Herpes Virus, Oral Clinical Signs and QoL: Systematic Review of Recent Data

Recommendations for the selection of nucleoside analogues as antihuman herpesvirus drugs: a real-world analysis of reported cases from the FDA adverse event reporting system

OBJECTIVE

The aim of this study is to provide guidance for refining medication protocols, developing alternative strategies, and enhancing protection against herpesvirus infections in personalized clinical settings.

METHODS

Adverse drug events (ADEs) data for anti-herpesvirus from the first quarter of 2004 to the fourth quarter of 2022 were collected from the FDA Adverse Event Reporting System (FAERS). Disproportionality analysis was performed using Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), and Bayesian Confidence Propagation Neural Network (BCPNN) methods for data mining.

RESULTS

A total of 18,591, 24,206, 6,150, and 419 reports of ADEs associated with acyclovir (ACV), valacyclovir (VACV), ganciclovir (GCV), and famciclovir (FCV) were screened and extracted from the FAERS. In this study, the report summarized the high frequency and strong correlation of ADEs for the four drugs at the Preferred Term (PT) level. Additionally, the analysis also identified the relationship between ADEs and factors such as age, gender, and severity of outcome at the System Organ Class (SOC) level.

CONCLUSION

The safety reports for the four-nucleoside analogue anti-herpesvirus drugs are diverse and interconnected. Dosing for patients with herpesvirus infections should be tailored to their specific conditions and the potential risk of disease.

A Review of Atypical Cutaneous Histological Manifestations of Herpes Zoster

The clinical and histopathological features of herpes zoster (HZ) are usually straightforward. Atypical histological presentations, in the absence of the classical viral cytopathic changes, are well documented and can make the diagnosis of HZ extremely difficult. Herein, we review the existing literature on atypical cutaneous histological manifestations of the disease, with emphasis on the subtle clues, use of immunohistochemistry, and potential pitfalls.

Inhibitory effects of algal polysaccharide extract from Cladophora spp. against herpes simplex virus infection

Herpes simplex virus (HSV) is a causative agent of fever blister, genital herpes, and neonatal herpes. Nowadays, edible algae are recognized as health food due to high nutrition content and their many active compounds that are beneficial to health. The purpose of this study is to investigate the inhibitory effects of algal polysaccharide extract from Cladophora spp. against herpes simplex virus type 1 and type 2 on Vero cells. In this study, the structure of polysaccharide extract is presented as S=O and C-O-S of the sulfate group, as identified by the FT-IR technique. The toxicity of algal polysaccharide extract on Vero cells was determined by MTT assay. The algal extract showed low toxicity on the cells, with 50% cytotoxic concentration (CC50) value greater than 5000 µg mL-1. The inhibition of HSV infection by the algal extract was then evaluated on Vero cells using plaque reduction assay. The 50% effective concentration (EC50) values of algal extract exhibited antiviral activity against HSV-1 upon treatment before, during, and after viral adsorption with and without removal of the extract were 70.31, 15.17, > 5000 and 9.78 µg mL-1, respectively. Additionally, the EC50 values of algal extract against HSV-2 upon treatment before, during and after viral adsorption with, and without removal of the extract were 5.85, 2.57, > 5000 and 26.96 µg mL-1, respectively. Moreover, the algal extract demonstrated direct inactivation of HSV-1 and HSV-2 virions as well as inhibitory effect against HSV replication. Accordingly, algal polysaccharide extract containing sulfated polysaccharides showed strong activity against HSV. Therefore, it is proved to be useful to apply Cladophora spp. polysaccharide extract as an anti-HSV agent.

Prevalence of human herpesvirus in plasma and saliva of cirrhotic patients: A pilot study

AIMS

The objective of this study was to identify the presence of human herpesvirus (HHV) in the plasma and saliva of hepatic-cirrhosis patients and correlate it with clinical data and laboratory tests. This is a pilot, observational, and cross-sectional study.

METHODS AND RESULTS

Specimens of plasma and saliva from 72 cirrhotic individuals were analyzed by means of polymerase chain reaction. The patient population had a mean age of 54.84 years old (SD ± 10) and was 70% males (51/72). Approximately 47% (n = 34) of the patients had leukopenia and HHV was not identified in the plasma specimens. The main species of HHV identified in the saliva were HHV-7 (n = 42, 62%) and Epstein-Barr virus (EBV) (n = 30, 41%). Moreover, there was a significant decrease in the total number of leukocytes and lymphocytes in saliva containing EBV (P = .038 and P = .047, respectively).

CONCLUSION

The results show that the presence of EBV in the saliva of cirrhotic patients was correlated with their circulating immune status. It may be possible that the immune dysfunction displayed by the cirrhotic patients plays a role in the shedding of EBV into saliva.

Clinical guidelines for herpes labialis: recommendations and quality evaluation according to AGREE II

Cold sores require Healthcare professionals to employ specific approaches for prevention and management, with the need for effective therapeutic guidelines and ongoing improvement in patient care.

AIM

To evalúate the methodological quality of Clinical Guidelines (CG), clinical guides and manuals for care of the population affected by herpes labialis, to verify their compliance with evidence-based health standards.

MATERIALS AND METHOD

A search was conducted for CG on labial herpes in the MedicalLiteratureAnalysis andRetrieval System Online (Medline) database, Google Scholar, Brazilian Virtual Health Library (BVS), and sites of institutions/professional categories, using the descriptors "herpes labialis" or "oral herpes". Document quality was assessed using the Appraisal of Guidelines for Research & Evaluation Instrument (AGREE II). The Kappa test was used to avoid randomness or poor agreement between results.

RESULTS

Analysis of the 12 selected publications on the management of labial herpes revealed flaws in quality, as the publications did not follow a quality standard. The main quality flaws identified were in "rigor in development" and "applicability. ".

CONCLUSIONS

Priorities need to be redefined in the development of CG for clinical practice related to fever blisters to reduce the variability of the quality standard, and generate reliable, applicable recommendations.

In vitro anti-HSV1 activity of aqueous extract of Areca catechu L

Background and Objectives

HSV-1 is known as a very contagious virus and the main cause of cold sores or fever blisters. Herein, the aqueous extract of Areca catechu L. was evaluated for its anti-HSV-1 activity, compared to the standard control (acyclovir). Also, the effect of extract on the expression of UL46 and US6 genes that accumulate late in viral infection, was studied.

Materials and Methods

The aqueous extract was obtained by the maceration of powdered plant in boiling water. Its antiviral activity was evaluated on Vero cells infected with HSV-1 at different times: 2 h pre-infection, simultaneous infection, and 4 h post-infection, using MTT assay. The effect of extract on the expression of genes was investigated with quantitative real-time PCR.

