Scavenging properties of metronidazole on free oxygen radicals in a skin lipid model system

Efficacy of Treatments in Reducing Inflammatory Lesion Count in Rosacea: A Systematic Review

INTRODUCTION

Rosacea is a chronic inflammatory skin condition affecting approximately 5.5% of the global population. Patients present heterogeneously with a mix of features in the central facial region, of which papules and pustules are considered to be a major feature. The identification of effective treatments for reducing inflammatory lesions in rosacea can alleviate the psychosocial burden that many rosacea patients experience, including reduced self-esteem, anxiety, and social withdrawal. The objective of this systematic review is to determine the effectiveness of topical and systemic therapies in reducing lesion count in rosacea patients.

METHODS/RESULTS

Medline, Embase, and Cochrane CENTRAL databases were searched, resulting in the inclusion of 43 clinical trials reporting on a total of 18,347 rosacea patients. The most well-studied treatments include ivermectin, metronidazole, azelaic acid, minocycline, and doxycycline. Oral isotretinoin was the most effective treatment in reducing inflammatory lesions and may be recommended for severe recalcitrant cases of rosacea.

CONCLUSIONS

Several topical and systemic therapies have demonstrated efficacy in reducing inflammatory lesion count in rosacea patients, with mechanisms of action centred around suppressing inflammation and killing Demodex folliculorum mites. Additional research is required to determine effective combination therapies in rosacea.

Lipid Biomimetic Models as Simple Yet Complex Tools to Predict Skin Permeation and Drug-Membrane Biophysical Interactions

The barrier function of the skin is primarily determined by its outermost layer, the Stratum Corneum (SC). The SC consists of corneocytes embedded in a lipid matrix composed mainly of ceramides, cholesterol, and free fatty acids in equimolar proportions and is organised in a complex lamellar structure with different periodicities and lateral packings. This matrix provides a diffusion pathway across the SC for bioactive compounds that are administered to the skin. In this regard, and as the skin administration route has grown in popularity, there has been an increase in the use of lipid mixtures that closely resemble the SC lipid matrix, either for a deeper biophysical understanding or for pharmaceutical and cosmetic purposes. This review focuses on a systematic analysis of the main outcomes of using lipid mixtures as SC lipid matrix models for pharmaceutical and cosmetic purposes. Thus, a methodical evaluation of the main outcomes based on the SC structure is performed, as well as the main recent developments in finding suitable new in vitro tools for permeation testing based on lipid models.

Rosacea in Older Adults and Pharmacologic Treatments

Rosacea is a chronic inflammatory skin condition that is often more severe in older patients. The main clinical features are erythema, telangiectasia, and inflammatory lesions of the face. The pathogenesis of this condition is not fully understood but certainly multifaceted. Immune and inflammatory dysregulation, genetics, neurogenic dysregulation, microbiome dysbiosis, and systemic disease have all been implicated in rosacea pathogenesis. As we better understand the various pathways that lead to rosacea, we acknowledge that the different symptoms may have unique underlying triggers and mechanisms. Aging also impacts rosacea diagnosis and treatment. Older adults have more severe rosacea symptoms while also having more sensitive and fragile skin than younger patients; therefore, rosacea treatments for older patients require a balance between delivering adequate potency while also minimizing skin irritation and other adverse effects. Until recently, rosacea diagnoses were based on concrete subtypes that did not necessarily capture each patient's manifestation of rosacea. There is now an emphasis on more personalized phenotype-based diagnoses and treatments, which allows for more emphasis on treating individual symptoms and accounting for the unique characteristics of older patients. Centrofacial erythema is best treated with brimonidine and oxymetazoline, while phymatous change and telangiectasia are best treated with surgery and laser ablation. Treatment for rosacea papules and pustules ranges from topicals, such as azelaic acid, ivermectin, metronidazole, minocycline, and encapsulated benzoyl peroxide, to systemics, such as doxycycline and isotretinoin. It is important to understand these treatments in relation to adverse effects and drug interactions that may specifically arise in older populations to provide optimal care. As we advance in understanding rosacea's pathogenesis and adopt personalized phenotype-based approaches, optimizing care for older patients becomes crucial. Continued research into novel treatments is essential to address their unique needs.

