Azelaic acid 15% gel in the treatment of rosacea

Rosacea: Practical Guidance and Challenges for Clinical Management

Rosacea is a common chronic dermatosis. Clinically, rosacea can present with flushing, erythema, papules, pustules, telangiectasias, phymatous changes, pruritus, burning, and stinging. In 2017, the National Rosacea Society Expert Committee recommended a phenotype-based classification for therapy. In this review, we identify monotherapies and multimodal treatment approaches for the clinical management of rosacea including topical, systemic, laser and light, alternative, and combination therapies.

Treatment strategies, including antibiotics, to target the immune component of rosacea

INTRODUCTION

Recent advances in the understanding of the pathophysiology of rosacea have led to increased focus on the disease's immunologic etiology and to the development of immunologically based treatments. With many patients suffering from incomplete control, addressing the immune components of the disease process may provide a more effective treatment option for rosacea patients that may improve quality of life.

AREAS COVERED

This review will provide a brief overview of the pathophysiology of rosacea, as well as specific immunologic contributions to the disease state. Current standard-of-care treatments will be described, including anti-parasitic, anti-inflammatory agents, and antibiotics. Emphasis will be placed on treatments that target the immune components of the disease process.

EXPERT OPINION

Rosacea remains a difficult dermatologic disease to treat, partially due to an incomplete understanding of the disease pathophysiology. The immune pathophysiology of rosacea, particularly the key role of inflammation, has been clarified over the past decade. Identification of specific molecules, including cytokines and nuclear transcription factors, may allow for the development of targeted rosacea-specific biologic and topical treatments. However, medication nonadherence is a limiting factor to achieving symptomatic control among rosacea patients. Focusing on the development of oral or injectable forms of therapy may circumvent poor adherence.

Rosacea Management: A Comprehensive Review

Rosacea is a chronic cutaneous disorder affecting primarily the face, characterized by erythema, transient or persistent, telangiectasia, and inflammatory lesions including papulo-pustules and swelling. The essential component of the disease is the persistent erythema of facial skin. Episodes of flushing (acute-subacute intermittent vasodilation) are common. Swelling and erythema of the nose along with dilatation of the pilosebaceous poral orifices, known as rhinophyma, can be noted in chronic cases. Rosacea affects up to 10% of the world population and is especially noted in fair skinned individuals aged 35 to 50. Women are affected more often than men. Several treatment modalities including topical medications, systemic drugs, lasers and light-based therapies have been used for the management of rosacea with variable results. Topical medications such as azelaic acid, metronidazole, and sulfacetamide/sulphur, oral antibiotics such as tetracyclines, and oral retinoids alone or, most commonly, in combination form the mainstay of treatment. Light therapies such as intense pulsed light and pulsed dye laser are best used for the eythemato-telangiectatic type. Topical brimonidine, oxymetazoline, ivermectin, tacrolimus, pimercrolimus, low-dose modified release tetracyclines and botulinum toxin are the new additions to the therapeutic armamentarium. This article provides a comprehensive review of the various therapies used for rosacea.

Azelaic Acid: A Bio-Based Building Block for Biodegradable Polymers

Azelaic acid is a dicarboxylic acid containing nine C atoms, industrially obtained from oleic acid. Besides its important properties and pharmacological applications, as an individual compound, azelaic acid has proved to be a valuable bio-based monomer for the synthesis of biodegradable and sustainable polymers, plasticizers and lubricants. This review discusses the studies and the state of the art in the field of the production of azelaic acid from oleic acid, the chemical and enzymatic synthesis of bio-based oligo and polyester and their properties, including biodegradability and biocompostability.

