanism of action and origins of the side effects of this broad-spectrum antiviral agent.