Clinical efficacy of topical docosanol 10% cream for herpes simplex labialis: A multicenter, randomized, placebo-controlled trial

Diagnostic Methods and Management Strategies of Herpes Simplex and Herpes Zoster Infections

Herpesviruses are medium-sized double-stranded DNA viruses. Of more than 80 herpesviruses identified, only 9 human herpesviruses have been found to cause infection in humans. These include herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), human cyto-megalovirus (HCMV), Epstein-Barr virus (EBV), and human herpesvirus (HHV-6A, HHV-6B, HHV-7, HHV-8). HSV-1, HSV-2, and VZV can be problematic given their characteristic neurotropism which is the ability to invade via fusion of its plasma membrane and reside within neural tissue. HSV and VZV primarily infect mucocutaneous surfaces and remain latent in the dorsal root ganglia for a host's entire life. Reactivation causes either asymptomatic shedding of virus or clinical manifestation of vesicular lesions. The clinical presentation is influenced by the portal of entry, the immune status of the host, and whether the infection is primary or recurrent. Affecting 60% to 95% of adults, herpesvirus-associated infections include gingivostomatitis, orofacial and genital herpes,and primary varicella and herpes zoster. Symptomatology, treatment, and potential complications vary based on primary and recurrent infections as well as the patient's immune status.

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.

Interventions for treatment of herpes labialis (cold sores on the lips)

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effects of interventions for treating herpes labialis among immunocompetent people.

Low-dose Oral Thimerosal for the Treatment of Oral Herpes: Clinical Trial Results and Improved Outcome After Post-hoc Analysis

BACKGROUND

Thimerosal (TML) is an organomercury antimicrobial. Low doses (1/250^th of the amount in a typical vaccine dose) may promote an antiviral immune response. Low-dose TML (BTL-TML) was evaluated for safety and efficacy against herpes labialis in two FDA-approved, randomized, double blind, placebo-controlled clinical trials.

METHODS

BTL-TML was evaluated in a Phase IIa trial for its ability to block progression to lesion in subjects with recurrent oral herpes caused by dental trauma. Subjects were administered BTL-TML or a saline control over a 7-day period. In a Phase IIb trial, BTL-TML was evaluated for its ability to block progression to lesion over a 7-day period in subjects with herpes lip infections induced by exposure to ultraviolet (UV) radiation.

RESULTS

Progression to lesion post-dental procedure was prevented in 54.5% (12/22) TML subjects versus 22.2% (2/9) control subjects (p = 0.106). Progression to lesion post-UV irradiation was blocked in 47.8% (11/23) BTL-TML treatment subjects and 42.8% (6/14) control subjects. A post-hoc analysis yielded 52.2% (12/23) BTL-TML subjects with no progression to lesion versus 28.6% (6/21) control subjects with no progression (p = 0.099). There were no significant differences in adverse effects between treatment and control groups in either trial.

CONCLUSIONS

Neither clinical trial showed a statistically significant effect of BTL-TML on progression to lesion. However, the post-hoc analysis suggested there is a 48-hour period following UV radiation exposure during which the anti-herpes activity of antivirals such as BTL-TML is reduced. Accordingly, BTL-TML may have promise in subsequent, properly designed and powered clinical trials.

Analysis of docosanol using GC/MS: Method development, validation, and application to ex vivo human skin permeation studies

Docosanol is the only US Food and Drug Administration (FDA) approved over-the-counter topical product for treating recurrent oral-facial herpes simplex labialis. Validated analytical methods for docosanol are required to demonstrate the bioequivalence of docosanol topical products. A gas chromatography/selected ion monitoring mode mass spectrometry (GC/SIM-MS) method was developed and validated for docosanol determination in biological samples. Docosanol and isopropyl palmitate (internal standard) were separated on a high-polarity GC capillary column with (88% cyanopropy)aryl-polysiloxane employed as the stationary phase. The ions of m/z 83 and 256 were selected to monitor docosanol and isopropyl palmitate, respectively; the total run time was 20 min. The GC/SIM-MS method was validated in accordance with US FDA guidelines, and the results met the US FDA acceptance criteria. The docosanol calibration standards were linear in the 100–10000 ng/mL concentration range (R²>0.994). The recoveries for docosanol from the receptor fluid and skin homogenates were >93.2% and >95.8%, respectively. The validated method was successfully applied to analyze ex vivo human cadaver skin permeation samples. On applying Abreva® cream tube and Abreva® cream pump, the amount of docosanol that penetrated human cadaver skin at 48 h was 21.5 ± 7.01 and 24.0 ± 6.95 ng/mg, respectively. Accordingly, we concluded that the validated GC/SIM-MS was sensitive, specific, and suitable for quantifying docosanol as a quality control tool. This method can be used for routine analysis as a cost-effective alternative to other techniques.

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Docosanol is used to treat recurrent oral-facial herpes simplex labialis.

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Analytical methods are required to demonstrate docosanol product bioequivalence.

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A GC/SIM-MS docosanol method was developed and validated as per USFDA.

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The GC/SIM-MS docosanol analytical method was sensitive, specific, and reproducible.

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The method was employed to quantify docosanol human skin permeation samples.