Rosacea: Pathogenesis and Therapeutic Correlates

Rosacea is a chronic inflammatory condition of which there is no cure. The pathogenesis of rosacea is likely multifactorial, involving genetic and environmental contributions. Current understanding suggests that pro-inflammatory pathways involving cathelicidins and inflammasome complexes are central to rosacea pathogenesis. Common rosacea triggers modulate these pathways in a complex manner, which may contribute to the varying severity and clinical presentations of rosacea. Established and emerging rosacea treatments may owe their efficacy to their ability to target different players in these pro-inflammatory pathways. Improving our molecular understanding of rosacea will guide the development of new therapies and the use of combination therapies.

A review on oxidant and antioxidant effects of antibacterial agents: impacts on bacterial cell death and division and therapeutic effects or adverse reactions in humans

Reactive oxygen species (ROS) are produced in the mitochondrial respiratory pathway and cellular metabolism. They are responsible for creating oxidative stress and lipid peroxidation. In living organisms, there is a balance between oxidative stress and the antioxidant system, but some factors such as medicines disturb the balance and cause many problems. These effects can impact bacterial death and division and also in humans can induce therapeutic or adverse reactions. Web of Science and Pubmed databases were used for searching. This review focuses on the oxidant and antioxidant effects of different classes of antibacterial agents and the mechanisms of oxidative stress. Some of these agents have beneficial effects on killing bacteria due to their antioxidant or oxidant effects. However, some of their side effects may be due to their oxidative effects. Based on the results of this review, minocycline is an antioxidant, but aminoglycosides, chloramphenicol, glycopeptides, antituberculosis drugs, fluoroquinolones, and sulfamethoxazole agents have oxidant effects. Furthermore, cephalosporins, penicillins, metronidazole, and macrolides have both oxidant and antioxidant effects in different studies. It is concluded that some antibacterial agents have oxidant and other antioxidant effects. These activities may affect their therapeutic effects or side effects. Some antioxidants can prevent the adverse effects of antibacterial agents. Clarifying the exact oxidant and antioxidant effects of some antimicrobial agents needs more research projects.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

Nav1.8 in keratinocytes contributes to ROS-mediated inflammation in inflammatory skin diseases

Reactive oxygen species (ROS)-activated proinflammatory signals in keratinocytes play a crucial role in the immunoregulation of inflammatory skin diseases, including rosacea and psoriasis. Nav1.8 is a voltage-gated sodium ion channel, and its abnormal expression in the epidermal layer contributes to pain hypersensitivity in the skin. However, whether and how epidermal Nav1.8 is involved in skin immunoregulation remains unclear. This study was performed to identify the therapeutic role of Nav1.8 in inflammatory skin disorders. We found that Nav1.8 expression was significantly upregulated in the epidermis of rosacea and psoriasis skin lesions. Nav1.8 knockdown ameliorated skin inflammation in LL37-and imiquimod-induced inflammation mouse models. Transcriptome sequencing results indicated that Nav1.8 regulated the expression of pro-inflammatory mediators (IL1β and IL6) in keratinocytes, thereby contributing to immune infiltration in inflammatory skin disorders. In vitro, tumor necrosis factor alpha (TNFα), a cytokine that drives the development of various inflammatory skin disorders, increased Nav1.8 expression in keratinocytes. Knockdown of Nav1.8 eliminated excess ROS production, thereby attenuating the TNFα-induced production of inflammatory mediators; however, a Nav1.8 blocker did not have the same effect. Mechanistically, Nav1.8 reduced superoxide dismutase 2 (SOD2) activity by directly binding to SOD2 to prevent its deacetylation and mitochondrial localization, subsequently inducing ROS accumulation. Collectively, our study describes a central role for Nav1.8 in regulating pro-inflammatory responses in the skin and indicates a novel therapeutic strategy for rosacea and psoriasis.

