Sinecatechins (Polyphenon E) ointment for treatment of external genital warts and possible future indications

[Anogenital warts-An update]

With a prevalence of around 1% in the sexually active population anogenital warts are the most frequent human papillomavirus (HPV)-related disease. In the vast majority of cases the underlying cause of the infection is due to HPV types 6 and 11. The diagnosis can usually be clinically established but in certain cases a histopathological work-up can be useful. Buschke-Lowenstein tumors represent such a scenario. The current therapeutic armamentarium for anogenital warts ranges from surgical ablative procedures up to local immunomodulatory treatment. All procedures have different advantages and disadvantages and are relatively time-consuming and sometimes also unpleasant for the patient. Anogenital warts are also a possible expression of an incomplete immunological control of HPV. Therefore, it should be emphasized that for certain affected individuals, especially immunosuppressed patients, special attention should be given to ensuring that screening investigations for HPV-associated dysplasia is carried out according to the respective valid guidelines. The primary prophylaxis by vaccination of girls and boys prior to first HPV exposure represents a very effective option to drastically reduce the prevalence of anogenital warts and other HPV-related diseases.

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

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

HPV co-infections with other pathogens in cancer development: A comprehensive review

High-risk human papillomaviruses (HR-HPVs) cause various malignancies in the anogenital and oropharyngeal regions. About 70% of cervical and oropharyngeal cancers are caused by HPV types 16 and 18. Notably, some viruses including herpes simplex virus, Epstein-Barr virus, and human immunodeficiency virus along with various bacteria often interact with HPV, potentially impacting its replication, persistence, and cancer progression. Thus, HPV infection can be significantly influenced by co-infecting agents that influence infection dynamics and disease progression. Bacterial co-infections (e.g., Chlamydia trachomatis) along with bacterial vaginosis-related species also interact with HPV in genital tract leading to viral persistence and disease outcomes. Co-infections involving HPV and diverse infectious agents have significant implications for disease transmission and clinical progression. This review explores multiple facets of HPV infection encompassing the co-infection dynamics with other pathogens, interaction with the human microbiome, and its role in disease development.

Inhibition of Cell Proliferation and Cell Viability by Sinecatechins in Cutaneous SCC Cells Is Related to an Imbalance of ROS and Loss of Mitochondrial Membrane Potential

The term sinecatechins designates an extract containing a high percentage of catechins obtained from green tea, which is commercially registered as Veregen or Polyphenon E (PE) and may be considered for treatment of cutaneous squamous cell carcinoma (cSCC) and actinic keratosis (AK). As shown here, treatment of four cSCC cell lines with 200 µg/mL of PE resulted in strong, dose-dependent decrease in cell proliferation (20–30%) as well as strongly decreased cell viability (4–21% of controls, 48 h). Effects correlated with loss of mitochondrial membrane potential, whereas early apoptosis was less pronounced. At the protein level, some activation of caspase-3 and enhanced expression of the CDK inhibitor p21 were found. Loss of MMP and induced cell death were, however, largely independent of caspases and of the proapoptotic Bcl-2 proteins Bax and Bak, suggesting that sinecatechins induce also non-apoptotic, alternative cell death pathways, in addition to apoptosis. Reactive oxygen species (ROS) were downregulated in response to PE at 4 h, followed by an increase at 24 h. The contributory role of initially reduced ROS was supported by the antioxidant N-acetyl cysteine, which in combination with PE further enhanced the negative effects on cell viability. Thus, sinecatechins inhibited cell proliferation and viability of cSCC cells, which could suggest the use of PE for AK treatment. The mechanisms appear as linked to an imbalance of ROS levels.

Current and future direction in treatment of HPV-related cervical disease

Human papillomavirus (HPV) is the most common sexually transmitted virus in the world. About 70% of cervical cancers are caused by the most oncogenic HPV genotypes of 16 and 18. Since available prophylactic vaccines do not induce immunity in those with established HPV infections, the development of therapeutic HPV vaccines using E6 and E7 oncogenes, or both as the target antigens remains essential. Also, knocking out the E6 and E7 oncogenes in host genome by genome-editing CRISPR/Cas system can result in tumor growth suppression. These methods have shown promising results in both preclinical and clinical trials and can be used for controlling the progression of HPV-related cervical diseases. This comprehensive review will detail the current treatment of HPV-related cervical precancerous and cancerous diseases. We also reviewed the future direction of treatment including different kinds of therapeutic methods and vaccines, genome-editing CRISPR/Cas system being studied in clinical trials. Although the progress in the development of therapeutic HPV vaccine has been slow, encouraging results from recent trials showed vaccine-induced regression in high-grade CIN lesions. CRISPR/Cas genome-editing system is also a promising strategy for HPV cancer therapy. However, its safety and specificity need to be optimized before it is used in clinical setting.