Results

The aqueous extract of A. catechu induced the inhibition of infection with the IC50 value of 110.52 ± 1.36 μg/ml. Also, it reduced the expression of UL46 when it was added 2 h pre-infection at 100 μg/ml. Moreover, reduction of expression of US6 was observed at the same concentration when the extract was used simultaneously with the occurrence of infection and 4 h post-infection.

Conclusion

A. catechu can be considered an essential element of natural-based anti-HSV-1 agents.

Common Oral Conditions: A Review

Importance

Dry mouth, oral candidiasis, and recurrent aphthous ulcers are 3 of the most common oral conditions that may be associated with patient discomfort, decreased quality of life, and morbidity.

Observations

In a meta-analysis of 26 population-based cohort and cross-sectional studies, the global prevalence of dry mouth symptoms was 23% (95% CI, 18% to 28%), placing individuals at risk of oral candidiasis, dental caries, dysgeusia, masticatory/speech impairment, and oropharyngeal dysphagia. Dry mouth is associated with using more than 3 oral medications per day (odds ratio [OR], 2.9 [95% CI, 1.4 to 6.2]), head and neck radiation, and Sjögren disease. Symptoms may include difficulty swallowing and speaking, thirst, and halitosis. Dry mouth is associated with an 11.5% (95% CI, 3.6% to 27%) higher risk of oral candidiasis, based on a meta-analysis of 6 observational cohorts. Management of dry mouth includes mechanical salivary stimulants, oral moisturizers, and/or systemic sialagogues. Oral candidiasis is an opportunistic fungal infection caused by overgrowth of the Candida genus with C albicans, which accounts for 76.8% of infections. The prevalence of oral candidiasis is higher in patients who are immunosuppressed, for example, those with HIV (35% [95% CI, 28% to 42%]) and those with salivary gland hypofunction (OR, 3.02 [95% CI, 1.73 to 5.28]). Common risk factors associated with oral candidiasis include use of antibiotics (P = .04) and oral mucosal disorders such as lichen planus. Oral burning and dysgeusia are common symptoms of oral candidiasis. Treatment includes addressing risk factors and use of topical and/or systemic antifungal medications. Recurrent aphthous stomatitis is characterized by symptomatic round or oval oral ulcers, which are covered by a gray-white fibrin layer and encircled by an erythematous ring. A meta-analysis of 10 case-controlled studies revealed an increased risk of recurrent aphthous stomatitis associated with polymorphism of IL-1β (+3954C/T) (OR, 1.52 [95% CI, 1.07 to 2.17]) and IL-1β (-511C/T) (OR, 1.35 [95% CI, 1.09 to 1.67]). Another meta-analysis of 9 case-control studies reported that patients with recurrent aphthous stomatitis had a higher frequency of nutritional deficiencies, including vitamin B12 (OR, 3.75 [95% CI, 2.38 to 5.94]), folic acid (OR, 7.55 [95% CI, 3.91 to 14.60]), and ferritin (OR, 2.62 [95% CI, 1.69 to 4.06]). Recurrent aphthous stomatitis can be associated with systemic diseases. A meta-analysis of 21 case-control studies revealed that celiac disease is associated with a higher incidence of recurrent aphthous stomatitis (25% vs 11%; OR, 3.79 [95% CI, 2.67 to 5.39]; P <.001). Topical corticosteroids are first-line agents to manage recurrent aphthous stomatitis; however, systemic medications may be necessary in more severe cases.

Conclusions and Relevance

Dry mouth, oral candidiasis, and recurrent aphthous ulcers are common oral conditions that may be associated with patient discomfort, decreased quality of life, and morbidity. First-line treatment includes over-the-counter sialagogues for dry mouth, topical antifungals for oral candidiasis, and topical corticosteroids for aphthous ulcers. Oral conditions that do not improve with first-line treatment may require treatment with systemic medications.

Oncolytic viruses in lung cancer treatment: a review article

Lung cancer has a high morbidity rate worldwide due to its resistance to therapy. So new treatment options are needed to improve the outcomes of lung cancer treatment. This study aimed to evaluate the effectiveness of oncolytic viruses (OVs) as a new type of cancer treatment. In this study, 158 articles from PubMed and Scopus from 1994 to 2022 were reviewed on the effectiveness of OVs in the treatment of lung cancer. The oncolytic properties of eight categories of OVs and their interactions with treatment options were investigated. OVs can be applied as a promising immunotherapy option, as they are reproduced selectively in different types of cancer cells, cause tumor cell lysis and trigger efficient immune responses.

Herpesviruses and SARS-CoV-2: Viral Association with Oral Inflammatory Diseases

The oral cavity is a niche for diverse microbes, including viruses. Members of the Herpesviridae family, comprised of dsDNA viruses, as well as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an ssRNA virus, are among the most prevalent viruses infecting the oral cavity, and they exhibit clinical manifestations unique to oral tissues. Viral infection of oral mucosal epithelia triggers an immune response that results in prolonged inflammation. The clinical and systemic disease manifestations of HHV have been researched extensively, and several recent studies have illuminated the relationship between HHV and oral inflammatory diseases. Burgeoning evidence suggests the oral manifestation of SARS-CoV-2 infection includes xerostomia, dysgeusia, periodontal disease, mucositis, and opportunistic viral and bacterial infections, collectively described as oral post-acute sequelae of COVID-19 (PASC). These diverse sequelae could be a result of intensified immune responses initially due to the copious production of proinflammatory cytokines: the so-called "cytokine storm syndrome", facilitating widespread oral and non-oral tissue damage. This review explores the interplay between HHV, SARS-CoV-2, and oral inflammatory diseases such as periodontitis, endodontic disease, and peri-implantitis. Additionally, the review discusses proper diagnostic techniques for identifying viral infection and how viral diagnostics can lead to improved overall patient health.

Efficacy of High-Voltage Pulsed Radiofrequency in Zoster-Associated Pain: A Meta-Analysis and Systematic Review

Background

Zoster-associated pain (ZAP) is often refractory to conventional treatments and can seriously affect patients' physical and mental health. High-voltage pulsed radio frequency (H-PRF) is a new method for treating ZAP with pulse voltages above 60 V or even up to 100 V. The purpose of this paper was to conduct a systematic review and meta-analysis to evaluate the efficacy of H-PRF in the management of ZAP.

Methods

PubMed, Embase, and the Cochrane library were searched from their inception to June 2022 to identify controlled trials which evaluated the effectiveness of H-PRF compared with standard PRF and sham operations. The primary outcome was pain scores at different treatment times. The secondary outcomes included SF-36 scores, rescue analgesic dose, and side effects.