Exploring metformin as a candidate drug for rosacea through network pharmacology and experimental validation

Rosacea is a common chronic inflammatory disease that affects the middle of the face. Due to the unclear pathogenesis, the effective treatment options for rosacea remain limited. In this study, weighted gene co-expression network analyses (WGCNA) identified three rosacea-related hub modules, which were involved in immune-, metabolic- and development- related signaling pathways. Next, the key genes from green and brown modules were submitted to CMap database for drug prediction and metformin was identified as a candidate drug for rosacea. Moreover, network pharmacology analysis identified pharmacological targets of metformin and demonstrated that metformin could help in treating rosacea partly by modulating inflammatory and angiogenesis signaling pathways. Finally, we verified the therapeutic role and mechanism of metformin on rosacea in vivo and vitro. We found that metformin treatment significantly improved rosacea-like skin lesions including immune cells infiltration, cytokines/chemokines expression and angiogenesis. Moreover, metformin suppressed LL37- and TNF-α-induced the ROS production and MAPK-NF-κB signal activation in keratinocytes cells. In conclusion, our findings identified and verified metformin as a novel therapeutic candidate for rosacea, and it alleviates the pathological symptoms, possibly by suppressing inflammatory responses, angiogenesis in rosacea.

Metronidazole gel (0.75%) in Japanese patients with rosacea: A randomized, vehicle-controlled, phase 3 study

Topical metronidazole is not currently approved in Japan as a treatment for the indication of rosacea, although 0.75% metronidazole gel was authorized in 2014 for the management of cancerous skin ulcers. We conducted a randomized, double-blind, vehicle-controlled study to evaluate the efficacy and safety of 0.75% metronidazole gel in Japanese patients with inflammatory lesions (papules/pustules) and erythema associated with moderate to severe rosacea. Overall, 130 patients were randomly assigned to receive 0.75% metronidazole gel (n = 65) or vehicle (n = 65), and 120 patients completed 12 weeks of treatment. The primary efficacy outcome was the proportion of patients who achieved both of the following at week 12: an improvement of >50% in the number of inflammatory lesions (papules/pustules) and a positive change of at least one degree in erythema severity. This composite outcome was achieved by 72.3% of metronidazole-treated patients versus 36.9% of vehicle-treated patients, with the between-group difference demonstrating significant improvement with 0.75% metronidazole gel (p < 0.0001). All secondary efficacy endpoints (patients achieving a score of ≥3 for percent change in the number of inflammatory lesions at week 12; patients achieving a score of ≥3 for change in erythema severity at week 12; patients achieving an Investigator's Global Assessment score of 0 or 1 at week 12; percent change over time in the number of inflammatory lesions; change over time in erythema severity) also showed improvement in the 0.75% metronidazole gel group. The incidence of adverse events was higher with metronidazole (40.0%) than with vehicle (29.2%). Of these, treatment-related, treatment-emergent adverse events occurred in 9.2% and 6.2% in the metronidazole and the vehicle group, respectively, but there were no new safety concerns. Overall, the results of this study have confirmed the efficacy and safety of 0.75% metronidazole gel in Japanese patients with rosacea.

Metronidazole does not show direct antioxidant activity in in vitro global systems

Metronidazole has been widely used topically and systemically for more than 50 years but data on its antioxidant properties are still incomplete, unclear and contradictory. Its antioxidant properties are primarily hypothesized based on in vivo results, therefore, studies have been performed to determine whether metronidazole has antioxidant activity in vitro. We used so-called global spectrophotometric and luminometric methods. Fe³⁺/Fe²⁺-reducing ability, hydrogen donor activity, hydroxyl radical scavenging property and lipid peroxidation inhibitory activity were investigated. Under the condition used, metronidazole has negligible iron-reducing ability and hydrogen donor activity. The hydroxyl radical scavenging capacity cannot be demonstrated. It acts as a pro-oxidant in the H₂O₂/^.OH-microperoxidase-luminol system, but it can inhibit the induced lipid peroxidation. According to our results, metronidazole has not shown antioxidant activity in vitro but can affect redox homeostasis by a ROS-independent mechanism due to its non-direct antioxidant properties.