Trends and strategies to combat viral infections: A review on FDA approved antiviral drugs

The infectious microscopic viruses invade living cells to reproduce themselves, and causes chronic infections such as HIV/AIDS, hepatitis B and C, flu, etc. in humans which may lead to death if not treated. Different strategies have been utilized to develop new and superior antiviral drugs to counter the viral infections. The FDA approval of HIV nucleoside reverse transcriptase inhibitor, zidovudine in 1987 boosted the development of antiviral agents against different viruses. Currently, there are a number of combination drugs developed against various viral infections to arrest the activity of same or different viral macromolecules at multiple stages of its life cycle; among which majority are targeted to interfere with the replication of viral genome. Besides these, other type of antiviral molecules includes entry inhibitors, integrase inhibitors, protease inhibitors, interferons, immunomodulators, etc. The antiviral drugs can be toxic to human cells, particularly in case of administration of combination drugs, and on the other hand viruses can grow resistant to the antiviral drugs. Furthermore, emergence of new viruses like Ebola, coronaviruses (SARS-CoV, SARS-CoV-2) emphasizes the need for more innovative strategies to develop better antiviral drugs to fight the existing and the emerging viral infections. Hence, we reviewed the strategic enhancements in developing antiviral drugs for the treatment of different viral infections over the years.

Clinical Study on the Effectiveness of Three Products in the Treatment of Herpes Simplex Labialis

Herpes simplex labialis (HSL) is a viral disease that affects the perioral region. No guidelines recommending an effective treatment exist. The treatment of HSL with three different products was examined. Herpatch Serum, a film-forming patch, was compared to Compeed Patches, a set of semiocclusive hydrocolloid patches, and Zovirax Cream (ingredient: 5% acyclovir). In this prospective, randomized, examiner-blind study, 180 patients with recurrent HSL were split into three groups (Compeed: n = 60, Herpatch: n = 60, Zovirax: n = 60) and examined within 24 hours of HSL outbreak (DRKS Registration No.: DRKS00007786). The primary endpoint was healing time. The secondary endpoints were the reaction rate and quality of therapy evaluated by the Clinician’s Global Assessment of Therapy (CGAT) and the Subject’s Global Assessment of Therapy (SGAT) (0 = no response; 10 = excellent response), respectively. There was no significant difference among the healing times for the different products. The mean (95% confidence interval) was 9.67 days (9.11–10.22) for Compeed, 9.30 days (8.75–9.85) for Herpatch, and 9.80 days (9.30–10.30) for Zovirax. The reaction rate and quality of therapy (CGAT and SGAT) of Herpatch were significantly higher than those of Compeed and Zovirax. Within the study limitations, Herpatch proved to be an effective, non-antiviral alternative in the treatment of HSL.

Anti-herpetic Activity of Macrocystis pyrifera and Durvillaea antarctica Algae Extracts Against HSV-1 and HSV-2

Herpes simplex viruses (HSVs) type 1 (HSV-1) and type 2 (HSV-2) are highly prevalent in the human population, and the infections they produce are lifelong with frequent reactivations throughout life. Both viruses produce uncomfortable and sometimes painful lesions in the orofacial and genital areas, as well as herpetic gingivostomatitis, among other clinical manifestations. At present, the most common treatments against HSVs consist of nucleoside analogs that target the viral polymerases. However, such drugs are poorly effective for treating skin lesions, as they only reduce in 1-2 days the duration of the herpetic lesions. Additionally, viral isolates resistant to these drugs can emerge in immunosuppressed individuals, and second-line drugs for such variants are frequently accompanied by adverse effects requiring medical supervision. Thus, novel or improved therapeutic drugs for treating HSV lesions are needed. Here, we assessed the potential antiviral activity of aqueous extracts obtained from two brown macroalgae, namely Macrocystis pyrifera and Durvillaea antarctica against HSVs. Both extracts showed antiviral activity against acyclovir-sensitive and acyclovir-resistant HSV-1 and HSV-2. Our analyses show that there is a significant antiviral activity associated with proteins in the extract, although other compounds also seem to contribute to inhibiting the replication cycle of these viruses. Evaluation of the algae extracts as topical formulations in an animal model of HSV-1 skin infection significantly reduced the severity of the disease more than acyclovir, as well as the duration of the herpetic lesions, when compared to mock-treated animals, with the D. antarctica extract performing best. Taken together, these findings suggest that these algae extracts may be potential phytotherapeutics against HSVs and may be useful for the treatment and reduction of common herpetic manifestations in humans.

Current Antivirals and Novel Botanical Molecules Interfering With Herpes Simplex Virus Infection

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are highly prevalent within the human population and are characterized by lifelong infections and sporadic recurrences due to latent neuron infection. Upon reactivations, HSVs may manifest either, symptomatically or asymptomatically and be shed onto others through mucosae body fluids. Although, HSVs can produce severe disease in humans, such as life-threatening encephalitis and blindness, the most common symptoms are skin and mucosal lesions in the oro-facial and the genital areas. Nucleoside analogs with antiviral activity can prevent severe HSV infection, yet they are not very effective for treating skin manifestations produced by these viruses, as they only reduce in a few days at most the duration of lesions. Additionally, HSV variants that are resistant to these antivirals may arise, especially in immunosuppressed individuals. Thus, new antivirals that can reduce the severity and duration of these cutaneous manifestations would certainly be welcome. Here, we review currently available anti-herpetic therapies, novel molecules being assessed in clinical trials and new botanical compounds reported in the last 20 years with antiviral activities against HSVs that might represent future treatments against these viruses.