Results

We reviewed 6 randomized controlled trials involving 428 patients. There was no significant difference between the H-PRF and standard PRF pain scores at 1 week after surgery and the sham operation group at 1 month. At 1, 3, and 6 months, the H-PRF group had better pain score than the standard PRF group, and at 3 months, the pain score was better than the sham operation group. The H-PRF group showed improvement in the SF-36 score, and there were no significant complications in the H-PRF group.

Conclusions

H-PRF is an effective and safe treatment method that has better effects in relieving pain and improving the quality of life and physical and mental health. Although H-PRF provides pain relief rates comparable to those of the control group in the early stages, it remains the preferred and alternative treatment for relieving herpes zoster-related pain.

The Quest for Immunity: Exploring Human Herpesviruses as Vaccine Vectors

Herpesviruses are large DNA viruses that have long been used as powerful gene therapy tools. In recent years, the ability of herpesviruses to stimulate both innate and adaptive immune responses has led to their transition to various applications as vaccine vectors. This vaccinology branch is growing at an unprecedented and accelerated rate. To date, human herpesvirus-based vectors have been used in vaccines to combat a variety of infectious agents, including the Ebola virus, foot and mouth disease virus, and human immunodeficiency viruses. Additionally, these vectors are being tested as potential vaccines for cancer-associated antigens. Thanks to advances in recombinant DNA technology, immunology, and genomics, numerous steps in vaccine development have been greatly improved. A better understanding of herpesvirus biology and the interactions between these viruses and the host cells will undoubtedly foster the use of herpesvirus-based vaccine vectors in clinical settings. To overcome the existing drawbacks of these vectors, ongoing research is needed to further advance our knowledge of herpesvirus biology and to develop safer and more effective vaccine vectors. Advanced molecular virology and cell biology techniques must be used to better understand the mechanisms by which herpesviruses manipulate host cells and how viral gene expression is regulated during infection. In this review, we cover the underlying molecular structure of herpesviruses and the strategies used to engineer their genomes to optimize capacity and efficacy as vaccine vectors. Also, we assess the available data on the successful application of herpesvirus-based vaccines for combating diseases such as viral infections and the potential drawbacks and alternative approaches to surmount them.

Amazonian medicinal plants efficiently inactivate Herpes and Chikungunya viruses

The Amazonian species investigated in this research are commonly utilized for their anti-inflammatory properties and their potential against various diseases. However, there is a lack of scientifically supported information validating their biological activities. In this study, a total of seventeen ethanolic or aqueous extracts derived from eight Amazonian medicinal plants were evaluated for their activity against Herpes Simplex type 1 (HSV-1) and Chikungunya viruses (CHIKV). Cytotoxicity was assessed using the sulforhodamine B method, and the antiviral potential was determined through a plaque number reduction assay. Virucidal tests were conducted according to EN 14476 standards for the most potent extracts. Additionally, the chemical composition of the most active extracts was investigated. Notably, the LMLE10, LMBA11, MEBE13, and VABE17 extracts exhibited significant activity against CHIKV and the non-acyclovir-resistant strain of HSV-1 (KOS) (SI > 9). The MEBE13 extract demonstrated unique inhibition against the acyclovir-resistant strain of HSV-1 (29-R). Virucidal assays indicated a higher level of virucidal activity compared to their antiviral activity. Moreover, the virucidal capacity of the most active extracts was sustained when tested in the presence of protein solutions against HSV-1 (KOS). In the application of EN 14476 against HSV-1 (KOS), the LMBA11 extract achieved a 99.9% inhibition rate, while the VABE17 extract reached a 90% inhibition rate. This study contributes to the understanding of medicinal species native to the Brazilian Amazon, revealing their potential in combating viral infections that have plagued humanity for centuries (HSV-1) or currently lack specific therapeutic interventions (CHIKV).

Supportive care and antiviral treatments in primary herpetic gingivostomatitis: a systematic review

OBJECTIVES

Herpes simplex virus 1 (HSV-1) is the main pathogen responsible for herpes infections. In 13-30% of the cases, primary HSV-1 leads to the primary herpetic gingivostomatitis (PHGS), often a self-limiting infection; however, it can limit the ability to drink/eat with, sometimes, the need for hospitalization. Multiple therapeutic methods have been proposed. This systematic review aims to collect and critically appraise the available evidence about the clinical management of PHGS.

MATERIALS AND METHODS

Literature search including three databases (PubMed, Scopus, Embase), study design, and data analysis were performed following PRISMA guidelines, according to the PICO tool (PROSPERO n° CRD42023391386). Risk of bias was assessed with RoB 2 and ROBINS-I.

RESULTS

Five studies on a total of 364 patients (average age: 7.6 years) were identified. The treatment regimens were summarized in acyclovir; acyclovir + honey; fluids and analgesic; maalox + diphenhydramine; lidocaine; chlorhexidine (CHX); CHX + ialuronic acid; CHX + Mucosyte®; antimicrobial photodynamic therapy (aPDT); topical antiviral; topical antiviral + aPDT; and others.

CONCLUSIONS

Although PHGS is a disease with a high worldwide prevalence, the lack of consensus about therapeutic management indicates gaps in existing evidence. Most of the proposed treatment consists in symptomatic drugs with empiric regimens which are ineffective for the viral replication. The main limit to realize randomized clinical trial is due to the rapid onset and remission of the disease. In fact, the diagnostic delay, estimated in 72 h, decreases the effectiveness of any antiviral drugs.

CLINICAL RELEVANCE

Out of the five studies included in this systematic review, only one was able to provide some weak evidence that ACV is an effective treatment, improving healing of oral lesions and reducing duration of symptoms.

Mechanism of herpesvirus UL24 protein regulating viral immune escape and virulence

Herpesviruses have evolved a series of abilities involved in the process of host infection that are conducive to virus survival and adaptation to the host, such as immune escape, latent infection, and induction of programmed cell death for sustainable infection. The herpesvirus gene UL24 encodes a highly conserved core protein that plays an important role in effective viral infection. The UL24 protein can inhibit the innate immune response of the host by acting on multiple immune signaling pathways during virus infection, and it also plays a key role in the proliferation and pathogenicity of the virus in the later stage of infection. This article reviews the mechanism by which the UL24 protein mediates herpesvirus immune escape and its effects on viral proliferation and virulence by influencing syncytial formation, DNA damage and the cell cycle. Reviewing these studies will enhance our understanding of the pathogenesis of herpesvirus infection and provide evidence for new strategies to combat against viral infection.

The Oral Lesion in the COVID-19 Patient: Is It True Oral Manifestation or Not?