Comparison of the efficacy of tea tree (Melaleuca alternifolia) oil with other current pharmacological management in human demodicosis: A Systematic Review

Various treatments are found to be moderately effective in managing Demodex-related diseases except tea tree oil (TTO) and terpinen-4-ol (T4O), which showed superior miticidal and anti-inflammatory effects in numerous clinical studies. Their possible effects include lowering mite counts, relieving Demodex-related symptoms, and modulating the immune system. This review summarizes the current clinical topical and oral treatments in human demodicosis, their possible mechanisms of action, side-effects and resistance in treating this condition. TTO (especially T4O) is found to be the most effective followed by metronidazole, ivermectin and permethrin in managing the disease. This is because TTO has anti-parasitic, anti-bacterial, anti-fungal, anti-inflammatory and wound-healing effects. Furthermore, nanoTTO can even release its contents into fungus and Pseudomonas biofilms. Combinations of different treatments are occasionally needed for refractory cases, especially for individuals with underlying genetic predisposal or are immuno-compromised. Although the current treatments show efficacy in controlling the Demodex mite population and the related symptoms, further research needs to be focused on the efficacy and drug delivery technology in order to develop alternative treatments with better side-effects profiles, less toxicity, lower risk of resistance and are more cost-effective.

Effect of Metronidazole on the Oxidoreductive Processes in the Submandibular and Parotid Glands in Experimental Research

Oxidative stress takes part in the pathomechanisms of many diseases, including oral disorders. The imbalance between oxidative and antioxidative processes may lead to periodontitis, osteitis, or oral cancers. Furthermore, many chemotherapeutics, e.g., metronidazole (MTZ), may also cause toxic reactions and affect oxidative reactions. The research focused on MTZ influence on oxidative destruction in the parotid and submandibular gland tissue in animal experimental model. Therefore, the concentrations of enzymatic and nonenzymatic markers of oxidative stress were measured in these two rat glands in the control and experimental MTZ-treated groups. The material for analysis included parotid and submandibular glands of male Wistar rats, which were treated with metronidazole for 7 days by gastric tube in a dose of 100 mg/kg b.w. On day 8, the material was obtained and frozen in temp. -80°C. Then, the following seven enzymatic and nonenzymatic parameters were measured: GPx, TOS, TAS, SOD, LPO, CAT, and GSH. The data were analysed using Statistica 10.0. Metronidazole treatment in the experimental model showed an increase in LPO, TOS, and TOS/TAS and a decrease in CAT, SOD, GPx, and TAS. The conclusions of this research were made. Metronidazole treatment in a dose of 100 mg/kg b.w. caused imbalance between oxidative and antioxidative reactions in the rat parotid and submandibular glands. An increase was observed in LPO, TOS, and TOS/TAS in both glands exposed to metronidazole. Decreased activity of CAT, SOD, GPx, and TAS was noted, which indicates attenuation of the gland antioxidative protective barrier.

A Review of the Current Modalities for the Treatment of Papulopustular Rosacea

Papulopustular rosacea is characterized by papules and pustules in the central facial region. We review the literature surrounding the treatment of papulopustular rosacea. PubMed, EMBASE, and Cochrane (Central) databases searches of articles published from 1980 to 2015 were performed using the MeSH terms or keywords "rosacea" and "clinical trial." Additional searches were performed to include rosacea and each treatment modality used. Topical metronidazole, azelaic acid, ivermectin, and oral doxycycline have the most robust data to support their use. Variation in assessment tools and a lack of clinical trial standardization makes comparison of therapeutic options difficult.

Systematic review and meta-analysis of the role of metronidazole in post-haemorrhoidectomy pain relief

AIM

Conventional haemorrhoidectomy is still considered the reference standard for the management of severe or recurrent haemorrhoids. Pain is reported by patients to be the most common postoperative complication. Although the literature lacks a consensus on its effectiveness, metronidazole is often used to reduce postoperative pain. We have performed a meta-analysis of all randomized controlled trials (RCTs) that investigated the use of metronidazole for pain relief after haemorrhoidectomy.

METHOD

A systematic review was undertaken in accordance with the PRISMA protocol using the MESH headings 'haemorrhoidectomy', 'hemorhoidectomy', 'hemorrhoidectomy', 'haemorrhoid', 'metronidazole', 'Flagyl^® ' 'antibiotic' and 'pain'. The search returned 421 articles of which eight were RCTs suitable for inclusion in the review with a total population of 437 patients. The outcomes of interest were postoperative pain intensity on days 1, 2 and 7 and on first defaecation as measured using a visual analogue scale.