Azelaic Acid Induces Mitochondrial Biogenesis in Skeletal Muscle by Activation of Olfactory Receptor 544

Mouse olfactory receptor 544 (Olfr544) is ectopically expressed in varied extra-nasal organs with tissue specific functions. Here, we investigated the functionality of Olfr544 in skeletal muscle cells and tissue. The expression of Olfr544 is confirmed by RT-PCR and qPCR in skeletal muscle cells and mouse skeletal muscle assessed by RT-PCR and qPCR. Olfr544 activation by its ligand, azelaic acid (AzA, 50 μM), induced mitochondrial biogenesis and autophagy in cultured skeletal myotubes by induction of cyclic adenosine monophosphate-response element binding protein (CREB)-peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)-extracellular signal-regulated kinase-1/2 (ERK1/2) signaling axis. The silencing Olfr544 gene expression abrogated these effects of AzA in cultured myotubes. Similarly, in mice, the acute subcutaneous injection of AzA induced the CREB-PGC-1α-ERK1/2 pathways in mouse skeletal muscle, but these activations were negated in those of Olfr544 knockout mice. These demonstrate that the induction of mitochondrial biogenesis in skeletal muscle by AzA is Olfr544-dependent. Oral administration of AzA to high-fat-diet fed obese mice for 6 weeks increased mitochondrial DNA content in the skeletal muscle as well. Collectively, these findings demonstrate that Olfr544 activation by AzA regulates mitochondrial biogenesis in skeletal muscle. Intake of AzA or food containing AzA may help to improve skeletal muscle function.

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.

Cathelicidin, kallikrein 5, and serine protease activity is inhibited during treatment of rosacea with azelaic acid 15% gel

BACKGROUND

Excess cathelicidin and kallikrein 5 (KLK5) have been hypothesized to play a role in the pathophysiology of rosacea.

OBJECTIVE

We sought to evaluate the effects of azelaic acid (AzA) on these elements of the innate immune system.

METHODS

Gene expression and protease activity were measured in laboratory models and patients with rosacea during a 16-week multicenter, prospective, open-label study of 15% AzA gel.

RESULTS

AzA directly inhibited KLK5 in cultured keratinocytes and gene expression of KLK5, Toll-like receptor-2, and cathelicidin in mouse skin. Patients with rosacea showed reduction in cathelicidin and KLK5 messenger RNA after treatment with AzA gel. Subjects without rosacea had lower serine protease activity (SPA) than patients with rosacea. Distinct subsets of patients with rosacea who had high and low baseline SPA were identified, and patients with high baseline exhibited a statistically significant reduction of SPA with 15% AzA gel treatment.

LIMITATIONS

Study size was insufficient to predict clinical efficacy based on the innate immune response to AzA.

CONCLUSIONS

These results show that cathelicidin and KLK5 decrease in association with AZA exposure. Our observations suggest a new mechanism of action for AzA and that SPA may be a useful biomarker for disease activity.

Azelaic acid reduced senescence-like phenotype in photo-irradiated human dermal fibroblasts: possible implication of PPARγ

Azelaic acid (AzA) has been used for the treatment for inflammatory skin diseases, such as acne and rosacea. Interestingly, an improvement in skin texture has been observed after long-time treatment with AzA. We previously unrevealed that anti-inflammatory activity of AzA involves a specific activation of PPARγ, a nuclear receptor that plays a relevant role in inflammation and even in ageing processes. As rosacea has been considered as a photo-aggravated disease, we investigated the ability of AzA to counteract stress-induced premature cell senescence (SIPS). We employed a SIPS model based on single exposure of human dermal fibroblasts (HDFs) to UVA and 8-methoxypsoralen (PUVA), previously reported to activate a senescence-like phenotype, including long-term growth arrest, flattened morphology and increased synthesis of matrix metalloproteinases (MMPs) and senescence-associated β-galactosidase (SA-β-gal). We found that PUVA-treated HDFs grown in the presence of AzA maintained their morphology and reduced MMP-1 release and SA-β-galactosidase-positive cells. Moreover, AzA induced a reduction in ROS generation, an up-modulation of antioxidant enzymes and a decrease in cell membrane lipid damages in PUVA-treated HDFs. Further evidences of AzA anti-senescence effect were repression of p53 and p21, increase in type I pro-collagen and abrogation of the enhanced expression of growth factors, such as HGF and SCF. Interestingly, PUVA-SIPS showed a decreased activation of PPARγ and AzA counteracted this effect, suggesting that AzA effect involves PPARγ modulation. All together these data showed that AzA interferes with PUVA-induced senescence-like phenotype and its ability to activate PPAR-γ provides relevant insights into the anti-senescence mechanism.