Objective

Many previously reported publications mentioned that oral lesion in COVID-19 patients was varied. The term oral manifestations refer to pathognomonic features that are found consistently with a specific cause and effect. In this context, the oral manifestation of COVID-19 was inconclusive. This systematic review aimed to analyse previously reported publications related to oral lesions in COVID-19 patients to define as oral manifestations or not. The PRISMA guidelines were implemented in this review.

Methods

All umbrella reviews, systematic reviews, systematic reviews and meta-analyses, comprehensive reviews, and original and non-original studies were included. Twenty-one of systematic review, 32 original studies and 68 non-original studies reported the oral lesion in COVID-19 patients.

Results

Most of the publications mentioned that ulcers, macular, pseudomembranes and crusts were frequent oral lesions. The reported oral lesions in COVID-19 patients did not show any pathognomonic features and might be unrelated directly to COVID-19 infections, however, more likely due to gender, age, underlying diseases, and medication.

Conclusion

The oral lesions found in previous studies do not have pathognomonic features and are inconsistent. Therefore, the reported oral lesion, in present time, cannot be defined as an oral manifestation.

Herpesvirus-Related Lesions of the Oral Mucosa

The human herpesvirus (HHV) family is a group of enveloped DNA viruses containing 8 members known to produce oral mucosal lesions. Following initial exposure, which may result in symptomatic primary infection, the viruses establish latency within specific cells/tissues. After reactivation, herpesviruses can cause localized symptomatic or asymptomatic recurrent (secondary) infections or diseases. HHV may have a significant role in the cause of oral mucosal infectious diseases in immunocompromised patients. This article discusses the role of those herpesviruses that can induce oral mucosal lesions, with focus on the clinical features and treatment/management.

Broad-Spectrum Antivirals Derived from Natural Products

Scientific advances have led to the development and production of numerous vaccines and antiviral drugs, but viruses, including re-emerging and emerging viruses, such as SARS-CoV-2, remain a major threat to human health. Many antiviral agents are rarely used in clinical treatment, however, because of their inefficacy and resistance. The toxicity of natural products may be lower, and some natural products have multiple targets, which means less resistance. Therefore, natural products may be an effective means to solve virus infection in the future. New techniques and ideas are currently being developed for the design and screening of antiviral drugs thanks to recent revelations about virus replication mechanisms and the advancement of molecular docking technology. This review will summarize recently discovered antiviral drugs, mechanisms of action, and screening and design strategies for novel antiviral agents.

A phase 3, randomized, double-blind, placebo-controlled study evaluating a single, patient-initiated dose of amenamevir for recurrent herpes labialis

Amenamevir (ASP2151), a novel, non-nucleoside analog, antiviral drug, inhibits the enzyme activities of helicase and primase, which are essential for replication of herpes viral genomic DNA. In this phase 3, randomized, double-blind, placebo-controlled, multicenter study, the authors investigated the efficacy and safety of a single patient-initiated dose of amenamevir to treat recurrent herpes labialis. Adult immunocompetent patients with recurrent herpes labialis who had the experience and ability to recognize prodromal symptoms were randomly assigned to administer amenamevir 1200 mg or placebo as a patient-initiated therapy within 6 hours after onset of prodromal symptoms. The primary efficacy end point was time to healing of all herpes labialis lesions in the modified intention-to-treat population. Secondary efficacy end points were time to crusting of all herpes labialis lesions, time to resolution of pain accompanying herpes labialis, proportion of patients with aborted lesions, and time to resolution of subjective symptoms accompanying herpes labialis. The modified intention-to-treat population, which excluded patients with aborted lesions, comprised 298 patients who self-initiated amenamevir and 307 who took placebo. Amenamevir demonstrated superiority over placebo for the primary end point; the median time to all lesion healing was 5.1 days for amenamevir versus 5.5 days for placebo (hazard ratio, 1.24; 95% confidence interval, 1.06-1.46; p = 0.0085). Time to crusting of all lesions was significantly shorter with amenamevir versus placebo (p = 0.0065); there were no significant between-group differences in other secondary outcomes. Treatment-emergent adverse events in both groups were generally mild in severity; there were two moderate events that were judged unrelated to study treatment, and no severe or serious events. In summary, a single patient-initiated dose of amenamevir 1200 mg taken within 6 hours of prodromal symptom onset significantly shortened the time to all lesion healing of recurrent herpes labialis compared with placebo, with no clinically important safety concerns.

COMPARATIVE EFFICACY OF ANTIVIRAL AGENTS FOR PREVENTION AND MANAGEMENT OF HERPES LABIALIS: A SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS

OBJECTIVE

To compare the relative efficacy and safety of antiviral agents used in the prevention and management of herpes labialis through a network meta-analysis of clinical trials.

METHODS

A systematic search was performed in Ovid Medline PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus and Clinicaltrials.gov for randomized controlled trials (RCTs) reporting a comparison of antiviral agents in the management and prevention of herpes labialis in healthy/immunocompetent adults. The data extracted from the selected RCTs were assessed and a network meta-analysis (NMA) was performed. The interventions were ranked according to the surface under the cumulative ranking (SUCRA).

RESULTS

A total of 52 articles were included for qualitative synthesis and for the quantitative part, 26 articles were analyzed for the primary treatment outcome and 7 studies were analyzed for the primary prevention outcome. The combination therapy of oral valacyclovir and topical clobetasol was the best ranked with a mean reduction in healing time of -3.50 (95% CI -5.22 to -1.78) followed by vidarabine monophosphate of -3.22 (95% CI -4.59 to -1.85). No significant inconsistencies, heterogeneity, and publication bias were reported for TTH outcome analysis. For primary prevention outcomes, only 7 RCTs fulfilled the inclusion criteria, and none of the interventions was shown to be superior to each other. The absence of adverse events was reported by 16 studies, whereas other studies reported mild side effects only.

CONCLUSION

NMA highlighted that several agents were effective in the management of herpes labialis among which the combination of oral valacyclovir with topical clobetasol therapy was the most effective in reducing the time to heal. However, further studies are required to determine which intervention is the most effective in preventing the recurrence of herpes labialis.

Advances in the oral microbiota and rapid detection of oral infectious diseases

Several studies have shown that the dysregulation of the oral microbiota plays a crucial role in human health conditions, such as dental caries, periodontal disease, oral cancer, other oral infectious diseases, cardiovascular diseases, diabetes, bacteremia, and low birth weight. The use of traditional detection methods in conjunction with rapidly advancing molecular techniques in the diagnosis of harmful oral microorganisms has expanded our understanding of the diversity, location, and function of the microbiota associated with health and disease. This review aimed to highlight the latest knowledge in this field, including microbial colonization; the most modern detection methods; and interactions in disease progression. The next decade may achieve the rapid diagnosis and precise treatment of harmful oral microorganisms.