RESULTS

The meta-analysis demonstrated a significant reduction in postoperative pain for patients treated with metronidazole with a reduced mean difference for the metronidazole group on day 1 of -1.42 (95% CI: -2.14 to -0.69, P = 0.0001), on day 2 of -1.43 (95% CI: -2.45 to -0.40, P = 0.006) and on day 7 of -2.40 (95% CI: -3.10 to -1.71, P < 0.00001). Pain on first defaecation was likewise reduced with a mean difference of -1.38 (95% CI: -2.15 to -0.60, P = 0.0005). Limitations of this study include variation in the grade of haemorrhoids treated and variability in the quality of included studies.

CONCLUSION

Metronidazole is a cheap, safe and effective intervention for reducing postoperative pain following conventional haemorrhoidectomy.

Dual anti-inflammatory and anti-parasitic action of topical ivermectin 1% in papulopustular rosacea

BACKGROUND

Recently, therapy of rosacea with inflammatory lesions (papulopustular) has improved substantially with the approval of topical ivermectin 1% cream. It is assumed to have a dual mode of action with anti-inflammatory capacities and anti-parasitic effects against Demodex, which however has not yet been demonstrated in vivo.

AIM

To find scientific rationale for the dual anti-inflammatory and anti-parasitic mode of action of topical ivermectin 1% cream in patients with rosacea.

METHODS

A monocentric pilot study was performed including 20 caucasion patients with moderate to severe rosacea, as assessed by investigator global assessment (IGA score ≥3) and a Demodex density ≥15/cm² . Patients were treated with topical ivermectin 1% cream once daily (Soolantra^® ) for ≥12 weeks. The density of Demodex mites was assessed with skin surface biopsies. Expression of inflammatory and immune markers was evaluated with RT-PCR and by immunofluorescence staining.

RESULTS

The mean density of mites was significantly decreased at week 6 and week 12 (P < 0.001). The gene expression levels of IL-8, LL-37, HBD3, TLR4 and TNF-α were downregulated at both time points. Reductions in gene expression were significant for LL-37, HBD3 and TNF-α at both follow-up time points and at week 12 for TLR4 (all P < 0.05). Reduced LL-37 expression (P < 0.05) and IL-8 expression were confirmed on the protein level by immunofluorescence staining. All patients improved clinically, and 16 of 20 patients reached therapeutic success defined as IGA score ≤1.

CONCLUSION

Topical ivermectin 1% cream acts by a dual, anti-inflammatory and anti-parasitic mode of action against rosacea by killing Demodex spp. in vivo, in addition to significantly improving clinical signs and symptoms in the skin.

Rosacea: Molecular Mechanisms and Management of a Chronic Cutaneous Inflammatory Condition

Rosacea is a chronic cutaneous inflammatory disease that affects the facial skin. Clinically, rosacea can be categorized into papulopustular, erythematotelangiectatic, ocular, and phymatous rosacea. However, the phenotypic presentations of rosacea are more heterogeneous. Although the pathophysiology of rosacea remains to be elucidated, immunologic alterations and neurovascular dysregulation are thought to have important roles in initiating and strengthening the clinical manifestations of rosacea. In this article, we present the possible molecular mechanisms of rosacea based on recent laboratory and clinical studies. We describe the genetic predisposition for rosacea along with its associated diseases, triggering factors, and suggested management options in detail based on the underlying molecular biology. Understanding the molecular pathomechanisms of rosacea will likely aid toward better comprehending its complex pathogenesis.

Topical Ivermectin 10 mg/g and Oral Doxycycline 40 mg Modified-Release: Current Evidence on the Complementary Use of Anti-Inflammatory Rosacea Treatments

Rosacea is a common, chronic inflammatory skin disease that can present with a variety of signs and symptoms. The potentially simultaneous occurrence of different signs and symptoms is due to different underlying inflammatory pathways, emphasizing the need for complementary treatment approaches. Topical ivermectin cream (10 mg/g) and systemic, oral anti-inflammatory doxycycline (40 mg modified-release) are both approved for the treatment of papulopustular rosacea (PPR). Whether or not a combined therapeutic approach may be more beneficial than monotherapy for patients with PPR remains to be tested. Here, we summarize underlying inflammatory pathways implicated in rosacea and clarify the impact of these two agents on selective pathways during inflammation, due to specific characteristics of their individual mechanisms of action (MoA). Based on the complementary MoA of doxycycline modified-release and ivermectin, a scientific rationale for a combined therapy targeting inflammatory lesions in rosacea is given. We propose that topical ivermectin cream is a promising new candidate as first-line treatment to target the inflammatory lesions of rosacea, which can be used in combination with systemic doxycycline modified-release to provide an optimal treatment approach considering all inflammatory pathways involved in PPR.