Assessment of sinecatechins 10% ointment used as proactive sequential therapy in recurrence rate of genital warts lesions after cryotherapy. The PACT-II Trial (postablation immunomodulator treatment of condylomata with sinecatechins): a prospective assessor-blinded, multicenter, pilot trial

BACKGROUND

Cryotherapy is commonly used as ablative treatment of external genital warts (EGW). However, after cryotherapy recurrence of lesions affects on average 45% (42-70%) of subjects in the 6 months after the treatment. Sinecatechins 10% are an effective topical treatment of EGW. A low recurrence rate (<6%) was observed in pivotal phase 3 trials conducted with this product. Topical sinecatechins have demonstrated to significantly reduce the recurrence rate of EGW in subjects treated with laser therapy (The PACT-I trial). So far, no prospective data are available regarding the efficacy of sinecathechins as immunomodulator sequential therapy after cryotherapy in EGW subjects. The purpose of this study was to assess the rate of recurrence lesions after the use of topical sinecatechins 10%, as sequential proactive immunomodulation treatment after cryotherapy in subjects with EGW (The PACT-II Trial: the postablation immunomodulator treatment of condylomata with sinecatechins trial) (Trial Registration number: ISRCTN44037479).

METHODS

In a prospective, assessor-blinded, multicenter trial a total of 55 subjects with a diagnosis of multiple EGW (36 men and 19 women, mean age 47±10 years) and a mean lesion number of 9±7, after their informed consent, were enrolled in the study. All subjects were treated with cryotherapy (an average of 2 sessions). After the ablative treatment, all subjects were instructed to apply sinecatechin 10% ointment 3 times daily for 4 consecutive months. The primary study endpoint was the evaluation (assessor-blinded) of recurrent lesions after 6 months (2 month of follow-up after the conclusion of topical treatment). The secondary study endpoints were the appearance of new EGW lesions (lesions affecting area not treated by cryotherapy) and the local tolerability.

RESULTS

At baseline, the mean number of EGW lesions were 9±7. After cryotherapy, the mean lesions number were reduced to 1.6±1.8. At month 4, EGW mean lesion number were 0.2±0.4 (P=0.0001 vs. after cryotherapy). At month 6, recurrence of lesions was detected in 10 subjects (18%; 95% CI: 9-30%) with an average of 1.4 lesions. Of these recurrent lesions, 6 occurred in completely healed lesions site after cryotherapy and 8 in partially healed ones. New lesions (outside the cryotherapy treated area) were observed in 10 subjects. The product was very well tolerated. No serious side effects were reported. Three subjects reported moderate skin irritation on the application site.

CONCLUSIONS

The PACT-II Trial has shown that the recurrence rate of EGW lesions after successful cryotherapy using sinecatechins as immunomodulator sequential therapy is lower in comparison with the percentage documented in the literature without sequential therapy (20 vs. 45%). These results are in line with already published data evaluating the role of sinecatechins after laser therapy (PACT-I trial). Future comparative, double-blind controlled trials assessing the efficacy of different proactive strategies are warranted.

Skin cancer biology and barriers to treatment: Recent applications of polymeric micro/nanostructures

Background

Skin cancer has been the leading type of cancer worldwide. Melanoma and non-melanoma skin cancers are now the most common types of skin cancer that have been reached to epidemic proportion. Based on the rapid prevalence of skin cancers, and lack of efficient drug delivery systems, it is essential to surge the possible ways to prevent or cure the disease.

Aim of review

Although surgical modalities and therapies have been made great progress in recent years, however, there is still an urgent need to alleviate its increased burden. Hence, understanding the precise pathophysiological signaling mechanisms and all other factors of such skin insults will be beneficial for the development of more efficient therapies.