Recurrent herpes labialis in the pediatric population: Prevalence, therapeutic studies, and associated complications

Recurrent herpes labialis (RHL) is an incredibly common condition, though the medical literature evaluating pediatric aspects is limited. This paper assesses prevalence and therapeutic studies of pediatric RHL as well as disease complications. A comprehensive literature search of English-language citations based on PubMed queries of selected terms was performed, with exclusion if methodology was not discussed, or if studies had 10 or fewer patients. RHL prevalence in pediatrics has been assessed by measures of point and periodic prevalence, though methodologic limitations may under- or over-estimate the true prevalence of RHL. Studies have been conducted to evaluate therapeutic safety, tolerability, and efficacy of antivirals in the pediatric population. Pediatric RHL point prevalence ranges from 0.72% to 5.2% depending on the population study and the methodologies used. Pediatric RHL carries a significant public health burden and is often implicated in patients with eczema herpeticum, erythema multiforme, reactive infectious mucositis eruptions, and hypersensitivity reactions. There are few studies that evaluate the rates of occurrence of these sequelae associated with pediatric RHL.

Intracellular imaging of docosanol in living cells by coherent anti-Stokes Raman scattering microscopy

Docosanol is an over-the-counter topical agent that has proved to be one of the most effective therapies for treating herpes simplex labialis. However, the mechanism by which docosanol suppresses lesion formation remains poorly understood. To elucidate its mechanism of action, we investigated the uptake of docosanol in living cells using coherent anti-Stokes Raman scattering microscopy. Based on direct visualization of the deuterated docosanol, we observed highly concentrated docosanol inside living cells 24 h after drug treatment. In addition, different spatial patterns of drug accumulation were observed in different cell lines. In keratinocytes, which are the targeted cells of docosanol, the drug molecules appeared to be docking at the periphery of the cell membrane. In contrast, the drug molecules in fibroblasts appeared to accumulate in densely packed punctate regions throughout the cytoplasm. These results suggest that this molecular imaging approach is suitable for the longitudinal tracking of drug molecules in living cells to identify cell-specific trafficking and may also have implications for elucidating the mechanism by which docosanol suppresses lesion formation.

Approved Antiviral Drugs over the Past 50 Years

Since the first antiviral drug, idoxuridine, was approved in 1963, 90 antiviral drugs categorized into 13 functional groups have been formally approved for the treatment of the following 9 human infectious diseases: (i) HIV infections (protease inhibitors, integrase inhibitors, entry inhibitors, nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and acyclic nucleoside phosphonate analogues), (ii) hepatitis B virus (HBV) infections (lamivudine, interferons, nucleoside analogues, and acyclic nucleoside phosphonate analogues), (iii) hepatitis C virus (HCV) infections (ribavirin, interferons, NS3/4A protease inhibitors, NS5A inhibitors, and NS5B polymerase inhibitors), (iv) herpesvirus infections (5-substituted 2'-deoxyuridine analogues, entry inhibitors, nucleoside analogues, pyrophosphate analogues, and acyclic guanosine analogues), (v) influenza virus infections (ribavirin, matrix 2 protein inhibitors, RNA polymerase inhibitors, and neuraminidase inhibitors), (vi) human cytomegalovirus infections (acyclic guanosine analogues, acyclic nucleoside phosphonate analogues, pyrophosphate analogues, and oligonucleotides), (vii) varicella-zoster virus infections (acyclic guanosine analogues, nucleoside analogues, 5-substituted 2'-deoxyuridine analogues, and antibodies), (viii) respiratory syncytial virus infections (ribavirin and antibodies), and (ix) external anogenital warts caused by human papillomavirus infections (imiquimod, sinecatechins, and podofilox). Here, we present for the first time a comprehensive overview of antiviral drugs approved over the past 50 years, shedding light on the development of effective antiviral treatments against current and emerging infectious diseases worldwide.

Forest biorefinery: Potential of poplar phytochemicals as value-added co-products

The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species.

Update on oral herpes virus infections

Oral herpes virus infections (OHVIs) are among the most common mucosal disorders encountered by oral health care providers. These infections can affect individuals at any age, from infants to the elderly, and may cause significant pain and dysfunction. Immunosuppressed patients may be at increased risk for serious and potential life-threatening complications caused by OHVIs. Clinicians may have difficulty in diagnosing these infections because they can mimic other conditions of the oral mucosa. This article provides oral health care providers with clinically relevant information regarding etiopathogenesis, diagnosis, and management of OHVIs.

Review of antiviral therapy for herpes labialis, genital herpes and herpes zoster

Acyclovir (Zovirax) was approved for the treatment of herpesvirus infections almost two decades ago. It was the first agent in a novel group of antiviral medications that now include valacyclovir (Valtrex), penciclovir (Denavir and famciclovir (Famvir). These agents have made a dramatic impact on the morbidity associated with herpes simplex virus infections and herpes zoster. Topical and oral antiviral use have shown modest but statistically significant efficacy in treating herpes labialis with most studies demonstrating a significant reduction in episode length and/or healing time. Oral acyclovir, valacyclovir and famciclovir are efficacious and safe for the treatment of the first episode and recurrent genital herpes and are useful as suppressive therapy for individuals with frequent genital herpes recurrences. In addition, high doses of oral acyclovir, valacyclovir and famciclovir have been shown to speed the healing of herpes zoster, and data suggests that these agents also decrease associated acute and chronic pain in people of 50 years of age or older. Further research is required to clarify the safety of these agents in pregnant women with genital herpes, the role of antiviral therapy in decreasing the sexual transmission of genital herpes, and the efficacy and cost-effectiveness of these agents in treating herpes zoster in people below the age of 50 years.