An Insight into Current Treatment Strategies, Their Limitations, and Ongoing Developments in Vaccine Technologies against Herpes Simplex Infections

Herpes simplex virus (HSV) infection, the most prevalent viral infection that typically lasts for a lifetime, is associated with frequent outbreaks of oral and genital lesions. Oral herpes infection is mainly associated with HSV-1 through oral contact, while genital herpes originates due to HSV-2 and is categorized under sexually transmitted diseases. Immunocompromised patients and children are more prone to HSV infection. Over the years, various attempts have been made to find potential targets for the prevention of HSV infection. Despite the global distress caused by HSV infections, there are no licensed prophylactic and therapeutic vaccines available on the market against HSV. Nevertheless, there are numerous promising candidates in the pre-clinical and clinical stages of study. The present review gives an overview of two herpes viruses, their history, and life cycle, and different treatments adopted presently against HSV infections and their associated limitations. Majorly, the review covers the recent investigations being carried out globally regarding various vaccine strategies against oral and genital herpes virus infections, together with the recent and advanced nanotechnological approaches for vaccine development. Consequently, it gives an insight to researchers as well as people from the health sector about the challenges and upcoming solutions associated with treatment and vaccine development against HSV infections.

A Comprehensive Overview of Epidemiology, Pathogenesis and the Management of Herpes Labialis

Herpes labialis remains exceedingly prevalent and is one of the most common human viral infections throughout the world. Recurrent herpes labialis evolves from the initial viral infection by herpes simplex virus type 1 (HSV-1) which subsequently presents with or without symptoms. Reactivation of this virus is triggered by psychosocial factors such as stress, febrile environment, ultraviolet light susceptibility, or specific dietary inadequacy. This virus infection is also characterized by uninterrupted transitions between chronic-latent and acute-recurrent phases, allowing the virus to opportunistically avoid immunity and warrant the transmission to other vulnerable hosts simultaneously. This review comprehensively evaluates the current evidence on epidemiology, pathogenesis, transmission modes, clinical manifestations, and current management options of herpes labialis infections.

Efficacy of Lazolex® Gel in the Treatment of Herpes Simplex Mucocutaneous Infections and the Prevention of Recurrences: A Pilot Study

Background. Previous in vitro and in vivo studies indicated that walnut extract has a therapeutic effect on herpes simplex infections. This study aimed to evaluate the efficacy and tolerance of Lazolex® Gel (Iveriapharma, Tbilisi, Georgia), an emollient gel to treat mucocutaneous lesions caused by herpes simplex virus. Methods. A single-center, single-arm, open-label, phase II clinical trial was conducted with 30 patients divided into two groups: 15 patients with herpes simplex virus type 1 (HSV-1) infections and 15 with herpes simplex virus type 2 (HSV-2). All received topical treatment with Lazolex® Gel four times a day for 10 days. The efficacy and tolerance of the treatment were evaluated on day 10 and day 20 of the study. Recurrence rates were also evaluated both prior to treatment with Lazolex® and over a 4-year follow-up period subsequent to treatment. Results. The median effective time to resolution of symptoms (itching, burning, and pain) was 1.97 days in the HSV-1 group and 3.11 days in the HSV-2 group. The median effective time for vesicles and erosion to disappear was 3.64 days in the HSV-1 group and 3.88 days for the HSV-2 group. Finally, the median effective time for inflammatory signs to disappear was 5.70 and 4.32 days, respectively. Following treatment with Lazolex® Gel, the frequency of outbreaks decreased from a median of 2.00 and 1.00 times per year in the HSV-1 and HSV-2 cohorts to 0.25 and 0.00 ( $p=0.001$ and $p=0.003$ ), respectively. Conclusions. Topical treatment with Lazolex® Gel applied to lesions four times a day for 10 days was shown to be effective and safe in the treatment of herpes simplex mucocutaneous infections and dramatically reduced the rate of recurrence. Clinical trial was approved by Drug Agency of Ministry of Labour, Health and Social Affairs of Georgia, registration # DA Nº CT-000032, date of approval 01.10.2007.

Development of a high specificity typing method for the detection of herpes simplex virus

Herpes disease is caused by Herpes simplex virus (HSV). It has become one of the global health problems. This paper reports a method for HSV type testing. First specific primers sequence for HSV-1 and HSV-2 were selected, designed, and synthesized. Then, these amplification products were proved by sequencing and analysis. Lastly, we optimized the reaction system and PCR reaction program by orthogonal design and sensitivity testing. Results showed that the lowest concentration in HSV-type testing is about 6.67 × 10⁶ copies/ml. Moreover, the specificity of detection was very high. So, this method has very great potentials for HSV type testing in clinical practice.

Characterization of the Immunologic Phenotype of Dendritic Cells Infected With Herpes Simplex Virus 1

Due to viral envelope glycoprotein D binding to cellular membrane HVEM receptor, HSV-1 can infect certain dendritic cells, which becomes an event in the viral strategy to interfere with the host’s immune system. We previously generated the HSV-1 mutant strain M6, which produced an attenuated phenotype in mice and rhesus monkeys. The attenuated M6 strain was used to investigate how HSV-1 infection of dendritic cells interferes with both innate and adaptive immunity. Our study showed that dendritic cells membrane HVEM receptors could mediate infection of the wild-type strain and attenuated M6 strain and that dendritic cells infected by both viruses in local tissues of animals exhibited changes in transcriptional profiles associated with innate immune and inflammatory responses. The infection of pDCs and cDCs by the two strains promoted cell differentiation to the CD103+ phenotype, but varied transcriptional profiles were observed, implying a strategy that the HSV-1 wild-type strain interferes with antiviral immunity, probably due to viral modification of the immunological phenotype of dendritic cells during processing and presentation of antigen to T cells, leading to a series of deviations in immune responses, ultimately generating the deficient immune phenotype observed in infected individuals in the clinical.

The role of Herpes Simplex Virus type 1 in oral diseases in children

Relevance. Herpes virus infections are the most common and poorly controllable viral infections. There are many difficulties in herpetic lesion verification and treatment in dental practice.

Purpose. The study aimed to present the results of a foreign publication investigation on the role of herpes simplex virus type 1 in the development of oral diseases in children.

Material and methods. Foreign scientific articles about the oral HSV-1 infections published from 2018 to 2022 formed the basis for the study. The study searched the publications on PubMed and Google Scholar bases.