Key scientific concepts of review

In this review, we explained new understandings about onset and development of skin cancer and described its management via polymeric micro/nano carriers-based therapies, highlighting the current key bottlenecks and future prospective in this field. In therapeutic drug/gene delivery approaches, polymeric carriers-based system is the most promising strategy. This review discusses that how polymers have successfully been exploited for development of micro/nanosized systems for efficient delivery of anticancer genes and drugs overcoming all the barriers and limitations associated with available conventional therapies. In addition to drug/gene delivery, intelligent polymeric nanocarriers platforms have also been established for combination anticancer therapies including photodynamic and photothermal, and for theranostic applications. This portfolio of latest approaches could promote the blooming growth of research and their clinical availability.

Epigallocatechin gallate from green tea effectively blocks infection of SARS-CoV-2 and new variants by inhibiting spike binding to ACE2 receptor

BACKGROUND

As the COVID-19 pandemic rages on, the new SARS-CoV-2 variants have emerged in the different regions of the world. These newly emerged variants have mutations in their spike (S) protein that may confer resistance to vaccine-elicited immunity and existing neutralizing antibody therapeutics. Therefore, there is still an urgent need of safe, effective, and affordable agents for prevention/treatment of SARS-CoV-2 and its variant infection.

RESULTS

We demonstrated that green tea beverage (GTB) or its major ingredient, epigallocatechin gallate (EGCG), were highly effective in inhibiting infection of live SARS-CoV-2 and human coronavirus (HCoV OC43). In addition, infection of the pseudoviruses with spikes of the new variants (UK-B.1.1.7, SA-B.1.351, and CA-B.1.429) was efficiently blocked by GTB or EGCG. Among the 4 active green tea catechins at noncytotoxic doses, EGCG was the most potent in the action against the viruses. The highest inhibitory activity was observed when the viruses or the cells were pre-incubated with EGCG prior to the infection. Mechanistic studies revealed that EGCG blocked infection at the entry step through interfering with the engagement of the receptor binding domain (RBD) of the viral spikes to angiotensin-converting enzyme 2 (ACE2) receptor of the host cells.

CONCLUSIONS

These data support further clinical evaluation and development of EGCG as a novel, safe, and cost-effective natural product for prevention/treatment of SARS-CoV-2 transmission and infection.

[Consensus on HPV of the Portuguese Society of Andrology, Sexual Medicine and Reproduction: Treatment]

The treatment of condyloma is generally a challenge in clinical practice. Although the spontaneous resolution rate is high, a significant proportion of patients seek treatment, not because of symptomatology, but mainly for aesthetic issues and concerns related to the transmission or worsening of existing lesions. The available treatments should be applied only for clinically evident macroscopic lesions. Ideally, available therapies should have rapid action onset and clearance, resolve symptoms, reduce recurrence rate and viral load, be effective in treating small lesions, and be well tolerated. However, none of the currently available treatments is clearly more effective than the others and there is no ideal treatment for all patients or for all condyloma. Therefore, the therapeutic decision should be based on the clinician's experience, available resources, lesion morphology, size, number and location, primary or recurrent lesions, disease severity, patient preference and expectations, patient's immune competence, convenience, tolerance, cost of treatment and results of previous therapies. The available treatments are divided into three groups: applied by the patient himself (imiquimod 3.75 or 5%, podophyllotoxin .5%, synecatekines 10% or 15%), applied by the health care provider (bi- and tricloacetic acids 80%-90%, intralesional interferon alpha, cryotherapy, surgical removal, electrofulguration, laser ablation) and experimental or alternative therapies (topical cidofovir, intralesional bleomycin, photodynamic therapy). Treatment methodologies can be further divided into their action - ablative or destructive treatment (cryotherapy, electrofulguration, laser ablation, surgical excision), cytotoxic or proapoptotic treatments (podophyllotoxin .5%, 5-fluoruracil, bleomycin) and immunomodulatory treatments (imiquimod 3.75% or 5%, synecatekines 10% or 15%, intralesional interferon alpha). The overall success rate of the various treatments available ranges from 23% to 94%. Only treatments that include cryotherapy or surgical excision are suitable in condyloma with any anatomical location and that have the highest success rate in monotherapy. Recurrences are common regardless of the treatment received. In contrast, immunomodulatory therapies despite having lower initial clearance rates appear to have higher probabilities of cure in the medium term, with low recurrence rates. Some treatments may be combined with each other and the effectiveness of combined therapies appears to be superior to monotherapy (proactive sequential treatment). The consensuses for the treatment of HPV also consider special situations: immunocompromised patients, meatus and intraurethral lesions and treatment of the partner.