Diagnostic methods and management strategies of herpes simplex and herpes zoster infections

Herpes infections are extremely prevalent in the adult population. Recognizing early signs and symptoms is essential to provide effective treatment. The immunocompromised population presents treatment challenges requiring prolonged antiviral therapy and more frequent recurrences. Viral culture is often considered the gold standard diagnostic technique; however, polymerase chain reaction (PCR) should be done in tandem with culture especially for varicella zoster virus infections. Antivirals can decrease viral shedding, recurrences of herpes simplex, and hasten healing of herpes zoster. Herpes virus can be a challenging entity to treat with significant morbidity (both physically and psychologically).

Single-day treatment for orolabial and genital herpes: a brief review of pathogenesis and pharmacology

Herpes simplex virus (HSV) infection is a highly prevalent condition responsible for significant morbidity and occasional mortality each year. Approximately half of all patients infected by HSV will experience at least one recurrence in their lifetime. For these recurrences, traditional therapy has included both suppressive and episodic treatment with nucleoside analogs. In regards to episodic treatment, 2- to 5-day oral regimens are best studied and most commonly reported. As with any medical condition having a well-understood mechanism of action and targeted treatment, therapeutic intervention is only as effective as allowed by patient compliance. Based on these concerns, recent studies have focused on shorter, less complicated, and more affordable options. This review delineates the evidence for single-day treatments of orolabial and genital herpes. Randomized, double-blind studies of both valacyclovir and famciclovir as single-day episodic therapy for HSV have been reported in the literature. Although no head-to-head studies between the drugs have been performed, both regimens produced significant improvement in healing time and symptom resolution over placebo. Single-day therapy for HSV infection is appealing for multiple reasons. First, it simplifies the regimen, increasing likelihood of patient compliance. Additionally, it allows complete delivery of the medication at the onset of symptoms, when viral replication is highest and intervention has greatest effect. Lastly, the reduced number of pills necessary for single versus multiple day therapy decreases the overall cost of treatment per episode, an important factor in modern-day healthcare.

Topical n-docosanol for management of recurrent herpes labialis

IMPORTANCE OF THE FIELD

Recurrent herpes labialis (RHL) is a significant disorder with social and health consequences that affects upwards of 20 - 40% of the adult population. Docosanol is the only FDA-approved topical agent that is available over the counter for management of RHL. Its mechanism of action is unique compared with other available antiviral agents.

AREAS COVERED IN THIS REVIEW

The authors conducted a comprehensive search of the published preclinical and clinical literature on topical docosanol for RHL. All of the published literature relating to docosanol and its use for the management of recurrent herpes labialis was reviewed, from the first report of docosanol to 31 January 2010.

WHAT THE READER WILL GAIN

The objective of this review was to summarize and critically evaluate the available literature with respect to topical docosanol's mechanism, safety and efficacy in the management of RHL.

TAKE HOME MESSAGE

Ten percent docosanol cream is a safe and effective topical treatment for the management of RHL in immunocompetent adults, with essentially equivalent efficacy compared with other available prescription topical antiviral agents. Owing to its unique mechanism of action, there is little to no risk of developing resistance.

The diagnosis and management of oral herpes simplex infection

Acute herpetic gingivostomatitis and recurrent herpes labialis are the most common manifestations of infection with herpes simplex virus type 1 (HSV-1). In primary and recrudescent HSV-associated disease, the symptoms may range from subclinical to debilitating and life-threatening, depending on the host's immune responses or competence level. In this paper, the typical and atypical manifestations, and the current diagnostic and treatment options for localized, non-complicated oro-labial HSV infection are reviewed, with attention to cumulative evidence for the efficacy and safety of systemic antiviral agents. Some recent data on HSV-1 seroprevalence, viremia, and viral shedding are discussed in relation to disease transmission and global importance of herpesvirus disease.

Comparing anti-HIV, antibacterial, antifungal, micellar, and cytotoxic properties of tricarboxylato dendritic amphiphiles

Three series of homologous dendritic amphiphiles--RCONHC(CH(2)CH(2)COOH)(3), 1(n); ROCONHC(CH(2)CH(2)COOH)(3), 2(n); RNHCONHC(CH(2)CH(2)COOH)(3), 3(n), where R = n-C(n)H(2n+1) and n = 13-22 carbon atoms--were assayed for their potential to serve as antimicrobial components in a topical vaginal formulation. Comparing epithelial cytotoxicities to the ability of these homologues to inhibit HIV, Neisseria gonorrhoeae, and Candida albicans provided a measure of their prophylactic/therapeutic potential. Measurements of the ability to inhibit Lactobacillus plantarum, a beneficial bacterium in the vagina, and critical micelle concentrations (CMCs), an indicator of the potential detergency of these amphiphiles, provided additional assessments of safety. Several amphiphiles from each homologous series had modest anti-HIV activity (EC(50) = 110-130 microM). Amphiphile 2(18) had the best anti-Neisseria activity (MIC =65 microM), while 1(19) and 1(21) had MICs against C. albicans of 16 and 7.7 microM, respectively. Two measures of safety showed promise as all compounds had relatively low cytotoxic activity (EC(50) = 210-940 microM) against epithelial cells and low activity against L. plantarum, 1(n), 2(n), and 3(n) had MICs490, 1300, and 940 microM, respectively. CMCs measured in aqueous triethanolamine and in aqueous potassium hydroxide showed linear dependences on chain length. As expected, the longest chain in each series had the lowest CMC-in triethanolamine: 1(21), 1500 microM; 2(22), 320 microM; 3(22), 340 microM, and in potassium hydroxide: 1(21), 130 microM; 3(22), 40 microM. The CMC in triethanolamine adjusted to pH 7.4 was 400 microM for 1(21) and 3900 microM for 3(16). The promising antifungal activity, low activity against L. plantarum, relatively high CMCs, and modest epithelial cytotoxicity in addition to their anti-Neisseria properties warrant further design studies with dendritic amphiphiles to improve their safety indices to produce suitable candidates for antimicrobial vaginal products.