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.

Rosacea and its ocular manifestations

BACKGROUND

Rosacea is a chronic condition affecting the facial and ocular surface tissues. It is historically underdiagnosed and affects people of all ethnicities. The exact pathophysiology of rosacea is poorly understood. A variety of medical therapies are available to treat the various signs and symptoms of rosacea. Currently, there is no cure for the condition.

METHODS

This report is a literature review.

RESULTS

The clinical manifestations of rosacea are diverse, with periods of exacerbation and remission. Many short- and long-term treatments are available to alleviate the symptoms and effects of rosacea. Variations are common in the medications used, dosages, and durations of treatment. Current topical, oral, and surgical treatment options are presented and reviewed. As a chronic condition, rosacea treatment should be tailored toward individuals and adjusted over time.

CONCLUSIONS

Subtle presentations of rosacea may be overlooked by health care providers. When treating the condition, certain individuals may require both systemic and topical therapy to effectively control rosacea outbreaks. Eye care professionals need to be aware of the presence of rosacea to appropriately treat ocular surface disease that is not responding as expected to standard topical therapy. Severe facial and ocular surface damage caused by rosacea may need surgical intervention. Specific treatment protocols are elusive because of the diversity of the disease. Additional research is needed to find the exact cause of rosacea to more effectively manage the dermatologic and ocular manifestations of the disease and to find a cure.

Rosacea treatments: What's new and what's on the horizon?

Rosacea is a common, chronic, cutaneous disorder presenting with recurrent episodes of facial flushing, erythema, papules, pustules and telangiectasias. It is a multifactorial disease and its various clinical presentations probably represent the consequence of combined different triggers upon a specific background. Its management is largely based on long-established treatments empirically tailored to the specific presenting symptoms and no real breakthrough has occurred to date. However, recent insights into the still rather obscure pathophysiology of rosacea seem to open the way for etiologically oriented treatments. These may include, on the one side, the more effective application of traditional drugs, such as tetracyclines and metronidazole, to specifically selected patients or, on the other side, new therapeutic options, such as vitamin D receptor antagonists. It is to be remarked that the quality of most studies evaluating rosacea treatment is rather poor, mainly due to a lack of proper standardization. For a major breakthrough to occur in the management of rosacea, we need both a better understanding of its pathogenesis and the adherence of future clinical trials to clearly defined grading and inclusion criteria, which are crucial for investigators to correctly compare and interpret the results of their work.

Azelaic acid modulates the inflammatory response in normal human keratinocytes through PPARgamma activation

Azelaic acid (AzA), a nine-carbon dicarboxylic acid, is an agent for the topical treatment of acne. It has also been shown to be effective in rosacea; however, the mechanism of action has not been clarified. Because inflammation is a common feature of both conditions, we investigated the effects of azelaic acid on the inflammatory response of normal human keratinocytes to ultraviolet B light, which is a photosensitizer agent in rosacea. AzA, at 20 mM, a concentration achievable following topical application of a 15% gel, suppresses ultraviolet B light-induced interleukins-1beta, -6 and tumor necrosis factor-alpha mRNA expression and protein secretion. Mechanistically, azelaic acid significantly reduced the ultraviolet B light-induced nuclear translocation of nuclear factor kB p65 subunit and the phosphorylation of the p38 mitogen and stress-activated protein kinase. Moreover, as peroxisome proliferators-activated receptor gamma, (PPARgamma) which has a crucial role in the control of inflammation, is activated by fatty acids and products of lipid peroxidation, we further investigated the effect of azelaic acid on the expression of this nuclear receptor. AzA induced peroxisome proliferators-activated receptor-gamma mRNA and its transcriptional activity. The PPARgamma antagonist GW9662 abrogated the inhibitory effects of AzA on the UVB-induced pro-inflammatory cytokines release and on the cell proliferation. Our study provides new insights into the molecular mechanisms of the activity of azelaic acid and lands additional evidences for its therapeutic effects on inflammatory skin diseases, such as rosacea.