Applications of a Standardized Green Tea Catechin Preparation for Viral Warts and Human Papilloma Virus-Related and Unrelated Cancers

Most cell-based and animal experiments have shown that green tea catechins (GTC) exhibit various health benefits. In human experimental and epidemiological studies, there are conflicting results, and more precise investigations are required. One of the most effective ways to prove beneficial health effects in humans might be clinical intervention studies. Polyphenon^®E was developed as a standardized GTC preparation, which was approved by Food and Drug Administration of US in 2006 as a medication to treat genital warts (Veregen^® or sinecatechins). Positive efficacy of Polyphenon^®E/sinecatechins/Veregen^® (PSV) on anogenital warts has been demonstrated in several epidemiological studies and there have been several case reports to show the clinical effectiveness of PSV. In addition, several studies have provided evidence to suggest that PSV is effective in other human papillomavirus (HPV)-related diseases, although some studies failed to show such effects. Since (−)-epigallocatechin gallate (EGCG) is the major component of PSV, the mechanism of the action of PSV might be deduced from that of EGCG. The microarray analysis of the biopsy samples from the patients suggested that apoptosis induction and the downregulation of inflammation are involved in the mechanism of the action of PSV in the clearance of anogenital warts. Cell-based and animal experiments using PSV also demonstrated effects similar to those elicited by EGCG, explaining how PSV works to induce apoptosis and exert anti-inflammatory actions in HPV-related diseases. Future studies would clarify what kinds of diseases respond effectively to PSV, showing health benefits of GTC and EGCG in humans.

Topical treatments for skin cancer

Skin cancer is a broad term used to describe a number of different malignant indications of the skin. Skin cancers mostly comprise of the keratinocyte cancers [Basal Cell Carcinoma (BCC) and cutaneous Squamous Cell Carcinoma (SCC)], and melanoma. Surgical excision of these malignancies has been the preferred treatment of patients for decades. However, the decision to perform surgery can be affected by various considerations, including co-morbidities of the patient, the anatomical site of the lesion and potential intolerance for repeated excisions. Topical treatment of skin cancer may therefore be more appropriate in certain instances. Topical treatment potentially allows for higher drug levels at the tumor site, and may result in less overall toxicity than systemic agents. This review will specifically address the current agents used in topical treatment of skin cancers, and introduce emerging treatments from the natural product field that may also find utility in these indications.

Multilevel structure-activity profiling reveals multiple green tea compound families that each modulate ubiquitin-activating enzyme and ubiquitination by a distinct mechanism

We developed and implemented a reconstituted system to screen for modulators of the ubiquitination of proliferating cell nuclear antigen, a process that activates pathways of DNA damage tolerance and drug resistance. We identified the primary putatively health-beneficial green tea polyphenol epigallocatechin gallate (EGCG) and certain related small molecules as potent inhibitors of ubiquitination. EGCG directly and reversibly targets the ubiquitin-activating enzyme Uba1, blocking formation of the Uba1~ubiquitin thioester conjugate and thus ubiquitination and in the cell. Structure–activity relationship profiles across multiple biochemical and cellular assays for a battery of EGCG analogues revealed distinct chemical and mechanism-of-action clusters of molecules, with catechin gallates, alkyl gallates, and myricetin potently inhibiting ubiquitination. This study defines a number of related though distinct first-in-class inhibitors of ubiquitination, each series with its own unique activity pattern and mechanistic signature.

Investigational drugs currently in phase II clinical trials for actinic keratosis

INTRODUCTION

Actinic keratoses (AKs) are limited areas of irregular epidermal growth on a background of excessive solar exposure. The entire sun-damaged skin is considered a field of cancerization with multiple visible and subclinical lesions. AK management requires field-directed therapies to block lesion relapse and prevent squamous cell carcinoma (SCC).