Human herpes simplex labialis

Humans are the natural host for eight of more than 80 known herpes viruses. Infections with herpes simplex virus type 1 (HSV-1) are ubiquitous worldwide and highly transmissible. Herpes simplex labialis (HSL) is the best-recognized recrudescent infection of the lips and perioral tissues caused by HSV-1. Facial lesions of HSL may be unsightly, frequent outbreaks unpleasant, and the infection itself more severe locally and systemically in immunocompromised people. This article highlights the pathogenesis, clinical presentation, diagnostic features and management issues for HSL.

Hippomanin A from acetone extract of Phyllanthus urinaria inhibited HSV-2 but not HSV-1 infection in vitro

Phyllanthus urinaria Linnea (Euphorbiaceae) is a commonly used traditional medicinal plant in oriental countries and has been reported to possess various biological activities. Previously, the acetone extract and some pure compounds from P. urinaria were found to suppress herpes simplex virus (HSV). In this study, another two pure compounds were isolated from acetone extract of P. urinaria and were tested for their in vitro anti-HSV-1 and HSV-2 activities. The results showed that hippomanin A impeded HSV-2 but not HSV-1 infection. Corilagin, however, inhibited neither HSV-1 nor HSV-2 replication. The similarity between corilagin and hippomanin A in structure, but difference in antiviral activity, therefore, merit further investigation.

Ethnomedicines and ethnomedicinal phytophores against herpesviruses

Herpesviruses are important human pathogens that can cause mild to severe lifelong infections with high morbidity in susceptible adults. Moreover, Herpes simplex virus (HSV) type 2, for example, has been reported to be responsible for increased transmission and disease progression of human immunodeficiency virus (HIV). Therefore, the discovery of novel anti-HSV drugs deserves great efforts. Herbal medicinal products have been used as source of putative candidate drugs in many diseases. However, in case of viral diseases the development of antivirals from natural source is less explored probably because within the virus there are few specific targets where the small molecules can interact to inhibit or kill the virus. The currently available antiherpes drugs are nucleoside analogs that did not cure the lifelong or recurrent infections and the use of these drugs often lead to the development of viral resistance coupled with the problem of side effects, recurrence and viral latency. However a wide array of herbal products, used by diverse medicinal systems throughout the world, showed high level of antiherpesvirus activities and many of them have complementary and overlapping mechanism of action, either by inhibiting viral replication, or viral genome synthesis. This chapter will summarize some of the promising herbal extracts and purified compounds isolated from the herbal sources by several laboratories. Cases with proven in vitro and documented in vivo activities, along with their structure-activity relationship against herpesviruses are discussed.

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

Management of recurrent oral herpes simplex infections

The literature has been reviewed for evidence of the efficacy of antiviral agents in both the prophylaxis and treatment of recurrent oral herpes simplex virus (HSV) infections and discussed by a panel of experts. Emphasis was given to randomized controlled trials. Management of herpes-associated erythema multiforme and Bell palsy were also considered. The evidence suggests that 5% acyclovir (ACV) in the cream base may reduce the duration of lesions if applied early. Recurrent herpes labialis (RHL) and recurrent intraoral HSV infections can be effectively treated with systemic ACV 400 mg 3 times a day or systemic valacyclovir 500 to 1000 mg twice a day for 3 to 5 days (longer in the immunocompromised). RHL in the immunocompetent can be effectively prevented with (1) sunscreen alone (SPF 15 or above), (2) systemic ACV 400 mg 2 to 3 times a day, or (3) systemic valacyclovir 500 to 2000 mg twice a day. Valacyclovir 500 mg twice a day is also effective in suppressing erythema multiforme triggered by HSV. Further studies are needed to compare treatment efficacy between topical penciclovir, docosanol, and ACV cream for RHL.

Single-dose famciclovir for the treatment of herpes labialis

BACKGROUND

Approximately 20% to 40% of the population experience recurrent herpes labialis caused by herpes simplex virus type 1 (HSV-1). Since there is no cure, patients typically use antiviral therapy to treat outbreaks as they occur. A large proportion of patients self-administer topical antiviral therapies at the onset of symptoms, but lack of efficacy, frequent dosing, and inconvenient long-term treatment regimens have made the use of oral antiviral therapies more common. Valacyclovir is currently the only oral antiviral approved for the treatment of herpes labialis in immunocompetent individuals. The pharmacokinetic/pharmacodynamic profile of famciclovir suggests that it could be utilized for episodic treatment for immunocompetent individuals as well.