Results. The article presents the newest data on the prevalence, clinical characteristics and diagnosis of oral HSV infection in children. Primary herpetic gingivostomatitis (PHGS), chronic recurrent herpetic gingivostomatitis, chronic recurrent herpes labialis are the main clinical presentations of herpes infection diagnosed in a dental practice. Primary herpetic gingivostomatitis is very common in children aged six months to fve years and occurs in newborns from 2 to 43 days of life. Modern virology success can improve diagnosis and treatment of oral herpetic lesions.

Conclusion. Primary herpetic gingivostomatitis is an acute infectious disease that requires the joint attention of a general practitioner and a dentist to ensure comprehensive treatment.

L-lysine: its antagonism with L-arginine in controlling viral infection. Narrative Literature Review

Knowledge about viral characteristics, mechanisms of entry into the host cell and multiplication/dissemination can help in the control and treatment of viral pathologies. Several nutritional factors linked to the host may favor viral multiplication and their control, may lead to new prophylactic alternatives and/or antiviral therapies. The objective of this review is to discuss the relationship between the amino acid L-lysine and the control of viral infections, aiming at a possible therapeutic property. This research used databases such as PubMed, Web of Science, Scielo, Medline and Google Scholar, as well as searching for references cited by journals. The time frame covered the period between 1964 and January 2022. The observed studies have shown that the usual antiviral therapies are not able to interfere with the viruses in their latent state, however, they can interfere with the adhesion and fusion of viral particles or the production of proteins, which play an important role in viral epidemiology and control, particularly in the initial moment and in the reactivation. Lysine is an amino acid that can interfere mainly in the formation of capsid proteins and DNA by a competitive antagonism with amino acid arginine, which is an essential amino acid for some viruses and also by promoting the increase of arginase, increasing the catabolism of arginine. Although there is evidence of the importance of L-lysine in viral control, more studies are needed, with a view to new antiviral therapies.

First report on herpesvirus in black-fronted titi (Callicebus nigrifrons) kept under human care

Keeping Neotropical primates in captivity puts them at great risk of illness because of their susceptibility to human herpesvirus. This is the first report on herpesvirus in Callicebus nigrifrons that developed clinical disease and was confirmed by immunohistochemical and RT-PCR. Diagnosis and prevention are essential for the conservation of species.

Pruritus, neuraxial morphine and recrudescence of oral herpes simplex and treatment: an educational review in obstetric patients

Neuraxial opioids are well known to cause itching, which may be challenging to treat. Neuraxial morphine has been demonstrated to cause recrudescent herpes simplex viruses (HSV-1), especially in women during labor and childbirth with neuraxial analgesia, and may be an occult etiology of refractory itching. This educational review summaries the clinical and epidemiological characteristics associated with recrudescent HSV-1 in patients treated with neuraxial opioids, especially morphine.

Influence of Human Papillomavirus on Alveolar Bone and Orthodontic Treatment: Systematic Review and Case Report

Background: As the human papillomavirus (HPV) infections are detected in healthy oral mucosa as well as in oral lesions, dental practitioners have an important role in detecting any possible lesions that might be caused by this virus. Therefore, the aim of this study was to investigate the outcomes of orthodontic treatments and HPV infections and to report a rare case of ongoing orthodontic treatment superposed on an HPV infection. Methods: An electronic English literature research of the articles published between the years 2011–2021 was conducted between December 2021–February 2022, accessing PubMed, Web of Science, Embase, Scopus, and Google Scholar. The terms “HPV”, “orthodontics”, “orthodontic treatment”, “tooth movement”, “tooth mobility”, and “malocclusion” were searched. The following inclusion criteria were pursued: articles published in English language; studies reporting HPV infection in subjects with past or ongoing orthodontic treatment; and case reports of subjects with HPV and orthodontic treatment. Exclusion criteria were: articles in languages other than English, studies related to malignancies other than HPV and orthodontic treatment; and studies reporting patients with HPV and no orthodontic treatment. Results: Following the systematic review, which includes six papers, a case of orthodontic treatment superposed on a HPV infection is presented. Conclusion: Incumbent, postponed HPV infection on an ongoing orthodontic treatment might affect treatment outcome and patient compliance.

Scaffold Flexibility Controls Binding of Herpes Simplex Virus Type 1 with Sulfated Dendritic Polyglycerol Hydrogels Fabricated by Thiol-Maleimide Click Reaction

Herpes Simplex Virus -1 (HSV) with a diameter of 155 - 240 nm uses electrostatic interactions to bind with the heparan sulfate present on the cell surface to initiate infection. In this work, we aim to deter the initial contact using polysulfate-functionalized hydrogels. The hydrogels provide a large contact surface area for viral interaction and sulfated hydrogels are good mimics for the native heparan sulfate. In this work, we have synthesized hydrogels of different flexibilities, determined by rheology. We prepared gels within an elastic modulus range of 10 - 1119 Pa with a mesh size of 80 - 15 nm, respectively. The virus binding studies carried out with the plaque assay show that the most flexible sulfated hydrogel performs the best in binding HSV viruses. These studies prove that polysulfated hydrogels are a viable option as HSV-1 antiviral compounds. Furthermore, such hydrogel networks are also physically similar to naturally occurring mucus gels and therefore may be used as mucus substitutes. This article is protected by copyright. All rights reserved.

[Herpes simplex factors: Literature review]

Herpes simplex virus, after the first infection, can remain dormant in the lymph nodes and reactivate at any time due to certain factors and/or stimuli causing effects in the patient. The purpose of this literature review is to update scientific information on the factors that predispose to the reactivation of herpes simplex virus. A comprehensive literature review was conducted in the LILACS, SciELO, PubMed, Scopus and the following keywords were used: herpes simplex, reactivation, latency and risks. A factor is reactivation by immunosuppression due to the intake of immunosuppressants or oncological therapy. Another factor is psychological stress, in which the hormones released act on mediating signs of reactivation. Sun exposure that reactivates the virus in infected neurons and infection in pregnant women can trigger complications in the fetus and delivery.

Medical-Grade Honey Outperforms Conventional Treatments for Healing Cold Sores-A Clinical Study

Cold sores are nasolabial blisters caused by herpes simplex virus (HSV) infections. Novel therapies demonstrating simultaneously antiviral activity and improved wound healing are warranted. The aim of this study was to investigate the efficacy of medical-grade honey (MGH) for treating HSV-induced cold sores. A crossover trial was performed in patients with recurrent cold sores (n = 29). The majority (65.6%) of these patients experience four or more episodes per year, thus forming a valid self-control group. In this study, patients applied an MGH-based formulation (L-Mesitran Soft) on their cold sore at the onset of symptoms (62.1%) or appearing of blister (37.9%) and compared it to their conventional treatments. After complete healing, patients filled in a questionnaire evaluating healing, pain, and itching. The average absolute healing time was 72.4% slower with conventional treatment (10.0 days) compared to MGH (5.8 days). After MGH treatment, 86.2% of all patients experienced faster objective healing (6.9% similar and 6.9% slower) and the subjective healing score was higher in 79.3% of the patients (20.7% similar). If the patients normally experience pain and itching during their cold sores, these levels were lower with MGH therapy compared to conventional treatment in 72.7% and 71.4% of the patients, respectively. Moreover, 100% of the patients prefer MGH treatment over conventional treatment and will use it again on future cold sores. MGH is a promising alternative treatment for cold sores, likely by combining both increased antiviral and wound healing activities while alleviating pain and itching.