AREAS COVERED

In this review, we focused on phase II clinical trials for AKs, involving well-known agents and newer molecules such as proapoptotic drugs (VDA-1102, SR-T100, oleogel-S10, ICVT, eflornithine), immunomodulants (isotretinoin, tretinoin) and chemopreventive agents (nicotinamide, perillyl alcohol, liposomal T4N5). We used the website 'ClinicalTrials.Gov' as main reference. We selected and discussed completed and ongoing trials and analysed chemical structure and mechanism of action of the investigated molecules.

EXPERT OPINION

AK therapy should be tailored on the patient's profile considering first of all the age and site of the AKs, which are relevant parameters for local immune response. The new molecules could be combined to obtain a synergic effect blocking the different steps of skin tumorigenesis. Phase II trials highlight a new therapeutic opportunity to block selectively cell proliferation regulators and work both on the field of cancerization and on the AKs currently present.

Position statement for the diagnosis and management of anogenital warts

BACKGROUND

Anogenital warts (AGW) can cause economic burden on healthcare systems and are associated with emotional, psychological and physical issues.

OBJECTIVE

To provide guidance to physicians on the diagnosis and management of AGW.

METHODS

Fourteen global experts on AGW developed guidance on the diagnosis and management of AGW in an effort to unify international recommendations. Guidance was developed based on published international and national AGW guidelines and an evaluation of relevant literature published up to August 2016. Authors provided expert opinion based on their clinical experiences.

RESULTS

A checklist for a patient's initial consultation is provided to help physicians when diagnosing AGW to get the relevant information from the patient in order to manage and treat the AGW effectively. A number of frequently asked questions are also provided to aid physicians when communicating with patients about AGW. Treatment of AGW should be individualized and selected based on the number, size, morphology, location, and keratinization of warts, and whether they are new or recurrent. Different techniques can be used to treat AGW including ablation, immunotherapy and other topical therapies. Combinations of these techniques are thought to be more effective at reducing AGW recurrence than monotherapy. A simplified algorithm was created suggesting patients with 1-5 warts should be treated with ablation followed by immunotherapy. Patients with >5 warts should use immunotherapy for 2 months followed by ablation and a second 2-month course of immunotherapy. Guidance for daily practice situations and the subsequent action that can be taken, as well as an algorithm for treatment of large warts, were also created.

CONCLUSION

The guidance provided will help physicians with the diagnosis and management of AGW in order to improve the health and quality of life of patients with AGW.

Efficacy of sinecatechins 10% as proactive sequential therapy of external genital warts after laser CO2 ablative therapy: The PACT study (post-ablation immunomodulator treatment of condylomata with sinecatechins): a randomized, masked outcome assessment, multicenter trial

External genital warts (EGW) are the most common viral sexually transmitted infection. Ablative treatments like cryotherapy, curettage, and CO₂ laser therapies offer rapid onset of effect, fast clearance, and reduction of virus load. However, these procedures are associated with high recurrence rates (RRs) ranging from 20% to 77% in the short and medium terms and do not provide sustained clearance. After laser therapy removal of EGW, an RR up to 77% has been reported. Topical sinecatechins (TS) 10% is a patient-applied regimen for the treatment of EGW with a low RR (<6.5%) at three months after completion of the therapy in the pivotal trials conducted so far. Sinecatechins can be considered a suitable proactive sequential therapy (PST) after ablative strategies to obtain a low RR. So far, no prospective data are available regarding the efficacy of sinecatechins 10% as PST. We evaluated the efficacy and tolerability of TS 10% ointment applied twice daily in subjects with "difficult to treat" EGW after CO₂ laser ablative treatment in a prospective controlled trial. A total of 87 subjects (76 men and 11 women; mean age 42 years) were enrolled in this three-month masked outcome assessment parallel group trial with imbalanced randomization allocation (2:1). One week after a successful CO₂ laser treatment, 60 subjects were randomized to TS 10% treatment and 27 subjects to no treatment (control group: ConTRol (CTR); no sequential therapy). All patients had a history of an average of 4.5 previous ablative treatments in the last 12 months due to recurrent EGW. Mean (standard deviation) baseline number of treated lesions was 6.5 (2.7). One subject in the TS arm dropped out due to burning sensation after the application of the product. Therefore, 86 subjects completed the study. After three months, in the TS group, three subjects presented new EGW lesions (RR: 5%) on treated sites. In the CTR group, eight subjects presented new EGW lesions (RR: 29%) on treated sites (p = 0.0024; odds ratio: 0.16; 95% confidence interval: 0.04-0.68). In the TS group, 34 subjects (56%) reported mild to moderate erythema or burning sensation at the application site. In this prospective multicenter trial, the use of TS 10% as PST after ablative treatment with CO₂ laser was associated with a lower recurrence rate of new EGW lesions in the short term in comparison with the control group. Comparative larger trials are warranted to evaluate the role of this approach as PST (Trial Registration Number: ISRCTN44037479).