FINDINGS

A recent study comparing single-dose vs. single-day bid famciclovir and placebo in the treatment of herpes labialis demonstrated single-dose famciclovir to be as efficacious as single-day bid dosing in time to healing of lesions and more efficacious than single-day bid famciclovir in time to resolution of pain and tenderness. Both were statistically superior to placebo. When results of this study were compared with recently published results of other frequently prescribed treatments, single-dose famciclovir appeared to produce similar or better improvements in healing time and duration of pain.

CONCLUSIONS

Single-dose famciclovir appears to be an effective, convenient therapy for recurrent herpes labialis. The convenience of single-dose therapy may lead to better overall management of the condition.

Single-dose, patient-initiated famciclovir: a randomized, double-blind, placebo-controlled trial for episodic treatment of herpes labialis

BACKGROUND

The brief period of viral replication in recurrent herpes labialis lesions suggests shorter therapeutic regimens are a logical episodic treatment strategy.

OBJECTIVE

We sought to assess the efficacy and safety of single-dose and single-day famciclovir treatments.

METHODS

In all, 701 randomly assigned patients self-initiated therapy with famciclovir (1500 mg once [single dose] or 750 mg twice a day for 1 day [single day]) or placebo within 1 hour of onset of the prodromal symptoms of an episode of herpes labialis. Lesion healing was monitored by diaries and frequent clinic visits.

RESULTS

Median healing times of primary (first to appear) vesicular lesions in the famciclovir single-dose, famciclovir single-day, and placebo groups were 4.4, 4.0, and 6.2 days, respectively. There was no significant difference between the famciclovir regimens. Adverse events in the famciclovir groups were similar to placebo.

LIMITATIONS

The active arms of this trial were not directly compared to other antiviral regimens.

CONCLUSION

Single-dose famciclovir reduced time to healing of herpes labialis lesions by approximately 2 days compared with placebo.

Oral and perioral herpes simplex virus type 1 (HSV-1) infection: review of its management

Herpes simplex virus type 1 (HSV-1) gives rise to a variety of clinical disorders and is a major cause of morbidity and mortality worldwide. HSV-1 infections are common in oral and perioral area. The aim of the present report was to critically examine the published literature to evaluate the advantages and limitations of therapy of HSV-1 infection in both immunocompetent and immunocompromised patients. Systemic antiviral therapy has been widely accepted as effective for primary herpetic gingivostomatitis. Aciclovir (ACV) 5% cream seems to be the accepted standard topical therapy for herpes labialis, being both effective and well tolerated, although penciclovir 1% cream has been proposed as a potentially useful treatment. Systemic ACV may be effective in reducing the duration of symptoms of recurrent HSV-1 infection, but the optimal timing and dose of the treatment are uncertain. Aciclovir and famciclovir may be of benefit in the acute treatment of severe HSV-1 disease in immunocompromised patients. There is also evidence that prophylactic oral ACV may reduce the frequency and severity of recurrent attack of herpetic infection in immunocompromised patients, but the optimal timing and duration of treatment is uncertain and can vary in different situations.

Yatein from Chamaecyparis obtusa suppresses herpes simplex virus type 1 replication in HeLa cells by interruption the immediate-early gene expression

Inhibitory effects of methanolic extracts from nine Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were studied. By a bioassay-guided fractionation procedure, yatein (C(22)H(23)O(7); M.W.399) was isolated from Chamaecyparis obtusa; yatein significantly suppressed HSV-1 multiplication in HeLa cells without apparent cytotoxicity. To further localize the point in the HSV-1 replication cycle where arrest occurred, a set of key regulatory events leading to the viral multiplication was examined, including viral immediate-early (alpha) and late (gamma) gene expression and DNA replication. Results indicated that levels of glycoprotein B (gB) and gC mRNA expression in HeLa cells were impeded by yatein. Data from polymerase chain reaction showed that replication of HSV-1 DNA in HeLa cells was arrested by yatein. Furthermore, yatein decreased ICP0 and ICP4 gene expression in HeLa cells. Results of an electrophoretic mobility shift assay demonstrated that yatein interrupted the formation of alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein complex. The mechanisms of antiviral action of yatein seem to be mediated, by inhibiting HSV-1 alpha gene expression, including expression of the ICP0 and ICP4 genes, and by arresting HSV-1 DNA synthesis and structural protein expression in HeLa cells. These results suggest that yatein is an antiviral agent against HSV-1 replication.

New antiviral agents

During the last three decades, a better understanding of viral replication and disease states caused by viral infections have led to the development of newer antiviral agents with enhanced activity and better tolerability. This review focuses on newer systemic and topical antiviral agents that are used in treatment of herpes viruses including herpes simplex type-1 (HSV-1) and type-2 (HSV-2), varicella-zoster virus (VZV) and cytomegalovirus CMV) as well as the human papilloma virus (HPV). Included in this article are the agents famciclovir, penciclovir, valganciclovir, imiquimod, docosanole and brivudin.

Herpes simplex virus type 1 propagation in HeLa cells interrupted by Nelumbo nucifera

Inhibitory effects of ethanolic extracts from 10 Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were investigated. By a bioassay-guided fractionation procedure, NN-B-5 was identified from seeds of N. nucifera. NN-B-5 significantly blocked HSV-1 multiplication in HeLa cells without apparent cytotoxicity. To elucidate the point in HSV-1 replication where arrest occurred, a set of key regulatory events leading to the viral multiplication was examined, including HSV-1 DNA synthesis and viral immediate early gene expressions. Data from polymerase chain reaction and Southern blotting showed that there were impairments of HSV-1 DNA replication in HeLa cells treated with NN-B-5. Results indicated that the production and mRNA transcription of infected cell protein (ICP) 0 and ICP4 were decreased in NN-B-5 treated HeLa cells. Results of an electrophoretic mobility shift assay demonstrated that NN-B-5 interrupted the formation of alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein/DNA complexes. The mechanisms of antiviral action of NN-B-5 seem to be mediated, at least in part, through inhibition of immediate early transcripts, such as ICP0 and ICP4 mRNA and then blocking of all downstream viral products accumulation and progeny HSV-1 production.