Funding Galderma.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some people. A range of treatment options are available but it is unclear which are most effective.

OBJECTIVES

To assess the efficacy and safety of treatments for rosacea.

SEARCH METHODS

We updated our searches, to July 2014, of: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 6), MEDLINE (from 1946), EMBASE (from 1974) and Science Citation Index (from 1988). We searched five trials registers and checked reference lists for further relevant studies.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, risk of bias assessment and analyses were carried out independently by two authors.

MAIN RESULTS

We included 106 studies, comprising 13,631 participants. Sample sizes of 30-100 and study duration of two to three months were most common. More women than men were included, mean age of 48.6 years, and the majority had papulopustular rosacea, followed by erythematotelangiectatic rosacea.A wide range of comparisons (67) were evaluated. Topical interventions: metronidazole, azelaic acid, ivermectin, brimonidine or other topical treatments. Systemic interventions: oral antibiotics, combinations with topical treatments or other systemic treatments, i.e. isotretinoin. Several studies evaluated laser or light-based treatment.The majority of studies (57/106) were assessed as 'unclear risk of bias', 37 'high risk ' and 12 'low risk'. Twenty-two studies provided no usable or retrievable data i.e. none of our outcomes were addressed, no separate data reported for rosacea or limited data in abstracts.Eleven studies assessed our primary outcome 'change in quality of life', 52 studies participant-assessed changes in rosacea severity and almost all studies addressed adverse events, although often only limited data were provided. In most comparisons there were no statistically significant differences in number of adverse events, most were mild and transient. Physician assessments including investigators' global assessments, lesion counts and erythema were evaluated in three-quarters of the studies, but time needed for improvement and duration of remission were incompletely or not reported.The quality of the body of evidence was rated moderate to high for most outcomes, but for some outcomes low to very low.Data for several outcomes could only be pooled for topical metronidazole and azelaic acid. Both were shown to be more effective than placebo in papulopustular rosacea (moderate quality evidence for metronidazole and high for azelaic acid). Pooled data from physician assessments in three trials demonstrated that metronidazole was more effective compared to placebo (risk ratio (RR) 1.98, 95% confidence interval (CI) 1.29 to 3.02). Four trials provided data on participants' assessments, illustrating that azelaic acid was more effective than placebo (RR 1.46, 95% CI 1.30 to 1.63). The results from three studies were contradictory on which of these two treatments was most effective.Two studies showed a statistically significant and clinically important improvement in favour of topical ivermectin when compared to placebo (high quality evidence). Participants' assessments in these studies showed a RR of 1.78 (95% CI 1.50 to 2.11) and RR of 1.92 (95% CI 1.59 to 2.32),which were supported by physicians' assessments. Topical ivermectin appeared to be slightly more effective than topical metronidazole for papulopustular rosacea, based on one study, for improving quality of life and participant and physician assessed outcomes (high quality evidence for these outcomes).Topical brimonidine in two studies was more effective than vehicle in reducing erythema in rosacea at all time points over 12 hours (high quality evidence). At three hours the participants' assessments had a RR of 2.21 (95% CI 1.52 to 3.22) and RR of 2.00 (95% CI 1.33 to 3.01) in favour of brimonidine. Physicians' assessments confirmed these data. There was no rebound or worsening of erythema after treatment cessation.Topical clindamycin phosphate combined with tretinoin was not considered to be effective compared to placebo (moderate quality evidence).Topical ciclosporin ophthalmic emulsion demonstrated effectiveness and improved quality of life for people with ocular rosacea (low quality evidence).Of the comparisons assessing oral treatments for papulopustular rosacea there was moderate quality evidence that tetracycline was effective but this was based on two old studies of short duration. Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99) (high quality evidence). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doxycycline, but there was evidence of fewer adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54) (low quality evidence). There was very low quality evidence from one study (assessed at high risk of bias) that doxycycline 100 mg was as effective as azithromycin. Low dose minocycline (45 mg) was effective for papulopustular rosacea (low quality evidence).Oral tetracycline was compared with topical metronidazole in four studies and showed no statistically significant difference between the two treatments for any outcome (low to moderate quality evidence).Low dose isotretinoin was considered by both the participants (RR 1.23, 95% CI 1.05 to 1.43) and physicians (RR 1.18, 95% CI 1.03 to 1.36) to be slightly more effective than doxycycline 50-100 mg (high quality evidence).Pulsed dye laser was more effective than yttrium-aluminium-garnet (Nd:YAG) laser based on one study, and it appeared to be as effective as intense pulsed light therapy (both low quality evidence).