The cytotoxic mechanism of epigallocatechin gallate on proliferative HaCaT keratinocytes

BACKGROUND

Epigallocatechin gallate (EGCG) is the major ingredient of sinecatechins ointment, approved for the treatment of external genital and perianal warts. However, the molecular mechanism for EGCG's effect on warts resulting from the human papillomavirus (HPV) infection of keratinocytes is not well understood. HPV may survive in proliferative keratinocytes and may be involved in cell cycle regulation and progression. The objective of this study was to investigate the mechanism underlying EGCG's treatment on external genital warts of HPV infection through the cultured keratinocyte cells from the HaCaT cell line.

METHODS

MTT and flow cytometry assays were used to measure cell viability and the cell cycle profile, with and without EGCG treatment, for HaCaT keratinocyte cells cultured in a calcium-free medium and 1.8 mM calcium which induced proliferative and differentiated keratinocytes, respectively, for 24 h. The expression levels of cytotoxic proteins and factors were evaluated with the RT-PCR and western blotting analysis.

RESULTS

EGCG influenced the proliferation stage but not the differentiation stage of keratinocytes. We suggest that apoptosis and autophagy might be the possible mechanism for the EGCG's effect on the proliferative HaCaT cells. Furthermore, we found that EGCG reduced the protein levels of cyclin D1 and Zac1 (a zinc-finger protein which regulates apoptosis and cell cycle arrest 1) dose-dependently in proliferative as compared to differentiated keratinocytes. It also induced the expression of p21 and DEC1 (differentiated embryo-chondrocyte expressed gene 1), and promoted G1 arrest of cell cycle in proliferative keratinocytes.

CONCLUSIONS

These results help clarify the mechanisms of EGCG treatment of HPV-infected keratinocytes and may contribute to new targets, such as Zac1 and DEC1 for external genital and perianal warts.

Sinecatechins and imiquimod as proactive sequential therapy of external genital and perianal warts in adults

This review about the proactive sequential therapy (PST) of external genital and perianal warts (EGW) is based on the most current available clinical literature and on the broad clinical experience of a group of international experts, physicians who are well versed in the treatment of human papillomavirus-associated diseases. It provides a practical guide for the treatment of EGW, including epidemiology, etiology, clinical appearance, and diagnostic procedures for these viral infections. Furthermore, the treatment goals and current treatment options, elucidating provider- and patient-applied therapies, and the parameters driving treatment decisions are summarized. Specifically, the mode of action of the topical treatments sinecatechins and imiquimod, as well as the PST for EGW to achieve rapid and sustained clearance is discussed. The group of experts has developed a treatment algorithm giving healthcare providers a practical tool for the treatment of EGW which is very valuable in the presence of many different treatment options.

Green tea in dermatology--myths and facts

Green tea consumption has a long tradition in Asian countries--especially China. The epidemiologically and experimentally observed anticarcinogenic and antiinflammatory effects of green tea have led to the implementation of green tea extracts in multiple therapeutic applications - both in dermatological and cosmeceutical preparations. The most abundant evidence exists for the anticarcinogenic and chemopreventive effect of green tea or its major constituent epigallocatechin-3-gallate. Almost equally evident is the effect in infectious diseases such as cutaneous viral infections. For external genital warts, a topical ointment with green tea extracts was licensed in the USA in 2010, and recently also in Europe. Experimental evidence pinpointing the block of central signal transduction factors in inflammatory mechanisms has led to the evaluation of catechins in inflammatory disorders such as atopic dermatitis. The belief of green tea as a "wonder weapon" against diseases dates back thousands of years. According to a Chinese legend, ancient Emperor Shen Nung noted a delightful aroma after some leaves of a nearby tree had fallen into boiling water. He immediately proclaimed the new "drink" as "heaven-sent", starting the belief - persisting until today - of green tea as a medication from nature against many different diseases. This review summarizes biological effects and clinical implications of green tea.