Mechanism of action of the suppression of herpes simplex virus type 2 replication by pterocarnin A

The purpose of this study was to investigate the in vitro antiviral properties of pterocarnin A, extracted from the bark of Pterocarya stenoptera (Juylandaceae). Results showed that pterocarnin A exhibited anti-herpes simplex virus (HSV) activity. It had a low selectivity index (SI) value and only possessed some level of cell cytotoxic effect at high antiviral concentrations. Mechanism studies demonstrated that pterocarnin A inhibited herpes simplex virus type 2 (HSV-2) from attaching and penetrating into cells. It also actively suppressed HSV-2 multiplication in Vero cells even when added 12 h after infection. This observation indicated that pterocarnin A affected the late stage(s) of HSV-2 infection cycle. Pterocarnin A also significantly reduced viral infectivity at high concentrations. From these observations, it was concluded that pterocarnin A suppressed both early and late in the replication cycle of HSV-2. The various modes of action of pterocarnin A in interfering with certain steps of viral infection thus merit further investigation.

Herpes simplex virus: an occupational hazard in dentistry

Approximately 70% of the population in the western world become infected with the herpes simplex virus type 1 (HSV-1) by the second decade of life. This review discusses the role of the HSV-1 as a potential occupational hazard for dental workers, focusing on herpes labialis, herpetic whitlow and keratitis. The risks associated with the dental treatment of patients with HSV-1, both from the perspective of the clinician and the patient are presented. Procedures for minimising the impact of HSV-1 within the dental practice, in particular infection control, delivery of treatment and patient education, are addressed. The management options for recurrent herpes labialis are also reviewed.

Treatment of herpes simplex virus infections

Herpes simplex virus (HSV) types 1 and 2 are ubiquitous organisms that cause infections in human populations throughout the world. The clinical manifestations of HSV infections are varied, ranging from asymptomatic disease to life-threatening illness in neonates and immunocompromised hosts. This article will review the common presentations for HSV disease and the current recommendations for the treatment of these infections. A detailed summary of the antiviral drugs used to treat HSV infections is also presented.

High-dose, short-duration, early valacyclovir therapy for episodic treatment of cold sores: results of two randomized, placebo-controlled, multicenter studies

Oral valacyclovir is better absorbed than oral acyclovir, increasing acyclovir bioavailability three- to fivefold. This provides the opportunity to explore whether high systemic acyclovir concentrations are effective in the treatment of cold sores (herpes labialis). Two randomized, double-blind, placebo-controlled studies were conducted. Subjects were provided with 2 g of valacyclovir twice daily for 1 day (1-day treatment), 2 g of valacyclovir twice daily for 1 day and then 1 g of valacyclovir twice daily for 1 day (2-day treatment), or a matching placebo and instructed to initiate treatment upon the first symptoms of a cold sore. In study 1, the median duration of the episode (primary endpoint) was reduced by 1.0 day (P = 0.001) with 1-day treatment and 0.5 days (P = 0.009) with 2-day treatment compared to placebo. Similarly, the mean duration of the episode was statistically significantly reduced by 1.1 days with 1-day treatment and 0.7 days with 2-day treatment compared to placebo. The proportion of subjects in whom cold sore lesion development was prevented and/or blocked was increased by 6.4% (P = 0.096) with 1-day treatment and 8.5% (P = 0.061) with 2-day treatment compared to placebo. The time to lesion healing and time to cessation of pain and/or discomfort were statistically significantly reduced with valacyclovir compared to placebo. In study 2, results similar to those in study 1 were obtained. AEs were similar across treatment groups. These studies provide evidence supporting a simple, 1-day valacyclovir treatment regimen for cold sores that is safe and effective. The 1-day valacyclovir regimen offers patients a unique and convenient dosing alternative compared to available topical therapies.

Therapeutic Options for Herpes Simplex Infections

Herpes simplex viruses are responsible for a number of disease states in infected individuals. Capable of establishing latent infection, herpes simplex can reactivate, causing pain, discomfort, and psychosocial consequences. Because no cure is available, treatment modalities for herpes simplex infection are required, from both personal and public health standpoints. To date, therapy has centered around the use of antiviral drugs to control infection and suppress recurrences. To expand the scope of available treatments, efforts have focused on the development of vaccines against herpes simplex virus and new agents such as immune response modifiers. Recent data suggest that these new agents are promising in their therapeutic potential.

Valaciclovir as a single dose during prodrome of herpes facialis: a pilot randomized double-blind clinical trial

BACKGROUND

Randomized clinical trials of valaciclovir in recurrent herpes labialis are lacking.

OBJECTIVES

To determine whether a single course of valaciclovir, i.e. 500, 1000 or 2000 mg, administered during the prodrome of herpes facialis, could be beneficial.