AUTHORS' CONCLUSIONS

There was high quality evidence to support the effectiveness of topical azelaic acid, topical ivermectin, brimonidine, doxycycline and isotretinoin for rosacea. Moderate quality evidence was available for topical metronidazole and oral tetracycline. There was low quality evidence for low dose minocycline, laser and intense pulsed light therapy and ciclosporin ophthalmic emulsion for ocular rosacea. Time needed to response and response duration should be addressed more completely, with more rigorous reporting of adverse events. Further studies on treatment of ocular rosacea are warranted.

Face-to-face with anti-inflammatory therapy for rosacea

In the past, our understanding of rosacea has been inadequate and limited to descriptions of factors that exacerbate and improve the disease. While the pathophysiology of rosacea is complex and multifactorial, cathelicidin peptides have emerged as key players in the pathogenesis of this common dermatological disorder. This article correlates recent findings in abnormal cathelicidin production and proteolytic processing in rosacea with therapeutic actions of current treatment options and, in this way, highlights potential points of intervention for the development of efficient therapeutic alternatives.

Recent advances in the understanding and management of rosacea

Rosacea is a chronic relapsing inflammatory facial dermatosis. There are several known triggers but the pathogenesis remains unknown. Recent achievements in understanding this disease point to the importance of skin-environmental interactions. This includes physical and chemical factors, but also microbial factors. The impairment of the skin barrier function and the activation of the innate immune defences are major and connected pathways contributing to an ongoing inflammatory response in the affected skin. This becomes modulated by endogenous factors like neurovascular, drugs, and psychological factors. These factors offer new therapeutic targets for rosacea treatment. There is a broader range of anti-inflammatory compounds available with a favourable safety record. Only recently have persistent erythema and flushing been addressed by new drug formulations.

Preparation and evaluation of topical microemulsion system containing metronidazole for remission in rosacea

The aim of this study was to prepare a topical water-in-oil type microemulsion containing metronidazole and to compare its effectiveness with a commercial gel product in the treatment of rosacea. A pseudo-ternary phase diagram (K(m)=2:1) was constructed using lecithin/butanol/isopropyl myristate/water. The microemulsion was chosen from the microemulsion region in the phase diagram. The formulation was a water-in-oil type microemulsion (droplet size: 11.6 nm, viscosity: 457.3 mPa·s, conductivity: 1.5 µs/cm, turbidity: 6.89 NTU) and the addition of the metronidazole did not alter the properties of the system. The release experiment showed that the release rate of metronidazole from the commercial gel product was higher than that of the microemulsion. Stability experiments showed that the metronidazole microemulsion remained stable for at least 6 months; none of the characteristic properties of the microemulsion had changed, the system retained its clarity and there was no sign that crystallization of metronidazole has occurred. Microemulsion was compared to a gel product in a randomized, double-blind, baseline-controlled, split-face clinical trial for the treatment of patients. After the 6-week treatment period there was a statistically significant difference in reduction of the main symptoms of rosacea. Of the patients treated with the microemulsion, 17% experienced complete relief from inflammatory lesions, and 50% from erythema. The microemulsion resulted in complete relief in 38% of the patients with telangiectasia while the commercial product did not provide any relief of telangiectasia symptoms. In conclusion, the microemulsion containing metronidazole was found to be more effective in reducing the symptoms of rosacea compared to the commercial gel product.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules, and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some patients. A range of treatment options are available but it is unclear which are the most effective.

OBJECTIVES

To assess the evidence for the efficacy and safety of treatments for rosacea.