Lignosulfonate Rapidly Inactivates Human Immunodeficiency and Herpes Simplex Viruses

Background: Very few studies of the antiviral potential of lignosulfonates have been published. With the aim of oral application, among various groups of natural products, the relative antiviral potency of lignosulfonate and its ability to rapidly inactivate viruses were investigated. Methods: As target cells, MT-4 cells in suspension and attached Vero cells were used for infections with human immunodeficiency virus (HIV) and human herpes simplex type-1 virus (HSV). Mock- or virus-infected cells were incubated for 3–5 days with various concentrations of test samples, and the viable cell number was determined with the MTT method. For the shorter exposure experiments, higher titers of HIV or HSV were exposed to test samples for 10 or 3 min, diluted to a normal multiplicity of infection (MOI), and applied to the cells. Antiviral activity was quantified by using the chemotherapy index. Results: In the long-exposure system, lignosulfonates showed comparable anti-HIV activity with those of AZT, ddC, and sulfated polysaccharides, and it exceeded those of hundreds of tannins and flavonoids. When the exposure time was shortened, the chemotherapeutic index of the lignosulfonates for HIV was increased 27-fold. At a physiological pH, lignosulfonate showed higher anti-HIV activity than commercial alkali-lignin, dealkali-lignin, and humic acid, possibly due to the higher solubility and purity. Conclusions: With their rapid virus-inactivation capabilities, lignosulfonates may be useful for the prevention or treatment of virally induced oral diseases.

Current vaccine approaches and emerging strategies against herpes simplex virus (HSV)

Introduction: Vaccine development for the disease caused by the herpes simplex virus (HSV) has been challenging over the years and is always in dire need of novel approaches for prevention and cure. To date, the HSV disease remains incurable and challenging to prevent. The disease is extremely widespread due to its high infection rate, resulting in millions of infection cases worldwide.Areas covered: This review first explains the diverse forms of HSV-related disease presentations and reports past vaccine history for the disease. Next, this review examines current and novel HSV vaccine approaches being studied and tested for efficacy and safety as well as vaccines in clinical trial phases I to III. Modern approaches to vaccine design using bioinformatics are described. Finally, we discuss measures to enhance new vaccine development pipelines for HSV.Expert opinion: Modernized approaches using in silico analysis and bioinformatics are emerging methods that exhibit potential for producing vaccines with enhanced targets and formulations. Although not yet fully established for HSV disease, we describe current studies using these approaches for HSV vaccine design to shed light on these methods. In addition, we provide up-to-date requirements of immunogenicity, adjuvant selection, and routes of administration.

Metal Nanoparticles: a Promising Treatment for Viral and Arboviral Infections

Globally, viral diseases continue to pose a significant threat to public health. Recent outbreaks, such as influenza, coronavirus, Ebola, and dengue, have emphasized the urgent need for new antiviral therapeutics. Considerable efforts have focused on developing metal nanoparticles for the treatment of several pathogenic viruses. As a result of these efforts, metal nanoparticles are demonstrating promising antiviral activity against pathogenic surrogates and clinical isolates. This review summarizes the application of metal nanoparticles for the treatment of viral infections. It provides information on synthesis methods, size-related properties, nano-bio-interaction, and immunological effects of metal nanoparticles. This article also addresses critical criteria and considerations for developing clinically translatable nanosized metal particles to treat viral diseases.

What the dental practitioner needs to know about pharmaco-therapeutic modalities of COVID-19 treatment: A review

BACKGROUND/PURPOSE

Several pharmacotherapeutic methods have been used for the treatment of COVID-19 with varying degrees of success. No definitive treatment or vaccine has been officially approved to-date. This review aimed to highlight COVID-19 pharmacotherapeutic agents that are relevant to dental practice in terms of their clinical indications in COVID-19 and dental practice, as well as their adverse effects as they impact the dental patient.

MATERIAL AND METHODS

Systematic search was performed using the following keywords combinations: Pharmacotherapy AND COVID-19 OR Pharmacotherapy AND SARS-CoV-2 OR Treatment AND COVID-19. Studies were categorized according to the type of pharmacotherapy used. Pharmacotherapeutic agents were extracted and only those relevant to dental practice were included for review.

RESULTS

For analysis, a total of 79 clinical trials research articles were included that included COVID-19 pharmacotherapeutic agents relevant to dental practice. Those were analgesics (paracetamol; non-steroidal anti-inflammatory agents); antibiotics (azithromycin, doxycycline, metronidazole); antivirals (penciclovir); and immunomodulatory agents (hydroxychloroquine, corticosteroids). While some COVID-19 drugs are less relevant to dental practice, as antivirals and hydroxychloroquine, their association with long-term adverse effects requires adequate knowledge among dental practitioners.

CONCLUSION

Many of COVID-19 pharmacotherapeutic agents are used to treat oral diseases particularly orofacial pain and inflammatory conditions. Furthermore, some of these drugs may induce adverse effects that complicate dental treatment. Thorough knowledge of COVID-19 therapy and its dental implications is essential for dental practitioners, and is expected to contribute to a better understanding and effective utilization of these therapeutic agents.

Diagnosis of Herpes Simplex Virus: Laboratory and Point-of-Care Techniques

Herpes is a widespread viral infection caused by the herpes simplex virus (HSV) that has no permanent cure to date. There are two subtypes, HSV-1 and HSV-2, that are known to cause a variety of symptoms, ranging from acute to chronic. HSV is highly contagious and can be transmitted via any type of physical contact. Additionally, viral shedding can also happen from asymptomatic infections. Thus, early and accurate detection of HSV is needed to prevent the transmission of this infection. Herpes can be diagnosed in two ways, by either detecting the presence of the virus in lesions or the antibodies in the blood. Different detection techniques are available based on both laboratory and point of care (POC) devices. Laboratory techniques include different biochemical assays, microscopy, and nucleic acid amplification. In contrast, POC techniques include microfluidics-based tests that enable on-spot testing. Here, we aim to review the different diagnostic techniques, both laboratory-based and POC, their limits of detection, sensitivity, and specificity, as well as their advantages and disadvantages.