METHODS

Three hundred and forty-five out-patients with herpes labialis were screened and randomized for a multicentre, double-blind clinical trial. Ninety-six patients had no recurrence after 6 months of follow-up; 249 patients were finally included in the intent-to-treat (ITT) population. The main outcome measure was the rate of aborted episodes at day 3. The three treatment groups were similar at baseline.

RESULTS

There was no statistically significant difference between the groups in rates of aborted lesions at day 3 in the ITT population, in particular between the 500 mg and 2000 mg treatment groups.

CONCLUSIONS

Although a placebo group was not included in this pilot study, a single dose of valaciclovir was not considered beneficial in patients with recurrent herpes facialis.

Viral diseases of the oral mucosa

A wide variety of both DNA and RNA viruses affect the oral cavity. When considered in conjunction with cutaneous features, careful examination of the oral mucosa and oropharynx aids the clinician in making a diagnosis. Examination of the oral cavity should be incorporated as a regular component of the dermatologic examination because diagnostic clues are readily available to assist in the evaluation of infectious processes.

Synergistic inhibition of herpesvirus replication by docosanol and antiviral nucleoside analogs

Interactions between docosanol (n-docosanol, behenyl alcohol) and nucleoside or pyrophosphate analogs were investigated in vitro. The anti-HSV activity of acyclovir (ACV) was synergistically enhanced by treatment of cells with docosanol as judged by inhibition of progeny virus production and plaque formation. This drug interaction between ACV and docosanol was observed with laboratory strains of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), oral and genital clinical isolates of HSV, cytomegalovirus (CMV), and varicella zoster virus (VZV). Near optimal concentrations of docosanol plus ACV inhibited HSV replication >99% more than either drug alone, including emergence of ACV-resistant variants. The response was observed with African Green Monkey kidney cells, normal human foreskin cells, and normal human lung cells. Treatment of cells with docosanol also synergistically intensified the inhibition of HSV production by all tested nucleoside analogs, including trifluorothymidine (TFT), adenine arabinoside (Ara-A), and ribavirin. An additive anti-HSV effect was observed with docosanol and phosphonoformate (PFA). No evidence was found for either synergistic inhibition of cellular DNA synthesis or induction of overt cellular toxicity when docosanol was combined with ACV, TFT, Ara-A, ribavirin, PFA, 8-azaguanine, or 5-fluorouracil. The ability of docosanol treatment to increase the antiviral activities of nucleoside analog antiviral drugs, coupled with a lack of toxic interactions, translates to substantial improvements in drug selectivity ratios.

Surveillance for antiviral-agent-resistant herpes simplex virus in the general population with recurrent herpes labialis

In a general population survey in the United States, the prevalence of antiviral-agent-resistant herpes simplex virus was very low among more than 1,000 isolates from individuals with an episode of recurrent herpes labialis not treated with topical antiviral agents. Two isolates had borderline resistance to acyclovir (0.2%), and all were susceptible to penciclovir.

Samarangenin B from Limonium sinense suppresses herpes simplex virus type 1 replication in Vero cells by regulation of viral macromolecular synthesis

Inhibitory effects of ethanolic extracts from 10 Chinese herbs on herpes simplex virus type 1 (HSV-1) replication were investigated. By a bioassay-guided fractionation procedure, samarangenin B (Sam B) was isolated from Limonium sinense; Sam B significantly suppressed HSV-1 multiplication in Vero cells without apparent cytotoxicity. Time-of-addition experiments suggested that the inhibitory action of Sam B on HSV-1 replication was not due to the blocking of virus adsorption. In an attempt to further localize the point in the HSV-1 replication cycle where arrest occurred, a set of key regulatory events leading to viral multiplication was examined, including viral immediate-early (alpha), early (beta), and late (gamma) gene expression and DNA replication. Results indicated that levels of glycoprotein B (gB), gC, gD, gG, and infected-cell protein 5 (ICP5) expression and gB mRNA expression in Vero cells were impeded by Sam B. Data from PCR showed that replication of HSV-1 DNA in Vero cells was arrested by Sam B. Furthermore, Sam B decreased DNA polymerase, ICP0, and ICP4 gene expression in Vero cells. Results of an electrophoretic mobility shift assay demonstrated that Sam B interrupted the formation of an alpha-trans-induction factor/C1/Oct-1/GARAT multiprotein complex. The mechanisms of antiviral action of Sam B seem to be mediated, at least in part, by inhibiting HSV-1 alpha gene expression, including expression of the ICP0 and ICP4 genes, by blocking beta transcripts such as DNA polymerase mRNA, and by arresting HSV-1 DNA synthesis and structural protein expression in Vero cells. These results show that Sam B is an antiviral agent against HSV-1 replication.

New treatments for genital herpes

Genital herpes is a sexually transmitted disease that has been widely investigated from both an epidemiological and a diagnostic viewpoint. Better knowledge of the disease has pointed to the important role of asymptomatic herpes simplex virus type 2 shedding as a major culprit for the spread of the virus in the world, the latest statistics showing that the incidence of genital herpes is constantly increasing. The reference compound for the treatment and prophylaxis of genital herpes is acyclovir. Recently, two drugs with better oral bioavailability, valaciclovir, the oral prodrug of acyclovir, and famciclovir, the oral prodrug of penciclovir, have been made available. Nevertheless, there is a need to develop additional approaches, to extend the therapeutic possibilities and to face the problem of emerging resistant viruses, mostly in immunocompromised patients. Therefore, efforts have been made in different directions including the exploration of new targets for antiviral chemotherapy, the use of immunomodulators and the development of specific vaccines.