SEARCH STRATEGY

In February 2011 we updated our searches of the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (Clinical Trials) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, and Ongoing Trials Registers.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, assessment of risk of bias, and analyses were carried out by two independent review authors.

MAIN RESULTS

Fifty-eight trials, including 27 from the original review, comprising 6633 participants were included in this updated review. Interventions included topical metronidazole, oral antibiotics, topical azelaic cream or gel, topical benzoyl peroxide and/or combined with topical antibiotics, sulphacetamide/sulphur, and others. Only two studies assessed our primary outcome 'quality of life'.Pooled data from physician assessments in three trials provided some evidence that metronidazole was more effective compared to placebo (RR 1.95, 95% CI 1.48 to 2.56). Three trials provided data, based on participants' assessments, illustrating azelaic acid was more effective than placebo (RR 1.52, 95% CI 1.32 to 1.76).Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doses of doxycycline, but there was evidence of less adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54).One study reported that cyclosporine ophthalmic emulsion was significantly more effective than artificial tears for treating ocular rosacea (for all outcomes).

AUTHORS' CONCLUSIONS

Although the majority of included studies were assessed as being at high or unclear risk of bias there was some evidence to support the effectiveness of topical metronidazole, azelaic acid, and doxycycline (40 mg) in the treatment of moderate to severe rosacea, and cyclosporine 0.5% ophthalmic emulsion for ocular rosacea. Further well-designed, adequately-powered randomised controlled trials are required.

Genotoxicity revaluation of three commercial nitroheterocyclic drugs: nifurtimox, benznidazole, and metronidazole

Nitroheterocyclic compounds are widely used as therapeutic agents against a variety of protozoan and bacterial infections. However, the literature on these compounds, suspected of being carcinogens, is widely controversial. In this study, cytotoxic and genotoxic potential of three drugs, Nifurtimox (NFX), Benznidazole (BNZ), and Metronidazole (MTZ) was re-evaluated by different assays. Only NFX reduces survival rate in actively proliferating cells. The compounds are more active for base-pair substitution than frameshift induction in Salmonella; NFX and BNZ are more mutagenic than MTZ; they are widely dependent from nitroreduction whereas microsomal fraction S9 weakly affects the mutagenic potential. Comet assay detects BNZ- and NFX-induced DNA damage at doses in the range of therapeutically treated patient plasma concentration; BNZ seems to mainly act through ROS generation whereas a dose-dependent mechanism of DNA damaging is suggested for NFX. The lack of effects on mammalian cells for MTZ is confirmed also in MN assay whereas MN induction is observed for NFX and BNZ. The effects of MTZ, that shows comparatively low reduction potential, seem to be strictly dependent on anaerobic/hypoxic conditions. Both NFX and BNZ may not only lead to cellular damage of the infective agent but also interact with the DNA of mammalian cells.

An ex vivo methodology to assess the lipid peroxidation in stratum corneum

Environmental risks, particularly UV radiation, provide a challenge to the function of the skin barrier. Protective measures such as the use of antioxidant products represent a possible method of providing protection to the skin. This paper reports the development of a non-invasive ex vivo method using tape strips of the outermost layers of stratum corneum (SC) from human volunteers in order to determine the effectiveness of an antioxidant emulsion topically applied to prevent lipid peroxidation (LPO) in the horny layer after an UV irradiation exposure. Two different formulations were used: formulation (A), containing Vitamin A, E and C, and formulation (B) containing fish extract. Both formulations were topically applied in vivo on volunteer forearms; then, a tape stripping of the SC of each volunteer was carried out. The lipid peroxidation was measured ex vivo after an UV irradiation of the SC samples. The amount of SC stripped to evaluate differences in lipid peroxidation, the UV irradiation intensity to form lipid peroxides and the accuracy of lipid peroxide analysis were optimized in this methodology using formulation (A). After an exposure application of seven days, a group of three strips of the outermost layers of SC of volunteers was irradiated with an intensity of 182.7 J/cm(2) to quantify the LPO inhibition. The percentage of LPO inhibition obtained after topical application of both formulations was in the range of 40-58% demonstrating the effectiveness of the formulations topically applied against lipid peroxidation on human SC. This methodology may be used as a quality control tool to determine ex vivo the percentage of the LPO inhibition on human SC for a variety of antioxidants topically applied.