Review of Whole Plant Extracts With Activity Against Herpes Simplex Viruses In Vitro and In Vivo

Herpes simplex viruses, HSV-1 and HSV-2, are highly contagious and cause lifelong, latent infections with recurrent outbreaks of oral and/or genital lesions. No cure exists for HSV-1 or HSV-2 infections, but antiviral medications are commonly used to prevent and treat outbreaks. Resistance to antivirals has begun to emerge, placing an importance on finding new and effective therapies for prophylaxis and treatment of HSV outbreaks. Botanicals may be effective HSV therapies as the constituents they contain act through a variety of mechanisms, potentially making the development of antiviral resistance more challenging. A wide variety of plants from different regions in the world have been studied for antiviral activity against HSV-1 and/or HSV-2 and showed efficacy of varying degrees. The purpose of this review is to summarize research conducted on whole plant extracts against HSV-1 and/or HSV-2 in vitro and in vivo. The majority of the research reviewed was conducted in vitro using animal cell lines, and some studies used an animal model design. Also summarized are a limited number of human trials conducted using botanical therapies on HSV lesions.

Human Papilloma Virus: Current Knowledge and Focus on Oral Health

The human papilloma virus (HPV) is responsible for different pathological manifestations in humans. This agent gives rise to lesions of different types and in different areas of the organism, including the oral cavity. The aim of this study is to show which are the main diseases for which HPV is responsible and to bring to light some of the interceptive and therapeutic strategies. The analysis was conducted by consulting the major scientific databases with the aim of obtaining information on the characteristics of oral HPV and its management; furthermore, the literature was supported by some clinical cases proposed by the authors. The role of dentistry is essential in the early diagnosis of this type of pathologies and above all in knowing how to direct patients towards a path that can lead to patient management, especially in the event that these lesions have a malignant potential. Enhancing the knowledge and role of dentistry can lead to early diagnosis of this type of injury, intercepting a pathology that could have multiorgan implications.

Pseudo-Dipeptide Bearing α,α-Difluoromethyl Ketone Moiety as Electrophilic Warhead with Activity against Coronaviruses

The synthesis of α-fluorinated methyl ketones has always been challenging. New methods based on the homologation chemistry via nucleophilic halocarbenoid transfer, carried out recently in our labs, allowed us to design and synthesize a target-directed dipeptidyl α,α-difluoromethyl ketone (DFMK) 8 as a potential antiviral agent with activity against human coronaviruses. The ability of the newly synthesized compound to inhibit viral replication was evaluated by a viral cytopathic effect (CPE)-based assay performed on MCR5 cells infected with one of the four human coronaviruses associated with respiratory distress, i.e., hCoV-229E, showing antiproliferative activity in the micromolar range (EC₅₀ = 12.9 ± 1.22 µM), with a very low cytotoxicity profile (CC₅₀ = 170 ± 3.79 µM, 307 ± 11.63 µM, and 174 ± 7.6 µM for A549, human embryonic lung fibroblasts (HELFs), and MRC5 cells, respectively). Docking and molecular dynamics simulations studies indicated that 8 efficaciously binds to the intended target hCoV-229E main protease (M^pro). Moreover, due to the high similarity between hCoV-229E M^pro and SARS-CoV-2 M^pro, we also performed the in silico analysis towards the second target, which showed results comparable to those obtained for hCoV-229E M^pro and promising in terms of energy of binding and docking pose.

Mori ramulus and its Major Component Morusin Inhibit Herpes Simplex Virus Type 1 Replication and the Virus-Induced Reactive Oxygen Species

Herpes simplex virus type 1 (HSV-1) is ubiquitous in many populations despite the use of acyclovir or related nucleoside analogs for treating infection. Drug resistance impairs the treatment of HSV-infected individuals who have immune deficits, underscoring the need for new safe and effective antiviral agents. Mori ramulus (the young twig of Morus alba L.) has long been used to treat diseases in Korea, Japan, and China. Recent studies have reported multiple pharmacological activities of Mori ramulus and its constituent morusin, but their effects on HSV-1 remain unknown. Here, we found that treatment with Mori ramulus ethanol extract (MRE) significantly reduced the replication of fluorescently labeled HSV-1 in Vero cells and inhibited the expression of HSV-1 envelope glycoprotein D (gD) and tegument protein VP16. MRE, furthermore, blocked HSV-1-induced production of reactive oxygen species (ROS), and this mediated the inhibition of viral replication. We identified morusin as the active antiviral component of MRE and found that morusin post-treatment was sufficient to inhibit viral gD and VP16 in addition to HSV-1-induced ROS production. Therefore, the inhibition of HSV-1-induced ROS may explain the antiviral activity of MRE against HSV-1. MRE or its component morusin may be potentially developed for anti-HSV-1 agents.

Epidemiology and pathological progression of erythematous lip lesions in captive sun bears (Helarctos malayanus)

This study investigates the occurrence of erythematous lip lesions in a captive sun bear population in Cambodia, including the progression of cheilitis to squamous cell carcinoma, and the presence of Ursid gammaherpesvirus 1. Visual assessment conducted in 2015 and 2016 recorded the prevalence and severity of lesions. Opportunistic sampling for disease testing was conducted on a subset of 39 sun bears, with histopathological examination of lip and tongue biopsies and PCR testing of oral swabs and tissue biopsies collected during health examinations. Lip lesions were similarly prevalent in 2015 (66.0%) and 2016 (68.3%). Degradation of lip lesion severity was seen between 2015 and 2016, and the odds of having lip lesions, having more severe lip lesions, and having lip lesion degradation over time, all increased with age. Cheilitis was found in all lip lesion biopsies, with histological confirmation of squamous cell carcinoma in 64.5% of cases. Single biopsies frequently showed progression from dysplasia to neoplasia. Eighteen of 31 sun bears (58.1%) had at least one sample positive for Ursid gammaherpesvirus 1. The virus was detected in sun bears with and without lip lesions, however due to case selection being strongly biased towards those showing lip lesions it was not possible to test for association between Ursid gammaherpesvirus 1 and lip squamous cell carcinoma. Given gammaherpesviruses can play a role in cancer development under certain conditions in other species, we believe further investigation into Ursid gammaherpesvirus 1 as one of a number of possible co-factors in the progression of lip lesions to squamous cell carcinoma is warranted. This study highlights the progressively neoplastic nature of this lip lesion syndrome in sun bears which has consequences for captive and re-release management. Similarly, the detection of Ursid gammaherpesvirus 1 should be considered in pre-release risk analyses, at least until data is available on the prevalence of the virus in wild sun bears.